Gamma camera positron emission tomography.
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Gamma Cameras↗
Biomedical subjects
N J Bird
Publications and source records attributed to N J Bird.
A comparison of performance of three gamma camera systems for positron emission tomography.
The development of coincidence positron imaging using a gamma camera should significantly increase PET utilization. This study has compared the performance of three such systems with each other and with an equivalent single photon emission computed tomography (SPECT) measurement. A Carlson phantom, which consisted of a 20 cm diameter cylinder containing areas of uniform activity, hot lesions, cold lesions and orthogonal alternate hot and cold lines, was filled with an activity of 18F chosen to try and best exploit each camera and imaged for a fixed time (27 min). The image quality of 9 mm thick slices in each section of the phantom was compared visually. Several image quality parameters were also compared including line source resolution and noise equivalent count rate. There were considerable differences in PET image quality between the three cameras but all were at least as good as the SPECT image. The full width at half maximum (FWHM) resolution of all systems was similar (approximately 4.5 mm) but the maximum noise equivalent count rates in a 20 cm cylinder were significantly different (6.3, 2.6 and 1.6 kcps) (where cps is counts per second) and correlated with the phantom image quality.
Fluorine Radioisotopes↗
Which patients with prostatic carcinoma require a staging bone scan?
OBJECTIVE: To determine whether the level of prostate-specific antigen (PSA) can be used to decide which patients with newly diagnosed prostatic carcinoma require a staging bone scan. PATIENTS AND METHODS: Of patients referred during an 18-month period for a staging bone scan, 98 (median age 72 years, range 52-89) had had their serum PSA level determined within 4 weeks of the bone scan and were assessed retrospectively for the presence of bony metastases. RESULTS: Of the 98 patients, 26 who had bone scans showing bony metastases had a PSA level > 40 ng/mL. Reviewing the other published studies showed that in those newly diagnosed patients with a PSA level of < 20 ng/mL, the probability of having bony metastases detected on a bone scan was < 1%. CONCLUSIONS: A staging bone scan can be omitted in the vast majority of patients with newly diagnosed prostatic carcinoma and a PSA level < 20 ng/mL.
Aged↗
Home reporting for the nuclear clinician?
The computer-based 'home office' is becoming a widely accepted mode of operation for modern businesses. It is implausible to believe that a nuclear medicine department can be covered permanently at a distance by a single physician, but it should be possible to provide cover for colleagues during sickness or at night or weekends. We have used a 486 PC with a high-resolution screen and software provided by LINK Medical Ltd to obtain images from hospital sites using a modem link to ADAC, Bartec and Nuclear Diagnostic SUN workstations. The data were transferred via standard telephone lines to the homes of two of the authors. During a trial period lasting several months, 60 lung scans, 20 bone scans, 1 gastrointestinal bleeding study, 4 leukocyte scans, 5 bone tomograms, 9 renograms, 6 myocardial perfusion tomograms and 2 gated cardiac studies were transferred. The system allowed transfer of a 128 x 128 eight-view lung scan to be completed in approximately 2 min. The program on the PC allowed alteration of individual image contrast, image rotation, cine display and a variety of colour scales to enhance image interpretation. A system to transfer chest X-rays has been developed and typical transfer times are approximately 3.5 min. Within the viewing protocol on the PC, a reporting window was available with the ability to fax the report directly to the hospital. The system allowed consultants who live at a distance from their nuclear medicine departments to provide cover and is now used as an integral part of our out-of-hours service. The system also allows cover of satellite units or to provide cover for junior staff at night or weekends.
Computer Communication Networks↗
Gastric emptying in patients with chronic renal failure on continuous ambulatory peritoneal dialysis.
Radionuclide gastric emptying studies were carried out on 20 patients with end-stage renal failure (ESRF) undergoing continuous ambulatory peritoneal dialysis (CAPD). Nine of the patients had diabetes mellitus. Eight normal volunteers were also studied to establish normal ranges. Solid and liquid emptying patterns were investigated simultaneously using a meal made up of a solid phase labelled with 99mTechnetium and a liquid phase labelled with 111Indium. The solid emptying fitted a model with a lag phase followed by a linear emptying phase and the liquid emptying fitted a single exponential. Nine of the 20 patients (four diabetic, five non-diabetic) were found to have delayed solid emptying, and four of these (two diabetic, two non-diabetic) also had delayed liquid emptying. No correlation was found between any of the parameters studied and the clinical symptoms of the patients. It is concluded that almost half of the patients studied had abnormal gastric emptying, but that many of these did not suffer from severe symptoms.
Diabetic Nephropathies↗