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Biomedical subjects

K Sandrasegaran

Publications and source records attributed to K Sandrasegaran.

17 recordsLinked to original sources
PubMed2006

Isotropic chest CT examination: diagnostic quality of reformats.

AIM: To evaluate the image quality of axial and coronal reformats obtained from isotropic resolution 40-channel chest computed tomography (CT) examinations. METHODS AND MATERIALS: Thirty consecutive patients with intravenous contrast-enhanced chest CT examinations using a 40-channel CT machine were enrolled for the study. The raw data were reconstructed into two sets of source axial images: 0.9 mm section width and 0.45 mm reconstruction interval (isotropic resolution) and 4mm section width with 3 mm reconstruction interval (anisotropic resolution; group A). The isotropic data set was reformatted into axial and coronal stacks (groups B and C, respectively) with 4 mm section width and 3 mm interval. Three independent readers evaluated stacks A to C using a three-point scale for resolution of right lower lobe segmental bronchi, edge sharpness of major and minor fissures, respiratory motion artefact, reconstruction artefact, noise and overall image quality. RESULTS: The sharpness of fissures scored significantly higher with the coronal reformats (group C) compared with the axial image sets (groups A and B) (p<0.01). Noise in group A scored significantly lower than groups B or C (p<0.01). For other parameters there was no statistical difference between the groups. There was substantial or excellent agreement between the reviewers. CONCLUSION: Isotropic imaging of the chest allows creation of reformats with similar image quality as similar thickness axial source images. These reformats are probably of sufficient quality to form the basis of clinical interpretation.

Adult↗
PubMed2006

Chemotherapy-induced sclerosing cholangitis.

AIM: To review the computed tomography (CT), magnetic resonance imaging (MRI) and cholangiographic findings of chemotherapy-induced sclerosing cholangitis (CISC). METHODS: Between January 1995 and December 2004, 11 patients in the endoscopic retrograde cholangiography database were identified with CISC. Twelve CT, four MRI, 69 endoscopic and nine antegrade cholangiographic studies in these patients were reviewed. Serial change in appearance and response to endoscopic treatment were recorded. RESULTS: CISC showed segmental irregular biliary dilatation with strictures of proximal extrahepatic bile ducts. The distal 5cm of common bile duct was not affected in any patient. CT and MRI findings included altered vascular perfusion of one or more liver segments, liver metastases or peritoneal carcinomatosis. Biliary strictures needed repeated stenting in 10 patients (mean: every 4.7 months). Cirrhosis (n=1) or confluent fibrosis (n=0) were uncommon findings. CONCLUSION: CISC shares similar cholangiographic appearances to primary sclerosing cholangitis (PSC). Unlike PSC, biliary disease primarily involved ducts at the hepatic porta rather than intrahepatic ducts. Multiphasic contrast-enhanced CT or MRI may show evidence of perfusion abnormalities, cavitary liver lesions, or metastatic disease.

Adult↗
PubMed2006

Routine isotropic computed tomography scanning of the abdomen and pelvis.

For 30 years, abdominal CT has been imaged and reviewed in the axial plane. It is now possible to carry out isotropic imaging of the whole abdomen and pelvis using a 40-channel scanner. This allows creation of coronal and sagittal reformats with the same image quality as the axial images. In this study, we present our experience of reviewing routinely coronal and, occasionally, sagittal reformats. We discuss situations where these nonaxial reformats are most beneficial.

Adult↗
PubMed2005

Mesenteric desmoid mimicking recurrent testicular cancer.

The detection of a solid abdominal mass after surgery for testicular cancer most frequently represents metastatic disease. We report an unusual case of mesenteric desmoid tumor presenting after retroperitoneal lymph node dissection for metastatic testicular cancer. To our knowledge, there are no similar reports in the radiology literature.

Adult↗
PubMed2004

Proximal small bowel intussusceptions in adults: CT appearance and clinical significance.

