Abhijit Raut

Benign Renal Neoplasms in Adults: Cross-Sectional Imaging Findings

OBJECTIVE A broad spectrum of benign renal neoplasms in adults shows characteristic ontogeny, histology, and tumor biology. Benign renal tumors are classified into renal cell tumors, metanephric tumors, mesenchymal tumors, and mixed epithelial and mesenchymal tumors. Select benign tumors show characteristic anatomic distribution and imaging features. However, because of overlapping of findings between benign and malignant renal tumors, histologic evaluation may be required to establish a definitive diagnosis. Accurate preoperative characterization facilitates optimal patient management. CONCLUSION We attempt to provide a comprehensive, contemporary review of benign renal neoplasms that occur in adults, focusing on cross-sectional imaging characteristics.

Pancreatic tuberculosis: A clinical and imaging review of 32 cases

Background: Tuberculosis of the pancreas is a rare entity, and anecdotal reports describing imaging features of pancreatic tuberculosis have been described in medical literature. The imaging features including computed tomography (CT) and ultrasonography in diagnosed cases of tubercular involvement of the pancreas are described, with an overview of clinical features and laboratory investigations. Materials and Methods: We analyzed records of 384 patients of diagnosed cases of abdominal tuberculosis for involvement of pancreas and detected 32 patients (8.33%) who had pancreatic involvement. This included 22 men and 10 women with an age range of 19 to 64 years (mean age of 42.5 years), who were detected to have pancreatic tuberculosis from 1999 to 2004 in our institute. We reviewed the clinical, radiologic (ultrasonographic and CT features), and laboratory findings of all patients. The criteria for diagnosis of tuberculosis were based on ascitic fluid adenosine deaminase level in 14 patients, fine-needle aspiration cytology of lymph nodes in 9 patients, and presence of pulmonary tuberculosis on chest radiograph, which was found in 9 patients. On follow-up, 6 months after antituberculous treatment, 25 patients showed response to anti-Kochs treatment, 3 patients had drug-resistant tuberculosis, 2 patients died, and 2 patients were lost to follow-up. Results: The male/female ratio was 2.2:1. The maximum number of patients was in the fourth decade (30-39 years). The duration of symptoms was spanning between 2 and 11 months, with a mean duration of 6 months. The most common symptom was abdominal pain localized to the epigastrium. Sixteen patients were seropositive for HIV-1 infection. Fourteen patients had history of tuberculosis of the lungs, whereas 18 patients had pancreatic and peripancreatic involvement as the primary manifestation. Ultrasonography showed bulky inhomogenous pancreas in 5 patients; solitary or multiple hypoechoic collections were observed in all 7 and 20 patients, respectively. CT findings demonstrated hypodense collections within the pancreas associated with peripancreatic lymphadenopathy in 29 patients. Three patients had a complex pancreatic mass lesion. Conclusions: Pancreatic tuberculosis can present with a variable spectrum of imaging findings. Tuberculosis of the pancreas should be considered as a diagnostic possibility in patients who present with a pancreatic space occupying lesion associated with peripancreatic lymphadenopathy.

Emphysematous cholecystitis: Imaging findings in nine patients

Objective: Emphysematous cholecystitis is a severe form of acute cholecystitis and can be rapidly fatal. We present the imaging features of nine patients with proven emphysematous cholecystitis.

Occipito-atlanto-axial osteoarthritis: a cross sectional clinico-radiological prevalence study in high risk and general population.

Study Design. A cross-sectional clinico-radiologic evaluation of occipito-atlantoaxial (OC1C2) region of 2 population groups. Objective. Determine the prevalence of OC1C2 osteoarthritis in porters involved in carrying loads on the head and general male population. Describe its clinico-radiologic manifestations. Summary of the Background Data. In addition to age, head loading is a known cause of degeneration affecting the occipito-cervical region. The impact of head loading in the population aged between third and sixth decade is unknown. Head loading is a common custom in the developing countries. Material and Methods. Study group (n = 107) included randomly selected male porters from railway stations who underwent computed tomography (CT) study of the OC1C2 region, plain radiographs of the cervical spine and detailed clinical examination. Control group (n = 107) included randomly selected male patients undergoing CT scan study for diseases of paranasal sinuses with coincidental screening of OC1C2 region along with clinical assessment. The data were analyzed using SPSS 15 software. Result. Mean age for study group was 32.6 years and controls was 34.6 years (P = 0.156). In the study group, duration of occupational exposure was 10.9 (±8.7) years; 81.3% porters being symptomatic with an age of 33.4 (±9.6) years. Radiologic prevalence of OC1C2 osteoarthritis in study group was 91.6% and in control group was 6.8%; age of affected individuals was 33.4 (±9.3) and 47.9 (±8.0) years, respectively. Most common complaint was suboccipital neck pain (69.7%); while the CT finding was decreased joint space with sclerosis and irregularity of the margins (81.3%). No statistically significant association was found between presence of radiologic changes and symptoms. Age, duration of occupational exposure and its relationship with various clinico-radiologicmanifestations was studied. Conclusion. This condition has significant prevalence in porters, beginning at an early age. Diagnosis is based on the clinico-radiologic presentation. CT is the investigation of choice. Resultant functional limitations make early identification of this condition imperative.

An unusual case of CV junction tuberculosis presenting with quadriplegia.

