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Biomedical subjects

J Martin

Publications and source records attributed to J Martin.

At least 1,225 records · Page 68Linked to original sources

Routine quantitative analysis of brain and cerebrospinal fluid spaces with MR imaging.

A computerized system for processing spin-echo magnetic resonance (MR) imaging data was implemented to estimate whole brain (gray and white matter) and cerebrospinal fluid volumes and to display three-dimensional surface reconstructions of specified tissue classes. The techniques were evaluated by assessing the radiometric variability of MR volume data and by comparing automated and manual procedures for measuring tissue volumes. Results showed (a) the homogeneity of the MR data and (b) that automated techniques were consistently superior to manual techniques. Both techniques, however, were affected by the complexity of the structure, with simpler structures (eg, the intracranial cavity) showing less variability and better spatial correlation of segmentation results between raters. Moreover, the automated techniques were completed for whole brain in a fraction of the time required to complete the equivalent segmentation manually. Additional evaluations included interrater reliability and an evaluation that included longitudinal measurement, in which one subject was imaged sequentially 24 times, with reliability computed from data collected by three raters over 1 year. Results showed good reliability for the automated segmentation procedures.

Body Fluid Compartments↗

Decrease of in vitro serum protein binding of salicylate in rheumatoid arthritis.

Free and bound fractions of salicylates were separated by equilibrium dialysis and measured by spectrofluorimetry in 27 patients with rheumatoid arthritis and in 16 controls. The results showed that in patients with rheumatoid arthritis, the binding of salicylate to proteins decreased in an overproportional manner with the decrease of serum albumin concentrations. This phenomenon was linked with the severity of the inflammatory syndrome. The saturation binding capacity per unit of protein concentration was lower in the patients suffering from active forms of the condition, a finding which suggests that the changes observed are not due only to quantitative changes in the serum albumins. This study confirms the importance of determining free salicylate concentrations in the treatment of patients with inflammatory diseases.

Adolescent↗

Primary biliary tract malignant melanoma: US, CT, and MR findings.

We report a case of primary biliary tract malignant melanoma occurring in a 47-year-old male. Ultrasonography and computed tomography showed multiple masses in the gallbladder and distal common bile duct that caused biliary tract dilatation. Magnetic resonance imaging showed that the polypoid masses in the gallbladder and common bile duct were of low signal intensity on T2-weighted images and of high signal intensity on unenhanced T1-weighted images.

Common Bile Duct Neoplasms↗

Hepatocellular carcinoma presenting as portal thrombosis with intrabiliary growth: US and MR findings.

We present an unusual case of hepatocellular carcinoma presenting as massive portal vein thrombosis with progression to the intrahepatic bile ducts without demonstrable primary hepatic tumor. Ultrasound, magnetic resonance, and percutaneous transhepatic cholangiography findings are described. The histologic diagnosis was achieved by means of percutaneous forceps biopsy of the endobiliary mass.

Biopsy, Needle↗

Graft distortion after endovascular repair of abdominal aortic aneurysm: association with sac morphology and mid-term complications.

PURPOSE: To investigate the incidence, significance, and mechanism of stent-graft distortion after endovascular repair (EVR) of abdominal aortic aneurysm. METHODS: EVR of abdominal aortic aneurysm was performed in 51 cases (49 modular, bifurcated; 2 tube). Thirty-two patients were followed for 6 or more months and had equivalent baseline and follow-up images which could be used to determine changes in graft configuration. Sac dimensions were measured using computed tomographic (CT) images and graft-related complications were recorded. RESULTS: Amongst 32 patients evaluated on follow-up, there was graft distortion in 24. Distorted grafts were significantly (p = 0.002) associated with sac diameter reduction (mean 5 mm) and sac length reduction (mean 8.1 mm). All graft-related complications occurred in the limbs of eight distorted grafts, with a mean reduction of sac length in this group of 7.8 mm on reformatted CT images. CONCLUSION: There was a highly significant association between graft distortion and limb complications, and reduced sac dimensions.

Aged↗