NM Cases 1, 2 and 5

Case 1 - no activity on Pertechnetate scan - most likely subacute thyroiditis

Case 2 - Single nodule with intense uptake and suppression of the rest of thyroid - autonomous nodule

Case 5- Cold Nodule - concern for thyroid carcinoma which is what it turned out to be.

• I-123 and Technitium-99m pertechnetate are most commonly used imaging radionuclides
• I-131 can also be used for uptake
• I-131 - Beta emitter and has 1/2 life of 8 days. principal gamma emission is 364 emitter. I-131 advantage - low price and ready availability. Disadvantage - long 1/2 life and high-beta emission (esp. to thyroid - about 1 rad/microCi); good for tumor follow up due to long half life
• I-123 - same behavior as iodine. Nuclide of choice for thyroid imaging. Decays by electron capture - 159 KeV and 1/2 of 13 hours. Low background activity. Disadvantages - high cost (produced by cyclotron), availability and delivery.
• Tech 99m - trapped by thyroid but not organified; 6 hour 1/2 life; 140 KeV - ideal for gamma camera; can give higher doses and acquire quickly w/ less risk of motion; higher background than iodine (only 1-5% trapped); Salivary glands - well seen; preferred nuclide when patient has been on thyroid blocking agents or unable to take medication orally or study must be completed in less than 2 hours.
• Both Tech and iodine - cross placenta and secreted in breast milk
• NRC recommends stopping breast feeding if I-131 exceeds 1 microCi
• I-131 - not recommended for children.
• Radioiodine Uptake test - Useful for clinical index of thyroid function.
• Often for determining how much uptake will be present for therapy.
• Useful for differentiating Grave's from subacute thyroiditis or factitious hyperthyroidism
• Basic idea - the more active the gland the more iodine will be taken up. Measurements obtained at 4-6 hours and 24 hours post administration.
• 4-6 - normal is 6-18%; 24 - 10-30%
• Patient should be NPO after midnight
• I-123 10-20 microCi; I-131 5 microCi
• Neck compared with neck phantom. Probe - 25-30 cm from anterior neck
• Equation - (neck counts-thigh counts)/counts in standard1
• 4-6 hour uptake recommended - esp for the possibility of a rapid turnover Grave's
• Factors affecting uptake - Too much iodine in diet (low uptake); too little (high uptake)
• Increased uptake factors - hyperthyroidism, early hashimoto's, recovery from subacute thyroiditis, Rebound after antithyroid meds; Enzyme defects; Iodine deficiency; Hypoalbuminemia; TSH; tumor secreted stimulators; Pregnancy
• Decreased uptake factors - hypothyroidism; iodine overload (contrast); meds; subacute or autoimmune thyroiditis; thyroid hormone tx; ectopic secretion from tumors (struma-ovarii etc); renal failure
• Compounds that decrease uptake - adrenocorticosteroids, amiodarone, bromides, butazolidine, Mercurials, methimazole, Propylthiouracil; nitrates; Perchlorate; salicylates; kelp, Cytomel, synthroid, contrast
• Renal failure - iodides are retained leading to larger pool of iodine which will compete with I-123 or I-1316.
• B-blockers - do not affect function of thyroid and does not affect uptake.
• Chronic Thyroiditis - Hashimoto's - most common form of inflammatory disease of thyroid
• Likely Autoimmune; usually female
• Thyromegaly - presenting w/ possibly mild hyperthyroidism or hypothyroidism
• Early - scan shows diffusely uniform like Grave's
• Later - coarse patchy activity - similar to multinodular goiter
• Acute (bacterial), subacute (viral or autoimmune) - usually diagnosed on clinical or physical grounds - scanning little role
• Subacute - painful swollen gland w/ elevated thyroid hormone levels but depressed uptake - little or no localization
• Cold Nodule - Most common - colloid cyst (70-75%)
• Carcinoma - 15-25% - this is why every cold nodule should get US and possible biopsy.
• Miscellaneous - <15%>
• Factors increasing risk of malignancy - younger patients, male, hx of rads to head and neck, hard lesion, other masses in neck, no shrinkage on thyroid hormone, family hx.
• Factors decreasing risk - older, female, sudden onset, tender or soft lesion, multiple nodules, shrinkage on thyroid hormone.
• US - useful for showing solid versus cystic (not benign vs malignant).
• Hot nodules almost always represent hyperfunctioning adenomas of which 1/2 are autonomous
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• Often not suppressible by thyroid hormone and independent of pituitary axis.
• Can suppress surrounding thyroid
• Warm - may represent a cold nodule that has overlying normal thyroid tissue - so have to get multiple views.

