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12/23/25

 


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Retrograde Pyelography

•indications:visualize the urinary collecting system via a cystoscope, ureteral catheterization, and

retrograde injection of contrast medium,visualized by radiography or fluoroscopy;ordered when the

intrarenal collecting system and ureters cannot be opacified using intravenoustechniques(patient

with impaired renal function, high grade obstruction,or allergy to IV contrast)

•findings:only yieldsinformation about the collecting systems (renal pelvis and associated structures),

no information regarding the parenchyma of the kidney

Voiding Cystourethrogram

•bladder filled with contrast to the point where voiding is triggered

•fluoroscopy (continuous, real-time x-ray) to visualize bladder during voiding

•indications:males or young females with recurrent UTls, hydronephrosis,hydroureter,suspected

lower urinary tract obstruction,suspected bladder trauma, or vesicoureteral reflux

•findings:evaluation of bladder contractility and evidence of vesicoureteral reflux

Retrograde Urethrogram

•a small Foley catheter placed into penile urethral opening,followed by instillation of contrast and

radiographic imaging

.indications:used mainly to study strictures or trauma to the male urethra;first-line study ifsigns of

urethral injury are present (i.e.trauma with blood at the urethral meatus,scrotal hematoma,or highriding prostate)

MRI

•advantages:better contrast resolution and tissue discrimination, lack of exposure to ionizing

radiation,safer contrast, ability to obtain imaging directly from multiple planes(coronal,sagittal,

oblique)

•indications:indicated over CT for depiction of renal masses in patients with previous nephron-sparing

surgery, patients requiring serial follow-up (less radiation dosage), patients with reduced renal

function, patients with solitary kidneys, clinical staging of prostate cancer (endorectal coil MRI)

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AL GRAWANY

MI18 Medical Imaging Toronto Notes 2023

Renal Nuclear Scan

Table 13. Renal Scan Tests

Type of Test Uses Radionuclide

IVSSmTc-pentetate (DTPA) or merfcatide (MAG3).and

imaged at1-3s intervals with a gamma camera over the

first 60 s to assess perfusion

Renogram Assess renal function and collecting system:evaluation

of renal failure,workup of urinary tract obstruction and

renovascular HTN.investigation of renal transplant

ARTERIAL ^mfc-DMSA

hhnlcglucoheptonate

Morphological Assess renal anatomy:investigation of pyelonephritisand

cortical scars

PHASE

Gynaecological Imaging

Ultrasound

• transabdominal and transvaginal are the primary'modalities, and are indicated for different scenarios

• transabdominal requires a full bladder to push out air-containing loops of bowel

indications: good initial investigation for suspected pelvic pathology

• TVUS provides a panoramic pelvic view and enhanced detail of deeper/smaller structures by allowing

use of higher frequency sound waves due to reduced distances

• indications: improved assessment of ovaries, first trimester development, and ectopic pregnancy

VENOUS

PHASE

Hysterosalpingogram

• performed by x-ray images of the pelvis after cannulation of the cervix and subsequent injection of

opacifying agent

• indications: useful for assessing pathology of the uterine cavity and fallopian tubes, evaluating

uterine abnormalities(e.g.bicomuate uterus), or evaluation of fertility (absence of flosv from tubes to

peritoneal cavity indicates obstruction)

CT/MRI

• indications:evaluating pelvic structures, especially those adjacent to the adnexa and uterus

• invaluable for staging gynaecological malignancies and detecting recurrence

Figure 24. Triphasic CT of a renal

cell carcinoma:showing arterial

enhancing right renal lesion with

venous washout (shunting)

Sonohysterogram

• transcervical saline introduction into uterine cavity to provide enhanced endometrial visualization

duringTVUS examination

• indications: abnormal uterine bleeding, uterine cavity abnormalities that are suspected or noted on

TVUS (e.g. leiomyomas, polyps,synechiae), congenital abnormalities of the uterine cavity, infertility,

recurrent pregnancy loss

• contraindications: pregnancy, pelvic infection Figure 25. Retrograde urethrogram

demonstrating stricture in the

membranous urethra Table 14.Typical and Atypical Findings on a Sonohysterogram

Finding Typical Atypical

A well-defined,homogeneous,polypoid lesion

isoectioic to tteendometrium with preservation of

the endometnal-myometrial interface

Well-defined,broad-based, hypoechoic. solidmasses Pedunculalion or multilobulated surface

witb shadowing.Overlying layer of endometrium is

echogenic and distorts the endometrial-myometrial

interface

Hyperplasia and Cancer Diffuse echogenic endometrial thickening without

focal abnormality,although focal lesions can occur.

Endometrial cancer is typically a diffuse process,but

early cases can be focal and appear as a polypoid

mass

Mobile,thin,echogenic bands that cut across the

endometrial cavity

Cystic components,multiple polyps,broad base,

hypoechogemciiy or heterogeneity

Polyps

leiomyoma

Figure 26.Transabdominal U/S:

pregnancy, 18 wk fetus

Adhesions Thick,broad-based bands that can completely obliterate

the endometrial cavity,as in Asherman'

s syndrome

Pregnancy should always be ruled out

by (J-hCG before CT of a female pelvis(or

any organ system) is performed

Figure 27. Hysterosalpingogram: left

hydrosalpinx

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MI19 Medical Imaging Toronto Notes 2023

Adrenal Mass

Modality

o

Based on Neuropathology

Presentation

• Cognitive decline ~ CT

• Cord compression - MRI

• Decreased level of consciousness

- CT

• Fish bone/other swallowed foreign

body - CT

• Low back pain,radiculopathy -MRI

• Multiple sclerosis - MRI

• Neck infection - CT

• Orbital infection - CT

• Rule out bleed - CT

• Rule out aneurysm - CTA.MRA

• Seizure - CT

• Sinusitis - CT

• Stroke - CT, MRI

• Trauma “CT

• Weakness,systemically unwell -CT

• imaging modality:most often identified on CT scan as‘

incidentaloma,

can also useCT/MR1to

distinguish benign from malignant masses

Table 15. Adrenal Mass Findings on CT and MRI

Adrenocortical

Adenoma

Adrenocortical

Carcinoma

Factors Pheochromocytoma Metastasis

Diameter (CT)

Shape (CT)

Usually *3 cm

Smooth margins and

roundi'oval

Homogeneous

Variable around <3 cm

Oval,

'irregular with unclear

margins

Heterogeneous withmiied Heterogeneous withcystic Heterogeneous with mired

areas

Usually vascular

'

50% at 10 min

Usually >3cm

lound'

oval withclear

margins

Usually >4cm

Irregular with unclear

margins

Texlure(CT)

densities

Usually vascular

<50% at 10 min

densities

Usually vascular

'

50% al10min

Vascularity (CT)

Washout of Contrast

Medium on CT

Growth

Not highly vascular

>50% at 10 min

Stableorveryslowl

'

1 Usually rapid(>2cnt'y>) Slow (0.5-1cm/yr)

cm/yr)

Usually low density due to Hetrosis.calcifications. Hemorrhage

and hemorrhage

Hyperintense inrelation

tokver

Variable

Other Findings Occasionallyhemorrhage

intracellular fal

MRI on T 2 Weighted

Imaging

Isointense in relation

to liver

Markedly hyperintense in Hyperinlense inrelation

relation to Inter to liver

Neuroradiology

Skull Films

• rarely performed,generally not indicated for non-penetrating head trauma

• indications:screening for destructive bony lesions (e.g. metastases),metabolic disease,skull

anomalies, postoperative changes and confirmation of hardware placement,skeletal surveys, multiple

myeloma

Figure 28. Epidural hematoma

CT

• CT is often the first line modality for most neuropathology,even in situations where MRI would lead

to better characterization

• CT is frequently the initialstudy performed because of itsspeed, availability, and lower cost

acute craniofacial trauma:CT is best for visualizing “bone and blood;

"

use MR1 when CT fails to

detect an abnormality despite strong clinicalsuspicion

acute stroke:MRI ideal,CT mostfrequently used

acute headache with focal neurologic signs

suspected hemorrhage (epidural,subdural,subarachnoid,intraparenchymal)

suspected hydrocephalus

• vascular structures and areas of blood-brain barrier impairment are bright (e.g.hyperdense or

enhancing) with contrast injection

• Danger signs on head CT:space-occupying process, hemorrhage, edema, mass effect, midline shift,

uncal and tonsillar herniation, loss of grev-white matter differentiation, hydrocephalus

