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Hemangioblastoma (HB) is the most common primary intra-axial posterior fossa tumor in adults and is a benign vascular neoplasm. We report the case of a 73-year-old man suffering from biochemical recurrence of prostate cancer where intense overexpression of prostate-specific membrane antigen (PSMA) was observed in HB in a PSMA PET/CT. Overexpression of PSMA in tumor-associated vascular structures has been proposed as an explanation of PSMA ligand uptake in several nonprostatic tumors. Given the pathological nature of HB, this mechanism may explain the intense overexpression of PSMA observed in present case.

Summary Objectif There are no guidelines regarding the content of information to be delivered in nuclear medicine. This study aimed at describing practices of French nuclear medicine physicians concerning results communication to patients undergoing PETs for oncological indications. Methodes A survey was performed among French nuclear medicine physicians using an electronic questionnaire. Resultats The study included 250 nuclear medicine physicians. Their practices regarding communication of PET results to patients were heterogeneous: (1) pre- and/or post-PET consultations were systematic for 56%, adapted on a case-to-case basis for 35%, and never performed for 9% of respondents; (2) oral communication of results was systematic for 13%, adapted on a case-to-case basis for 63%, and never performed for 24% of respondents. Working in a private center, presence of post-PET consultations, being older and more years of experience were significantly associated with more oral communication of results. Finally, 80% of physicians admit that current recommendations are not clear enough. Conclusion The heterogeneity of practices among French nuclear medicine physicians concerning communication of PET results to patients probably results from lack of clear recommendations. An inter-collegial, ethical, and multi-disciplinary reflection is needed to better guide nuclear medicine physicians in relation to the communication of results to patients suffering from serious disease.

Objectives The estimation of fracture risk using clinical risk factors (CRFs) is of primary concern in osteoporosis management, but only some risk factors have been thoroughly evaluated and incorporated in predictive models. We have launched a large prospective study, the ‘Fracture Risk Brussels Epidemiological Enquiry’ (FRISBEE), to develop a new predictive model for osteoporotic fractures. The aims of this report are to describe the methodology of the FRISBEE study and to compare the distribution of CRFs in our cohort with those reported in other large studies. Study design FRISBEE is a new study that prospectively evaluates a cohort of 3560 post-menopausal women (aged 60–85 years) followed yearly for the occurrence of fragility fractures. Multiple validated CRFs, densitometry (DXA) values and intake of medication were systematically registered at baseline. The distribution of the FRISBEE CRFs has been compared with the distributions of CRFs in the cohorts used to develop the FRAX ® model as well as in more recent cohorts. For these recent cohorts, we focused on CRFs not included in FRAX ® . Results The most frequently encountered CRFs used in FRAX ® were a prior fragility fracture (27.1%) and a parental history of hip fracture (13.4%). The prevalence of some CRFs not integrated in FRAX ® was relatively high, such as the use of proton pump inhibitors (20.8%) and a history of fall(s) (19.7%). The prevalence of many CRFs was quite variable between cohorts; for example, the prevalence of ‘personal prior fragility fracture’ ranged from 9% to 51%. Conclusion We found considerable heterogeneity in the prevalence of CRFs between cohort studies. The impact of these differences on the predictive value of a particular CRF is unknown. We will construct a predictive model calibrated to the Belgian population. More importantly, the FRISBEE study should allow us to determine the predictive value of newly recognized CRFs in addition to the FRAX ® algorithm to reliably estimate fracture risk.

In many European countries, obstetric ultrasound (US) is performed routinely during normal pregnancies. This leads to the discovery of many fetal anomalies, and, among them, uro-nephropathies represent one of the largest groups amenable to neonatal management. They are now included in the so-called CAKUT [congenital anomalies of the kidney and urinary tract] group (Renkema et al. 2011; Wiesel et al 2005; Ek et al. 2007).