Study Design. Isolated tubercular involvement of craniovertebral junction in a human immunodeficiency virus–positive patient causing paraplegia and sudden death with radiologic features is presented. Objectives. Isolated involvement of craniovertebral junction by tuberculosis causing quadriparesis is a rare entity. The role of imaging features is presented in diagnosis of craniovertebral junction tuberculosis, which is a treatable disease. Early detection of this entity with prompt treatment can prevent a fatal outcome. Summary of Background Data. Tuberculosis of the cervical spine is a rare and potentially dangerous manifestation of extrapulmonary tuberculosis. The incidence is probably less than 1% of all cases of spinal tuberculosis. However, in the developing countries this constitutes an increasingly important cause of craniovertebral junction instability and cervicomedullary compression. Most of the patients present with pain in the neck and local tenderness. Neurologic deficits of varying degrees have been reported in 24–40% of cases of craniovertebral junction tuberculosis. Quadriplegia followed by sudden death is exceptional (as seen in our case). The incidence of craniovertebral junction tuberculosis in immunocompromised patients is not known. Dramatic recovery is possible if craniovertebral junction tuberculosis is detected early in its course. Prompt medical and surgical treatment may avert a potential catastrophic event in such cases. Imaging methods such as computed tomography and magnetic resonance imaging are diagnostic of this condition and aid in the detection and prompt treatment of the same. Method. Frontal radiograph of the cervical spine and chest, and lateral view of cervical spine followed by plain and contrast enhanced computed tomography scan of the cervical spine was performed to detect the lesion. Result. These radiographic features were correlated with the clinical findings. The computed tomography findings of bone destruction, prevertebral and extradural peripherally enhancing soft tissue and infiltrating opacities in the lung apexes were consistent with tuberculosis. Conclusions. The computed tomography findings described in this report are very specific for tuberculosis of the craniovertebral junction. Clinical and radiologic correlation could help in making the early diagnosis and prompt treatment possible.

Nonalcoholic, Nonbiliary Pancreatitis: Cross-Sectional Imaging Spectrum

OBJECTIVE The purpose of this review is to describe the epidemiologic, etiopathogenetic, clinical, and imaging characteristics of various nonalcoholic, nonbiliary pancreatitis syndromes. CONCLUSION The spectrum of nonalcoholic, nonbiliary pancreatitis includes autoimmune pancreatitis, groove pancreatitis, hereditary pancreatitis, tropical pancreatitis, tuberculous pancreatitis, and metabolic pancreatitis. Advances in genetics and molecular pathology have shed new light on the etiopathogenesis and course of these syndromes. Accurate diagnosis aided by imaging findings allows optimal management.

Imaging of skull base: Pictorial essay

The skull base anatomy is complex. Numerous vital neurovascular structures pass through multiple channels and foramina located in the base skull. With the advent of computerized tomography (CT) and magnetic resonance imaging (MRI), accurate preoperative lesion localization and evaluation of its relationship with adjacent neurovascular structures is possible. It is imperative that the radiologist and skull base surgeons are familiar with this complex anatomy for localizing the skull base lesion, reaching appropriate differential diagnosis, and deciding the optimal surgical approach. CT and MRI are complementary to each other and are often used together for the demonstration of the full disease extent. This article focuses on the radiological anatomy of the skull base and discusses few of the common pathologies affecting the skull base.

Imaging Spectrum of Extrathoracic Tuberculosis

The incidence of extrathoracic tuberculosis (ETB) continues to increase slowly, especially in immunocompromised and multidrug-resistant tuberculosis (TB) patients. ETB manifests with nonspecific clinical symptoms, and being less frequent, is less familiar to most physicians. Imaging modalities of choice are computed tomography (lymphadenopathy and abdominal TB) and MR imaging (central nervous system and musculoskeletal system TB). ETB commonly involves multiple organ systems with characteristic imaging findings that permit accurate diagnosis and timely management.

Percutaneous management of complications (aortoenteric fistula and sac abscess) following bypass surgery for abdominal aortic aneurysm.

A 45-year-old man initially presented with pulsatile abdominal swelling and uncontrolled hypertension of 3 months’ duration. He was diagnosed to have atherosclerotic abdominal aortic aneurysm, for which he underwent proximal and distal ligation of the aneurysmal aorta and aortoaortic bypass graft of the descending thoracic aorta to the infrarenal abdominal aorta with a right iliorenal bypass graft. One year after this surgery, he developed hematemesis, malena, and severe backache. Angiography revealed persistent filling of the ligated native aortic aneurymal lumen through the active leak at the proximal bypass graft anastomosis with the descending thoracic aorta (Figs.1a and 1b). A Zenith custom-made aortic stent graft (Cook Inc., Australia) was placed across the anastomosis to treat the leak (Fig. 1c). Antibiotic prohylaxis was given for a week in view of arteriotomy. The patient was asymptomatic for 1 year after the aortic stent graft placement, and subsequent follow-up imaging (CT scan) was unremarkable (Fig. 2a). Six months later, i.e., 18 months after placement of the stent graft, he developed pyrexia of unknown origin, with chills and rigors, that was not responsive to antipyretics. All the routine investigations for pyrexia of unknown origin were unremarkable. However, CT scan showed a high-density fluid collection, with an air fluid level in the native aortic aneurysmal lumen suggesting an abscess in the native aneurysmal sac (Fig. 2b). A 10-Fr pigtail drainage catheter was inserted into the abscess cavity under CT guidance (Figs. 3a and b). It drained frank greenish pus, microscopic examination of which showed enterococci. Daily intracavitary antibiotic flushes of chloramphenicol and gentamycin were given through the drainage catheter for 3 weeks, along with parenteral antibiotics. The fever subsided and the drain output decreased gradually. Repeat CT scan, once the drain output was nil and the patient had become asymptomatic, showed a collapsed native aortic aneurysmal cavity with no residual pus (Fig. 3b). The patient remained symptom-free at 1-year clinical and imaging follow-up.