Figure 29. Subdural hematoma

Myelography

• introduction of water-soluble,low-osmotic contrast media into subarachnoid space via lumbar

puncture followed by x-ray

• largely replaced by MRI or CT myelogram

• indications:excellent study for disc herniation,traumatic nerve root avulsion, patients with

contraindication to MRI, extensive hardware from spinal surgery that may create MRI artifacts

MRI

• indications: finer neuroanatomic definition, better grey-white matter differentiation (especially '

11-

weighted series), better evaluation of edema extent (better tumour detection), allows evaluation of

structures obscured by bony artifacts on CT (posterior fossa structures), multiplanar imaging helpful

in preoperative assessment

Cerebral Angiography/CT Angiography/MR Angiography

• indications:evaluation of vascular lesionssuch as atherosclerotic disease, aneurisms,vascular

malformations, arterial dissections

• conventional DSA remainsthe gold standard for the assessment of neck and intracranial vessels;

however, it is an invasive procedure requiring arterial (typically femoral) access and catheter

manipulation, which confers risk of vessel injury (e.g.dissection,occlusion, vasospasm,emboli)

• MRA methods(phase contrast, time of flight,gadolinium-enhanced) and CTA are much less invasive

without risk to intracranial or neck vessels

• MRA and CTA are often used first for the assessment ofsuspected T1A,subarachnoid hemorrhage,

vasospasm, or aneurysms

Figure 30. Subarachnoid

hemorrhage

Figure 31. Intraparenchymal

hemorrhage

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MI20 Medical Imaging Toronto Notes 2023

T *

m In

'

4

v mm §

'

Figure 32. Hydrocephalus:ventricular dilatation(may see periventricular low attenuation due to

transependymaICSF flow)

Table 16. Two Types of Hydrocephalus

Type Cause

Communicaling/Eitraventricular Impaired CSF reabsorption with unobstructed flow in ventricular

system:imaging shows all ventricles dilated

Obstruction within the ventricularsystem (e.g. massobstructing the

aqueduct or loramen ol Monro); imaging shows dilatation ol ventricles

pronimaltothe obstruction

Non-Communicating

Nuclear Medicine

• SPECT imaging using

"

m'

l

'

c-exametazime (HMPAO) and

"

mTc-bicisate (ECU) assesses cerebral

blood flosv, as radionuclides diffuse rapidly across the blood-brain barrier and become trapped within

neurons at a magnitude proportional to cerebral blood flow

• ISEDG PET imaging assesses cerebral metabolic activity

• indications:differentiation of residual tumour vs.radiation necrosis; localization of epileptic seizure

foci, and evaluation of atypical dementia

Figure 33.Sagittal (A) and coronal

(B) views of the vertebrobasilar

circulation (note the incidental

basilar tip aneurysm)

Approach to Head Computed Tomography

• think anatomically, work from superficial to deep

• scan:confirm the time and ima

alignment, and presence of arti

• skin/soft tissue:examine the soft tissue superficial to the skull for thickening suggestive of hematoma

or edema; also evaluate the ear, orbital contents (globe, fat, muscles), parotid glands, muscles of

mastication (masseter, temporalis, pterygoids), visualize pharynx

• bone and airspace (use the bone window):check calvarium, visualize mandible, visualize C-spine

(usually Cl and maybe part of C2) for fractures, absent bone, lytic/sclerotic lesions;inspect sinuses

and mastoid air cells for fractures or opacity that may suggest fluid, pus, blood, or tumour;status of

the orbital floor in cases of facial trauma (coronal series best)

• dura and subdural space: crescent-shaped hyperdensity in the subdural space suggestssubdural

hematoma; lentiform hyperdensity in the epidural space suggests epidural hematoma; check

symmetry of dural thickness, where increased thickness may suggest the presence of blood

• parenchyma:asymmetry of the parenchyma suggests midline shift; poor contrast between grey and

white mattersuggests possible infarction, tumour, edema,infection,or contusion;a hyperdensity in

the parenchyma suggests an enhancing lesions,intracerebral hemorrhage, or calcification;if central

grey matter nuclei (e.g.globus pallidus, putamen,internal capsule) are not visible,suspect infarct,

tumour,or infection

• ventricles/sulci/cisterns: examine position of ventricles for evidence of midline compression/shift;

hyperdensities in the ventriclessuggest ventricular/subdural hemorrhage; enlarged ventriclessuggest

hydrocephalus;obliteration ofsulci may suggest presence of edema causing effacement, possible blood

filling in the sulci,or tumour;cistern hyperdensities may suggest blood, pus,or tumour

ging of the correct patient, whether contrast was used, patient

ifact

Approach

%

to the CT Head

Some - Scan

Sore "Skin/Soft Tissue

Brains - Bone/Airspace

Demonstrate -

Dura 'Subdural space

Pushed - Parenchyma

Ventricles- Ventrides/SulciiCistems

TIAs are not associated with radiological

findings

Figure 34. Insular ribbon sign

(arrow):hypodensity of insular

cortex representing early sign of

infarction +

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MI21 Medical Imaging Toronto Notes 2023

Selected Pathology

DOx

w

for Ring Enhancing Cerebral

Lesion •see Neurosurgery, NS11 for intracranial masslesions

- see Neurosurgery. NS35 for head trauma and Plastic Surgery. PL31 for craniofacial injuries

•see Emergency Medicine,ER9 forspinal trauma

•see Neurosurgery. NS28 and Orthopaedic Surgery. OR25 for degenerative spinal abnormalities

MAGIC DR

Metastasis

Abscess

Glioblastoma multKoimc

Infarction (subacute.’chronic)

Contusion/hematoma

Demyelinating disease (e g. MS)

Radiation necrosis

Cerebrovascular Disease (see Neurosurgery. NS21)

•pathogenesis of stroke:see Neurology.N51

•best imaging modality:MRI

•initial imaging modality:Cl

Table 17. Temporal Findings of Infarction with CT and MRI

Time from Stroke CT

Onset

MRI

Hyperacute(0-24h) Usually normalnitnn6 h Hypermteisityon DWI within minutes of arterial occlusion

Edema (loss of grey-white mailer differentiation - due torestriction of water movement indicative of cytotoxic

“insular ribbonsign*

,effacement of sulci,mass effect) edema

Hyperattenuating artery “

hyperdense MCA sign" Hypointensity on ADC within minutes

representing intravascular Ihrombus/emboh may be Hypennteisily on T 2/FLAIR approi malely 6 h alter onset

seen in ischenac stroke due loedema (loss olgrey-white matter differentiation.

Hyperattenuating acute blood surroundedby edema effacement of sulci,mass effect)

may be seen in hemorrhagic stroke

Increasing edema (seen as hypoattenuakon) may result Continued kyperintensity on DWI

Hypointensity on ADC reaches nadir at 3-5 dand begins to

increase

Continued hyperintensity on T2/FUUB

Resolution of edema leads to increased attenuation of Continued kyperintensity on DWI due to *

12 shine through*

infarcted area that may regain near-normal density and Intensity on ADC continues lo rise,pseudo-normalizes at10-

15 d.and then surpasses that of surrounding normal tissue

Continued kyperintensity on T2.FlAllt

Encephalomalaea (parenchymal volume toss) appears Hyperintensity on DWI/12/FLAIR progressively decreases

as hypoatlenuationwith negative masseHect

Acute (24 h-1wit)

Figure 35. CT image of early infarct

hyperdense artery

in significantpositive mass effect

Subacute (1-3wk)

mask stroke“

fogging phenomenon”

Chronic (>3 wk)

ADC intensity remains elevated

• carotid artery disease

best imaging modality:Duplex (Doppler U/S)

• other modalities:MRA orCTA if carotid angioplasty or endarterectomy is under consideration

(conventional angiography reserved for inadequate MRA orCTA)

Figure 36. DWI of patient with right Multiple Sclerosis frontotemporal infarct (see Neurology. N55)