Congenital anomalies may involve any level of the collecting system; the most usual presentation is urinary tract dilatation that may already be detected during fetal life. The role of imaging is to determine the origin of the dilatation, i.e., obstructive versus nonobstructive (Table 1 lists the causes of urinary tract dilatation). Other useful information includes the level of the impairment to drainage (so-called obstruction) and its impact on renal function. All these data are important in order to determine the best therapeutic approach.

The treatment of complicated urinary tract infection in children is still a matter of debate. In our hospital, antimicrobial treatment is initiated intravenously, and the duration of this treatment is adapted according to the results of a Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy. This study was conducted to evaluate retrospectively the frequency and the importance of late renal sequelae when treating intravenously for 7 days those patients with an abnormal acute DMSA. A review was conducted of the medical charts of all patients consecutively admitted between 2005 and 2008 with positive urine culture and clinical and biological evidence of complicated urinary tract infection (UTI). There were 144 patients (59 %) with abnormal early DMSA scintigraphy and 98 (41 %) with normal scintigraphy. The median duration of intravenous treatment was 7.0 days in the children with DMSA lesions and 5.0 days in those without lesions. Obvious renal sequelae were observed on late DMSA scintigraphy in 4 (6 %) out of the 65 patients with an abnormal early DMSA who came back for control scintigraphy. Sequelae of acute DMSA lesions observed during complicated UTI treated 7 days intravenously were infrequent. Whether the mode and duration of antimicrobial treatment might explain the low rate of sequelae remains to be demonstrated.

OBJECTIVES: The aim of the study was to evaluate prospectively the usefulness of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in investigation of fever of unknown origin (FUO) in HIV-positive patients and to determine whether HIV viraemia impacts on FDG-PET/CT performance. METHODS: The FDG-PET/CT results of 20 HIV-infected patients with FUO were analysed and compared with the FDG-PET/CT results of 10 HIV-infected viraemic patients without FUO. The performance of FDG-PET/CT for identifying the aetiology of FUO was assessed. Final diagnosis for FUO was based on histopathology, microbiological assays, or clinical and imaging follow-up. RESULTS: FDG-PET/CT contributed to the diagnosis or exclusion of a focal aetiology of the febrile state in 80% of patients with FUO. The presence of increased FDG uptake in the central lymph node has 100% specificity for focal aetiology of fever, even in viraemic patients. The absence of hypermetabolic central lymph nodes in FUO patients has 100% negative predictive value for focal disease. Lymph node biopsy in central hypermetabolic areas allowed, in 100% of cases, identification of underlying disease in patients with FUO. Biopsy of peripheral lymph nodes should be performed in lymph nodes with maximum standardized uptake value (SUVmax) ≥ 6-8 (sensitivity 62.5%; specificity 75%) and avoided in lymph nodes with SUVmax = 0-4 (specificity 0%). High HIV viraemia does not prevent correct interpretation of FDG-PET/CT. CONCLUSIONS: As in HIV-negative patients, we confirm the usefulness of FDG-PET/CT in investigation of FUO in HIV-positive patients even if they are viraemic.

BACKGROUND: Output efficiency (OE) and normalized residual activity (NORA) are two parameters that allow quantifying the renal drainage at any moment of renographic acquisition. Although OE is theoretically more accurate than NORA in case of a decreased overall renal function, both parameters present some weaknesses. OBJECTIVES: To compare both parameters and to evaluate whether the clinical information provided by both parameters is identical. METHODS: From a large database of Tc-99m mercaptoacetyltriglycine 3 renographic studies, 450 kidneys were selected covering a large range of ages, overall function, split function, and quality of drainage. NORA and OE were calculated at the end of the 20-min renogram, as well as on the late post erect postmicturition (PM) views. RESULTS: An inverse correlation was observed between NORA 20 and OE 20 (r=-0.926), as well as between NORA PM and OE PM (r=-0.936). Discrepancies were noted in approximately 10% of the kidneys, but main discrepancies, which would result in a different estimation of the quality of drainage, were only observed in 2% of the kidneys. There was no bias in the discordances; OE could reveal a better as well as a worse quality of drainage than NORA. It is likely therefore that imperfections of both parameters might be the cause of the divergences. The stratification of the kidneys according to age, overall renal function, split function, or quality of drainage did not modify the results. CONCLUSION: NORA, being much easier to program, can replace the output efficiency in the evaluation of renal drainage. © 2011 Wolters Kluwer Health

