Biomedical subjects
Publications and source records attributed to T McCauley.
Four cases of osteoid osteomas are presented. An uncharacteristic magnetic resonance finding of soft tissue edema is reported. This observation should not be misinterpreted as indicating a more aggressive pathologic process and, thereby, exclude osteoid osteoma from the differential.
A simple reversed-phase high-performance liquid chromatographic assay of 2-hydroxydesipramine (2-OH-DES) in plasma is described, using 2-hydroxyimipramine (2-OH-IMI) as the internal standard. Extraction of the plasma samples by methylene chloride-isoamyl alcohol was followed by back-extraction of 2-OH-DES into acidic phosphate buffer. Precautions include silanizing test tubes and rinsing pipettes to minimize adsorptive loss, and washing with extraction solution to eliminate chromatographic interference peaks. Analyses are carried out by using a high carbon load C-18 column (15%) with phosphate buffer-acetonitrile as the mobile phase at 43 degrees C. Detection of 254 nm was monitored at extended attenuation of 0.001 or 0.002 a.u.f.s. Peak height ratios of 2-OH-DES/2-OH-IMI were linearly correlated with 2-OH-DES concentration between 10 and 100 ng/ml of plasma. Detection limit was 3 ng. Coefficients of variation for within-run and day-to-day studies were 2.2% and 5.0%, respectively. A significant amount of 2-OH-DES was identified from the plasma extract of a psychiatric patient taking a daily dose of desipramine. This assay may be used for monitoring of 2-OH-DES in evaluating clinical side effects and for pharmacokinetics studies.
OBJECTIVE: Our goal was to evaluate the image quality, contrast characteristics, and possible clinical utility of STIR images obtained using a fast SE (FSE) technique. MATERIALS AND METHODS: The signal and contrast characteristics of FSE STIR images were evaluated using a lipid/water phantom and normal volunteers. Based upon these results, optimal FSE STIR imaging parameters were chosen. Conventional STIR and FSE STIR images were then obtained (while maintaining an equal number of section locations between the two sequences) in a series of 14 patients with known musculoskeletal abnormalities. These images were compared side by side by two experienced MR radiologists for image quality and lesion detection. RESULTS: There were no statistically significant differences between the FSE STIR images and conventional STIR images in lesion detection, image quality, motion artifact, or final diagnosis. CONCLUSION: STIR imaging provides optimal contrast for detection of many pathologic abnormalities. This is especially true for musculoskeletal tumors and infection. The long imaging time and reduced number of sections obtainable with conventional SE (CSE) STIR sequences limit their routine use. Our results show that FSE STIR images of the musculoskeletal system can be obtained up to seven times more rapidly than CSE STIR images without compromising lesion detection or image quality.