Kp Sreekumar

Role of 64-MDCT in Evaluation of Pulmonary Atresia With Ventricular Septal Defect

OBJECTIVE The purposes of this article are to describe the technical factors in performing 64-MDCT of pulmonary atresia with ventricular septal defect (PA-VSD), to describe the anatomic variations in pulmonary arterial circulation and other associated anomalies, and to describe the postoperative evaluation of this condition. CONCLUSION The management of this complex condition has been largely determined by the morphology of pulmonary arteries and the extracardiac sources of pulmonary blood supply. Although echocardiography and catheter angiography are the traditional imaging techniques used to diagnose PA-VSD, 64-MDCT has become a valuable noninvasive imaging technique in comprehensive evaluation of this condition.

Clinical applications of diffusion weighted MR imaging: A review

Diffusion MR imaging is now a routine component of the brain MR imaging examination and is critical in the evaluation of stroke patients. However, high signal intensity on diffusion MR and hypo intensity on apparent diffusion co-efficient (ADC) images, which are features of acute cerebral infarction, have been reported in such diverse conditions as hemorrhage, abscess, tumor and even in Wernicke encephalopathy. Differentiating between there conditions is critical for determination of appropriate treatment. We present a systematic review of hyperintense lesions on diffusion MR images and their potential clinical applications.

Diffusion-weighted MRI in acute posterior ischemic optic neuropathy

Blindness following surgery, especially cardiac surgery, has been reported sporadically, the most common cause being ischemic optic neuropathy. The role of MRI in the diagnosis of this condition is not well established. We present a case of postoperative posterior ischemic optic neuropathy that was diagnosed on diffusion-weighted MRI.

Para duodenal hernias- a pictorial essay

Intestinal obstruction is a common clinical condition that is usually suspected on the basis of clinical signs and patient history. For many decades, evaluation was based on findings at conventional radiography, with a sensitivity of 69% and a specificity of 57% (1). Several studies have demonstrated the value of CT in confirming the diagnosis and revealing the cause of small bowel obstruction, with a sensitivity of 94%-100% and an accuracy of 90%-95% (1,2). Internal hernias are rare cause for intestinal obstruction. Para duodenal hernias constitute approximately 53% of all internal hernias (3,4). These rare hernias have unique radiological finding which allow definitive diagnosis to be made. In this article we will review relevant anatomy of the peritoneal cavity and characteristic CT appearance of para duodenal hernias.

In the workup of patients with obscure gastrointestinal bleed, does 64-slice MDCT have a role?

Purpose: The purpose was to prospectively determine the sensitivity of 64-slice MDCT in detecting and diagnosing the cause of obscure gastrointestinal bleed (OGIB). Materials and Methods: Our study included 50 patients (male 30, female 20) in the age range of 3–82 years (average age: 58.52 years) who were referred to our radiology department as part of their workup for clinically evident gastrointestinal (GI) bleed or as part of workup for anemia (with and without positive fecal occult blood test). All patients underwent conventional upper endoscopy and colonoscopy before undergoing CT scan. Following a noncontrast scan, all patients underwent triple-phase contrast CT scan using a 64-slice CT scan system. The diagnostic performance of 64-slice MDCT was compared to the results of capsule endoscopy, 99m-technetium-labeled red blood cell scintigraphy (99mTc-RBC scintigraphy), digital subtraction angiography, and surgery whenever available. Results: CT scan showed positive findings in 32 of 50 patients. The sensitivity, specificity, positive predictive value, and negative predictive values of MDCT for detection of bleed were 72.2%, 42.8%, 81.2%, and 44.4%, respectively. Capsule endoscopy was done in 15 patients and was positive in 10 patients; it had a sensitivity of 71.4%. Eleven patients had undergone 99mTc-RBC scintigraphy prior to CT scan, and the result was positive in seven patients (sensitivity 70%). Digital subtraction angiography was performed in only eight patients and among them all except one patient showed findings consistent with the lesions detected on MDCT. Conclusion: MDCT is a sensitive and noninvasive tool that allows rapid detection and localization of OGIB. It can be used as the first-line investigation in patients with negative endoscopy and colonoscopy studies. MDCT and capsule endoscopy have complementary roles in the evaluation of OGIB.