Noninvasive techniques have poor sensitivity and specificity in diagnosing endometriosis, which is often associated with an inflammatory process. In several benign diseases, measurement of hypermetabolism using fluorodeoxyglucose (18F 18FDG) reflects the degree of inflammation and aggressiveness of the disease. This prospective study evaluated the value of (18)FDG positron emission tomography (PET)-computed tomography (CT) in assessing the presence of endometriosis.Ten consecutive patients suspected with endometriosis were prospectively included in this study. A preoperative 18FDG PET-CT was performed in all the patients during the follicular phase of their cycle, which preceded laparoscopic surgery. Surgical endometriosis staging and histopathological analysis of removed tissue were confronted with the results from 18FDG PET-CT.Of the 10 patients, 9 had endometriosis confirmed by laparoscopy; 6 had advanced stage of the disease and 5 had histologically proven lesions. Nevertheless, none of the patients had 18FDG-demonstrated hypermetabolism at PET-CT.In this preliminary series, we did not observe hypermetabolic activity in relation to endometriosis using 18FDG PET-CT. This study's most important limitation is the use of 18FDG as an isotopic tracer, which is not specific to endometrial tissue.

Objectives: I-123 ioflupane (FP-CIT) single-photon emission computed tomography is a recognized tool in the diagnosis of Parkinsonian syndromes. In practice, data interpretation relies on visual and semiquantitative analyses. Good interobserver reproducibility is a prerequisite before claiming the robustness of a technique. This study aimed at evaluating interobserver reproducibility of this approach. Methods: Thirty nuclear medicine physicians participated in the study. Data included FP-CIT images and semiquantitative measurements of 12 cases, covering a wide spectrum of scintigraphic patterns and for which a 'true' clinical diagnosis based on long-term follow-up was available. Interobserver agreement was defined, for each case, as the highest percentage reached among the three proposed answers with complete agreement arbitrarily set at 80% or more. Variability in an individual observer's sensitivity to assess data as normal, equivocal or abnormal was scored using a three-point scale. Results: Response rate was 99.7%. Among the three possible answers, 'normal' accounted for 41.2% of the total, 'abnormal' for 49.8% and 'equivocal' for 8.1%. The mean interobserver agreement was 76% (range: 37-100%), with complete agreement being reached only in five cases. The interpretation proposed by most observers accorded to clinical diagnosis in 75% of the cases. Abnormalities of the central nervous system were encountered in all the cases with disagreement between the observer's interpretation and clinical diagnoses. An important variability in the observers sensitivity was seen. Conclusion: In the particular setting of this preliminary study evaluating the reproducibility of FP-CIT single-photon emission computed tomography interpretation in a group of nuclear medicine physicians with various experiences, interobserver agreement was suboptimal. Collegial discussion and standardized interpretation criteria could contribute to an improved reproducibility. © 2010 Wolters Kluwer Health

Objective To evaluate the interobserver reproducibility in reporting on technetium-99m (Tc-99m) dimercaptosuccinic acid (DMSA) scan in children. Methods Sixty Tc-99m-DMSA scans, issued from three centres, were distributed by e-mail to nuclear medicine physicians from the five continents interested in paediatric nuclear medicine. Observers had to choose, for each kidney, among four answers: normal, abnormal, equivocal or poor quality. An additional question was the location of the lesion if any: upper part, mid part, lower part. The responses had to be returned by e-mail. Results Sixty-one observers, with an experience of approximately five or more Tc-99m-DMSA/month, contributed to the study. Median agreement was 93%. The agreement was less than 80% in 29 kidneys (24%) but only in 13% (16 kidneys) was there disagreement between normality and abnormality, the remaining cases being related to 'equivocal' responses. Disagreement was mainly related to the following patterns: (i) normal variants: pear-shaped kidney, hypoactive poles contrasting with important parenchymal mass, triangular kidney, unusual shape of the columns of Bertin; (ii) congenital abnormalities: hydronephrosis, normal duplex kidney; (iii) small defects. Conclusion Interobserver reproducibility can be considered as good among a wide number of observers from the five continents. Disagreement among observers could be reduced by taking the normal variants into account.

