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)

5/9/2009 Case 2 - answer

The CT - demonstrates contrast adjacent to the iliac limb in the aneurysm sac (it changed on the delayed scan so is not a calcification).

The angiogram - demonstrates the endograft in the aorta and selective catheterization of the artery that supplies a lumbar artery that is causing an endoleak to the sac around the graft.

The answer is type II endoleak in association with an abdominal aortic endograft repair of an abdominal aortic aneurysm.

• Endoleaks are leakage of blood into the excluded aneurysm sac after endograft treatment for an aneurysm (usually AAA)
• Endoleaks are classified and the type has prognostic factors and can indicate the severity of need for treatment.
• Type I - defect in apposition of an end of the stent-graft (proximal or distal) that leads to leakage into the sac.
• - can be seen immediately after deployment due to steep angulation, incomplete expansion, or tortuosity.
• - can be seen late due to changes from shrinking of the sac
• - high pressure situation and needs to be treated urgently.
• - contrast seen centrally with extension to the affected edge of the graft; us - may show pulsation at the edge.
• Type II - most common - a branch is supplying retrograde flow into the aneurysmal sac
• - low pressure situation and may not need repair if the sac is decreasing in size
• - imaging - peripheral contrast within sac
• - if increasing in size - should treat with embolizing of branch
• - often in abdominal aorta - lumbar or IMA is source.
• - many close spontaneously
• Type III - break in body of stent graft or defect in components
• - high pressure situation requiring urgent care
• - a jet may be visible - contrast seen around graft
• - often large amount of contrast seen.
• Type IV - opacification of sac seen at time of procedure and no obvious source identified and stop on their own
• Type V - "endotension" - increasing size of sac (over studies) without sign of source - not emergent but needs treatment.

reference: http://www.ajronline.org/cgi/content/full/192/4/W178

5/9/2009 Case 1 - answer

The plain film demonstrates massive dilatation of the sigmoid colon. The CT demonstrates massive dilatation of the descending and particularly the sigmoid with a transition in the distal sigmoid. No focal lesion or obstructing process identified.

These findings are consistent with Ogilvie's syndrome or Pseudoobstruction of the colon.

1. Can be acute or chronic
2. Acute needs rapid decompression especially when there is dilatation of the cecum (to prevent rupture).
3. Not paralytic ileus as it has a transition but not obstructive as no stricture will be found and the air should change with position.
4. Treatment - can be conservative - NG, enemas, neostigmine - or aggressive with colonoscopic decompression or even percutaneous cecostomy.
5. Loss of parasympathetic ganglions may be a factor
6. Transition is often seen at splenic flexure (not our case) which may be related to change in parasympathetic control from vagus to sacral nerves at this level.
7. Acute - often related to recent surgery (of any sort) or major illness.
8. Chronic - recurrent and rarely perforates.

References: http://www.ajronline.org/cgi/content/full/190/6/1521 ; http://radiographics.rsnajnls.org/cgi/reprint/6/6/995.pdf

5/3/09 case 3 answer

Fan's of Rob's Radiology - the image shows a port overlying the chest wall on the right and the detached catheter portion embolized into the pulmonary arterial system.

Diagnosis - detached catheter embolized into the PA system.

Next step - Consult IR who can retrieve the tubing with snares under fluoroscopy.

This is an uncommon complication.

5/3/2009 Case 2 Answer

Fan's of Rob's Radiology

The original image shows an esophogram that has contrast in the airway. Going back and looking at the oral transfer - the patient is aspirating.

Therefore - the primary team needs to be notified about the severity and fact that the patient is aspirating spontaneously. Other information that is helpful is whether the patient responds and knows that he/she is aspirating. This patient cannot be trusted to eat or drink. This patient is at high risk for pneumonia and other problems.

You do not want to use water soluble contrast agents (like gastrograffin) as this can cause a life-threatening mediastinitis when aspirated. Therefore, barium is the contrast of choice.

5/3/2009 Case 1 Answer

Fans of Rob's Radiology - this is a Colloid Cyst.

