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Biomedical subjects

A E Southee

Publications and source records attributed to A E Southee.

11 recordsLinked to original sources
PubMed1995

99Tcm-pyrophosphate myocardial scintigraphy: the role of volume-rendered three-dimensional imaging in the diagnosis of acute myocardial infarction.

The aim of this study was to evaluate the role of volume-rendered three-dimensional imaging in the diagnosis of acute myocardial infarction (AMI) using 99Tcm-pyrophosphate (99Tcm-PYP) scintigraphy in a diagnostically difficult group of patients. In total, 117 patients were studied using planar, single photon emission tomography (SPET) and 3-D volume-rendered imaging performed 3 h after receiving 555 MBq (15 mCi) of 99Tcm-PYP intravenously. 555MBq (15 mCi) of 99Tcm-PYP intravenously. Two teams of physicians reported in a blinded and random fashion on each planar, SPET and 3-D rotating image study. Individual reports were compared with reports that used all three imaging modalities in combination. Observer reproducibility was between 85 and 90% and inter-observer team agreement was between 87 and 91%. A score based on clinical history, electrocardiography, serum cardiac enzyme levels and cardiac risk factors was validated and used as a de facto 'gold standard' for AMI for 75 of the subjects for whom all these details were available. The sensitivity, specificity and overall accuracy of combined planar, SPET and 3-D rotating image modalities were all 84%. Analysis of each modality in isolation showed SPET imaging to have the highest sensitivity (74%) and specificity (89%). In combination with SPET and planar imaging, 3-D rotation image presentation increases diagnostic sensitivity without appreciably altering overall diagnostic accuracy. 99Tcm-PYP myocardial SPET imaging shows good utility in the diagnosis of AMI in diagnostically difficult patients.

Adult↗
PubMed1992

Gallium imaging in metastatic and recurrent soft-tissue sarcoma.

Fifty-six patients with metastatic or recurrent soft-tissue sarcoma were evaluated by 67Ga-citrate imaging. Prior to entry on the therapy protocol, 52/56 (93%) patients had true-positive 67Ga studies. Two of four patients with liposarcoma, one of twelve with leiomyosarcoma and one with an epithelioid sarcoma had false-negative studies; 89/105 disease sites (85%) were 67Ga positive, including 100% of pleural lesions, 94% in bone, 88% in the abdomen, 85% in soft tissue, 78% in lung parenchyma and 56% of liver metastases. There was significant association between 67Ga avidity and tumor grade with the exception of mesothelioma. No relationship was seen between 67Ga avidity and tumor cell type, disease site or lesion size. Following therapy, 67Ga correctly identified 11/12 sites of active disease in 8/9 patients. Mean pre- and post-therapy 67Ga avidity scores did not differ significantly. Gallium-67 appears to have an important role in the evaluation of patients presenting with either primary or metastatic soft-tissue sarcoma.

Adolescent↗
PubMed1991

PEEP and "reverse mismatch". A case where less PEEP is best.

A V/Q lung scan was obtained in a patient with LLL collapse who was receiving IPPV and PEEP. This revealed absent ventilation and hyperperfusion to the collapsed lobe. After a reduction in PEEP from 12 to 5 cm H2O, a repeat V/Q scan showed a more even distribution of pulmonary perfusion. Arterial hypoxemia improved.

Aged↗
PubMed1990

Current role of gallium scanning in the management of lymphoma.

Gallium 67 scanning in the malignant lymphomas has been done, with variable success, for over 20 years. After initial enthusiasm, the technique fell into disrepute and it was not until the early 1980s that it enjoyed a revival. There have been many major contributions to the literature, both favourable and unfavourable. The reasons for the latter include: poor instrumentation (only single-pulse height analysis), low gallium 67 doses, impatient and careless scanning techniques, timing of the study after treatment (chemotherapy, radiation) and insensitive methods of confirmation of the presence or absence of disease ("truth"). Anatomical diagnostic techniques (computed tomography, plain X-radiography, magnetic resonance imaging and others) are incapable of distinguishing viable tumour in normal-size lymph nodes or necrotic/fibrotic residual masses. With improvements in instrumentation (triple-pulse height analysis, gamma camera resolution and tomographic techniques) gallium 67 can detect active tumour in residual masses and in normal-size nodes. This is due to gallium 67's unique ability to localize in viable tumour cells. It has greater than 90% sensitivity, specificity, accuracy and positive predictive value in patients with lymphoma. Its major contributions are in: staging (changing management of mediastinal disease, obviating the need for a laparotomy and clearly identifying stage IV disease); detecting relapse or residual, progressive disease (it establishes true complete remission and is often the first and only evidence of relapse before clinical evidence); predicting response to therapy (failure to convert to a negative scan post-treatment signals a poor prognosis and alternative therapy is required); and predicting outcome--prognosis (it is the only diagnostic modality to predict outcome accurately).