• best imaging modality:MRI has high sensitivity in diagnosing MS (>90%) but low specificity (71-74%)

• characteristic lesion locations:juxtacortical (grey-white junction), periventricular,infratentorial, and

spinal cord

• cerebral lesions typical of MS:

involvement of the brainstem, cerebellum, and corpus callosum

“Dawson'

sfingers” refers to perivenular regions of demyelination that are seen to radiate

outwards into the deep periventricular region

» plaques usually hyperintense on T2, and hypointense on T1

perivascular and interstitial edema may be prominent; enhances with gadolinium contrast when

actively inflamed

• spinal cord lesions typical of MS:

little or no cord swelling

lesslikely to enhance with gadolinium contrast

incomplete involvement of the cord in cross-section (dorsolateral common)

CNS Infections

• meningitis

pathogenesis:inflammation of the pia or arachnoid mater, most often secondary to hematogenous

spread from infection or via direct seeding of organisms through areas not protected by the

blood-brain barrier (choroid plexus or circumventricular organs)

• pathogens include: S.pneumoniae, H.influenzae, N. meningitidis, L.monocytogenes

• best imaging modality:MRI (T2-weighted/FLAlR)

• findings:

meningeal enhancement (following the gyri/sulci and/or basal cisterns), hydrocephalus

(communicating), cerebral swelling,subdural effusion

• a normal MRI does not rule out leptomeningitis

• herpessimplex encephalitis(see Infectious Diseases, 1D18)

pathogenesis:inflammation of the brain parenchyma secondary to infection with herpes simplex

virus, asymmetrically affects the limbic regions of the brain (i.e. temporal lobes, orbitofrontal

region,insula, and cingulate gyrus)

best imaging modality:MRI (

'

l l- and 12-weighted)

r T

Figure 37. T2-weighted FLAIR

(A) sagittal(B) axial images

of multiple sclerosis with

periventricular "Dawson’s Fingers”

L J

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MI22 Medical Imaging Toronto Xotes 2023

findings:

acute (within 4-5d):asymmetric high intensity'lesions on T2 MR1in temporal and inferior

frontal lobesstrongly suggestive

CT may show hypodensity in temporal lobe and insula; rarely basal ganglia involvement

long-term may show parenchymal loss to affected areas

• DDx:infarct, tumour,status epilepticus,limbic encephalitis

• cerebritis cerebral abscess

» pathogenesis:an infection of the brain parenchyma (cerebritis) which can progress to a collection

of pus(abscess), most frequently due to hematogenousspread of infectious organisms, commonly

located in the distribution of the MCA

pathogens include:S. aureus (often in IV drug users, nosocomial), Streptococcus,Gram negative

bacteria,Bacteroides

best imaging modality:MRI including DWI imaging series (abscess will be DW1 positive); CT still

used as a viable alternative

findings according to one of four stages of abscess formation:

early cerebritis(1-3d):inflammatory infiltrate with necrotic centre,low intensity on TI, high

intensity on T2

late cerebritis(4-9 d):ring enhancement may be present

early capsule (10-13d):ring enhancement

late capsule (>14 d):well demarcated ring-enhancing lesion, low intensity core, with mass

effect;considerable edema around the lesion,seen as hyperintensity on T2

Figure 38. T2-weighted (FLAIR)

coronal image of herpes simplex

virus encephalitis affecting temporal

lobes

Musculoskeletal System Characterization of totiiofCiff Tears:Ultrasoiid

is.Magnetic Resonance Imaging

Orthopaedics M17;4tem-e13fl

Purpose De:erm c» «•»•

_•«U4 or MRI is more

accurate and precise m nabatxg the characteristics

of full-thickness rotator ci5tearsin a surgical

pogolation.

Methods:Re-aiew of1Hpatientswho underwent

repair of a full-thickness rotator cuff tear cner a1 jt

period.Of these patents.(1had both preoperatie

MBand U/5for renew.Iwee radiologists etabated

each UJS and MRI m a randomned.blinded fashion

oo 2occasions,tearsicretracton status,muscle

atrophy,and fatty mStratao were analyzed and

rapa red between tte2 sodalities.

Results:114 measuremects were statistically smaher

e both tear size (M.00T) and retraction status

(P-0.001) compared with Mil. MRI showed greater

mterobserver reliability m assessment of tearsac

retraction status,and atrophy.

Conclusion:Independentoisemrsare more Uefy

toagreeon measurements of fie characteristicsa

rotator cuff tearswhen using Mil compared with111

istearsize increases,the 2 siage modaktiesshow

greaser differences in measuredeotof tear we and

retractor status. U rS sapbe best used to identrfg a

tear,and Mil issuperiorfor use in surgical planning

for largerfears.

Modalities

•see Imaging Modalities, M12 for advantages and disadvantages of the following:

Plain Film/X-Ray

•usually initialstudy used in evaluation of bone and joint disorders

•indications:fractures and dislocations,arthritis, assessment of malunion or nonunion,orthopaedic

hardware, and bone lesions(initial)

•minimum of two orthogonal views (usually AP and lateral) to rule out a ffacture/assess bone lesion

•image the joint proximal and distal to injury site to ensure there is no associated dislocation or second

fracture site, particularly important with bony rings(e.g.radius/ulna, tibia/fibula)

•soft tissue assessment limited,but can identify joint effusions (elbow, knee),soft tissue gas

(necrotizing fasciitis) and radiodense foreign bodies

CT

•evaluation of fine bony detail

•indications: preoperative assessment of complex, comminuted,intra-articular, or detection of

radiographicallv-occult fractures including scaphoid,skull,spine, pelvis,midfoot, and calcaneus

•evaluation ofsoft tissue calcification/ossification and bone tumours

MRI

•indications:evaluation of internal derangement of joints (e.g.ligaments, joint capsule, menisci,

labrum.cartilage), assessment of tendons and muscle injuries, characterization and staging ofsoft

tissue and bony masses,infection of bone (osteomyelitis),occult fracture assessment

Ultrasound

•indications:tendon injury (e.g.rotator cuff,Achilles tendon), detection and characterization ofsoft

tissue masses(i.e.cystic orsolid), detection of foreign bodies, U/S-guided biopsy and injections, bone/

joint evaluation pre-ossification (e.g. DDH in early months),dynamic imaging (i.e.snapping hip,

extensor carpi ulnarissubluxation),small joint doppler assessment for arthritis

•Doppler determines vascularity ofstructures

Nuclear Medicine (Primarily Bone Scan/Skeletal Scintigraphy)

•determines the location and extent of bony lesions using radiopharmaceuticals (99mTc-methylene

diphosphonate)

•increased binding when increased blood supply to bone and/or high bone turnover (active osteoblasts)

•indications:bone lesion characterization,occult fractures(spine,scaphoid,small bones),bone

pain of unknown origin,staging or restaging of cancer with bony metastases(or primary bone

cancer), imaging of polyarthritis, imaging of arthroplasty complicationslike loosening or infection,

osteomyelitis imaging

when used to assessfor osteomyelitis,usually done in combination with gallium or white blood

cellscan

•DDx of positive bone scan:bone metastases(primary breast,prostate,lung,thyroid), primary bone

tumour,arthritis, fracture,infection, anemia,Paget’s disease

•caution:bone tumoursthat do not elicit osteoblastic response are often occult on bone scan (myeloma,

highly vascular tumourssuch as RCC,or thyroid carcinoma)

n

L J

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MI23Medical Imaging Toronto Notes 2023

Approach to Bone X-Rays

• identification: name, MRN, age of patient, type ofstudy, region of investigation

• soft tissues:swelling, calcification/ossification

• joints: alignment, joint space, presence of effusion, osteophytes, erosions, bone density, overall

pattern,symmetry of affected joint

• bone:periosteum, cortex, medulla, trabeculae, density, articularsurfaces, bone destruction, bone

production, appearance of the edges or borders of any lesions

Figure 39. X-ray findings of first

carpometacarpal joint:normal

image (left) and osteoarthritis (right)

with joint space narrowing and

subchondral sclerosis

Trauma

Fracture/Dislocation

• description of fractures

• site of fracture (bone, region of bone, intra-articular vs. extra-articular)