1. Benign lesion in the anterior 3rd ventricle (near foramen of Monro)
2. Neuroepithelial in origin - is the leading theory
3. Can cause sudden death by obstructing the foramen of Monro
4. May have pendulous attachment to 3rd ventricular roof
5. Usually found in adults but has been reported in children
6. Often found incidentally
7. Headaches - brief and intermittent
8. Headaches - in some patients are positional
9. Hydrocephalus, drop attacks, momentary loss of consciousness, progressive dementia, papilledema, diplopia,
10. CT - typically dense and near the foramen of Monro
11. MRI - variable appearance depending on the contents - most common Bright on T1 and dark on T2
12. Can be followed but commonly surgically resected to prevent the risk of sudden death.

references - http://www.ajnr.org/cgi/content/full/21/8/1470 and emedicine.com

The best case of whatever it is - Answer

The answer is - Acute epiploic appendagitis

This is inflammation of the epiploic appendages (fat outpouching on the serosal surface of the colon). This is likely secondary to torsion or venous obstruction in this fat outpouching.

It has a nonspecific presentation. Commonly has focal tenderness (usually lower abdomen/pelvis). The most common presentation is focal left lower quadrant pain. It is most commonly in the sigmoid followed by descending, cecum and then the ascending. Commonly misdiagnosed as diverticulitis or appendicitis. Often in 4th-5th decade and usually male. Risk factors - obesity, hernia and "unaccostomed exercise".

Typical imaging appearance - CT - fatty process adjacent to the colon (commonly 1-3 cm but can be as big as 5 cm) with enhancing rim and adjacent inflammatory changes. It often has a dense center that represents the occluded central vein (about 54% of the time) - aka central dot sign.

US - oval noncompressible hyperechoic focus adjacent to colon at site of maximum tenderness with no central flow on color doppler.

MRI - T1 and T2 show lesion that looks like fat that has a peripherally enhancing rim on postcon T1 fat sat.

Evolution - images obtained at 6 months or greater show total resolution.

Treatment - conservative with pain medications.

Complications - RARE - adhesions, bowel obstruction, intussusception, intraperitoneal loose body (does that mean the appendage falls off and calcifies as loose body in the abdomen? - not clear from reference) and abscess formation.

DDX - Omental infarcts, sclerosing mesenteritis, acute diverticulitis, fatty masses in peritoneum

references - http://www.ajronline.org/cgi/content/full/183/5/1303 ; http://radiographics.rsnajnls.org/cgi/content/full/25/6/1521 - Notice that the primary author is same guy

Eye Test - the Answer

So the plain films (see photo album on Rob's Radiology fan page on Facebook) demonstrate subcutaneous emphysema and air streaks outlining the mediastinum and proximal vessels. This is consistent with:

Pneumomediastinum.

• Pneumomediastinum - air in the mediastinum
• Sources
• - rupture of alveoli - most common cause - increased pressure (ventilator, mucous plug, foreign body, strain against closed glottis) or damage of cells (pneumonia, emphysema, ARDS)
• - laceration of tracheobronchial tract
• - GI tract (esp esophagus)
• - passage of air from head and neck (sinus fx, dental extraction, vascular channels etc), retroperitoneum, chest wall
• The mediastinum communicates with the submandibular space, retropharyngeal space and vascular sheaths in the neck
• The retroperitoneum communicates with the mediastinum through the sternocostal insertion of the diaphragm which also communicates with flanks and pelvis
• Retroperitoneum also communicates through the periaortic and periesophageal spaces
• Clinically - often asymptomatic. Can cause dyspnea and chest pain
• Complications - can cause pneumothorax; rarely - cause hypotension due to decreased venous return to the heart from high pressure in pneumomediastinum
• Features
• Radiograph - look for lucent streaks and bubbles - especially a pleural line above the left heart lateral to PA and aortic arch on frontal view
• Lateral View - Air may outline ascending aorta, PA, trachea and bronchi; can outline thymus, sternal insertion of diaphragm and brachiocephalic veins.
• Lateral - can see air outline anterior to the heart - in a "pneumoprecardium"
• Continuous diaphragm - air between diaphragm and pericardium
• Naclerio's V sign - air along descending aorta inserts into an insertion along left hemidiaphragm and forms a V shape (frontal view)
• Ring around the artery sign - air around right pulmonary artery (best seen on lateral)
• infants - thymic spinnaker sign
• Can also get apical cap of lucency - can look like pneumothorax but won't move with position
• Pneumomediastinum usually doesn't completely surround the heart and usually has multiple thin streaks

Vs. Pneumopericardium

• Usually from penetrating trauma or recent heart surgery
• If from ventilator will have pneumomediastinum usually as well - but requires much higher pressures than pneumomediastinum
• Not as common as Pneumomediastinum
• Often a complete band seen around left ventricle and right atrium
• Does not usually extend into the neck or upper mediastinum
• Halo sign - band around the entire heart
• May outline ascending aorta and main PA but does not extend to arch or trachea
• Pneumopericardium - can change with position but pneumomediastinum won't

References - http://www.ajronline.org/cgi/reprint/166/5/1041 ; http://radiographics.rsnajnls.org/cgi/content/full/20/4/1043 ; and Primer of Diagnostic Imaging by Weissleder et al.