Gallium Radioisotopes↗
PubMed1990

Tc-99m white cell scintigraphy in suspected acute infection.

The usefulness of In-111 labeled white cells in acute infection is well documented but the role of Tc-99m labeled white cell scintigraphy (WCS) has not been as clearly established. Using stannous fluoride colloid and a simple labelling procedure with 20 ml of autologous whole blood, three cases are presented in which Tc-99m WCS established unexpected diagnoses in patients who had remained undiagnosed despite extensive investigation.

Acute Disease↗
PubMed1989

Normalised radionuclide measures of left ventricular diastolic function.

Abnormal left ventricular diastolic function is being increasingly recognised in patients with clinical heart failure and normal systolic function. A simple routine radionuclide measure of diastolic function would therefore be useful. To establish this, the relationship of peak diastolic filling rate (normalized for either end diastolic volume, stroke volume, or peak systolic emptying rate), and heart rate, age, and left ventricular ejection fraction was studied in 64 subjects with normal cardiovascular systems using routine gated heart pool studies. The peak filling rate, when normalized to end diastolic volume, correlated significantly with heart rate, age and left ventricular ejection fraction, whereas normalization to stroke volume correlated significantly to heart rate and age but not to left ventricular ejection fraction. Peak filling rate normalized for peak systolic emptying rate correlated with age only. Multiple regression equations were determined for each of the normalized peak filling rates in order to establish normal ranges for each parameter. When using peak filling rate normalized for end diastolic volume or stroke volume, appropriate allowance must be made for heart rate, age and ejection fraction. Peak filling rate normalized to peak ejection rate is a heart rate independent parameter which allows the performance of the patient's ventricle in diastole to be compared with its systolic function. It may be used in patients with normal systolic function to serially follow diastolic function or if age corrected, to screen for diastolic dysfunction.

Adolescent↗
PubMed1989

Gallium scanning in the management of mediastinal Hodgkin's disease.

Gallium-67 scanning was performed pre- and post-therapy in 25 patients with Hodgkin's disease and a mediastinal mass. At restaging after therapy, radiographs (or CT scans) did not predict the presence of active disease whereas gallium scans did with a high degree of accuracy. Gallium-67 determined disease activity in those patients who had a residual mediastinal mass predicting outcome in 11 out of 12 patients; one had a late relapse at 7 years. In patients without a residual mass gallium scanning was again accurate, predicting outcome in 11 of 13 patients. Two patients with negative gallium scans but subsequent active disease were scanned too soon after chemotherapy. The results suggest that gallium scanning has an important role in the management of mediastinal Hodgkin's disease and is superior to all current methods of assessing disease activity irrespective of the presence of a residual mediastinal mass.

Adolescent↗
PubMedDate not supplied

Lymphatic flow rates and first-aid in simulated peripheral snake or spider envenomation.

OBJECTIVES: To demonstrate and define normal lymphatic transit times by lymphoscintigraphy and to evaluate the efficacy of the currently recommended first-aid measures for the management of snake or spider envenomation. SETTING: The nuclear medicine department of a major teaching hospital. PARTICIPANTS AND DESIGN: Twenty-four subjects received either intradermal or subcutaneous injections of 99mtechnetium antimony sulfur colloid (0.1 mL) in both hands/forearms and feet/legs. This simulated a snake or spider bite. Fifteen of the subjects had first-aid in the form of firm bandages and splints applied to an upper and a lower limb immediately after injection. MAIN OUTCOME MEASURES: The progress of the radiotracer was followed with a large field of view gamma camera. If no egress of radiotracer was seen in the bandaged limbs, the subject walked until radioactivity was detected. RESULTS: The mean (+/- SEM) periphery-to-systemic circulation transit time after subcutaneous injection was 58 (+/- 7) minutes. The first-aid was found to be very effective when applied with bandage pressures ranging from 40 to 70 mmHg (5.3-9.3 kPa) in the upper limb and 55 to 70 mmHg (7.3-9.3 kPa) in the lower limb. Lower and higher bandage pressures were ineffective. However, despite first-aid measures, egress of radiotracer, even in the upper limbs, was seen in all subjects who walked for 10 minutes or more. CONCLUSIONS: Firm pressure bandaging is an effective means of restricting the lymphatic flow of toxins after envenomation, provided the bandage is applied within the defined pressure range. Strict limb immobilisation is necessary to minimise lymphatic flow, and walking after upper or lower limb envenomation will inevitably result in systemic envenomation despite first-aid measures.

Adult↗