• pattern of fracture line (simple vs.comminuted)

• displacement (distal fragment with reference to the proximal fragment)

• soft tissue involvement (calcification,gas,foreign bodies)

• type of fracture (stress vs. pathologic)

• for specific fracture descriptions and characteristics of fractures,see Orthopaedic Surgery.OR5

Arthritis

• see Rheumatology for radiographic features ofspecific arthritides

Bone and Soft Tissue Tumours

Bone Tumours

• benign bone lesions (e.g. hemangiomas, enostoscs, enchondromas) are more common than malignant

bone lesions

• primary bone tumours are rare after 3rd decade; metastases to bone are relatively common after 3rd

decade

• MRI is helpful for detection, characterization,staging,soft tissue involvement and surgical planning

• plain film is important for assessing pattern of destruction, mineralization, and aggressiveness

• biopsy may be required if no primary is identified, or suspect primary bone tumour

• may present with pathological fractures or bone pain

• most common metastatic bone tumours:breast, prostate, lung

• for specific bone tumours,see Orthopaedic Surgery, OR50

Figure 40. X-ray findings of

rheumatoid arthritis (A) compared

with osteoarthritis (B)

Soft tissue Tumours

• soft tissue masses are most commonly benign

• common benign soft tissue massesinclude lipomas, benign peripheral nerve sheath tumours,and

vascular malformations

• soft tissue sarcomas are uncommon but require urgent workup and specialized treatment

• U/S is helpful for differentiating lipoma from cyst from mass

• MRI is helpful for diagnostic workup

• if the mass is not clearly benign, biopsy or wide excision is required for diagnosis

Patterns olcortical

disturbance

Patterns of medullary

destruction

Periosteal new

bone formation

Margination

of lesions

77 |

r

I. i ' - •

Punched fllayered ixpinsile Permeative it

lytic *

decreased density

Sclerotic -Increased density

f'

-f hodmans

friangle indosteal

scalloping 9

Thin rim of

sclerosis 411 •stimulated 8

nvisible

nargin •

#

J

Sunburst Moth-eaten fivergem iaucerization Thick rim of 6

sclerosis

ri

fa olid L J

£ ndulating -

Figure 41.Radiographic appearance of bone remodelling and destruction processes

+

MI24 Medical Imaging Toronto Notes 2023

Table 18. Distinguishing Benign from Malignant Bone Lesions on X-Ray

Benign Malignant

No periostealreaction or benign appearing reaction (e.g.uniform

smooth periosteal thickening as seen inahealing fracture)

Acute periostealreaction

- Codman’s triangle

-

"

Onion skin"

- "Sunburst"

Poorly definedborders,with a wide tone of transition,orinfiltrative

(suggesting fast-growing lesion)

Varied bone formabon

Eitraosseous and irregular calcification

Soft tissue mass present

Aggressive cortical destruction or tumour infiltration without cortical

destruction

Sharp,well-demarcated borders,narrow zone of Iransilion (between

lesion andnormal bone,suggesting slow-growing lesion)

Well-developed bone formation

Intraosseous and even calcification

No soft tissue mass

No cortical destruction or uniform cortical destruction in some low

grade and locally aggressive benign lesions

Adapted from:Suckhoftt RW.Heckman JD.Rockwood and Green'

s FracturesinAdults.Volume1Philadelphia:lippincott Williams & Wilkins.2001.

. .

Infection

Osteomyelitis

•modern workup includes MRI or x-ray

x-ray can detect osseous destruction seen with subacute osteomyelitis (>1 week) or chronic

change,and can detect lucenciessurrounding infected orthopedic hardware

• MRI is more sensitive,with loss of normal fatty T1 marrow signal diagnostic of esteomyelitis,and

can also assess for extra-osseous soft tissue involvement orspread

•nuclear medicine (

"

mic, followed by 1

In-labeled white cell scan or gallium radioisotope scan) may

be used where available, or in the setting of hardware

Septic Arthritis

•surgical emergency in large joints (i.e. hip)

•x-ray usually normal early

•aspiration required if concern forseptic arthritis

•imaging modalities can detect joint fluid in some points,but imaging cannot rule outseptic arthritis

Necrotizing Fasciitis

•surgical emergency

•X-ray can detect gas, but absence does not rule out necrotizing fasciitis

•in the perineum,referred to as Fournier'

s gangrene

•surgical referral required

Metabolic Bone Disease

Osteoporosis

• reduction in amount of normal bone mass; fewer and thinner trabeculae;diffuse process affecting all

bones

typicalsites of fragility fracture:spine, hip, pelvis.

• DEXA:gold standard for measuring bone mineral density,typically'measured hip and lumbarspine

• CAROC guidelinesfor use of DEXA: diagnosis,determining fracture risk/therapy,and monitoring

diagnosis driven by '

l

'

-score:the number ofstandard deviationsfrom the young adult mean, most

clinically valuable

osteopenia:-2.5< T-score <-l

osteoporosis:T-score <-2.5

Z-score:the number ofstandard deviationsfrom the age-matched mean, helpful in diagnosing

secondary osteoporosis

risk of fracture:patients classified aslow, medium or high risk based on bone mineral density,

age, history of previousfragility fractures,steroid therapy. Presence of certain criteria such as hip

or spine fragility fracture automatically places patients in the high risk category

• see Endocrinology, E46

§

wrist,humerus,rib

Osteoporosis

Reduced amount of bone

OsteoMalada

Normal amount of bone, but reduced

Mineralization of normal osteoid

Hyperparathyroidism

• most common cause is renal failure (secondary hyperparathyroidism)

• chondrocalcinosis is a common complication

• calcium crystal deposition in hyaline cartilage or hbrocartilage (including arteries and peri-articular

soft tissue)

• resorption of bone typically in hands(subperiosteal and at tufts),sacroiliac joints(subchondral),

skull (“salt and pepper"

appearance),subligamentous resorption (ischial tuberosity, trochanters, and

clavicle),osteoclastoma (brown tumours)

“rugger jersey spine”:band-like osteosclerosis atsuperior/inferior margins of vertebral bodies

n

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MI25 Medical Imaging Toronto Notes 2023

Paget’s Disease

• abnormal remodelling involving single or multiple bones- especially skull,spine, pelvis

• 3 phases: 1st phase = lytic, 2nd phase = mixed (lytic/sclerotic), 3rd phase = sclerotic

• coarsening of the trabeculae with bone expansion

• bone softening/bowing

• bone scintigraphy will reveal high activity

• thickened cortex;widening of diploe in skull,osteoporosis circumscripta (lytic phase in skull); “blade

of grass” sign (lytic phase in a long bone like the femur);“picture frame” appearance to vertebra (due

to thickening and sclerosis of vertebral cortex)

• see Endocrinology, E50

Nuclear Medicine

Brain

. 99mTc-exametazime (HMPAO) and ««mTc-bicisate (ECD) imaging used in SPECT to assess cerebral

blood flow and cellular metabolism

taken up predominantly in grey matter

• used for dementia, traumatic brain injury;and toa lesser extent vasculitis, neuropsychiatric

disorders, and occasionally stroke

• PET imaging to assesses metabolic activity

used for dementia imaging,grading and stagingof brain tumours, occasionally for seizure

disorder imaging,and vasculitis

•CSF imaging via intrathecal administration of minDTPA

to evaluate CSF leak or to differentiate normal pressure hydrocephalusfrom brain atrophy

• CSF shunt evaluation for obstruction (most commonlv ventriculoperitoneal) with sterile or pyrogen

free «mTc (usually) or

'"

ln-DTPA

Radioactive

index

Thyroid

of thyroid

Iodine

function

Uptake

(trapping

(see

and

Endocrinology

organification

.

of

E25

iodine

)

)

i • radioactive 1231 given PO to fasting patient (small quantity') and percentage of administered iodine

taken up by thyroid is measured

• increased RAIU:toxic multinodular goitre, toxic adenoma,Graves’disease

• decreased RA1U:subacute thyroiditis, late Hashimotos disease, exogenous thyroid hormone or

iodine, falsely decreased in patient with recent radiographic contrast studies, high dietary iodine (e.g.

seaweed, taking supplements containing desiccated thyroid)

• important-iodine uptake helps in the differential of hyperthyroidism only, not hypothyroidism

Thyroid Imaging (Scintiscan)

"

mTc-pertechnetate IV or radioactive iodine (

12J

1)

• prosides functional anatomic detail

• hot (hyperfunctioning)lesions:usually benign (e.g.adenoma, toxic multinodular goitre), cancer

unlikely (<1%) - No FNA

• cold (hypofunctioning) lesions:cancer must be considered until biopsy negative even though only

6-10% are cancerous- decision to biopsy should be based on clinical and sonographic features

• isointense i.e. “warm"

lesions:cancer must be considered as an isointense lesion;may represent cold

nodulessuperimposed on normal tissue;if cystsuspected, correlate with VIS

Figure 42. Multinodular goitre (top).

