Extraperitoneal urine leak after renal transplantation: the role of radionuclide imaging and the value of accompanying SPECT/CT - a case report

<p>Abstract</p> <p>Background</p> <p>The differentiation of the nature of a fluid collection as a complication of kidney transplantation is important for management and treatment planning. Early and delayed radionuclide renography can play an important role in the evaluation of a urine leak. However, it is sometimes limited in the evaluation of the exact location and extent of a urine leak.</p> <p>Case Presentation</p> <p>A 71-year-old male who had sudden anuria, scrotal swelling and elevated creatinine level after cadaveric renal transplantation performed Tc-99 m MAG3 renography to evaluate the renal function, followed by an ultrasound which was unremarkable. An extensive urine leak was evident on the planar images. However, an exact location of the urine leak was unknown. Accompanying SPECT/CT images confirmed a urine leak extending from the lower aspect of the transplant kidney to the floor of the pelvic cavity, presacral region and the scrotum via right inguinal canal as well as to the right abdominal wall.</p> <p>Conclusions</p> <p>Renal scintigraphy is very useful to detect a urine leak after renal transplantation. However, planar imaging is sometimes limited in evaluating the anatomical location and extent of a urine leak accurately. In that case accompanying SPECT/CT images are very helpful and valuable to evaluate the anatomical relationships exactly.</p

Ekologické zemědělství, učebnice pro školy i praxi. I. díl. Základy EZ, agroenvironmentální aspekty a pěstování rostlin

První učebnice ekologického zemědělství v České republice. Obsahuje základy filosofie a praxe v ekologickém zemědělství, zaměřené na rostlinnou produkci a v samostatné kapitole informuje o biodynamickém zemědělství

Comparison of (18)F SPECT with PET in myocardial imaging: A realistic thorax-cardiac phantom study

BACKGROUND: Positron emission tomography (PET) imaging with fluorine-18 ((18)F) Fluorodeoxyglucose (FDG) and flow tracer such as Rubidium-82 ((82)Rb) is an established method for evaluating an ischemic but viable myocardium. However, the high cost of PET imaging restricts its wider clinical use. Therefore, less expensive (18)F FDG single photon emission computed tomography (SPECT) imaging has been considered as an alternative to (18)F FDG PET imaging. The purpose of the work is to compare SPECT with PET in myocardial perfusion/viability imaging. METHODS: A nonuniform RH-2 thorax-heart phantom was used in the SPECT and PET acquisitions. Three inserts, 3 cm, 2 cm and 1 cm in diameter, were placed in the left ventricular (LV) wall to simulate infarcts. The phantom acquisition was performed sequentially with 7.4 MBq of (18)F and 22.2 MBq of Technetium-99m ((99m)Tc) in the SPECT study and with 7.4 MBq of (18)F and 370 MBq of (82)Rb in the PET study. SPECT and PET data were processed using standard reconstruction software provided by vendors. Circumferential profiles of the short-axis slices, the contrast and viability of the inserts were used to evaluate the SPECT and PET images. RESULTS: The contrast for 3 cm, 2 cm and 1 cm inserts were for (18)F PET data, 1.0 ± 0.01, 0.67 ± 0.02 and 0.25 ± 0.01, respectively. For (82)Rb PET data, the corresponding contrast values were 0.61 ± 0.02, 0.37 ± 0.02 and 0.19 ± 0.01, respectively. For (18)F SPECT the contrast values were, 0.31 ± 0.03 and 0.20 ± 0.05 for 3 cm and 2 cm inserts, respectively. For (99m)Tc SPECT the contrast values were, 0.63 ± 0.04 and 0.24 ± 0.05 for 3 cm and 2 cm inserts respectively. In SPECT, the 1 cm insert was not detectable. In the SPECT study, all three inserts were falsely diagnosed as "viable", while in the PET study, only the 1 cm insert was diagnosed falsely "viable". CONCLUSION: For smaller defects the (99m)Tc/(18)F SPECT imaging cannot entirely replace the more expensive (82)Rb/(18)F PET for myocardial perfusion/viability imaging, due to poorer image spatial resolution and poorer defect contrast

Non-invasive imaging of atherosclerotic plaque macrophage in a rabbit model with F-18 FDG PET: a histopathological correlation

BACKGROUND: Coronary atherosclerosis and its thrombotic complications are the major cause of mortality and morbidity throughout the industrialized world. Thrombosis on disrupted atherosclerotic plaques plays a key role in the onset of acute coronary syndromes. Macrophages density is one of the most critical compositions of plaque in both plaque vulnerability and thrombogenicity upon rupture. It has been shown that macrophages have a high uptake of (18)F-FDG (FDG). We studied the correlation of FDG uptake with histopathological macrophage accumulation in atherosclerotic plaques in a rabbit model. METHODS: Atherosclerosis was induced in rabbits (n = 6) by a combination of atherogenic diet and balloon denudation of the aorta. PET imaging was performed at baseline and 2 months after atherogenic diet and coregistered with magnetic resonance (MR) imaging. Normal (n = 3) rabbits served as controls. FDG uptake by the thoracic aorta was expressed as concentration (μCi/ml) and the ratio of aortic uptake-to-blood radioactivity. FDG uptake and RAM-11 antibody positive areas were analyzed in descending aorta. RESULTS: Atherosclerotic aortas showed significantly higher uptake of FDG than normal aortas. The correlation of aortic FDG uptake with macrophage areas assessed by histopathology was statistically significant although it was not high (r = 0.48, p < 0.0001). When uptake was expressed as the ratio of aortic uptake-to-blood activity, it correlated better (r = 0.80, p < 0.0001) with the macrophage areas, due to the correction for residual blood FDG activity. CONCLUSION: PET FDG activity correlated with macrophage content within aortic atherosclerosis. This imaging approach might serve as a useful non-invasive imaging technique and potentially permit monitoring of relative changes in inflammation within the atherosclerotic lesion