Background and aim: Radio-labelled Aprotinin has been shown to bind with amyloid fibrils in vitro as well as in vivo. The aim was to test the usefulness of Tc-99m-Aprotinin imaging in systemic amyloidosis. Methods: Thirty-five cases who had Tc-99m-Aprotinin scans for the assessment of systemic amyloidosis were reviewed retrospectively. Eighteen had biopsy-proven amyloidosis and 17 were controls (amyloidosis was excluded by negative biopsies and non-invasive tests). Five of 18 patients with amyloidosis had final diagnosis of cardiac amyloid. Results: Physiological uptake of Tc-99m-Aprotinin was noted in the urinary tract (kidneys and bladder) and in the liver of all patients and controls; and non-specific uptake of Tc-99m-Aprotinin was visualised in the spleen and oro-facial structures in the majority of both groups. Myocardial Tc-99m-Aprotinin uptake was noted in all five patients with final diagnosis of cardiac amyloidosis and in none of the 30 subjects who did not have cardiac amyloid. The median heart to background uptake ratio was 2.0 in cardiac amyloid patients and 1.1 in subjects without cardiac amyloid (P = 0.0004). Single Photon Emission Tomography (SPECT) studies of the thorax confirmed that the site of uptake lay within the myocardium. In the amyloidosis group, site-specific Tc-99m-Aprotinin uptake was also identified in the subcutaneous tissue of the legs and in a breast nodule shown to be positive for amyloidosis on biopsy. Conclusions: Tc-99m-Aprotinin imaging may be a useful non-invasive method for the assessment of the presence and extent of extra-abdominal amyloid, particularly cardiac amyloidosis. It has little role in diagnosis of amyloidosis involving the oro-facial and abdominal structures.

Department of Nuclear Medicine, The Royal Infirmary, Glasgow, UK Abstracts of the 34th Annual Meeting of the British Nuclear Medicine Society Manchester International Conference Centre, UK, 27–29 March 2006

Aims: Venous thromboembolism (VTE) has an increased incidence in pregnancy and the puerperium. We have retrospectively studied the efficacy of imaging of suspected VTE in pregnant and postnatal women in our institution. Methods: Patients referred for investigation from the maternity unit in 2002–2003 were identified from nuclear medicine records. Clinical and radiological records and images were reviewed. Results: Fifty-two patients were identified. All underwent radionuclide ventilation perfusion (V/Q) imaging, using reduced dose technetium labelled macro-aggregated albumin (MAA) and technegas. Thirty-two patients (62%) had a normal or near normal scan, effectively excluding VTE. Eleven (21%) had a low probability scan, and 8 (15%) were indeterminate. One patient (2%) had a high probability scan. Further imaging was carried out in 28 patients (54%). Twenty-six underwent leg ultrasound (single leg in 4, bilateral in 22); 2 patients were found to have deep vein thrombosis (DVT). Four patients underwent repeat V/Q scanning, and 2 CT pulmonary angiography (CTPA), both of which were negative. Conclusions: VTE is frequently suspected but unequivocally demonstrated relatively infrequently in this patient group (3/52, 6%). Reduced dose V/Q scanning produces clinically useful results in the majority. Leg ultrasound is a valuable supplementary technique. CTPA may be underused.

McNeill, J. S.; Toshner, R.; Bessent, R. G.; Poon, F. W.; Gray, H. W.; Neilly, J. B. Author Information

s of the 31st Annual Meeting of the British Nuclear Medicine Society, Manchester, UK, 29 April to 1 May 2003 - BONE AND SOFT TISSUE

Department of Nuclear Medicine, The Royal Infirmary, Glasgow, G31 2ER, UK e-mail: [email protected]

s of the 30th Annual Meeting of the British Nuclear Medicine Society Manchester, UK, 8-10 April 2002. POSTER PRESENTATIONS

s of the Twenty-Ninth Annual Meeting of The British Nuclear Medicine Society. Brighton Conference Centre, 9-11 April 2001. Wednesday 11 April: NEUROLOGY Hall A

s: Abstracts of the Twenty-Eighth Annual Meeting of The British Nuclear Medicine Society Brighton Conference Centre, 10-12 April 2000: Wednesday 12 April LUNG East Wing-Alpha Hall

s: Abstracts of the Twenty-Eighth Annual Meeting of The British Nuclear Medicine Society Brighton Conference Centre, 10-12 April 2000: Wednesday 12 April LUNG East Wing-Alpha Hall

Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) white cell scintigraphy is invaluable for assessing the presence and extent of disease activity in patients with inflammatory bowel disease. Interpretation of images can be compromised by physiological excretion of tracer into the bowel via the biliary tree. This study assesses the effect of intravenous pethidine administered with the labelled white cells in an attempt to reduce the enterohepatic circulation of the tracer. Ninety-one subjects with proven or suspected inflammatory bowel disease were included in this study, all of whom underwent 99mTc-HMPAO white cell scintigraphy. The control group of 50 subjects underwent the standard protocol for this study performed in our department. The other 41 subjects received an intravenous injection of 0.3 mg/kg of pethidine at the same time as re-injection of the labelled white cells. Images were graded using a five-point scale at both 1 and 2.5 h and categorised as positive, negative or non-diagnostic. Each scan was also assessed for the presence of a visible gall-bladder. The pethidine group had significantly fewer non-diagnostic scans than the control group (P=0.003), and significantly (P=0.001) more studies in which the gall-bladder was visualised. It is concluded that the use of pethidine appears to reduce biliary excretion of tracer during 99mTc-HMPAO white cell scintigraphy. This may allow the delayed images, and early images with low-grade tracer uptake in the bowel, to be interpreted with greater confidence and thereby reduce the number of scans classified as non-diagnostic.

Reporting of lung scans for pulmonary embolism (PE) using a descriptive probability notation is tried and tested. Subjectivity in interpretation of this jargon can be a problem for internists. Parallel descriptive and numerical probability reporting has been recommended, but the numerical probability scale is less precise than likelihood ratios expressed as odds. We therefore assessed internists' intuitive understanding of lung scan reports in the odds format compared to the descriptive probability notation. A questionnaire was sent to Scotland's 217 internists to assess their intuitive understanding of odds reporting and to compare their management strategies when confronted by lung scan reports in both an odds and a descriptive probability notation. There was a broad understanding of numerical odds. Internists used 'normal' and '100:1 against PE' identically; similarly, 'low probability' and '10:1 against PE'. There was a statistically significant preference for the diagnosis of PE when internists were given the '1:1 evens' report compared with the 'indeterminate' report. There does appear to be a greater awareness of the risk of PE when non-diagnostic lung scans are reported in numerical odds as compared with the descriptive probability format.

To assess the value of magnetic resonance imaging (MRI) in the investigation of patients with suspected but nonproven vertebral metastases 45 consecutive patients referred in a 6 month period with known primary malignancy and back pain in whom an isotope bone scan was reported as equivocal were studied. All patients had abnormal isotope uptake localized to the spine. Twelve patients were shown to have bony metastases on plain X-ray. In the remainder, where X-rays showed normal or benign appearance, MRI of the spine was offered. Twenty-four patients underwent MRI examination which showed vertebral metastases in 11 cases. Magnetic resonance imaging is shown to be a useful, noninvasive, complementary investigation for evaluation of patients known to have malignant disease and suspected of having vertebral metastases on bone scintigraphy.