Cold nodule (bottom)

Radioiodine Ablation

• UII for Graves’disease,multinodular goitre,thyroid cancer (in the case of thyroid cancer, ablation

performed at higher dose and after thyroidectomy)

• serum thyroglobulin used to detect recurrent thyroid cancer in a patient who has received ablation

• advice should be given for patient-specific precautions to remain away from family members and

caregivers to reduce radiation exposure after thyroid ablation, do not initiate pregnancy for 6 mo,

small risk of exophthalmos,thyroid storm,secondary malignancy

Respiratory

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V/Q Scan

• evaluate areas of lung in which there is a ventilation/perfusion mismatch

• ventilation scan - assess air flow within lungs

• patient breathes radioactive gas (nebulized %nTc-DTPA, 133Xe, or most commonly Technegas "

)

through a closed system,filling alveoli proportionally to ventilation

• ventilation scan defectsindicate: airway obstruction (i.e. air trapping),chronic lung disease,

bronchospasm,tumour mass obstruction

V/OScan

for PE investigation: normalscan makes i

PE unlikely '

Probability of PE: high 80-100%.

intermediate 20-80%.low <20%.very

low <10%

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MI26 Medical Imaging Toronto Xotes 2023

• perfusion scan - assess blood circulation within lungs

radiotracer injected IV (MmTc-MAA) -> trapped in pulmonary capillaries(0.1% of arterioles

occluded) according to blood flow

relatively contraindicated in severe pulmonary HTN, right-to-left shunt, previous history of

pneumonectomy, and small children

• indicated to rule out PE

• areas of lung that are well-ventilated but not perfused (unmatched defect) are suspicious for acute

infarction

defects are wedge-shaped, extend to periphery, usually bilateral and multiple

useful in finding clinically important emboli

• modified V/Q scan ( perfusion only,lower dose contrast) may be used for pregnant patients ifCXR is

normal or if there are ventilatory problems

Ventilation Scan Delects Indicate...

ABC Tumour

Airway obstruction

Bronchospasm

Chronic lung disease

T umour mass obstruction

Perfusion Scan DelectsIndicate...

Reduced blood flow due to PE

COPD

Asthma

Bronchogenic carcinoma

Inflammatory lung diseases(pneumonia,

sarcoidosis)

Mediastinitis

Mucous plug

Vasculitis

Cardiac

Myocardial Perfusion Scan/Nuclear Stress Test

• indications:diagnose and assess treatment of coronary artery disease (CAD), preoperative risk

stratification, viability testing before percutaneous intervention or bypasssurgery

• "

mic-sestamibi or 9%iTc-tetrofosmin is injected:at peak exercise (85% max predicted heart rate

by the Bruce protocol, chest pain, EGG changes), after persantine challenge (vasodilator), or after

dobutamine infusion (chronotropic, again to 85% predicted heart rate)

• persistent defect (present at rest and stress)suggests infarction or myocardialscar

• reversible defect (only present during stress) suggests ischemia

• used to discriminate between reversible (ischemia) vs. irreversible (infarction) changes when other

investigations are equivocal

• COURAGE trial indicates that patients with >10% ischemic myocardium benefit most from

revascularization

• see Cardiology and Cardiac Surgery.06

Radionuclide Ventriculography

• "

ml'

c-tagged to red blood cells

• non-invasive method of assessing ventricular function and intracardiac hemodynamics(i.e.ejection

fraction, presence ofshunts,ventricular volume and regional wall motion)

• cardiac MUGA scan sums multiple cardiac cycles, usually at least 200 beats

• indications:most commonly to monitor potential cardiac toxicity with chemotherapy or herceptin, as

a gold standard of ejection fraction in defibrillator workup

Abdomen and Genitourinary System

HIDA Scan (Cholescintigraphy)

• IV injection of 99mlc-disofenin (DIS1DA) or

"

mT'

c-mebrofenin which is bound to protein, taken up by

hepatocytes, and excreted into the biliary system

• indicated for patients who are suspected of having an obstruction in the biliary tract, to assess for bile

leaks postoperatively, and for biliary dyskinesia

• indicated in workup of cholecystitis when abdominal U/S result is equivocal:

acute cholecystitis:no visualization of gallbladder at 4 h or 1 h after administration of morphine

chronic cholecystitis:no visualization of gallbladder at 1 h but seen at 4 h or after morphine

administration

• DDx of obstructed cystic duct:acute/chronic cholecystitis, decreased hepatobiliary function

(commonly due to alcoholism), bile duct obstruction, parenteral nutrition, fasting <4 h or >24 h

RBC Scan

• IV injection of radiotracer with sequential images of the abdomen (

"

m'

Tc RBGs)

• G1 bleed evaluation

if bleeding acutely at <0.5 mL/min,the focus of activity in the images generally indicates the site

of the acute bleed

if bleeding acutely at >0.5 mL/min, use angiography (more specific, better for localizing, both

diagnostic and therapeutic)

• liver lesion evaluation

hemangioma has characteristic appearance: cold early (limited blood flow to lesion),fills in later

(accumulation of tagged cells greater than surrounding liver parenchyma)

Urea Breath Test

• indication:diagnosis of gastric H. pylori infection

• patient administered MC-labelled urea orally, urea metabolized by H. pylori to ammonia and 14C02,

,

'

*C-labelled C02 is measured via plastic filament detectors orliquid scintillation

Advanced ischemia patientsshould

receive surgery rather than thrombolysis

Chemoembolization delivers

chemotherapy directly into the tumour

through itsfeeding blood supply and

trapsthe drug in place by embolization r “t

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MI27 Medical Imaging Toronto Notes 2023

Functional Renal Imaging

• evaluation of renal function and anatomy using 99mic DTPA (static imaging) or

^

mTc MAG3

(dynamic imaging)

• frequently used to provide index of relative function between two kidneys

• in adults,used to assess for UP) obstruction, renal transplants,or as a nuclear Gl'

R study in patients

wanting to donate kidneys

• in children,used to assess for pyelonephritis and reflux Ultrasoud vs.Fluoroscopic Guided Femoral

Arterial Accessialoicardiac Vascular Patients

J Vase Sor;201*

docMIOK

Purpose loceepe'esbeprocedureloctconesand

complicatioo ratesof IJS-gadri cosmos femoral

artery (CM) access3fluoroscopic gu dance in

soocardacwocsdures.

Neibods t BUI of 635 patesa oaderpoing femoral

accessfor eacurd.

-ee d ag-pstc or mferrecbonal

procedures mere rardomied1:1to retene either

fluorascopc or U 5-gu ded access.The primary

endpoint o‘tte study massuccessful CFA cannulation.

Besofts:Success1

.! CFAunru ation occurred in 93%

ofU S-gu drdofKr4.rescumparedwitk 86% of

fluoroscopy-gxded access(M.0021.US guidance

wes essKated wi:rrcreasedreSs of frit-attempt

success,fewer nadierteit veuipentiures.end

decreased neda-time3cataiaam compared with

fluoroscopy.Petes of com; cetoas dd not dffer at 24

h or 30390 d iifeorasenpy vs.U Sc.ded access.

Coodusioas .- corpansoo So fl.oioscopy. U.'Sgu ded CFA causiatioo had a frgher rate of success,

faster canuietne.ltd fewer ren.ponctures in the

ahserce of ecreesed com pfrcahoos.