July 14 Cases 1-3 answers

Case 1 - 2 different examples of Meningioma.

Case 2 - BB to the eye.

Case 3 - Epidural hematoma.

Sorry my family got back from long trip so not a lot of time for detailed descriptions. Will do more later promise.

As far as Case 2 - the movie was -

Case 1 Answer 7-6-2009 Thyroid (Grave's) Ophthalmopathy

What we see is enlargement of the extraocular muscles that "spares" the myotendinous junction.

This is Thyroid Ophthalmopathy

• Usually occurs in patients with Grave's disease - but can be seen in any thyroid state


• Resolves in >90% of patients


• Most common cause of proptosis in adults


• Histology - inflammatory leukocytic infiltration with edema and deposition of mucopolysaccharides - leading to fibrosis, lipomatosis, fatty degeneration.


• Can compress optic nerve leading to optic neuropathy


• Can cause diplopia due to muscle entrapment


• Proptosis - can lead to corneal ulcers and conjunctival congestion


• Most frequently involves medial and inferior recti - IMSLow - Inferior, medial, superior, lateral; muscles >4 mm


• More frequent in women but more severe in men


• Expansion of orbital fat


• Upper and lower eyelid retraction


• Often bilateral and symmetric


• Painless


• TX - prednisone, radiotherapy, surgical decompression, thyroid surgery, I-131


• DDX - pseudotumor (painful, unilateral, involves tendons, inflammed fat, good response to steroids) [can be idiopathic, sarcoid, endocrine, focal infections, foreign bodies], cavernous hemangioma of the orbit, Histiocytosis X, cavernous sinus thrombosis, intraconal varices, lacrimal gland tumor and don't forget mets (usually osseous)


• Imaging - Ultrasound, CT (good bone imaging and shows all the features but has radiation), MRI

References: http://emedicine.medscape.com/article/383412-overview ; Neuroradiology Companion by Mauricio Castillo and Primer of Diagnostic Imaging by Weissleder et al.

Case 2 Answer 7-6-2009 - Perineural spread.

The imaging demonstrates a lesion in Meckel's cave that is low on T1, dark on T2 and enhances. There is denervation atrophy of the pterygoid muscles on the right and opacification of the right mastoid air cells.

With imaging like this, you need to think of peritumoral spread along the cranial nerves. This is an odd example in that biopsy revealed Lymphoma.

