PubMed Health⌕ Search

Biomedical subjects

J R Buscombe

Publications and source records attributed to J R Buscombe.

At least 55 records · Page 3Linked to original sources
PubMed1998

SPECT imaging of feet using uniplanar fad-beam collimators.

BACKGROUND: This study was performed to assess the utility of bone SPECT in the feet using a new commercially available uniplanar fan-beam collimator originally designed for cardiac imaging. METHODS: 18 patients with symptoms or signs of probable skeletal pathology in either the foot or ankle were imaged using a two headed gamma camera fitted with uniplanar fan-beam collimators. All patients were imaged 2.5-4 h after administration of 500-750 MBq 99mTc MDP. If indicated planar dynamic and blood pool images were also obtained. The SPECT acquisition was performed in a 128 x 128 matrix, giving a pixel size of 2.00-2.30 mm depending on the radius of orbit. Images were displayed as transaxial, coronal and sagittal slices and a three dimensional volume rendered image and displayed for reading by three readers blind to the clinical results. Sites of abnormal uptake on the foot SPECT scan were then compared with the site of known or suspected pathology and in 17 patients with planar radiology. RESULTS: The SPECT images produced using the uniplanar fan-beam collimators were of good quality in all patients with all three readers finding localisation easiest on the sagittal and three-dimensional images. In 10 patients abnormalities were found which could explain the patient's symptoms or signs and at the site expected from the patient's clinical history. In 5 patients there were abnormalities on the bone scan in the ipsilateral foot but at a different site, all were interpreted as degenerative disease. 2 patients had contralateral degenerative disease to side suggested by the clinical history and no abnormality in the bones of the foot with symptoms. One patient had bilateral degenerative disease. Planar radiology was normal or unhelpful in 13 of the 17 patients in which it was performed. CONCLUSION: SPECT imaging of feet is possible and provides accurate localisation of abnormal uptake when performed using uniplanar fan-beam collimators with a standard acquisition time of 15 min for a double headed gamma camera.

Journal Article↗
PubMed1997

The effect of chemotherapy on the uptake of technetium-99m sestamibi in breast cancer.

Technetium-99m sestamibi scintimammography has been used primarily in the diagnosis of breast cancer. It has also been suggested that this technique could be used to monitor response to chemotherapy and possibly to predict those patients in whom no response can be expected. An initial study was performed in nine patients with primary breast cancer. All patients underwent prone lateral and anterior 99mTc-sestamibi imaging at diagnosis and 4-7 months later, after they had received cytotoxic chemotherapy. The uptake of 99mTc-sestamibi in the breast was compared with that in normal surrounding breast tissue and this ratio was expressed as the target to background ratio. In all patients treated there was a reduction in uptake of 99mTc-sestamibi after treatment, such that whilst all the tumours could be seen before treatment, only three were visible following chemotherapy. There was a significant fall in the mean target to background ratio of the patients undergoing chemotherapy: the tumour to background ratio was 2.48 before chemotherapy and 1.40 after treatment (P<0.001, paired Student's t test). This fall in tumour activity was observed both in those patients in whom a clinical response was seen and in the two patients in whom the tumour enlarged despite chemotherapy. It appears that the reduced uptake of 99mTc-sestamibi seen after chemotherapy may be a non-specific change and therefore may not be predictive of the clinical response to treatment.

Adult↗
PubMed1997

Computer-generated attenuation correction does not improve the accuracy of myocardial perfusion scintigraphy.

A short study was performed to determine if it is possible to increase the accuracy of thallium-201 (201T1) single photon emission tomographic myocardial perfusion imaging using computer-generated ('Chang') attenuation correction. The stress and rest myocardial perfusion studies from 22 patients with suspected or known ischaemic heart disease were reconstructed with and without "Chang' attenuation correction. For all patients, the scintigraphy results were compared with those of coronary angiography. Attenuation correction improved the accuracy of 201T1 myocardial perfusion imaging for defining myocardial ischaemia or infarction in 8% of coronary artery territories (23% of patients), but it was worse in 5% of coronary artery territories (14% of patients). These changes were not significant (McNemar's test). Therefore, computer-generated 'Chang' attenuation correction does not appear to improve the accuracy of myocardial perfusion scintigraphy. It is important that all techniques suggested to improve the accuracy of clinical images should be tested on patients before being widely used.