Aim: The aim of this study was to evaluate retrospectively the usefulness of [18F]fluorodeoxyglucose (FDG)-PET/computed tomography (CT) in patients affected by human immunodeficiency virus and suffering from fever of unknown origin (HIV-associated FUO). Material and methods: Ten patients (six males, four females, age 24-48 years) suffering from HIV-associated FUO were studied by FDG-PET/CT. Final diagnosis was established either by microbiological or histopathological analysis or by a more than 6-month follow-up. FDG-PET/CT was regarded as 'helpful for diagnosis' when the abnormal uptake pointed to the organ or location where the cause of fever was thereafter identified. Results: Nine out of 10 FDG-PET/CT were abnormal and the cause of fever was further demonstrated by other diagnostic procedures. An infectious process (tuberculosis) was diagnosed in six patients and a neoplasm in three (two lymphomas, one Kaposi's sarcoma). FDG-PET/CT directly suggested sites for biopsy in six patients (tuberculous lymphadenitis and neoplasm). The only patient with normal FDG-PET/CT suffered from drug-induced fever. Conclusion: FDG-PET/CT is a valuable tool in patients with HIV-associated FUO. FDG-PET/CT was categorized as 'helpful for diagnosis' in nine out of the 10 patients we studied. Adding the CT anatomical landmarks to the PET findings allowed an accurate and easy localization of the sites to be punctured in the six patients in whom histopathological diagnosis was needed. © 2009 Wolters Kluwer Health

This work was undertaken to identify, in hypertensive patients suspected of having renovascular hypertension (RVH), scintigraphic images and curves whose interpretation could be difficult. The baseline and postcaptopril Tc-99m MAG 3 images and curves from 10 patients clinically suspected of having RVH were retrospectively selected to have a wide sample of images and curves. The data and a multiple-choice questionnaire were presented as a PowerPoint file, which was sent electronically to Belgian nuclear medicine physicians; they had to answer if the images and curves were or were not suggestive of the diagnosis of RVH or if it was impossible to answer. There was near-complete interobserver agreement for normal baseline and postcaptopril data, for unilateral postcaptopril delayed transit and/or impaired uptake. Agreement was not as good for bilateral and symmetrical changes, for mild changes, or in cases of impaired function. This study shows that the analysis by the Internet of interobserver agreement is an easy and rapid method allowing one to identify difficult to interpret pre- and postcaptopril renographic data.

The split renal function, obtained using Technetium 99m mercaptoacetyltriglycine renography, is currently considered as a robust, accurate and reproducible parameter, provided that it is calculated at a time when no escape of the tracer from the kidney has occurred. The question arises as to whether the simultaneous administration of furosemide with the tracer (F0 test) might accelerate the escape of the tracer, resulting in an underestimation of the split renal function. From a large database, we selected 36 clinically stable children in whom both F0 and F+20 (administration of furosemide 20 min after the tracer) diuretic renography had been performed. In all cases, the F+20 test preceded the F0 test. The mean interval between the two tests was 17 months. The split renal function was calculated on the basis of the 1-2 min background-corrected renal activity using the integral method, slope method and Rutland-Patlak plot. In order to evaluate the effect on the split renal function of an early escape of the tracer, the patients were analysed according to the T(max) value of the renogram for both the F0 and F+20 tests. For the F+20 test, all T(max) values were more than 3 min. For the F0 test, the T(max) value was more than 3 min in 53 kidneys and less than 3 min in 19 kidneys (unilateral in all 19 patients). For the F0 test, for the kidneys with a T(max) value of less than 3 min, there was a tendency to underestimate the split renal function, taking as reference the split renal function observed in the F+20 test. This observation, however, was only statistically significant for the slope method (P=0.03). There was a tendency for lower values with the Rutland-Patlak plot (P=0.07), but, for the integral method, no difference was observed (P=0.5). In conclusion, the simultaneous administration of furosemide with the tracer induces an early acceleration of renal transit. This should be taken into account when calculating the split renal function, for example by favouring the integral method.