Interventional Radiology

Vascular Procedures

Angiography

• injection of contrast material through a catheter placed directly into an artery or vein to delineate

vascular anatomy

• can be used in the operating room to provide fluoroscopic guidance for exposure of diseased vessel

• indications:diagnosis of primary occlusive or stenotic vascular disease,aneurysms, coronary,

carotid and cerebral vascular disease, PE, trauma,bleeding (GI, hemopty sis, hematuria), vascular

malformations,as part of endovascular procedures (endovascular aneurysm repair, thrombolysis,

stenting,and angioplasties)

• complications (<5% of patients): puncture site hematoma, pseudoaneurysm,dissection, thrombosis,

infection. AV fistula, embolic occlusion of a distal vessel

• due to improved technology, non-invasive evaluation of vascular structuresis being performed more

frequently (colour Doppler U/S, CTA, and MRA)

• see Neuroradiology,MI19

Percutaneous Transluminal Angioplasty and Stents

• introduction and inflation of a balloon into a stenosed or occluded vessel to restore distal blood supply

• common alternative to surgical bypass grafting with 5 yr patency ratessimilar to surgery,depending

on site

• renal,iliac,femoral,mesenteric,subclavian, coronary, and carotid artery stenoses are amenable to

treatment

• vascular stents may help improve long-term results by keeping the vessel wall patent after angioplasty;

also used for angioplasty failure or complications

• stent grafts (metal mesh covered with durable fabric) may provide an alternative treatment option for

aneurysms and AV fistulas

• complications:similar to angiography, but also includes vessel rupture

Thrombolytic Therapy

• may be systemic (IV ) or catheter directed

• infusion ofa fibrinolytic agent (urokinase,streptokinase, I NK, tPA - used most commonly) via a

catheter inserted directly into a thrombus

• can restore blood flow in a vessel obstructed with a thrombus or embolus

• indications: treatment of ischemic limb (most common indication),early treatment of Ml or stroke to

reduce organ damage, treatment of deep venous thrombosis(D\T) or PE

• complications:bleeding,stroke, distal embolus, reperfusion injury in delayed intervention with

myoglobinuria, and renal failure if advanced ischemia present

Embolization

• injection of occluding material into vessels

• permanent agents: amplatzer plugs, coils, glue,and onyx

• temporary:gel foam, autologous blood clots

• indications:management of hemorrhage (epistaxis, trauma, Gl bleed,GU bleed), treatment of

arteriovenous malformation, preoperative treatment of vascular tumours(bone metastases, renal

cell carcinoma), ovarian vein embolization for chronic pelvic pain (pelvic venous disease), varicocele

embolization for infertility,symptomatic uterine fibroids

• complications:post-embolization syndrome (pain, fever, leukocytosis), unintentional embolization of

a non-target organ with resultant ischemia

9

Ilronbolytk Tfterspyfor Pulmonary Embolism

tera-e 03Syst Bn 20155TM04437

fcrpose: o assesstte effects of tsrom bo lytic

therapy n oetertswdi cake pulmonary empolism

Methods:5istemetrc rerew of 80sevaluating

throohofytic therapy bowed Sy bepsric is.heparin

close,heyan p us pecebo orsurgical intervention

m patentswes acutePE.Studies comparing two

different thnrmtroipc agents nr different doses of the

same ttromhctyticfrag were cot cons:dered eligible.

Main outcomes of interest wee death,recurrence of

PE. and saot aad moot hemorrhagic evens.

Besolts: ugSee:rials with 219? participantswee

winded.ThreePc types plus Sepam wete associated

with a red.t.'cr - odds or deas re at;re to heparin

alone or hepare piss(08-0.5?.95% 0.0.37 lo 0.8?.

P*

0.02) and recurrence of PE 108*

0.51;95% Cl.

0.29 to 0.89.P -0.02k Ixdence of rwyp- and minor

hemorrhage events wasstatistically significantly

lagher T the tirossotytres grxpSan the control

group (08*250.95% CL1.9534.31.P <0.001).

length•< hospitalstay (sean dffererce (MO) -L35.

95% Cl.-427to158) and gua rty of life were similar

tretween groups.Eased on one study,stoke occurred

pore after in tte“-p-pOytrcs group I0IM2.10.95%

CL157io 93.391-

Coadisior lowcpality evidence suggests

thromhotytesreduce death fat lowing aate PE

compared with hepann and may be helpful in

redueng PE recu-nence.is*nay cause more major

end minor hemorrhage everts and stroke events.

Inferior Vena Cava Filter

• insertion of temporary or permanent metallic “umbrellas"

to mechanically trap DVT emboli to

prevent subsequent PE

• inserted via femoral vein, jugular vein, or basilic vein

• usually placed infrarenally to avoid renal vein thrombosis

• indications:contraindication to anticoagulation, failure of adequate anticoagulation (e.g. recurrent

PE despite therapeutic anticoagulant levels), complication of anticoagulation therapy necessitating

termination of anticoagulation (e.g. life-threatening hemorrhage )

i

[]

)\

+

Figure 43. Retrievable IVC filter

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MI28 Medical Imaging Toronto \otcs 2023

Central Venous Access

• variety of devices available (P1CC, external tunneled catheter (Hickman or dialysis catheters),

subcutaneous port (Bortacath*))

• indications:chemotherapy, TPN, long-term antibiotics, administration of fluids and blood products,

blood sampling

• complications: venous thrombosis, central venousstenosis, infection including sepsis, and

pneumothorax

Indications (or Central Venous Access

FAT CAB

Fluids

Antibiotics

TPN

Chemotherapy

Administration of blood Nonvascular Blood sampling Interventions

Percutaneous Biopsy

• alternative to open surgical procedure

• many sites are amenable to biopsy using U/S,fluoroscopy,CT,or MR guidance

• complications:false negative (sampling error or tissue necrosis), hemorrhage (particularly forsplenic

biopsies), pneumothorax in 30% of lung biopsies (chest tube required in ~5%), needle tract seeding,

pancreatitis(pancreatic biopsies), bleeding from liver biopsies in patients with uncorrectable

ilopathies or ascites(can be minimized with transjugular approach)

acute

coagu

Abscess Drainage

• placement of a drainage catheter into a deep infected fluid collection

• superficial skin and soft tissue infections are best treated with incision and drainage: needle

aspiration and drainage catheter insertion is not recommended for cutaneous abscesses

• administer broad spectrum IV antibiotics prior to procedure

• routes: percutaneous (most common), transgluteal, transvaginal, transrectal

• complications: hemorrhage, injury to intervening and nearby structures (e.g. bowel), bacteremia,

sepsis, access failure

Percutaneous Biliary Drainage/Cholecystostomy

• placement of drainage catheter ± metallic stent into obstructed biliary system (PBD) or gallbladder

(cholecystostomy) for relief of obstruction or infection

• percutaneous gallbladder access can be used to crush or remove stones

• indications

cholecystostomy:acute cholecystitis

PBD: biliar)'obstruction secondary to stone or tumour, cholangitis, acute biliary pancreatitis

• complications

acute:sepsis, hemorrhage

long-term:tumour ingrowth and stent occlusion

V

i

\

M I

u

Percutaneous Nephrostomy

• placement of catheter into renal collecting system

• indications: hydronephrosis, pyonephrosis, ureteric injury with or without urinary peritonitis

(traumatic or iatrogenic)

• complications: bacteremia and septic shock, hematuria due to pseudoaneurysm or AV fistulas, injury

to adjacent organs

Gastrostomy/Gastrojejunostomy

• percutaneous placement of catheter directly into either stomach (gastrostomy) or through stomach

into small bowel (transgastriejejunostomy)

• indications:prolonged inadequate oral intake (e.g.impaired swallowing, oromotor dysfunction,

dysphagia esophageal obstruction,or decompression in gastric outlet obstruction)

• complications:gastroesophageal reflux with aspiration, peritonitis, hemorrhage, bowel orsolid organ

injur)'

