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A Shetty

Publications and source records attributed to A Shetty.

47 records · Page 3Linked to original sources
PubMedDate not supplied

A comparison of selective saturation and selective echo chemical shift imaging techniques.

We report on a comparative study of two methods of chemical shift imaging which can be used to selectively image fat and water in vivo. Both methods require a B0 field sufficiently homogenous to resolve the methylene and water spectral lines. One method, called CHESS, uses a chemically selective pulse to saturate the unwanted spectral line. The other method, called SECSI, achieves chemical selectivity by using a soft 180 degree RF pulse in forming a spin echo image. Both methods require that the strength of the B1 RF field be accurately calibrated and homogenous. We show by theoretical analysis that the suppression of unwanted spectral lines is sensitive to the first power of B1 errors in the CHESS method but to the second power of B1 errors in the SECSI method. Experiments with phantoms confirmed the expected non linearity of the SECSI method, and showed superior water suppression factors in phantoms with it. Experiments with a large phantom and a living rabbit showed superior results using the SECSI method, and the best results were obtained using a combination of the two techniques.

Adipose Tissue↗
PubMedDate not supplied

A method for reducing motion induced errors in T2-weighted magnetic resonance imaging.

It is known that motion of an object imaged by magnetic resonance imaging leads to errors and artifacts in the image. This effect is especially important when a pulse sequence with long echo time (TE) and long TR is used to provide T2-weighted images. We have modified the usual spin warp imaging pulse sequence in a way which greatly reduces the severity of such errors. The method was tested on both a moving phantom and a living rabbit. The pulsing of the scanner was gated in synchrony to the motion of the phantom; two pulses per mechanical cycle were used to create a special situation which served to verify the validity of a theoretical analysis of the loss of signal with echo time. Under such conditions it was shown that the conventional method led to a progressive loss of signal with increasing TE while the new method gave a pure exponential decay of signal in accordance with the known T2 of the sample. When either the phantom or the animal was scanned without gating, the new pulse sequence showed far less artifacts attributable to motion. The potential application of the technique to improved quantitative imaging of the abdomen in clinical situations is discussed.

Abdomen↗
PubMedDate not supplied

Successful management of spontaneous pneumothorax during general anaesthesia in a patient with eosinophilia.

A 10-year-old male patient posted for left elbow arthrolysis developed pneumothorax during general anaesthesia. He had history of upper respiratory tract infection and high eosinophil count, which remained high in spite of treatment. In such patients, it is advisable to use steroid pre-operatively & intraoperatively to produce transient eosinopenia so that complications of eosinophilia are avoided.

Anesthesia, General↗
PubMedDate not supplied

Blood utilisation in elective general surgery cases: requirements, ordering and transfusion practices.

AIMS: For elective surgeries, over ordering of blood is a common practice. This can be decreased by simple means of changing the blood cross matching and ordering schedule depending upon the type of surgery performed. The principle aim of the study was to improve the efficacy of ordering system for maximum utilisation of blood and formulation of maximum surgical blood order schedule (MSBOS) for procedures where a complete cross-match appears mandatory. MATERIAL AND METHODS: We evaluated blood ordering and transfusion practices in 500 elective general surgical procedures at our institute. With the help of different indices such as cross-match to transfusion ratio (C/T ratio), transfusion probability (% T) and transfusion index (TI), blood ordering pattern was changed in the next 150 patients. RESULTS: Out of 1145 units of blood crossmatched for the first 500 patients only 265 were transfused with non-utilisation of 76.86% of ordered blood. With the help of the indices the wastage was reduced in next 150 patients, i.e. from 76.86% to 25.26% and improved the utilisation of blood, i.e. from 23.14% to 74.74%. CONCLUSIONS: Change of blood ordering patterns with use of MSBOS can avoid the over ordering of blood.

Blood Grouping and Crossmatching↗
PubMedDate not supplied

Continuous ambulatory peritoneal dialysis in end-stage renal disease due to multiple myeloma.

OBJECTIVE: To evaluate (1) the disease course, (2) the response to recombinant human erythropoietin (rHuEPO), and (3) the morbidity and mortality of patients with end-stage renal disease (ESRD) due to multiple myeloma (MM) who were treated with continuous ambulatory peritoneal dialysis (CAPD) DESIGN: Retrospective study. SETTING: Tertiary teaching hospital--The Toronto Hospital, Toronto, Ontario, Canada. PATIENTS: Seven patients with ESRD due to MM who were treated with CAPD. RESULTS: Mean age of the patients was 77.2 years (median 80 years, range 65-88 years). Two were in stage IB, 1 was in stage IIB, and the remaining 4 were in stage IIIB, according to Durie and Salmon's staging. Three patients received rHuEPO; 2 of these also were receiving chemotherapy for myeloma. The mean rHuEPO requirement was 277 U/kg/wk, which was more than other ESRD patients' requirements. Mean duration of CAPD was 20.6 months (6-58 months). The peritonitis rate was one episode in 14.4 months. The frequency of hospitalization was once in 5.6 months, and the mean number of days spent in hospital was 20 days per year. Quality of life did not get worse and, if anything, improved marginally while they were on CAPD. Three patients died after a mean survival of 32.7 months, and the remaining 4 patients are still alive. CONCLUSIONS: Myeloma patients with ESRD do fairly well on CAPD without deterioration in their quality of life and with an acceptable peritonitis rate.

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