• Perineural spread - tumor or other pathology spreads along tissues of neural sheath
• Common in head and neck cancer
• In head and neck cancer - major negative prognostic indicator
• Most common malignancies - salivary, mucosal and cutaneous
• Adenoid cystic frequently spreads by perineural tumor spread
• SCC of mucosal and cutaneous can
• Desmoplastic melanoma is common
• Often present at time of diagnosis; rarely present prior to detection
• Can present as recurrence or occur at the same time as recurrence
• Common hx - new cranial neuropathy
• Any tumor that are adjacent the skull base foramina are at risk of Perineural tumor spread; esp - masticator space, Meckel's cave, cavernous sinus and Pterygopalatine fossa
• Perineural spread - can be retrograde (toward CNS) or antegrade (away from CNS)
• Benign - some benign disorders spread along cranial nerves (essentially like PNS or similar to it by imaging) - schwannoma/neurofibroma, meningioma, rhinocerebral mucormycosis, sarcoidosis etc.
• Signs and Symptoms - pain and paresthesias
• V3 - weakness and denervation of muscles of mastication
• Facial - variable weakness or paralysis
• Most commonly affected - trigeminal and facial
• V2 (maxillary) and V3 (mandibular) - most common branches of CN V involved
• V1 - sensory to eye, lacrimal gland, conjunctiva, some nasal mucosa and upper face
• V1 - often from cutaneous lesion in supraorbital region; rare for intraorbital process to spread to V1
• V2 - sensory to mid and upper lateral face, mucosa of palate, sinonasal region, maxillary gingiva and maxillary teeth
• V2 - to spread along V2 from nasopharynx - must access pterygopalatine fossa (PPF) - often by nasal cavity then sphenopalatine foramen
• V2 - from skin along maxillary distribution - infraorbital nerve or zygomatic nerve
• Pterygopalatine fossa - Pterygopalatine ganglion, internal maxillary artery; bounded posteriorly by pterygoid plates, medially by palatine bone, anteriorly by maxillary sinus
• PPF - communicates laterally with infratemporal fossa with pterygomaxillary fissure
• PPF - communicates w/ intracranial space by foramen rotundum
• PPF - communicates with nasal cavity (medially) via sphenopalatine foramen
• PPF - Vidian nerve provides preganglinonic parasympathetic component of pterygopalatine ganglion
• PPF - communicates with greater and lesser palatine foramina inferiorly through the palate
• V3 - sensory innervation to skin of lower face and pre-auricular/temporal region, mandibular teeth, mucosa of mandibular gingiva, floor of mouth, ant 2/3 of tongue, buccal mucosa
• V3 - motor to musscles of mastication, mylohyoid and anterior digastric
• V3 - PNS - travel through foramen Ovale to Meckel's cave
• Facial Nerve (CN VII) - typically only 2 branches are affected - descending facial nerve (from parotid malignancies or lesions that involve the parotid) and the GSPN (greater superficial petrosal nerve)
• Descending facial nerve - can travel to geniculate ganglionand even through labyrinthine segment to involve internal auditory canal
• GSPN - small branch that leaves geniculate ganglion and exits superior surface of temporal bonte through facial hiatus to become intracranial; courses anteromedially beneath Meckel's cave to foramen Lacerum to join deep petrosal nerve (carotid sympathetic plexus) and become the Vidian nerve through Vidian canal
• Imaging - minimum need axial T1, axial T2, and 3 plane postcon T1 (with at least one in fat-suppressed form)
• T1 - look for loss of normal fat
• Look for widening of foramina - foramen ovale, mandibular foramen, foramen rotundum, PPF, foramen and canal for infraorbital nerve, vidian canal, palatine foramen, stylomastoid foramen, descending facial canal
• Look for enhancement
• Look for involvement of Meckel's cave
• Indirect findings - denervation of masticator muscles, anterior digastric, mylohyoid
• Early denervation - T2 bright and enhancement with post con
• Late - atrophy and fatty infiltration

Reference - MR Imaging of Perineural Tumor Spread by Lawrence E. Ginsberg; Neuroimaging Clinics of North America 14 (2004) 663-667

6-27-2009 Case 2 answer - Capillary Telangiectasia

Lesion that is not seen on T1 precon but demonstrates "stipple" enhancement on postcontrast images in the pons - this is consistent with capillary telangiectasia.