BACKGROUND: According to the clinical literature, intestinal intussusception in adults is rare, is associated with a pathologic lead point, and is usually treated surgically. Nonobstructing small bowel intussusception has been reported as a transient finding on computed tomographic (CT) studies. METHODS: We evaluated the radiographic and clinical findings in 24 patients who were found to have 26 proximal small bowel intussusceptions on abdominal CT scans performed for a variety of indications. RESULTS: Twenty patients with intussusceptions had no evidence of small bowel obstruction. The transient and clinically insignificant nature of 22 intussusceptions in these 20 patients was proven radiologically (n = 14), surgically (n = 1), or by clinical follow-up (n = 7). These patients demonstrated a bowel-within-bowel pattern on multiple contiguous images and absence of strangulation or intestinal dilatation. No lead points were demonstrated in these patients. Three other patients had symptoms of low-grade small bowel obstruction and were treated conservatively. Extensive follow-up investigations showed no recurrence of intussusception or a lead point. One patient had high-grade obstructive intussusception with intestinal ischemia and required surgical resection of necrotic bowel. CONCLUSIONS: Proximal small bowel intussusceptions are likely to be transient and nonobstructive and unlikely to have a significant lead point.

Adult↗
PubMed1999

Temporal bone: comparison of isotropic helical CT and conventional direct axial and coronal CT.

OBJECTIVE: The objective of the study was to compare helical CT (with reformation of coronal images from the axial data set) with conventional direct axial and coronal CT of the temporal bones. SUBJECTS AND METHODS: Nineteen patients underwent both conventional 1-mm direct axial and coronal CT and helical 0.5-mm axial CT. The helical data set was reconstructed at 0.2-mm increments, and axial and coronal images were reconstructed in a plane similar to that of the conventional study, with a slice width of 0.5 mm and 0.5-mm increments. Forty small structures were evaluated independently by three observers, who were unaware of the method of imaging. Observers graded the 40 structures using a modified Likert scale. The graded differences between the two techniques were evaluated using a paired t test. Correlation between observers' gradings was evaluated using analysis of variance. RESULTS: The helical CT technique scored significantly higher than the conventional technique for many individual structures and groups of structures (scutum [p = .041], stapes footplate [p = .006], stapes crura [p = .004], oval window [p = .026], crista falciformis [p = .006], whole temporal bone [P = .012], middle ear [p = .033], inner ear [p = .021], ossicles [p = .044], and stapes [p = .010]). The correlation coefficient among observers was .91 for the whole temporal bone. CONCLUSION: Helical CT using 0.5-mm technique and reconstruction produces diagnostic images comparable with or superior to conventional 1-mm technique because helical CT can obtain thinner slices.

Adolescent↗
PubMed1998

Gender differences in alcohol metabolism: relationship to liver volume and effect of adjusting for body mass.

BACKGROUND & AIMS: Alcoholic liver disease purportedly develops more readily in women than in men. Some studies have demonstrated faster rates of alcohol elimination in women. This study examined whether gender differences in alcohol metabolism are related to differences in liver volume and/or differences in lean body mass. METHODS: Ten men and 10 women had alcohol elimination rates determined by clamping of the breath alcohol concentration at 50 mg/dL by means of a constant rate of intravenous infusion of 6% ethanol. Liver volume was determined by computed tomography. RESULTS: Mean alcohol elimination rate and mean computed liver volume were not significantly different in men and women. Lean body mass was 42% greater in men than in women. Consequently, the calculated alcohol elimination rate and liver volume per kilogram of lean body mass were 33% and 38% higher in women than in men, respectively. When the alcohol elimination rate was calculated per unit liver volume, no gender-related difference was found. CONCLUSIONS: Women have greater clearance of ethanol per unit lean body mass, confirming previous oral alcohol administration studies. Women have approximately the same liver volume as men, explaining the equivalent alcohol elimination rates seen when men and women are compared on the basis of liver size.

Adult↗
PubMed1994

Magnetic resonance imaging of septic sacroiliitis.

Five cases of septic sacroiliitis diagnosed by magnetic resonance imaging (MRI) are presented. Imaging was performed between 2 and 14 days after onset of symptoms and consisted of varying combinations of coronal short tau inversion recovery (STIR), axial T2-weighted spin echo (SE), and coronal and axial pre- and postcontrast T1-weighted SE scans. Abnormalities included demonstration of sacroiliac joint effusions, bone oedema and adjacent inflammation as high signal on STIR and T2-weighted SE scans, and identification of abscesses in two cases as rim-enhancing lesions anterior to the joint on gadolinium-enhanced T1-weighted SE scans. The role of MRI and other forms of imaging in septic sacroiliitis is discussed.

