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Biomedical subjects

C M Boyd

Publications and source records attributed to C M Boyd.

At least 37 records · Page 2Linked to original sources
PubMed1990

Diagnostic value of Tc-99m MAA radionuclide venography of lower extremity: as a simultaneous procedure of ventilation-perfusion scan for pulmonary embolism.

A total of 336 cases received a ventilation-perfusion(V/Q) scan for the detection of pulmonary embolism (PE). Among these, 155 cases simultaneously underwent a successful radionuclide venography study (RNV) of the lower limbs using Tc-99m macro-aggregated albumin (MAA). Concomitant pulmonary arteriography (PA) was performed in 120 cases. Fifty-four of these 120 cases successfully completed the RNV scan. There was a statistical significance in the V/Q scan for the detection of PE as confirmed by the PA (p less than 0.0001). The positive predictive value (PPV) of the RNV for PE was 75% (3/4). The negative predictive value (NPV) was 48% (24/50). The sensitivity and specificity were 10% (3/29) and 96% (24/25) for the 54 patients who had both the RNV scan and PA. For the 155 patients who had simultaneous V/Q and RNV scans, there was no statistically significant correlation between these two scans. The PPV, NPV, specificity and sensitivity were 42%(8/19), 75%(103/136), 90%(103/114) and 20%(8/41), respectively. Despite the low sensitivity and no significance of positive RNV for diagnosis of PE, RNV is still recommendable because it is a simple, non-invasive, simultaneous procedure during perfusion lung scan and has high specificity.

Femoral Vein↗
PubMed1989

Technetium-99m RBC bleeding images in normal subjects: confusion with gastrointestinal bleeding sites.

The normal appearance of a gastrointestinal bleeding study using labeled red blood cells has been discussed frequently, but the actual appearance is not well known. In this atlas article, the authors report on unusual findings in non-bleeding subjects and have tabulated the visualization of various structures. Vascular structures other than the aorta and inferior vena cava were seen in 42 of 48 patients. One or both kidneys were seen in 10 (21%) of 48 patients. The urinary bladder was seen in 23 (48%) of 48 patients, although gastric activity caused by free pertechnetate was never observed.

Erythrocytes↗
PubMed1989

Technetium-99m hysterosalpingography in infertility: an accurate alternative to contrast hysterosalpingography.

Thirteen infertile women who had undergone tubal surgery within the previous year for the correction of tubal obstruction, were studied with both conventional and radionuclide hysterosalpingography. The studies were performed on the same day, were interpreted independently, and the results were then compared. Three cases were excluded from analysis because of the technical inadequacy of one of the studies. Assuming the findings of the conventional studies to represent "truth," the sensitivity, specificity and accuracy of the radionuclide studies were 100%, 60% and 80% respectively.

Fallopian Tubes↗
PubMed1989

Prosthetic vascular graft infections: diagnosis and treatment.

The diagnosis of infection in prosthetic vascular grafts is difficult clinically but very important due to the high associated morbidity and mortality. Various radiographic and imaging procedures have been used. 111In-labeled white cells have been used with a sensitivity approaching 100% and a specificity of approximately 90%. Computed tomography (CT) has also been advocated as a means of detecting these infections by some. Similarly, ultrasound has been used. More recently, magnetic resonance imaging (MRI) has been advocated in hopes that the signal of the infected graft would differ from that of the noninfected graft. This article reviews the data supporting each of these modalities.

Blood Vessel Prosthesis↗
PubMed1988

Stachyose Synthesis in Source Leaf Tissues of the CAM Plant Xerosicyos danguyi H. Humb.

Leaf tissues from Xerosicyos danguyi H. Humb., a succulent member of the Cucurbitaceae, were found to possess both galactinol synthase activity and the capacity for photosynthetic production of stachyose, the phloem transport oligosaccharide common to other nonsucculent cucurbits. The amounts of stachyose isolated from leaf tissues, and the extractable activity of galactinol synthase, were somewhat higher in leaf tissues obtained from plants operating in the Crassulacean acid metabolism (CAM) mode (well watered plants) compared to leaf tissues from plants operating in the CAM-idling mode (water-stressed plants). In contrast, in leaf discs, the photosynthetic incorporation of label into stachyose following pulse labeling with (14)CO(2) was similar for stressed and for nonstressed tissues. Stachyose could be extracted from, and was synthesized photosynthetically by, leaf discs which contained no vascular tissues, indicating that synthesis of stachyose can occur in photosynthetic mesophyll cells of Xerosicyos.

Journal Article↗
PubMed1987

Early and delayed indium 111 leukocyte imaging in Crohn's disease.