• Most are in pons - but can be seen in cerebral, cerebellar and spinal cord tissue
• Nearly always asymptomatic and no further intervention necessary
• 16-20% of intracerebral vascular malformations at autopsy
• CT - almost always normal
• T1 - hypo to iso to brain
• T2 - normal (often) or slightly hyperintense
• T2* - can be normal or low in signal - but not due to hemorrhage or calcification - and likely represents deoxyhemoglobin in slow flowing blood
• T1 postcon - brush like or stippled pattern
• No mass effect
• 2/3 have enlarged vessel that may represent a draining vein.
• Often considered an acquired lesion and may represent obstructed venous drainage
• Can be seen in association with cavernomas and AVMs
• Does not show up on angiography

Reference - http://www.ajnr.org/cgi/content/full/22/8/1553 and http://emedicine.medscape.com/article/337451-overview

6-27-2009 Case 1 Answer - Choroid Plexus Carcinoma

CT - demonstrates a hyperdense structure in the lateral ventricle causing hydrocephalus in a young patient. Pathology revealed a choroid plexus carcinoma.

• Neoplasms of ventricular system are usually easy to recognize but pathology is sometimes difficult to determine by imaging characteristics
• Choroid plexus - found in the ventricles - highly vascular and produces CSF
• Choroid plexus neoplasms - usually highly vascular and produce hydrocephalus
• Benign - papilloma; Malignant - carcinoma
• Most frequently found in atria and posterior portion of lateral ventricles
• Other highly vascular tumors are commonly seen in this site - mets and meningioma
• Ependymal cells - ependymoma
• Subependymal glial cells - subependymomas and subependymal giant cell astrocytoma
• Septum pellucidum - central neurocytoma
• Choroid plexus - found most commonly in atria, third ventricle and 4th ventricle (not seen in temporal horns or aqueduct of Sylvius)
• 50% of tumors are in lateral ventricles, 40% in 4th and 5% in 3rd.
• Rare - extraventricular areas like CPA, suprasellar cistern etc
• Choroid plexus tumors aren't that common overall but 10-20% of brain tumors in those less than 1 yr.
• 80% are benign papilloma and rest are carcinoma
• Those in lateral ventricle are most likely to present <10
• Most present due to symptoms of hydrocephalus
• Other symptoms - cranial nerve palsies, seizures, coma, and one report of psychosis
• Choroid plexus tumors - have an association with Li-Fraumeni and Aicardi syndromes
• Choroid plexus papilloma - 5 yr survival - practically 100%
• Choroid plexus carcinoma - 5 yr survival - 26-50%
• Choroid plexus tumors - cauliflower like well circumscribed masses with lobulations
• hemorrhage and cyst formation can be seen
• Signs of carcinoma - necrosis and parenchymal invasion
• Lateral ventricle choroid plexus - attached at trigone
• 3rd ventricle - attached at roof
• 4th ventricle - attached at posterior medullary velum
• Can have ball-valve effect for hydrocephalus
• Atypical choroid plexus papilloma - one or 2 histologic malignant features but not enough for carcinoma
• Papilloma and Carcinoma (but much more frequent for carcinoma) can have seeding of CSF
• CT - most tumors are iso or hyperattenuating
• CT - with enhancement - avid enhancement
• CT - 24% see calcifications
• T1 MR - iso or hypo to brain
• T2 - variable and often see flow voids within the lesion
• T1 postcon - avid enhancement
• Carcinoma - may have more variable CT and MR appearance; may have less hydrocephalus; look for parenchymal invasion and vasogenic edema
• Carcinoma - Increased uptake on FDG PET
• Imaging - papilloma and carcinoma has a lot of overlap therefore unless obvious malignant features are present cannot exclude carcinoma when imaging looks like a papilloma
• Lateral ventricular lesions - supplied by anterior choroidal, medial posterior choroidal and lateral posterior choroidal arteries
• 4th ventricular - choroidal branches of PICA
• Lesions in trigone - less than 10 - think papilloma/carcinoma; 10-40 - think low grade glial like ependymoma or subependymoma; >/= 40 - think meningioma, mets, lymphoma
• Intraventricular meningioma - rare and almost always older (caveat - 1/5 of all meningiomas in children are intraventrciular)

References - http://radiographics.rsnajnls.org/cgi/content/full/22/6/1473 and http://www.ajnr.org/cgi/content/full/20/5/882

6-23-2009 Case 1 - DNET

Alright - the images from top to bottom - CT, FLAIR, GRE/T2*, ADC, DWI, postcon T1, precon T1 and T2

This case represents a Dysembryoplastic Neuroepithelial Tumor (DNET).

