Tuesday, November 16, 2010

Radiology MCQs from AIIMS November-2010

 These MCQs were sent to us by our students from DAMS and are based on memory recall.  We will be releasing fully solved version of all subjects with detailed explanation with Elsevier within 10 days. 
DAMS (Delhi Academy of Medical Sciences [p] Ltd) is the leader in the PG medical entrance preparation currently in the country. 

AIIMS November 2010 Radiology

Radiation exposure is the least in the following procedure:
a. micturating cystourethrogram
b. IVP
c. bilateral nephrostomogram
d. Spiral CT for stones

Answer-A) MCU
 IVP radiation exposure is 2.5mSv (125CXR), Spiral CT abdomen for abdomen-10mSv( 500CXR), MCU-1.7mSv.  Bilateral nephrostomogram is a procedure will require fluoroscopy twice, once for each kidney and possibly will have higher radiation.

A 35 yr old lady with chronic backache. On X ray she had a D12 collapse. But Intervertebral disc space is maintained. All are possible except 
a.) multiple myeloma 
b.) osteoporosis 
c.) metastasis
d) tuberculosis

Answer-d) Tuberculosis
As a rule neoplastic and traumatic/osteoporotic collapse show sparing of the intervertebral disc, while tuberculosis classically is paradiscal, involvement of disc is usual. Common neoplasms in adult causing disc collapse are metastasis and multiple myeloma, while in children vertebral collapse may indicate histiocytosis (vertebra plana). This question has been asked previously in AIIMS but with different framing of the question.

 Bone marrow transplant receipient patient developed chest infection. ON chest Xray Tree on Bud appearance . The cause of this is
a.) klebsiella
b.) pneumocystis 
c.) TB 

Reference- March 2002 Radiology, 222, 771-772.
Answer-b) Pneumocystis carnii
The tree-in-bud sign is a finding seen on thin-section computed tomographic (CT) images of the lung.  Peripheral (within approximately 3–5 mm of the pleural surface), small (2–4 mm in diameter), centrilobular, and well-defined nodules of soft-tissue attenuation are connected to linear, branching opacities that have more than one contiguous branching site, thus resembling a tree in bud. Pulmonary infectious disorders involving the small airways are the most common causes of the tree-in-bud sign.  Any infectious organism, including bacterial, mycobacterial, viral, parasitic, and fungal agents, can involve the small airways and cause a tree-in-bud pattern. In pulmonary infectious disorders, the tree-in-bud sign has most commonly been described in patients with endobronchial spread of M tuberculosis. However,  bronchogenic dissemination of atypical mycobacterial organisms or pyogenic bacteria can result in tree-in-bud opacities. Less frequently, the tree-in-bud sign is seen with viral and fungal infections (eg, invasive aspergillosis of the airways) and Pneumocystis carinii pneumonia.

Frontal Sinus can be best visualised by :
a. Caldwell's view
b. Water's view
c. Towne's view
d. Schuller's view

Answer-A) Caldwell’s view
The Waters view or occipitomental projection is taken at an angle 37° caudal to the canthomeatal line. This view optimally visualizes the superior and inferior orbital rims, nasal bones, zygoma, and maxilla. The Caldwell view, angled 15° caudal to the canthomeatal line, allows additional views of the frontal sinus and superior orbital rim. The 6-ft Caldwell view is helpful intraoperatively for frontal sinus obliteration surgeries.

Most sensitive test to detect ductal carcinoma in situ is-
a.       Mammography
b.      MRI

Answer-b) MRI
Researchers from Germany have reported that MRI (magnetic resonance imaging) detects almost twice as many DCIS as mammography and is especially effective for detecting high-grade DCIS. The details of this study appeared in the August, 2007 issue of Lancet Oncology.This data was also presented at the 2007 meeting of the American Society of Clinical Oncology.
The goal of cancer screening is to detect cancer at an early stage, when treatment will be most successful. For the early detection of breast cancer, the American Cancer Society recommends an annual mammogram and clinical breast exam starting at the age of 40. In addition to mammography, women at high-risk of breast cancer are advised to receive annual screening with breast MRI. Although MRI has been reported to detect more breast cancers than mammography, it is also much more expensive and more likely to produce false-positive test results. Although it has been demonstrated that MRI is more sensitive than mammography in detecting invasive breast cancers, MRI's ability to detect DCIS has been doubted since this technique does not detect calcium.