Diffusion-weighted magnetic resonance imaging in acute reversible toxic leukoencephalopathy: A report of two cases

Acute toxic leukoencephalopathy may be caused by endogenous or exogenous toxins. It may reverse clinically if the offending agent is withdrawn or the underlying condition is treated. However, demonstration of reversibility on imaging, especially with diffusion-weighted MRI, has been reported only very recently. We report two such cases.

Utility of C-arm CT in overcoming challenges in patients undergoing Transarterial chemoembolization for hepatocellular carcinoma

Transarterial chemoembolization (TACE) is the well-known treatment for hepatocellular carcinoma. Multiple digital subtraction angiography (DSA) acquisitions in different projections are required to identify difficult arterial feeders. Moreover, the tell-tale tumor blush can be obscured by proximity to lung base, small size of lesion, and breathing artifacts. C-arm CT is a revolutionary advancement in the intervention radiology suite that allows acquisition of data which can be reformatted in multiple planes and volume rendered incorporating both soft tissue and vascular information like multidetector computed tomography (MDCT). These images acquired during the TACE procedure can provide critical inputs for achieving a safe and effective therapy. This case series aims to illustrate the utility of C-arm CT in solving specific problems encountered while performing TACE.

Infrapopliteal angioplasties for limb salvage in diabetic patients: Does the clinical outcome justify its use?

Purpose: To analyze the results of infrapopliteal percutaneous transluminal angioplasty (PTA) as a primary treatment modality in diabetic patients with non- healing ulcers or gangrene. Materials and Methods: We retrospectively studied 35 angioplasties, performed as the first line of treatment to salvage diabetic feet. The patients were followed up for 12 months. Results: Grade 1 and 2 ulcers were seen in only 20% of patients (5.71 and 14.28%, respectively); 37.14% of patients had grade 3 ulcer, and 42.8% were in the gangrene stage (grade 4 - 34.2% and grade 5 - 8.5%). A total of 77 lesions in 46 arteries (including six popliteal and suprapopliteal lesions) were dilated in 35 limbs. Of the 71 infrapopliteal lesions, 86% of lesions were classified as group C or D (group A - 9.3%, group B - 4.65%, group C - 37.2%, and group D - 48.83%). Overall technical success rate was 84.7%. The vascular complication rate was 26% (12 arteries out of 46). Clinical success was achieved in 29.1% of cases at the end of 6 months and 58.6% at the end of one year. Limb salvage rates were 79.4% at the end of 6 months and 75.8% at the end of one year. Conclusions: A high technical success rate can be achieved even in situations traditionally considered unfavorable for angioplasty. Infrapopliteal angioplasty can produce limb salvage rates comparable to bypass surgery in diabetic patients with extensive disease.

Technical Note: Thoracic duct embolization for treatment of chylothorax: A novel guidance technique for puncture using combined MRI and fluoroscopy

Thoracic duct embolization (TDE) is an established radiological interventional procedure for thoracic duct injuries. Traditionally, it is done under fluoroscopic guidance after opacifying the thoracic duct with bipedal lymphangiography. We describe our experience in usinga heavily T2W sequence for guiding thoracic duct puncture and direct injection of glue through the puncture needle without cannulating the duct.

Imaging in diabetic ischemic foot

Diabetic microangiopathy largely affects the infrapopliteal vessels. Extensive infrapopliteal calcification and occlusions, without the presence of collaterals, are common in diabetic patients. When the diabetic patient presents with a nonhealing ulcer, the investigation of first choice should be duplex ultrasound. Ultrasound is not only safe and noninvasive, it also serves to guide further patient management. In a subset of patient in whom intervention is planned, catheter angiogram is the best choice; if the patient has diabetic nephropathy, MR angiogram is an alternative. Multidetector computed tomography angiogram is not a preferred modality in the diabetic patient because there is likely to be extensive calcification in infrapopliteal vessels.