1. Benign tumor of neuroepithelial tissue arising from cortical or deep grey matter.

2. Virtually always in patients with refractory partial seizures

3. Majority - younger (in 20's or younger) and male

4. Neurologic deficits are not common

5. temporal (often amygdala/hippocampus) > frontal > parietal; can also be seen in caudate, pons, and cerebellum

6. Cerebellar - present with vertigo, ataxia and gait disturbances

7. Tend to be stable, recurrence is rare but malignant degeneration has occured - therefore long term follow up is recommended.

9. Imaging - similar to low-grade gliomas - can be difficult do differentiate from diffuse astrocytoma, ganglioglioma and oligodendroglioma

10. CT - hypoattenuating mass with occasional calcifications, may see remodeling of inner table; minimal or no mass effect; may resemble a stroke but no evolution over time

11. MR - low signal on T1, high on T2 without surrounding edema; 1/3 enhance and usually peripheral or nodular (i.e. 2/3 don't); if enhancing - may be something more ominous

12. Some have a "soap bubble" appearance; some appear like an enlarged gyrus; can have multicystic appearance

13. Often when cortical - wedge shaped with point toward ventricle

14. FLAIR - mixed hypo/iso with bright rim; GRE - occasionally bleed and can be confused with cavernoma (rare); PD - hyperintense rim; No restricted diffusion

15. HMPAO - hypoperfusion (ictal may have uptake); No uptake on Thallium-201; PET - hypometabolism

16. DDX - Taylor Dysplasia (single Tubersous sclerosis lesion - expand gyrus, nonenhancing, looks like a tuber), Neuorepithelial cyst (nonenhancing single or complex cyst, no bright rim), ganglioglioma (strong enhancement, calcs, cyst), PXA (enhancing nodule adjacent to pia and look for dural tail)

References - http://radiographics.rsnajnls.org/cgi/content/full/21/6/1533 ; statdx.com

Case 2 - Developmental Venous Anomaly

This is a postcon T1 image. It has a "medusa head" appearance of enhancing branching pattern in left frontal lobe. This represents dilated veins in a Developmental Venous Anomaly (DVA). You do not biopsy it.

1. DVA - aka venous vascular malformation or venous angioma
2. Congenital venous anatomical variant in venous drainage of brain.
3. 2% of population and is the most common venous malformation
4. Incidental and don't cause symptoms
5. If symptoms - likely due to a cavernoma which are sometimes seen in conjunction with DVA
6. No surgery as can cause venous infarct
7. 15-30% are associated with another vascular malformation (cavernoma, AVM, capillary telangiectasia) - the most common is a cavernoma
8. Complications - hemorrhage (likely from associated cavernoma), thrombosis of venous malfomation (which leads to venous infarct and can lead to hemorrhage), seizures (mentioned in literature but not much literature to support claim)
9. DVA - fine network of enlarged medullary venules that join to form central venous flow tract that drains to superficial or deep venous system
10. Thought to occur as alternative when normal drainage is not present.
11. CT - not seen on noncon; contrasted CT - large vascular structure in brain parenchyma w/ smaller radiating veins and the large vascular structure draining to superficial or deep venous system
12. MRI - best seen on postcon images - spoke wheel or caput medusa of venules to larger vein that will drain to deep or superficial venous system; intervening brain parenchyma is normal; draining vein usually has straight course
13. If draining vein is near lateral ventricle - usually drains to subependymal vein which is often enlarged
14. Look for other vascular malformations - MRI preferred method

Reference - emedicine.com

Femoral Artery Pseudoaneurysm - Answer Case 1 6/14/2009

This series of images from an abd/pelvis CT demonstrates a hyperdense focus of contrast adjacent to the left common femoral artery with a small neck communicating the two. The patient had a recent cardiac catheterization. This represents a Left common femoral artery pseudoaneurysm.

