Biomedical subjects

K L Gupta

Publications and source records attributed to K L Gupta.

117 records · Page 7Linked to original sources

PubMedDate not supplied

Wide anulus rent appearance on axial MR imaging: a sign of postdiskectomy recurrent disk herniation.

A band of high intensity extending from a hyperintense nucleus pulposus at the center of a lumbar disk toward the thecal sac is occasionally encountered on axial MR images with a long TR technique. A retrospective review of 195 patients who previously underwent surgery of the lumbar spine revealed eight instances of this wide anulus rent appearance. Four were confirmed to have recurrent disk herniation at re-operation, and the other four were clinically strongly suggestive. Wide anulus rent appearance is a useful sign of a postdiskectomy recurrent disk herniation.

Adult↗

PubMedDate not supplied

MR imaging of malignant uveal melanoma: role of pulse sequence and contrast agent.

To determine the most sensitive pulse sequence and to clarify the role of each pulse sequence in the MR diagnosis of uveal malignant melanoma, noncontrast T1- and T2-weighted, and postcontrast T1-weighted, spin-echo images were compared blindly and independently by two experienced observers. Thirty uveal malignant melanomas, preselected by ophthalmoscopy and sonography for size greater than 2 mm, were examined with a 1.5-T superconducting MR unit with an orbital surface coil. Fifteen tumor studies were done after the patient was injected with gadopentetate dimeglumine. Postcontrast T1-weighted images were the most sensitive in detecting melanomas, demonstrating tumors 2 mm in height accurately on axial planes and 1.6 mm in height on combined orthogonal planes. The contrast-to-noise ratio between melanoma and vitreous fluid was greatest on postcontrast T1-weighted images (average, 72.1), followed by noncontrast T1-weighted images (average, 32.9), and then by T2-weighted images (average, -21.2). Postcontrast T1-weighted images also proved useful in differentiating melanomas from subretinal fluid collections when combined with noncontrast images. We conclude that postcontrast T1-weighted images are most helpful in detecting small uveal melanomas and in differentiating melanomas from subretinal fluid collections.

Contrast Media↗

PubMedDate not supplied

CT and MR of lymphomatoid granulomatosis of the CNS: report of four cases and review of the literature.

Lymphomatoid granulomatosis is an uncommon disease characterized by a perivascular pleomorphic cellular infiltration and necrosis. CNS involvement occurs in 20% of the cases. CT findings have been described in five of the previously reported cases of CNS lymphomatoid granulomatosis, and include unifocal, multifocal, and diffuse contrast-enhancing supratentorial lesions. We reviewed the CT scans of three patients and the MR image of a fourth patient with histologically confirmed CNS lymphomatoid granulomatosis. The lesions were in the posterior fossa in three of the four cases. Hemorrhage, which was present in three of the four cases, was detected by imaging studies in two and at autopsy in the third. Systemic involvement was present at autopsy in three cases and was clinically suspected in the fourth. A diagnosis of CNS lymphomatoid granulomatosis should be considered when hemorrhagic or posterior fossa lesions occur in patients with constitutional symptoms.

Aged↗

PubMedDate not supplied

CT demonstration of extracranial carotid artery aneurysms.

Aneurysms arising from the extracranial carotid arteries are uncommon lesions. Clinically, they may present as lateral masses in the superior cervical area, as medial masses in the tonsillar fossa or parapharyngeal region, or as a mass palpable in both areas. Tenderness or pain may or may not be present. Pulsation is usually detectable. Embolic neurological episodes are a common event leading to discovery of these lesions. Etiologies include trauma, atherosclerosis, fibromuscular dysplasia, infection, and congenital predisposing factors. We report the CT appearance of this condition in three patients. In all three patients (four aneurysms) the CT findings were characteristic. Thus far, we have discovered only one account in the English literature that included the CT demonstration of an extracranial carotid aneurysm.

Adult↗

PubMedDate not supplied

Orbital pseudotumor: association of orbital vein deformities and myositis.