Twenty-seven patients with Crohn's disease were studied for the presence and location of activity by both early (4 h) and delayed (18-24 h) indium 111 leukocyte imaging. The results were compared with other parameters of disease activity including Crohn's disease activity index, barium studies, and endoscopy. There was a correlation between early images and Crohn's disease activity index (r = 0.78) and between delayed images and index (r = 0.82). Based upon the corresponding Crohn's disease activity index, the sensitivity of early and delayed imaging was 81.0% and 95.2%, respectively. Specificity of early and delayed imaging was 75.0% and 87.0%, respectively. Presence of activity on the early and delayed imaging agreed with activity on barium studies and colonoscopy in approximately 80% of cases. Correlation of location of disease by leukocyte imaging and x-ray was observed in 58.9% of early scans and 55.0% of delayed scans. Correlation of the location of disease by imaging and endoscopy was observed in 71.4% of early and 75.0% of delayed studies. Because of the possibility of occurrence of false-negative results in early images, delayed imaging should always be included in evaluation of disease activity in patients with Crohn's disease who are suspected of having mild activity. Delayed imaging is not required if the early imaging study clearly shows activity.

Adult↗
PubMed1987

Indium-111 leukocyte accumulation in submandibular gland saliva as a cause for false-positive gut uptake in children.

Unexplained false-positive accumulation of In-111 leukocyte in the gastrointestinal tract has been reported previously. In a pediatric population, uptake in the submandibular gland was noted in 19 of 42 children. This is believed to be a normal finding in children that is not seen in adults. In some of these 19 children, unexplained gastrointestinal activity was also noted. Saliva from a patient with false-positive gastrointestinal uptake and positive submandibular activity was positive for In-111. One suggested cause of unexplained gut activity may be secondary to swallowed activity in the saliva from the normal submandibular activity in children.

Child↗
PubMed1987

Hyperdense parapelvic cyst confused with renal tumor.

We have reported a case of a hyperdense parapelvic renal cyst that could not be easily differentiated from a solid tumor by multiple diagnostic studies. However, the typical findings of a hyperdense parapelvic cyst may allow less aggressive surgery.

Diagnostic Errors↗
PubMed1987

Uptake of indium-111-labeled leukocytes by brain metastasis.

Uptake of indium-labeled leukocytes was seen in two cases of histologically proven brain metastasis. In one, this led to misdiagnosis of the lesion as an abscess. On histological evaluation, a large number of white blood cells or macrophages was seen at the neoplastic sites. Reasons for leukocyte accumulation around metastatic brain neoplasms are discussed. In contrast to the current reports that indium-labeled leukocyte scans can differentiate intracranial infection from tumor, these cases demonstrate their lack of specificity in the detection of brain abscess.

Aged↗
PubMed1987

Posture and MPD.

Explore the source record for details and available documents.

Humans↗
PubMed1986

An autonomous functioning cystic thyroid adenoma. An unusual occurrence.

An asymptomatic thyroid nodule that appeared cystic on ultrasound was seen in a 14-year-old girl. Tc-99m pertechnetate thyroid imaging was expected to show a cold nodule, but surprisingly revealed a hyperfunctioning nodule. A partial thyroidectomy revealed an hemorrhagic cystic adenoma. The occurrence of a cystic nodule, which continued to show hyperfunction, is unusual.

Adenoma↗
PubMed1986

Precise intraoperative location of gastrointestinal bleeding with a hand-held counter. Work in progress.

The nuclear medicine bleeding scan is frequently insufficient to locate sites of bleeding precisely, in spite of its great sensitivity. A small, hand-held Geiger-Müller counter, placed directly on exposed intestine in the operating room, enables precise location of the probable bleeding site. In three patients, the technique allowed a minimal amount of intestine to be resected, distinguished between large- and small-intestinal hemorrhage, and eliminated other foci as sites of bleeding.

Gastrointestinal Hemorrhage↗
PubMed1986

Radiation dosimetry considerations in the treatment of cystic suprasellar neoplasms.

Methods and results are given to enable the computation of radiation dose as a function of depth in the wall of a suprasellar cyst containing radioactivity. Both beta- and gamma-emitting nuclides are considered. The methodology considers distribution of the radioactivity on the cyst wall (spherical shell geometry) and distribution uniformly in the fluid (volume geometry).

Beta Particles↗
PubMed1986

111 In-labeled leukocytes in the detection of prosthetic vascular graft infections.

Making a clinical diagnosis of infection in prosthetic vascular grafts is difficult but when undiagnosed, this condition has a high mortality rate. Using Indium-111-labeled white-blood cells, 30 scans were performed in 21 patients suspected of having a prosthetic graft infection. The diagnosis of infected graft was confirmed by surgery in all cases, and lack of infection was established by resolution of symptoms with conservative therapy. Twenty-four hour scans of autologous Indium-111 leukocytes were obtained, and correlative CT studies were done in 11 cases. There were 13 infected grafts at surgery (purulent material present), and scans were positive in all (100% sensitivity); of 17 scans, there were 15 true negatives and two false positives (88% specificity). Using the criteria of gas or fluid around the graft, the sensitivity of CT was only 37% in a small subset of these patients. One-half of the cases in which infection was suspected clinically had no infection and had negative scans. Various types of grafts and graft materials were used, and there was no correlation with presence or absence of infection on the basis of the type of graft. Extragraft infection sites were found in five patients. In conclusion, use of Indium-111 leukocytes has been found to be an accurate and valuable diagnostic method for evaluation of suspected prosthetic vascular graft infection, and to have higher diagnostic accuracy than CT.

Aged↗