1. < 5% of arterial access

2. Risks - large catheter, anticoagulation, calcified arteries, HTN, too low a puncture, obesity

3. Physical Exam - pulsatile hematoma at puncture site with a bruit.

4. Ultrasound - rapid diagnosis

5. Small - spontaneously resolve

6. Complication - infection and rupture

7. Tx - surgery, ultrasound guided compression and ultrasound guided thrombin injection

8. US-compression - neck - compress 20-30 min - complications are embolization and thrombosis

9. US-thrombin - thrombin 1000 Units/mL - use 1mL syringe - slow injection into pseudoaneurysm away from the neck; occasionally require more than 1 injection; complication - distal thrombosis from thrombin in system.

Reference - VIR requisites (Kaufman et al)

Pneumotosis - Answer Case 2 6/14/2009

In this image, there is air outlining the wall of large bowel. This reflects pneumotosis intestinalis. The differential for this process is long.

DDx
1. Mesenteric ischemia/infarction.
2. Necrotizing enterocolitis
3. Post anastomosis
4. Intestinal obstruction/volvulus
5. Gastric, duodenal ulcers
6. Perforation of diverticulum
7. Pseudomembranous colitis
8. Post endoscopy and post trauma
9. COPD
10. Steroids
11. Collagen vascular disease
12. Mesenteric abscess
13. Neoplastic bowel wall damage

Therefore, the key is to know the patient's history and clinical scenario. This turned out to be a benign pneumotosis.

reference - http://www.ajronline.org/cgi/content/full/177/6/1319; uhrad; http://radiographics.rsnajnls.org/cgi/content/full/22/5/1093

Colon cancer - Answer Case 3 6/14/2009

The first image from a single contrast water soluble enema demonstrates abrupt cutoff in the descending colon. CT images of the abdomen and pelvis demonstrates descending bowel wall thickening and adjacent lymph nodes consistent with cancer of the colon. Additionally, there is a hypodense lesion in the liver that is irregular and most likely represents a metastasis to the liver.

TAR syndrome Case 3 6/7/2009

So what we see is bilateral absent radii. Absence of the radius is associated with multiple disorders and syndromes. Therefore because both radii are missing suggests a syndrome and the history of thrombocytopenia helps come up with a diagnosis.

TAR syndrome - thrombocytopenia absent radius syndrome.

Differential - Fanconi's Anemia, VACTERL syndrome (Vertebral anomalies, anal atresia, cardiac anamolies, tracheo-esophageal fistula, radial ray anomalies) etc.

Fanconi's - oftentimes has missing thumbs. Short stature, skeletal dysplasias, bone marrow failure, cellular sensitivity and risk for solid tumors and leukemias; needs bone marrow transplant; generally considered to be Auto recessive.

VACTERL - obviously has a lot of other additional problems.

References - http://www.wikipedia.org/ and http://www.medcyclopaedia.com/

Melorheostosis - Case 2 6/7/2009.

What we see is hyperostosis of the cortical bone of the left humerus. It is benign in appearance. No soft tissue mass, no abnormal periosteal reaction or destructive changes. This is most consistent with melorheostosis.