Twenty adult patients with orbital pseudotumor were studied with orbital venography and magnification arteriography. Computed tomography (CT) scans were obtained in 14 patients. Occlusive and constrictive changes of the proximal segments of the superior ophthalmic veins were the most frequent vascular abnormalities. The affected ophthalmic arteries were often attenuated but not occluded. Myositis and surrounding connective tissue inflammatory changes are thought to result in sufficient mass effect to cause the venous stasis with narrowing and subsequent occlusion. Such venographic changes are not distinctive for orbital pseudotumor but may also be seen in cases of thyrotoxicosis, Tolosa-Hunt syndrome, and orbital tumors.

Adult↗

PubMedDate not supplied

Contrast-enhanced gradient-echo MR imaging of the head and neck: experimental and clinical assessment.

To clarify the enhancement pattern of gradient-echo (GE) MR imaging, phantom experiments and 24 clinical examinations of the head and neck region were performed. Both long repetition time (TR) GE and short TR GE pulse sequences demonstrated an enhancement pattern similar to T1-weighted spin-echo imaging in phantom experiments, although the signal intensity of water and gadopentetate dimeglumine (Gd) solution was higher and the signal intensity of fat was lower with the GE technique. In clinical examinations, contrast-enhanced GE imaging was beneficial for tumors within fatty tissue, and for tumors with calcification or other magnetic susceptibility difference.

Contrast Media↗

PubMedDate not supplied

Non-T1-weighted spin-echo MR imaging with contrast material: experimental and preliminary clinical assessment.

To clarify the role of contrast-enhanced non-T1-weighted spin-echo (SE) MR imaging, phantom experiments and 20 clinical examinations were conducted. All of the SE pulse sequences demonstrated enhancement on gadopentetate dimeglumine solution phantoms. Enhancement effect was also observed on proton density-weighted and T2-weighted images in tumors. This property might be better recognized and utilized in selecting pulse sequences in routine MR examinations.

Adipose Tissue↗

PubMedDate not supplied

Neuroimaging features of neurenteric cysts: analysis of nine cases and review of the literature.

PURPOSE: To gain a better understanding of neurenteric (NE) cysts via correlation of imaging findings and surgical and pathologic data. METHODS: The medical records, imaging studies, surgical information, and pathologic material were retrospectively reviewed in nine patients with NE cysts, including seven proved and two very probable cases. RESULTS: NE cysts occurred in the cerebellopontine angle in one case and extended from the cerebellopontine angle to the C2 level in a second. In the latter patient and the remaining seven with intraspinal lesions, the NE cyst was always located anterior to the spinal cord. The most common myelographic and CT myelographic appearance was that of a lobulated intradural extramedullary (IDEM) mass. Two patients had an intramedullary NE cyst with a somewhat unusual appearing exophytic IDEM-appearing expansion that can be a characteristic feature of these lesions. MR imaging demonstrated the NE cyst to be isointense to hyperintense relative to cerebrospinal fluid on long TR sequences and isointense or slightly hyperintense to cerebrospinal fluid on T1-weighted images. These signal characteristics correlate with the high-protein-content fluid within the cysts, usually described at surgery as milky or mucinous in character. CONCLUSION: The diagnosis of NE cyst should be considered when imaging studies reveal the presence of a lobulated IDEM or an exophytic intramedullary cystic mass, especially in association with anterior spina bifida or other vertebral anomalies. MR can uniquely confirm the cystic nature of these masses and is the method of choice for their imaging investigation. Because cyst recurrence can occur, MR should also be used for long-term patient follow-up.

Adolescent↗

PubMedDate not supplied

Gastrointestinal complications after renal transplantation. 10 Year data from a North Indian Transplant Center.

Gastrointestinal complications are responsible for substantial morbidity and mortality among renal allograft recipients in developing countries. During a 10 year period, 166 (62.6%) of 265 allograft recipients developed gastrointestinal complications. This figure reflects the high incidence of infectious complications, especially acute diarrheas. Also notable was the incidence of esophageal candidiasis (7.2%), ischemic colitis (2.6%), and gastrointestinal and peritoneal tuberculosis (3.0%). Almost one quarter of the complications developed in the first 6 months after transplantation. Mortality was the highest with acute ischemic colitis (100%), pancreatitis (60%), and upper gastrointestinal hemorrhage (40%). Improvements in standards of living and sanitary conditions, pre transplant evaluation and assessment of risk factors, prophylaxis with anti ulcer drugs, early diagnosis, and appropriate treatment are needed to decrease the frequency and severity of gastrointestinal complications in renal allograft recipients.

Adolescent↗