Adolescent↗
PubMed1992

Sub-clinical systemic lupus erythematosus presenting with acute myocarditis.

A 46 year old woman presented with fever and normochromic anaemia followed rapidly by severe myocardial failure, unresponsive to maximum inotropic support and broad spectrum antibiotics. There were no classical clinical stigmata of systemic lupus erythematosus (SLE) but a possible immunological cause was looked for, and on the basis of her immuno-serology a diagnosis of SLE-like disease was made. She responded rapidly to high dose steroids. The importance of considering the possibility of SLE or 'lupus overlap' in an acutely ill 'undiagnosed' patient is emphasized. The relevance of instigating appropriate immuno-serological tests in the course of such an illness is discussed.

Acute Disease↗
PubMedDate not supplied

Radiology of small bowel obstruction: contemporary approach and controversies.

The radiologic workup of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this complex situation have undergone considerable changes over the past two decades. The diagnosis and treatment of small bowel obstruction, a common clinical condition often associated with signs and symptoms similar to those seen in other acute abdominal disorders, continue to evolve. This article examines the changes related to the use of imaging in the diagnosis and management of patients with this potentially dangerous problem and revisits pertinent controversies.

Barium Sulfate↗
PubMedDate not supplied

Enteric drainage pancreatic transplantation.

Enteric drainage is currently the preferred method of pancreatic transplantation. This technique results in long-term good control of diabetes. In this report we discuss the postoperative radiologic anatomy and complications.

Anastomosis, Surgical↗
PubMedDate not supplied

Hepatic peliosis (bacillary angiomatosis) in AIDS: CT findings.

Patients with acquired immunodeficiency syndrome are at risk of developing opportunistic infections and aggressive tumors. Computed tomographic examination is the usual method of evaluating the abdomen and pelvis in these patients. Although this technique is reasonably sensitive in detecting pathology, findings are often nonspecific. A case of hepatic peliosis (bacillary angiomatosis) in a patient with acquired immunodeficiency syndrome is presented.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Measurement of liver volume using spiral CT and the curved line and cubic spline algorithms: reproducibility and interobserver variation.

BACKGROUND: The purpose of this article was to evaluate the accuracy and reproducibility of spiral computed tomography (CT) and the curved line and cubic spline algorithms in measuring liver volume. METHODS: Spiral CT was performed in phantoms, cadaveric liver specimens, and 35 live human subjects (19 healthy volunteers and 16 patients). Images were transferred to a workstation, and volumes were measured by two observers. One observer repeated the measurements at a separate sitting. RESULTS: The correlation between the CT measurement and the gold standard measurement of the cadaveric livers was very strong (r = 0.94). For the live human subjects, the intraobserver and interobserver correlations were extremely high (r = 0.999 and 0.997, respectively). The mean difference in liver volume measurements between the separate observations was 1%. CONCLUSION: The accuracy and reproducibility of this method of assessing liver volume are very high.

Algorithms↗
PubMedDate not supplied

Postinfective diarrhoea and bile acid malabsorption.

Postinfective irritable bowel syndrome with diarrhoea and idiopathic bile acid malabsorption remains an enigma. We examined the records of 84 patients whose 75SeHCAT scans were indicative of bile acid malabsorption (< 15% one week retention). Identifiable causes of bile acid malabsorption were: previous ileal surgery (7), Crohn's disease (22), radiation enteritis (13), vagotomy, gastrectomy or cholecystectomy (10) and miscellaneous (3). Sixteen of 29 patients with apparently idiopathic bile acid malabsorption gave a clear history of acute gastroenteritis before the onset of chronic diarrhoea lasting from 0.25-18 years until their positive 75SeHCAT scan. Only four cases of campylobacter, and one each of shigella and salmonella were documented. Extensive investigation failed to detect other possible pathologies. In response to bile acid sequestrants, mean stool frequency fell from 7.2 per day to 2.1 per day (p < 0.001). We have observed that postinfective chronic diarrhoea is associated with chronic bile acid malabsorption, which can be successfully treated with bile acid sequestrants such as cholestyramine.

Adult↗