Shashi Aggarwal

Carcinoma of the Gallbladder: CT findings in 50 cases

Fifty patients with histologically proven carcinoma of the gallbladder were examined by computed tomography (CT). The gallbladder masses were categorized into two broad groups: group 1 (74%) included patients in whom the gallbladder was identified along with a mass lesion; and group 2 (26%), where a large mass was present in the gallbladder fossa with no identifiable gallbladder. Group 1 was further divided into three types according to the nature of the tumor: Type 1, mass almost filling the entire gallbladder lumen; Type 2, a polypoidal mass projecting into the lumen; type 3, an infiltrating tumor seen as focal or diffuse wall thickening. Liver involvement, in the form of localized invasion in the vicinity of the primary gallbladder malignancy, was the most common associated finding (80%). Other ancillary features included presence of calculi, lymphadenopathy, and biliary obstruction. CT was found useful for characterizing and defining the extent of carcinoma of the gallbladder. However, it may not consistently demonstrate involvement of the gastrointestinal tract, omentum, and abdominal wall. CT can also be used for aspiration/biopsy guidance of the gallbladder mass in selected cases.

MR features of tuberculous arachnoiditis.

Although tuberculosis is an uncommon cause of spinal arachnoiditis, it needs to be differentiated from other causes of arachnoiditis because it is a treatable disease. Myelography, which is the imaging modality of choice for the chronic adhesive stage of tuberculous arachnoiditis, usually reveals irregularity of the thecal sac, nodularity and thickening of nerve roots, clumping of roots to each other or to the thecal sac, or CSF block. Recently Gd-diethylenetriamine pentaacetic acid enhanced MRI has been found to be useful for the active phase of tuberculous infection, effectively demonstrating abnormally thickened and enhancing meninges, intra- and extramedullary tuberculous nodules, and spinal cord changes. We present the MRI features in a case of acute tuberculous arachnoiditis.

Posterior fossa surgery: an unusual cause of superficial siderosis.

With the widespread use of magnetic resonance imaging, an increasing number of cases of superficial siderosis are being discovered. However, the cause remains uncertain in almost half the cases. We report a case where previous surgery for a pontine hematoma established a pathway for extravasation of blood into the 4th ventricle, resulting in superficial siderosis that was demonstrated on a follow-up magnetic resonance imaging scan 8 years later. This case presents an unusual iatrogenic cause of superficial siderosis that has not been reported previously.

Pharyngoesophageal (Zenker's) diverticulum mimicking thyroid nodule on ultrasonography: report of two cases.

The pharyngoesophageal, or Zenkers, diverticulum is the most common diverticulum of the esophagus. If large in size, it can project to one side (particularly the left side) and be in close proximity to the thyroid, simulating a variety of thyroid nodules depending on its contents. However, awareness of sonographic fea• tures of this entity and real-time demonstration of movement of the contents (air, water, or debris) to and from the diverticulum help make the correct diagnosis. We report two cases of Zenkers diverticulum diagnosed by ultrasonography.

Bony ankylosis of the temporomandibular joint: a computed tomography study.

Bony ankylosis of the temporomandibular joint is a disabling disease that almost invariably manifests itself in the first two decades of life. CT of the temporomandibular joints was performed in 50 patients--axial CT in 2 and coronal CT in 48--of whom 43 (86%) had received trauma to the joints. New bone of variable form and thickness was observed in 64 joints (the involvement was bilateral in 14 patients). These joints were classified into one of two categories: type I, medially angulated condyle with deformed articular fossa and a mild-to-moderate amount of new bone formation; and type II, no recognizable condyle or fossa but instead a large mass of new bone. Type I was etiology-specific and seen only when trauma was the antecedent, whereas type II was a sequelae of either insult. A pseudofracture in the new bone was seen in 49 (77%) joints. Six joints showed subtle deformities but no new bone. Since coronal CT fully characterizes the lesion at acceptable radiation exposure levels, it appears to be valuable in the preoperative workup of these patients.

Superselective angiography of a spinal dural arteriovenous fistula having a common segmental origin with the artery of Adamkiewicz

SummaryThe artery of Adamkiewicz infrequently originates from the same radicular vessel that also supplies a dural arteriovenous fistula. This variant is not adequately emphasized in the neuroradiological literature. Awareness of this entity is essential to prevent catastrophic complication during embolization. We report such a case, and our experience with attempted, embolization. We are unaware of any previously reported instance of such an attempt being made.

Angiographic abnormalities of the morphologically left ventricle in the presence of Ebstein's malformation

Cineangiography of the morphologically left ventricle was performed in 10 patients with Ebsteins malformation. The angiographic findings included left ventricular contour abnormalities (8), mitral valve prolapse (7) and global hypokinesia (5). Left ventricular abnormalities were present whether the left ventricle was normally placed or in mirror-image position in congenitally corrected transposition. Abnormalities of the morphologically left ventricle in Ebsteins malformation have received little attention in the past. Frequent occurrence of these abnormalities should make careful evaluation of the morphologically left ventricle mandatory in all patients with Ebsteins malformation.

Intravenous digital subtraction angiography in non-specific aorto-arteritis

We have studied 40 patients with non-specific aorto-arteritis (Takayasus disease) using intravenous digital subtraction angiography (DSA). The aorta, its major branches and (in 18 patients) pulmonary arteries were evaluated to determine the degree and extent of involvement. No complications related to the procedure were encountered. Good quality diagnostic images were obtained in 39 out of 43 instances. The unsuccessful examinations were in patients with congestive cardiac failure, and in one patient who would not co-operate. Aortic wall thickness and mild involvement of the descending aorta in the region of the diaphragm could not be assessed. Intravenous DSA is acceptable for the diagnosis and follow-up of aorto-arteritis in suitable patients.

CT findings of malignant change in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis is a chronic disease of children and young adults associated with various complications, one of which is malignant change. We report CT findings of malignant change in a case of recurrent respiratory papillomatosis.

Value of CT in diagnosing nonneoplastic osteolysis in Paget disease

We present an unusual case of osteolysis, likely due to a stress fracture, in a pagetic pubic bone simulating sarcomatous transformation.