ABSTRACT
BACKGROUND: Schistosomiasis is one of the most common parasitic diseases in subtropical and tropical areas and still is considered of public health significance. This disease affects about 200 million people around the world. Intestinal schistosomiasis is mainly diagnosed by parasitological, serological, and molecular methods. CASE PRESENTATION: A 36-year-old Eritrean man who had lived in Denmark for the past 3 years presented to the hospital with 4 months' history of abdominal pain, back pain, and weight loss of 12 kg. He underwent 18F-FDG-PET/CT scanning. The scan findings were consistent with schistosomiasis, which were confirmed by serological and pathological tests. CONCLUSION: PET/CT is a common modality neither to detect schistosomes nor to diagnose schistosomiasis. A presumptive diagnosis can be made based on coincidence of high FDG uptake in visceral lymph nodes below the diaphragm and in relation to abdominal viscera, travel history suggestive of schistosome infection, and exclusion of other causes of abdominal pain.
ABSTRACT
PURPOSE: Perfusion CT (PCT) measurements of regional cerebral blood flow (rCBF) have been proposed as a fast and easy method for identifying angiogenically active tumours. In this study, quantitative PCT rCBF measurements in patients with brain tumours were compared to the gold standard PET rCBF with (15)O-labelled water ((15)O-H(2)O). METHODS: On the same day within a few hours, rCBF was measured in ten adult patients with treatment-naïve primary brain tumours, twice using (15)O-H(2)O PET and once with PCT performed over the central part of the tumour. Matching rCBF values in tumour and contralateral healthy regions of interest were compared. RESULTS: PCT overestimated intratumoural blood flow in all patients with volume-weighted mean rCBF values of 28.2 ± 18.8 ml min(-1) 100 ml(-1) for PET and 78.9 ± 41.8 ml min(-1) 100 ml(-1) for PCT. There was a significant method by tumour grade interaction with a significant tumour grade rCBF difference for PCT of 32.9 ± 15.8 ml min(-1) 100 ml(-1) for low-grade (WHO I + II) and 81.5 ± 15.4 ml min(-1) 100 ml(-1) for high-grade (WHO III + IV) tumours, but not for PET. The rCBF PCT and PET correlation was only significant within tumours in two patients. CONCLUSION: Although intratumoural blood flow measured by PCT may add valuable information on tumour grade, the method cannot substitute quantitative measurements of blood flow by PET and (15)O-H(2)O PET in brain tumours.
Subject(s)
Brain Neoplasms/diagnostic imaging , Perfusion Imaging/methods , Tomography, X-Ray Computed/methods , Adult , Brain Neoplasms/blood supply , Female , Humans , Male , Middle Aged , Oxygen Radioisotopes , Positron-Emission Tomography , RadiopharmaceuticalsABSTRACT
BACKGROUND: Regional cerebral blood flow [rCBF] measurements are valuable for identifying angiogenically active tumours, and perfusion computed tomography [CT] has been suggested for that purpose. This study aimed to validate rCBF measurements by perfusion CT with positron-emission tomography [PET] and15O-labelled water [15O-H2O] in healthy subjects. METHODS: RCBF was measured twice in 12 healthy subjects with15O-H2O PET and once with perfusion CT performed over the basal ganglia. Matching rCBF values in regions of interest were compared. RESULTS: Measured with perfusion CT, rCBF was significantly and systematically overestimated. White matter rCBF values were 17.4 ± 2.0 (mean ± SD) mL min-1 100 g-1 for PET and 21.8 ± 3.4 mL min-1 100 g-1 for perfusion CT. Grey matter rCBF values were 48.7 ± 5.0 mL min-1 100 g-1 for PET and 71.8 ± 8.0 mL min-1 100 g-1 for perfusion CT. The overestimation of grey matter rCBF could be reduced from 47% to 20% after normalization to white matter rCBF, but the difference was still significant. CONCLUSION: RCBF measured with perfusion CT does contain perfusion information, but neither quantitative nor relative values can substitute rCBF measured by15O-H2O PET yet. This, however, does not necessarily preclude a useful role in patient management.
