Superior Mediastinal Syndrome Misdiagnosed as Foreign Body Aspiration: A Case Report.

Superior mediastinal syndrome is a life-threatening pediatric oncological emergency that requires high level of awareness and clinical suspicion to avoid misdiagnosis and devastating outcomes. Early diagnostic evaluation and management of underlying etiology are of utmost significance for optimal results. In children, it is most commonly caused by non-Hodgkin's lymphoma and T-cell lymphoblastic leukemia. We report a case of a six-year-old boy with superior mediastinal syndrome secondary to T-cell acute lymphoblastic leukemia, initially misdiagnosed as foreign body aspiration and underwent a procedure with a life-threatening outcome.

Role of renal arterial resistive index (RI) in obstructive uropathy.

OBJECTIVE: To determine the diagnostic accuracy of renal arterial resistive index on doppler ultrasound in patients with acute renal colic to diagnose obstructive uropathy taking non-enhanced helical computed tomography as the gold standard. METHODS: The descriptive study, conducted at the Radiology Department of Pakistan Naval Ship Shifa Hospital, Karachi, from October 10, 2010 to July 17, 2011, comprised 160 patients referred from the Emergency Department with complaint of unilateral renal colic. Ultrasound was carried out. Subsequently, computed tomography scan of kidney, ureter and bladder was performed. Data was collected on prescribed proforma and analysed using SPSS 19. RESULTS: By taking the resistive index value of > 0.70 as a discriminatory level for obstruction, the overall sensitivity of the index was 76.23% and specificity was 88.13%. The positive predictive values of the index in patients with obstructive uropathy was 91.6%, and negative predictive value was calculated to be 68.42%. The diagnostic accuracy of the test was 80%. CONCLUSION: Duplex Doppler ultrasound can detect acute renal obstruction with sensitivity of approximately 77%. However, ultrasound is an operator-dependent examination, and the results are much affected by patient body habitus.

Magnetic resonance imaging of metronidazole induced encephalopathy.

We describe a case demonstrating Magnetic Resonance (MR) imaging findings in association with Metronidazole (Flagyl) toxicity. MRI brain showed abnormal signal intensity involving dentate nuclei of cerebellum bilaterally symmetrical. The diagnosis of metronidazole toxicity was made by the MR imaging findings and supported clinically. In hospital, course of treatment drug was discontinued. Patient improved clinically with discontinuation of metronidazole. No follow-up MR imaging was obtained. In this report, we present a case depicting MR imaging changes within the dentate nuclei of cerebellum.

Diagnosis of hepatoma using grayscale and Doppler ultrasound in patients with chronic liver disease.

OBJECTIVE: To determine the diagnostic accuracy of liver ultrasound for the detection of hepatoma in chronic liver disease (CLD) patients by either taking histopathology or serum α-fetoprotein levels or a biphasic computed tomography (CT) scan (whichever is available) as the gold standard. STUDY DESIGN: Cross-sectional. PLACE AND DURATION OF STUDY: Radiology Department, The Aga Khan University Hospital, Karachi, Pakistan, from January 2007 to January 2010. METHODS: A total of 239 patients (156 males and 83 females) with clinical suspicion or surveillance of hepatoma in CLD referred to the radiology department for ultrasound evaluation followed by either liver biopsy and histopathology or serum α-fetoprotein level or biphasic CT scan. RESULTS: The sensitivity of ultrasound for hepatoma detection in CLD was 65%, specificity was 85%, and accuracy was 70%, and positive predictive value and negative predictive value were 92% and 45%, respectively. CONCLUSION: Ultrasound is a relatively quick, safe, reasonably accurate, and noninvasive imaging modality for the detection of hepatoma in CLD and can be complemented with clinical assessment of screening high-risk patients.

Negative predictive value of mammography and sonography in mastalgia with negative physical findings.

OBJECTIVE: To determine the negative predictive value of mammography and sonography in patients with focal/ diffuse breast pain with negative physical examination of the breasts. METHODS: A descriptive study, conducted at Radiology Department ofAga Khan University Hospital from 2006-2007 for a period of 2 years. A total of 207 women were referred for mammography and sonography because of focal or diffuse breast pain. Complete follow-up was available only in 55 patients. The outcome or gold standard was mammograms or ultrasound after an average follow-up period of 18 months with negative/benign findings or histopathology of the suspicious lesion or imaging which was the gold standard to determine the negative predictive value. RESULTS: Out of 55 patients, 17 (31%) had negative findings, benign findings were reported in 34 patients (62%), and 4 (7%) patients were subjected to mammographically guided breast biopsy. All the biopsies were done on the basis of abnormal findings on mammograms. All of the 4 patients had no evidence of cancer on subsequent histopathology. The negative predictive value of mammography and ultrasound in women with focal or diffuse breast pain was 100%. CONCLUSION: Breast imaging using mammography and/or sonography in women who present with local or diffuse breast pain is of significant value, to reassure the patient as well as the clinician. However if imaging findings are suggestive of pathology a biopsy should not be delayed.