Coronary Angiography↗
PubMed1997

Scintigraphic imaging of breast cancer: a review.

Scintimammography is a recently verified technique that will expand the use of nuclear medicine to a new group of patients in whom scintigraphic imaging has not been widely used. If performed correctly, and in certain groups of patients, it delivers a sensitivity as high as X-ray mammography or magnetic resonance imaging (MRI) in palpable tumours but with greater specificity. It is best used in patients in whom X-ray mammography, ultrasound and MRI prove non-diagnostic or unhelpful, particularly those women with dense breasts or who have had previous breast surgery. The mechanism of uptake of 99Tcm-MIBI in breast tissue is only partly understood and in itself may help in determining important aspects of tumour function, such as the response to cytotoxic chemotherapy. Other scintigraphic methods for imaging breast cancer may be able to look at other aspects of cancer function, for example blood supply, metabolic rate or the in vivo assessment of oestrogen or somatostatin receptor status. This in turn may be useful in planning treatment. Metastatic disease may best be monitored with 18F-FDG PET, which has a sensitivity greater than MRI but a similar specificity. Much furtner work will need to be done on the use of nuclear medicine in breast cancer, but the addition of unique functional information to the anatomical data from X-ray and MRI should benefit future patients' management.

Breast Neoplasms↗
PubMed1997

Prospective study of hepatobiliary scintigraphy and endoscopic cholangiography for the detection of early biliary complications after orthotopic liver transplantation.

BACKGROUND: Biliary complications are a significant cause of morbidity and death after orthotopic liver transplantation (OLT). This study was a prospective evaluation of endoscopic retrograde cholangiography (ERC) and hepatobiliary scintigraphy (HBS), using 99mTc Mebrofenin, to detect early biliary complications following OLT. METHODS: One hundred consecutive patients who had OLT with a biliary duct-to-duct anastomosis were studied. Of these, 67 had both ERC and HBS performed within 30 days of OLT. Sensitivity, specificity and diagnostic accuracy of HBS in identifying biliary leak or stricture was calculated. RESULTS: Of the 67 cholangiographies performed 45 were normal. In 22 patients there was radiological evidence of a leak (n = 14) or stricture (n = 8) which required further intervention in nine and four patients respectively. The sensitivity and specificity of scintigraphy for the detection of biliary leak after transplantation was 50 and 79 per cent and for biliary stricture 62 and 64 per cent respectively. No patient with normal scintigraphy required biliary intervention. Only six of 14 patients with biliary leaks and two of 20 with strictures suggested by scintigraphy required intervention. If both ERC and HBS reported leak or stricture, the intervention rate was considerably higher at five of seven leaks and two of five strictures. CONCLUSION: This study suggests that scintigraphy is a useful screening test for biliary complications after OLT, ERC is only necessary if HBS is abnormal.

Adolescent↗
PubMed1995

Patterns of Ga-67 citrate accumulation in human immunodeficiency virus positive patients with and without Mycobacterium avium intracellulare infection.

Infection with Mycobacterium avium intracellulaire (MAI) is an increasingly important problem in patients infected with Human Immunodeficiency Virus (HIV). The objective of this study was to identify whether specific patterns of accumulation of Ga-67 citrate occur in HIV antibody positive patients with disseminated MAI infection. A retrospective review of Ga-67 scinigraphy was performed in 18 HIV antibody positive patients with MAI and 20 HIV antibody positive patients without MAI (who acted as a control group). A wide range of abnormalities was seen in both groups of patients and no single abnormality was diagnostic of MAI. However MAI was likely (sensitivity 89%, specificity 70%) in the presence of two or more of the following; accumulation of Ga-67 in lymph nodes, paranasal sinuses or colon or reduced uptake in the bone marrow. No specific abnormality on Ga-67 scintigraphy in HIV antibody positive patients enables a diagnosis of MAI to be made. Subtle and non specific abnormalities of Ga-67 may be the only scintigraphic evidence of active Mycobacterium avium intracellulare infection.