What's happening here? - Answer

So what we see here is air in the stomach and proximal duodenum but not in the rest of the digestive tract. This is the so-called "Double Bubble" sign.

The double bubble is indicative of obstruction of the duodenum. This can be from intrinsic or extrinsic etiologies. Far and away the most common consideration is duodenal atresia. The differential should include duodenal web and stenosis, annular pancreas, Ladd's bands, malrotation, preduodenal portal vein and duodenal or retroperitoneal tumor.

Considerations for next step - Depends on clinical appearance. Surgery consult, possible upper GI. If the patient has any signs of peritoneal symptoms - Ladd's bands and malrotation with volvulus must be considered and may urgently/emergently go to surgery. If the patient is doing well and surgery may be delayed then may want to do Upper GI to exclude malrotation.

This example - Annular Pancreas. The annular pancreas can present in a variable pattern. The pancreas may actually encircle the duodenum or the ventral pancreas could be incorporated into the wall of the duodenum. According to radiographics, only 10% actually obstruct the duodenum. According to emedicine, it always causes at least some stenosis if not outright atresia like in this case. It is a congenital variant. It can be isolated or associated with other congenital anomalies. In neonates when symptomatic - presents like above with obstructive symptoms such as biliary vomiting or as pancreatitis. In adults - if symptomatic at all - may present with "peptic ulcer" symptoms, pancreatitis, or duodenal obstruction.

Duodenal Atresia

• Extreme end of the spectrum (diaphragm or web, stenosis then atresia)
• Failure of recanalization (favored theory) vs. ischemia
• Death without surgery - due to electrolyte loss and fluid imbalance
• Associated with Trisomy 21 (Down's) - approximately 20-30%
• Anomalies (such as Down's and others) are found in 50% of patients - heart disease, VACTERL, renal anomalies, TE fistula
• If has esophageal atresia as well - stomach will be fluid filled midabdominal mass as it is obstructed on both ends
• Prenatally - polyhydramnios and double bubble on ultrasound.
• Clinically - often have bile stained vomiting
• Stenosis and web - are not complete obstructions so often will have some air beyond the narrowing in the 2nd portion of the duodenum.
• Patients should do well after corrective surgery.

references: http://radiology.rsnajnls.org/cgi/content/full/220/2/463 , http://radiographics.rsnajnls.org/cgi/content/full/26/3/715 , emedicine.com and Primer of Diagnostic Imaging by Weissleder et al.

What is your Diagnosis? - Answer

The finding - tracheal deviation to the left.
The differential - superior mediastinal masses - Thyroid goiter, thyroid malignancy, adenopathy, lymphatic malformation (and cysts), aneurysm, vascular masses (malformations, hemangiomas), Ascending through thoracic inlet - Small Cell, parathyroid mass (uncommon), not commonly listed but I have seen - esophageal cancer.

The most likely diagnosis - far and away the most common is thyroid goiter. This case turned out to be thyroid cancer.

Workup - The first and easiest is history and physical exam. Next may consider ultrasound. Ultrasound can demonstrate the thyroid and find areas of concern and be used for biopsy. If the history and physical exam is inconsistent with thyroid - may consider CT.

The patient had ultrasound which revealed a worrisome lesion. The lesion was biopsied showing thyroid cancer. The patient had surgery and the second image is from an I-123 scan which is used to find areas of residual thyroid and possible metastases. There is normal uptake in the salivary glands and GI tract and 2 foci of uptake in the thyroid bed and a lymph node. The patient is then treated with I-131 which is radioactive Iodine that is taken up by thyroid tissue and then the Iodine radiates it. Patients do remarkably well after the therapy but will have to be on lifetime of thyroid hormone replacement.

references - Primer of Diagnostic Imaging by Weissleder et al.