• Classically described as flowing hyperostosis
• Dripping candle wax sign
• Monostotic (single bone), monomelic (single limb), or polyostotic (multiple bones) - but often on a single side of body even when polyostotic
• Often follows a sclerotome
• Irregular thickening of cortical bone (cortical hyperostosis)
• Rare sclerosing bone dysplasia
• Patient's often discovered incidentally when looking for something else
• When symptomatic - often doesn't present till late teens early adulthood - limb stiffness and pain
• Can progress to disability even amputation.
• Can cause muscle contractures, tendon and ligament shortening and soft tissue involvement; growth disturbances (increased width, angulation, unequal limb length)
• Soft tissue - tense, erythematous and shiny skin; anomalous pigmentation; induration and edema of subq tissues; fibrosis; weakness and atrophy of muscles; and linear scleroderma
• Predominately limbs with lower more common than upper extremity
• Also can be seen in skull, facial bones, ribs and vertebrae
• If clavicle, scapula, or pelvis - adjacent limb usually also involved
• Can have endosteal hyperostosis as well
• Can appear like osteopoikilosis - esp in tarsal and carpal areas
• Pelvis and scapula (flat bones) - may appear radiating or localized sclerotic patches
• 25% have soft tissue calc and/or ossification
• Can be associated with linear scleroderma, osteopoikilosis, osteopathia striata, Neurofibromatosis, tuberous sclerosis, hemangiomas
• Have also been associated with glomus tumors and AVMs
• 5 basic imaging patterns - classic, osteoma-like, myositis-ossificans like, osteopathia striata like, mixed

References - http://radiology.rsnajnls.org/cgi/content/full/246/2/638 ; Bone and Joint Imaging (Resnick - i.e. Baby Resnick)

Situs Inversus - Case 1 6/7/2009

Great job - Elisha - you got it within 5 minutes of posting.

So the first image shows dextrocardia. In the original set, the second image shows the stomach bubble on the scout film on the right. In the second image shown here, the stomach is clearly on the right and the ileocecal valve is noted on the left (best seen at the left iliac crest).

This patient has situs inversus.

• Situs - describes position of cardiac atria and viscera
• Situs solitus - normal position
• Situs inversus - mirror image of situs solitus
• Cardiac situs - dictated by atria. (but not the apex - i.e. you can have reversal of left and right atria but apex still points to left)
• Can have situs inversus with cardiac in normal axis (levocardia) or dextrocardia.
• When there is situs inversus - the lungs are often inverted as well - the left has 3 lobes and the right has 2 lobes.
• Dextrocardia may be present but viscera is in the correct position.
• When mirror image is exact - called situs inversus totalis.
• When can't tell - situs ambiguous - heterotaxy - liver may be midline, spleen absent or multiple, atrial morphology unclear, and possibly malrotated bowel.
• 2 primary types of situs ambiguous - asplenia syndrome (right isomerism) and polysplenia syndrome (left isomerism)
• Classic asplenia - double right sidedness - bilateral right atria, absent speen, both lungs have 3 lobes, central liver, aorta and IVC on same side of spine
• Classic polyspenia - double left sidedness - multiple spleens, bilateral left atria, IVC dicontinuity with azygos or hemiazygos continuation, both lobes of lungs have 2 lobes
• All the different varieties are rare - with situs inversus - 0.01%
• Situs inversus totalis - associated with Kartagener syndrome (primary ciliary dyskinesia) (my patient didn't have it).
• Kartagener's - repeated sinus and pulmonary infections - with pulmonary sometimes leading to bronchiectasis (esp lower lobes); 20% of patients with situs inversus; transmitted by Auto Recessive; only 50% of those with Kartagener's have situs inversus; also reduced fertility or infertility is common
• Situs inversus - normal life expectancy (except for those with severe pulmonary complications and those with cardiac anomalies)
• False positive and negative results are usually due to human error with labeling - that is why quality assurance is so important.

Reference - http://www.emedicine.com/ - Dr. Annamaria Wilhelm from Mayo Clinic

5/17/2009 case 3 answer

The finding is dislocation of the left shoulder with fracture of the greater tuberosity. This is an excellent example of how you need to look at all corners of the film. If this patient had multiple injuries, the dislocation could be missed with possible complications later.

5/17/2009 case 2

The image above is the follow up examination. The original image demonstrated a pathologic fracture within a lytic lesion. If you look closely, there is a splinter of cortical bone at the bottom of this image which was obtained with the patient upright and represents the "fallen fragment" sign. This sign is consistent with a cystic structure i.e. a simple bone cyst. This is the most common location for a simple bone cyst and 20% of SBC's have the "fallen fragment" sign.