AIDS-Related Opportunistic Infections↗
PubMed1995

High-resolution renal SPECT in eight minutes using a multi-detector gamma camera.

Planar renal scintigraphy with Tc-99m DMSA has become established as a standard diagnostic test to determine if a kidney has been scarred by infection. It has been suggested that high resolution SPECT may improve the sensitivity of detection of renal scars. To determine if it is possible to produce good quality renal SPECT with a short acquisition time, 10 adults were examined with a new multi-detector gamma camera using 8 minute, 16 minute, and 32 minute acquisitions. The number of defects seen (N = 16) with an 8 minute acquisition was not significantly different from the defects (N = 15) seen using a 16 minute and a 32 minute acquisition. In adults when imaging with a multi-detector gamma camera there was no clinical advantage in using an acquisition of longer than 8 minutes.

Adolescent↗
PubMed1995

Localization of infection in HIV antibody positive patients with fever. Comparison of the efficacy of Ga-67 citrate and radiolabeled human IgG.

Patients who are human immunodeficiency virus (HIV) antibody positive are at increased risk of life threatening infection. Scintigraphic imaging with Ga-67 citrate has been used to identify the presence and site of focal infection. However, focal accumulation of Ga-67 is not specific for infection. A retrospective study was performed to compare the accuracy of Ga-67 citrate and pooled human polyclonal immunoglobulin G (HIG) labeled with Tc-99m HIG and In-111 HIG in identifying infection in HIV antibody positive patients. Twenty-five studies were performed using Ga-67 and Tc-99m HIG were compared with a second group of 25 studies using In-111 HIG in HIV antibody positive patients presenting with fever, but without localizing symptoms or signs. In-111 HIG identified 20 of 22 sites of infection and also accumulated in 5 sites without infection (accuracy = 90%). This was significantly more accurate (X2, P < 0.05) than Ga-67 which identified 19 of 20 sites of infection, but accumulated in 18 sites without infection (accuracy = 74%) and Tc-99m HIG which identified infection in 11 of 20 sites, but accumulated in 8 sites without infection (accuracy = 77%). There was no significant difference between the accuracy of Ga-67 and Tc-99m HIG. From this preliminary study In-111 HIG would seem to be the best agent for identifying infection in HIV antibody positive patients with fever.

AIDS-Related Opportunistic Infections↗
PubMed1995

A comparison of 111In-HIG scintigraphy and chest radiology in the identification of pulmonary infection in patients with HIV infection.

Prospectively, we compared the results of chest radiology and functional imaging, using 111In-labelled polyclonal human IgG (111In-HIG), in the identification of pulmonary infection in patients infected by the human immunodeficiency virus (HIV). Sixty-three studies were performed on 57 HIV-infected patients presenting with suspected chest infection or fever of unknown cause, in each of whom a planar chest radiograph was obtained within 24 h of the 111In-HIG study. The results of the two imaging modalities were compared with the final microbiological or cytological diagnosis. Forty patients were found to have pulmonary infection, 25 of whom were correctly identified with chest radiology (sensitivity 62%) and 39 with 111In-HIG (sensitivity 97%). In those patients without infection, chest radiology was abnormal in 13 cases (specificity 43%), while there was only one false-positive 111In-HIG study (specificity 95%). 111In-HIG correctly identified the presence or absence of active lung infection in 61 of 63 cases (accuracy 93%). This was significantly better (chi 2 = 8.25, upsilon = 1, P < 0.01) than chest radiology, which correctly identified the presence or absence of infection in 35 of 63 cases (accuracy 55%). In HIV antibody-positive patients, functional imaging with 111In-HIG is more accurate than chest X-ray in the identification of pulmonary infection.

AIDS-Related Opportunistic Infections↗
PubMed1995

Use of polyclonal IgG in HIV infection and AIDS.