,death

1

rim</

Kn

AT u L

Figure 44. Femoral arteriogram:

distal occlusion of superficial

femoral artery

Radiofrequency Ablation

• U/S- or CT-guided probe is inserted into tumour, radiofrequency energy delivered through probe

causes heat deposition and tissue destruction

• indications: hepatic tumours(HCC and metastases), renal tumours, lung tumours

• complications:destruction of neighbouring tissues and structures, bleeding, periprocedural embolism

r i

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MI29 Medical Imaging Toronto Notes 2023

Breast Imaging

Modalities

Mammography

Description

• x-ray imaging of the breasts for screening in asymptomatic patients, or diagnosis of clinically-detected

or screening-detected abnormalities (see General and I horack Surgery.GS65)

• routine evaluation Involves two standard views: cranio-caudal and medial-lateral-oblique

Indications

• screening (for guidelines,see family Medicine. I ,VM )

guidelines may vary bv region

• surveillance

• follow-up of women with previous breast cancer

• diagnostic: includes mammography with special views and/or VIS

workup of an abnormality that may be suggestive of breast cancer including a lump or thickening,

localized nodularity, dimpling or contour deformity, a persistent focal area of pain, overlying skin

changes, and spontaneousserous or sanguinous nipple discharge from a single duct

women with abnormal screening mammograms

suspected complications of breast implants

Table 19. Breast Imaging Reporting and Data System (BI-RADS ) Mammography Categories

Assessment

Categories

Imaging Findings Likelihood of

Malignancy (%)

Follow-Up Recommendations

BI-RADS 0 Incomplete N/A Additional imaging

Comparison to prior films

Routine screening

Routine screening

Unilateral mammogram at 6 mo

BI-RADS1

BI-RADS 2

Negative "0

Benign

Probably benign

Likelihood of malignancy is <2%

Suspicious abnormality

Low suspicion for malignancy

Low suspicion for malignancy

Low suspicion for malignancy

Highly suspicious of malignancy

Malignancy confirmed by biopsy

“0

BI-RADS 3 0-2

BI-RADS 4 3-94

BI-RADS 4A

Biopsy

Biopsy

Biopsy

Biopsy

Biopsy

Delinitive therapy

3-10

BI- RADS 4B

BI-RADS 4C

11-50

51-94

BI-RADS 5 >95

BI-RADS 6 100

Breast Ultrasound

Supplemental MilScreening lor Women with

Eitremely Dense Breast Tissue

ME JM 2019:381:2091-2102

Purpose: Eitremely dense breast 1issue is a risk

factor for breasUancer with poor mammography

detection. Data is needed on the use olsupplemental

Ml to unprone early detection and reduce Interval

breast cancersin such patients.

Methods NJ teenier. RCT where 40313 women

with eitremely dense breast tissue and normal

mammography were assigned toa group undergoing

supplemental MRI oi to a group that received

mammography streaming only.Ihe primary Pulcome

was the between-group difference in the incidence

mterval

^ cancers during a 2 yr screening penpd.

Results: he interval-canter rate was 2.5 per 1000

screenuigs m t-e Mil - v talion group and 5.0 per

1000 screenings in the mammography-only gioup

(P<0.001).Ihe MRI cancel-detection rate among the

women who actually underwent MRI screening was

16 5 per WOO screenings.Ihe positive predictive

value was12.4% (95% Cl.14.2 to 21.2) for recall lor

additional testing and 26.3% (95% Cl.21.2lo 31.61

lor biopsy.Ihe false positive rate was 29.8 per 1000

screenings.

Conclusion:Ihe use of supplemental MRI screening

- women with eitremely dense breast tissue and

normal results on mammography resulted in the

diagnosis of significantly fewer interval cancers than

mammography alone.

Indications

• characterization of palpable abnormalities

• U/S is 1st line in <30 yr - denser breast tissue makes mammograms less sensitive in young

females

• first line in lactating and pregnant women

>30 yr need mammogram first

• further characterization of manimographic findings

• guidance for interventional procedures

Breast MRI

Description

• contrast-enhanced MRI of the breasts

• sensitive for detecting invasive breast cancer (95-100%) but specificity variable (37-97%)

• for diagnosis, used only after mammography and U/S investigation

• use as a screening modality islimited to high-risk patients, in conjunction with mammography

Indications

• “problem-solving"of indeterminate findingsfollowing complete mammographic and U/S workup

• evaluation of occult primary in patients presenting with axillary metastases

• evaluation of patients with suspected silicone implant rupture and problems associated with breast

implants

• evaluation of previously diagnosed breast cancer: positive margins, recurrence, response to

chemotherapy

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MI30 Medical Imaging Toronto Notes 2023

• high-risk screening

• known BRCAI or BRCA2 mutation, or other gene predisposing to breast cancer, or untested firstdegree relative of a carrier ofsuch a gene mutation

family history consistent with a hereditary breast cancersyndrome and/or estimated personal

lifetime cancer risk >25%

high-risk marker on prior biopsy (atypical ductal hyperplasia, atypical lobular hyperplasia,

lobular carcinoma in situ)

radiation therapy to chest (before age 30)

Breast Interventional Procedures

Description

• includes core needle biopsy,stereotactic biopsy, MRl-guided biopsy, abscess drainage, and cyst

aspiration

Indications

• cystic mass: complex cyst,symptomatic,suspected abscess

• solid mass:confirm diagnosis of a lesion suspicious for malignancy (BI-RADS* Category 4 or 5)

• suspicious calcifications: confirm diagnosis of a lesion suspiciousfor malignancy (BI-RADS’Category

4 or 5) -stereotactic biopsy

• initial percutaneous biopsy procedure that was insufficient or discordant with imaging

• presurgical wire localization of a lesion

Breast Findings

Breast Masses

• definition: a space-occupying lesion seen in two different projections;ifseen in only a single

projection it should be called an “asymmetry” until itsthree-dimensionality is confirmed

tapactof UF-F06 PET.PETIT,asd PET Hitsi

Staging aid Naugcant asaiInitialStaging

Hodalit;ia Breast Caacet

Ckt tdMad2021:46(4)J7T-232

Pnpost!

mintte;ipactof1SF-FD5PEI.PEI

'

CT.adPETillHoastagagadsaaageaeatdr-g

ratalstagingof tireast caoce.

Methods:Studies ntict reported5e proportion

of breastoncer patientsntose cttiicel stage

ormenegeseotnerealtered tgPEI scansnere

incorporated intoaraadoas-efetismodel

Results:42J6 petiats froa 29 stridesnere

metoded iattepooledraadom-eSects codel.Pooled

prcportions of elterelioss ia stagewas 2S4(954 CL

2ftPi30%) adro maaageneot masS4(953,CL

M41D 2R).

Conclusions lisa rffif-fGGPET.PELUorPEI

'

KBleads to signi&cant ctsaages ins

^

gingand

managemeit for tarty dagnosed drees!cancer

paterts.PET staidPe considered for raataeclrical

nse for mtei stagingofBreast caicer

Table 20. Mammographic Features of Benign and Malignant Breast Masses

Benign Malignant

Shape

Margin

Density

Oval,round,lobular Inegular

Indistinct,microlobulated.spiculated

Radiodense

Circumscribed,well-defined

Radiolucent (oil cyst lipoma,fibrolipoma.

galactocele.hamartoma)

Calcifications (amass) Popcorn (hyalinizing fibroadenoma),lucent Pleomorphic (varyinsize and shape),

centred(oil cyst/falnecrosis),layering (milk of amorphous (indistinct),linelinear,coarse

calcium),vascular,round,scattered heterogeneous,regional,segmental,clustered

Other Findings

• tubular density/dilated duct:branching tubularstructures usually represent enlarged ducts(milk

ducts);if they are clearly identified assuch, these densities are oflittle concern

• intramammary lymph node:typical lymph nodes are well-circumscribed,reniform and often have

a fatty notch and centre; usually <1 cm, and usually seen in the outer,often upper part of the breast;

when these characteristics(particularly fatty centre or notch) are wellseen,the lesion is almost always

benign and insignificant

• focal asymmetry:area of breast density with similarshape on two views, but completely lacking

borders and conspicuity of a true mass; must be carefully evaluated with focal compression to exclude

findings of a true mass or architectural distortion

• if focal compression shows mass-like character-or if the area can be palpated -biopsy generally

recommended

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MI31 Medical Imaging Toronto Notes 2023

Landmark Radiology Trials

Trial Name Reference Clinical Trial Details

VASCULAR PROCEDURES

PREPIC NEJM 1998;338:409-416 Purpose;to study the efficacy and safety of vena cava!filtersin preventing the formation of PEs in patients with proximalDVI.