However, this study suggests that MRI may be better than mammography at detecting DCIS—particularly high-grade DCIS. These findings can only lead to the conclusion that MRI outperforms mammography in tumour detection and diagnosis. MRI should thus no longer be regarded as an adjunct to mammography but as a distinct method to detect breast cancer in its earliest stage.

Reference: [1]  Kuhl CK, Schrading S, Wardelmann E, Braun M, Kuhn W, Schild HH. Magnetic resonance imaging versus mammography for diagnosing ductal carcinoma in situ. Proceedings of the American Society of Clinical Oncology. Chicago/ IL.  2007. Abstract # 1504.
[2] Boetes C, Mann RM. Ductal carcinoma in situ and breast MRI. Lancet Oncology. 2007; 370:459-460.

Patient with 6th cranial nerve palsy on T2 weighted MRI Hyperintense shadow which shows homogenous contrast enhancement. most probable diagnosis is?
 a)schwannoma b)meningioma c)cavernous sinus hemangioma 

Answer is c )cavernous sinus hemangioma.
Schwannoma are heterogenously enhancing, while meningiomas usually are isointense on both T1 and T2 weighted images. Although both meningiomas and hemangiomas will have homogenous enhacement better answer is haemangioma.Cavernous hemangiomas occur very rarely in the cavernous sinus and are difficult to diagnose preoperatively.  MR images showed hypointensity on T1-weighted images and well-defined hyperintensity on T2-weighted images with marked homogeneous enhancement after contrast material administration. AJNR Am J Neuroradiol 2003 Jun-Jul;24(6):1148-51.

Which one of the following is not a CT feature of Adrenal adenoma?

a. Low attenuation
b. Homogeneous density and well defined borders
c. Enhances rapidly, contrast stays in it for relatively longer time and washes out late
d. Calcification is rare.
Adenoma have early washout of contrast not delayed also low attenuation is because of fat content. Well defined border is obvious as it is benign, and calcification is rare.
Reference-December 2000 Radiology, 217, 629-632.
Rapid early CT enhancement washout is a highly sensitive and specific feature of adrenal adenomas; with nonenhanced CT densitometry in the depiction of lipid-rich adenomas, it makes CT the most useful and accurate imaging method in the characterization of adrenal masses. In our department, we first evaluate known adrenal masses by using nonenhanced CT. If the attenuation of the mass is 10 HU or less, we make a diagnosis of lipid-rich adrenal adenoma (a small fraction of these will be cysts rather than adenomas), and no further evaluation is advised

Pt goin for coronary angiography and now to prevent contrast nephropathy what is not needed to be done

a. fenlodopam
b. N acetylcystine
c. hemofilteration
d. NS

Several investigators have suggested that ICM nephrotoxicity can be reduced with the use of oral or intravenous theophylline, acetylcysteine, fenoldopam, or bosentan (an endothelin antagonist). Some prospective studies have suggested that prophylactic administration of 600 mg acetylcysteine twice daily in combination with hydration reduces the incidence of ICM nephrotoxicity. Hemodialysis is required only in treatment of extreme cases. In this case more or less prophylaxis is required not treatment. NS means normal saline


Anonymous said...

sir in ur buk tree in bud appearence is given tb..not pneumo
cystis carinii

Sumer Sethi said...

yes tree in bud is most commonly seen in endobronchial spread of TB however, the patient is post transplant thats why answer is changed.

Anonymous said...

sir in ques1 option d) was spiral ct- stones protocol.

Anonymous said...

thanks a lot sir...
is mri more sensitive than mammography in detecting DCIS....??

Kapil said...

thanks a lot sir...ur efforts r really appreciable.

priyank said...

sir in tb spine earliest radiological change is reduction of intervertebral disc space....

electron said...

sir 4th option was RSV in case of tree in bud appearnce. Are viral infections of lung more common after BM transplant?

Anonymous said...

sir thanx fr ur ans,in dat cavernous hemangioma q it was gvn dat d tumour is present inside d cavernous sinus,does it change d ans....

Shrihari said...

Sir the other two options for in situ ductal ca were USG and PET. Are u sure about MRI...?

Shrihari said...

The other 2 options for in situ ductal ca were USG and PET. U still support MRI as correct response ?

raksha said...

thanx sir...ur class on radiology helpd a lot...

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