Nuclear Medicine should have a pivitol role to play in the investigation of patients infected with the human immunodeficiency virus (HIV). Unfortunately the use of scintigraphic techniques to localise infection have not become widely used in Europe. Neither 67Ga citrate or labelled leukocytes are ideal. In a search for new agents which can be used to identify the presence of infection both 99mTc and 111In labelled polyclonal immunoglobulin-C have been investigated. It was found that 99mTc labelled polyclonal immune-globulin-G was not able to localise infection in either the chest or the abdomen. In contrast 111In labelled polyclonal immunoglobulin-G had both high sensitivity and specificity for imaging infection in HIV infected patients. If these preliminary results are confirmed immunoglobulin-G could find an important clinical application in this specialised patient group.

AIDS-Related Opportunistic Infections↗
PubMed1994

Indium-111 labelled pooled human immunoglobulin imaging to monitor the efficacy of specific therapy for Pneumocystis carinii pneumonia.

Functional imaging is ideally suited to monitoring the effect of specific therapy on disease processes. In this pilot study five patients with AIDS and Pneumocystis carinii pneumonia (PCP) were imaged with Indium-111 labelled pooled human immunoglobulin (111In-HIG) during infection and after therapy for PCP. The lung activity of 111In-HIG, measured as a lung/heart ratio, was calculated in a study performed during infection with PCP and after therapy. In all five patients the lung/heart ratio of 111In-HIG was reduced after treatment. The mean reduction in heart/lung ratio was 27% (range 12%-53%). If these results are confirmed by a larger study, 111In-HIG will be useful in monitoring the response of PCP to therapy in patients with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1994

Clinical experience with a multidetector SPET system (Toshiba GCA-9300A).

The clinical experience with the Toshiba GCA-9300A single photon emission tomography (SPET) system is discussed along with typical acquisition protocols for various SPET studies. The system was used to perform SPET studies in normals and in a variety of brain and body disorders. Its three Anger-type gamma cameras forming a triangular aperture offer a substantial increase in sensitivity compared to a single rotating gamma camera. This has allowed the routine use of lead fanbeam super high-resolution collimators (SHR FB) for 99Tcm-hexamethylpropyleneamine oxime (HMPAO) brain SPET studies and high-resolution parallel-hole collimators (HR PH) for cardiac and other body studies. The resulting improvement in spatial resolution coupled with the ease of patient positioning and the greater patient throughput compared to a conventional tomographic gamma camera, will enhance the role of brain and body SPET for both routine and research purposes.

Bone and Bones↗
PubMed1994

67Ga scintigraphy in HIV antibody positive patients; a review of its clinical usefulness.

We reviewed the results of 67Ga scintigraphy in HIV antibody positive patients in order to determine how the result affected management. Case records of 37 HIV antibody positive patients undergoing 41 67Ga scintigraphic studies over a 31 month period were examined. New and additional information was provided by 67Ga scintigraphy in 22 studies (53%). In 13 studies (32%) there was a positive effect on patient management. 67Ga scintigraphy was most useful in differentiating Pneumocystis carinii pneumonia from Kaposi's sarcoma in the chest and for the diagnosis of unsuspected lymphoma. Factors which reduced the effectiveness of 67Ga scintigraphy included empirical use of antibiotics in patients with suspected infection and the low specificity of the test.

Adult↗
PubMed1993

Biodistribution and tumour localisation of 131I SWA11 recognising the cluster w4 antigen in patients with small cell lung cancer.

The biodistribution of radiolabelled SWA11, a mouse monoclonal antibody recognising the cluster w4 group antigen associated with small cell lung cancer (SCLC) was studied in patients with SCLC. Five patients were injected intravenously with approximately 5 mCi of 131I conjugated to 1 mg of SWA11. The half-life of the radiolabel in blood was short but there was a prolonged second phase of clearance with a half-life of about 40 h. Tumour was detected by gamma camera imaging two patients. However, most of the whole body radioactivity was located in the bone marrow. At least 35% of the radioactivity in blood 18 h after injection was bound to circulating granulocytes and this probably accounted for the unusual biodistribution of the radiolabel in man. This study shows that the biodistribution of radiolabelled SWA11 in man differs from human tumour xenograft models and that the antibody in unsuitable for targeting therapy to SCLC in man.

Antibodies, Monoclonal↗