SBC

• originally defined in 1910
• fluid filled cyst commonly in the metaphysis of long bones
• benign
• idiopathic - possibly venous obstruction and blockage of interstitial fluid drainage in an area of rapidly growing/remodeling cancellous bone
• cyst contains serous fluid and maybe blood products
• May have septa especially after fracture.
• wall - mesothelial cells and sometimes multinucleated giant cells
• M:F; 2:1; usually in the first or second decade of life
• usually single - if multiple tend to be older and male
• Humers and femur are most common (esp proximally) ; less common - tib, fib, radius, ulna
• older patients (esp >20) - calcaneus and iliac bone and other flat bones
• Asymmetric unless fx
• X-ray - well defined (geographic), lytic lesion with narrow zone of transition, intramedullary and usually abut the physis. thin sclerotic wall
• May cause thinning and expansion of the bone and can be multiloculated.
• Fallen fragment sign - pathognomonic
• Tx - curretage, bone grafting, steroid injections, cryotherapy, nailing

reference: emedicine.com and http://radiology.rsnajnls.org/cgi/reprint/209/3/884-b?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=fallen+fragment+sign&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

5/17/2009 case 1

On the first image - there is loss of the Arcs of Gilula and a pie shaped lunate bone. On the lateral view, there is loss of normal alignment between radius and lunate and the lunate with the capitate. This is called the "spilled teacup" sign. Additionally, there is a dorsal (posterior) chip of bone which signifies a fracture of the triquetral bone of the wrist. This is called a transtriquetral lunate fracture-dislocation.

Lunate dislocations - are the most severe and most unstable of the carpal dislocations. There are multiple tears of the carpal ligaments such as the scapholunate ligament, lunocapitate, lunotriquetral and radiolunate ligaments. The most common dislocation is the perilunate dislocation which is where the alignment between the lunate and capitate is disrupted but the radius-lunate alignment is maintained.

reference: http://www.ajronline.org/cgi/reprint/133/3/503.pdf and http://radiographics.rsnajnls.org/cgi/content/full/28/6/1771?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=lunate+dislocation&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT

5/9/2009 Case 5 Answer

This poor unfortunate patient was having complications with the patient's hemodialysis catheter. Evaluation demonstrates large clot burden in the IVC above the renal vein origins. This patient is at risk for pulmonary embolus.

Treatment options include - IVC filter placement, oral anticoagulation and thrombolysis. Because the patient has multiple venous occlusions in the neck and upper extremity veins, IVC filter cannot be placed.

References: VIR Requisites (Kaufman et al)

5/9/2009 Case 4 - Answer

What we see is active extravasation from the distal common iliac artery on the right just above the bifurcation.

Treatment - could include surgery or endovascular stent-graft placement

Interventional techniques are not ideal in Ehlers-Danlos patients as they have a lot of complications but in this emergent case it is acceptable. Endovascular stent-graft was applied.

Reference - VIR Requisites (Kaufman et al)

5/9/2009 Case 3 - Answer

The first image demonstrates a narrowing in the cephalic vein. The second image shows angioplasty of the vein. The third image (which is the image from the Rob's Radiology fan page) demonstrates extravasation after angioplasty.

The procedure is a fistulogram with resultant complication from angioplasty.

Surprisingly, treatment often is easily treated with inflating the balloon until the bleeding stops. The vein often seals after the inflation and no further problems are usually seen. Other treatments include compression or stent-grafts. But stent-grafts are not ideal for crossing joints as in this case which is at the elbow.

Other acute complications - thrombosis and dissection. Thrombosis can be treated by drug or mechanical. Dissection can also be treated with balloon.

References - VIR Requisites (Kaufman et al) and Handbook for Interventional Radiologic Procedures (Kandarpa and Aruny)