Methods:RCT consisting of 400 patients with proximal OVI who were randomiced to receive heparin in conjunction with either a

caval filter or no filter.

Results: 2 patients with

*

the treatment group and 9 patients within the contiol group had experienced a PE within 12 d.37

patients within the treatment groupand 21 patients within the control group experiencedrecurrent DVT within 2 yr.

Conclusion: 8enefrts of vena caval filters were counterbalanced by their risks.Filtersresulted in no significant difference in

mortality or other outcomes and although they preventedPE within12 d.they increased therisk of recurrent DVT within 2yr.

Purpose:To understand Lielong term implications of endovascular repair of abdominal aortic aneurysms.

Methods:RCT consisting of1252 patients with abdominalaortic aneurysms were randomized toundergo an endovascular or open

repair.The outcomes ofinterest includedmortality,graft-related complications, and re-mtervenbons.

Results: The 30 d postoperativemortality was lower in the endovascular repair group (1.8% vs.4.3%).However, due to graft

ruptures,the mortality rates equilibrated over time.The rates of graft-related complications andre-interventions were higher in

the group thatunderwent endovascular repair.

Conclusion:Mortality at30 d post-operation was significantly lower for endovascular repair compared to openrepair.At theend

of follow-up (5-10 yr).there was no significant differenceinmortality and rates of complication were higher in the endovascular

treatment group.

N Engl J Med 2022;386:1303- Title:Endovascular Therapy for Acute Stroke with a Large Ischemic Region

Purpose:Endovascular therapy is often avoided for patients with large cerebrovascular infarctions,however the benefits of

endovascular therapy in combination with stroke medical carehasnot been studied.

Methods: RCT consisting of 203 patients with occlusion of large cerebral vessels and an Alberta Stroke Program Early Computed

TomographicScore between3-5.Patients were randomized to receive endovascular therapy in conjunction with medical care or

medical care alone.The primary outcome is a modified Rankin score between 0 and 3.90-d post-tteatmenl.

Results: A larger proportion of patients treated with endovascular therapy inconjunction with medical care achieved a modified

Rankin score between 0and 3 (31%) compared to medical carealone (12.7%).

Conclusion:In patients with large cerebrovascular occlusions,treatmentwith endovascular therapyin conjunction with medical

care resulted in improved functional outcomes when compared to treatment with medical care alone.

EVAR NEJM 2010;362:1863-1871

KCT03702413

1313

VASCULAR PROCEDURES

N Engl J Med 2022:386:923 Title: Thyroidectomy without RadioiodineinPatients with Low-Risk Thyroid Cancer

Purpose: To assess the clinicalbenefit of postoperabve rad oiodine. after thyroidectomy inlow-risk thyroid cancer.

Methods: RCT consisting of 730 patients with low-risk differentiated thyroid cancer undergoing thyroidectomy.Patients were

randomized to either receive or not receive radioiodine.The outcomes of interest were the presence of abnormalradioiodine foci,

abnormal neck ultrasound,or presence of increased thyroglobulin/lhyroglobulin antibodies.

Results:There was no significant difference in postoperative abnormalities between pabents that received (4.1%) and didnot

receive postoperabve radio!nine (4.4%).

Conclusion:The use of radioiodine isnegligible in theprevenban of post-thyroidectomy abnormalities.

EVAR

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MI32 Medical Imaging Toronto Notes 2023

References

Boden WE. O'Rourke RA.leoKK.et at.Optimal medical therapy with or without PCI for stable coronary disease.NEJM 2007:356:1503 1516.

Brant WE,Helms CA.Fundamentals of diagnostic radiology. 5th ed.Philadelphia:Lippincott Williamsand Wilkins.2018 .

Canadian Association olRadiologists (CAR) standard lor breast imaging.Ottawa:Canadian Association oIRadiologists.2016.

Canadian Association of Radiologists (CAR) standard lor performance of breast ultrasound examination.Ottawa:Canadian Association of Radiologists,2016.

Canadian Association of Radiologists (CAR) standards for the performance of ultrasound-guided percutaneous breast interventional procedures.Ottawa:Canadian Association of Radiologists.2003.

Chen MYM,Pope XL.Ott DJ.Basic radiology.2nd ed.Hew York:Lange Medical BookslMcGraw Hill,2011.

Daffner RH.Clinical radiology:the essentials.4th ed.Baltimore:WilliamsiWilkins.2013.

D'Orsi CJ,Sickles EA.Mendelson EB.et al.ACR BI-RADS1 Allas.Breast Imaging Reporting and Data System.Reston.VA.AmericanCollege of Radiology;2013

Erkoncn WE.Smith WL.Radiology101.Philadelphia:Lippincotl WilliamsiWilkins.2005.

Fleckcnslcin P,Iranun-Jensen J.Anatomy in diagnostic imaging.2nd ed.Copenhagen:Blackwell Publishing.2001.

Gay S. Woodcock Jr RJ.Radiology recall.2nd ed. Baltimore: Lippincotl Williams(Wilkins.20007.

Goldstein S.Saline infusion sonohysteiogiam.Rose BD (editor).Waltham:UpToOate.2012.

Goodman LR. felson's principles of chest roentgenology:a programmed text. 3rded.Philadelphia: Saunders Elsevier. 2007.

Herring W.Learning Radiology:Rccogmcing theBasics. 4th ed.Philadelphia:Elsevier|

lmpiml)Elseviei •Health Sciences Division.2019.

Joffe SA.Scrvaes S.Okon S.et al.Multi-detector row Cl urography in the evaluation oihematuria.Radiogiaphics 2003:23:1441 1455.

Juhl JH.Crummy A8.Kuhlman JE (editors). 7th ed.Paul and Juhl'sessentials of radiologic imaging.Philadelphia:lippincolt-Raven. 2005.

Kate DS. Malh KR,Groskin SA.Radiology secrets. Philadelphia:Hanley andBelfus.1998.

MacMahon H.Haidich DP.Goo JM.etal.Guidelines for Management of Incidental Pulmonary Nodules Detected on ClImages:From the Fleischner Society 2017.Radiology 2017:284:228-243.

Mettler FA Jr.Huda W.YoshicumiIT,etal.Effective doses in radiology and diagnosbc nuclear medicine: a catalog.Radiology 2008:248:254-263.

Novelline RA.Squire's fundamentals of radiology.6th ed.Cambridge:Harvard University Press.2004.

Ouellette H.letreault P.Dinicalradiology made ridiculously simple.Miami:MedMaster.2002.

Owen RJ.Hiremath S.Myers A.elal.Canadian Association of Radiologists consensus guidelines for the prevention of contrast-inducednephropathy:update 2012.CanAssoc Radiol J 2014:65:96-105.

Som PM.Curtin HD.Head and neck imaging,3rd ed.St.Louis:Mosby.1996.

Smith 0L.HeldtJP,Richards GO.etal.Radiation exposure during continuous andpulsed fluoroscopy.J Endourol 2013;27(3):384-388.

Warner E. Messer smith H.Causer P.et al.Cancer Care Ontario'sPrograminEvidence-based Care. Magnetic resonance imaging screening of women alhigh-risk foi breast cancer:a clinical practice guideline.

2007.

Warner E. Messer smith H.Causer P.et al.Magnetic resonance imaging screeningof women al high-risk for breast cancer:a clinical practice guideline.Program inEvidence Based Care.Cancer Care Ontario,2007.

Wcissledcr R.Rieumont MJ.Wittenberg J.Primer of diagnostic imaging. 2nd ed. Philadelphia: Mosby.1997.

Young WE.Clinical practice.Ihc incidentally discovered adrenalmass. NEJM 2007:356:601- 610.

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Nephrology

David Buchan and Huaqi Li, chapter editors

Karolina Gaebe and Alyssa Li, associate editors

Wei Lang Dai and Camilla Giovino, EBM editors

Dr. Damien Noone, Dr. Gemini l

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