Patients frequently ask the nuclear medicine physician or the radiologist for conclusions at completion of a diagnostic procedure. The present study tried to assess opinions from both patients and referring physicians. Answers from both parties were grossly discordant : most of the referring physicians thought patients should not be given results of a diagnostic procedure by the nuclearist or radiologist an approach most of the patients disagreed with. Deontological guidelines of the official Belgian association do not authorize nuclear medicine physicians nor radiologists to give the patients any result directly; according to our data, this rule should be adapted.

The aim of this study was to evaluate renal function during the acute phase of symptomatic urinary tract infection and the changes observed several months later. Overall glomerular filtration rate (GFR) as well as single kidney GFR (SKGFR) were calculated using the combination of a left/right uptake ratio obtained from technetium 99m-dimercaptosuccinic acid (DMSA) scintigraphy and 51chromium-EDTA plasma clearance. Forty-four patients with obvious unilateral or bilateral DMSA abnormalities were studied. In patients with unilateral lesions, both the overall GFR and the SKGFR were significantly higher during the acute phase of infection than several months later, on the abnormal side as well as the normal side. The relative percentage uptake was lower on the abnormal side than the normal side, obviously due to loss of functional parenchyma. This percentage increased significantly during the recovery phase, reflecting the total or partial healing of the renal lesions, despite the decrease of the corresponding SKGFR. However, during both the acute and the recovery phase, the relative percentage uptake of the abnormal kidney was in the normal range and often close to 50%. In patients with bilateral lesions, no significant changes were observed between the acute phase and the recovery phase.

To evaluate inter- and intra-observer reproducibility of renographic quantitative parameters of input and output in children.100 children with unilateral or bilateral uropathy were selected, aiming to cover the entire range of ages, overall glomerular filtration rate (GFR), differential renal function (DRF) and quality of drainage. Renograms were acquired and processed according to the EANM guidelines, using a non-commercial software. Following parameters were tested: DRF using integral and Patlak methods, normalized residual activity (NORA) and output efficiency (OE) at 20 min and on the late post-erect post-micturition acquisition. Three observers from the same department and one from Santiago (Chile) processed independently the 100 renograms using the same renal software. Two observers reprocessed the 100 renograms again two months later in order to evaluate the intra-observer reproducibility.No significant difference was observed between the four observers, whatever the considered parameter of input function or output. For left DRF (Integral and Patlak methods), 95% of the individual differences were between -5% and +5 %. They were between -0.5 and +0.5 units for both NORA 20 and NORA PM, and between -10% and +10% for OE 20 and OE PM. Inter-and intra- observer reproducibility were comparable. Outliers tended to be more frequent for Patlak than for Integral. Very low GFR (20 mL/min/1.73 m(2)), very young age (first days of life), huge megaureters, NORA values higher than 2.0, OE values below 60% and bladder in the renal background area (ectopic kidney) were the main characteristics of extreme differences.

Purpose of the study: Fever of unknown origin (FUO) is a challenging clinical entity in HIV patients. FDG-PET/CT is well validated in the work-up of FUO in HIV-negative patients but in HIV viremic patients, metabolism of HIV reactive lymph nodes could decrease its specificity. We prospectively evaluated the usefulness of FDG-PET/CT in FUO in HIV-positive patients and in particular whether HIV viremia impacts on FDG-PET/CT performance. Methods: FDG-PET/CT was performed in 20 HIV patients with FUO and compared with FDG-PET/CT in 10 HIV viremic patients without FUO. Final diagnosis for FUO was based on histopathology, microbiology, or clinical and imaging follow-up. Mode of diagnosis, accordance of FDG-PET/CT with final diagnosis, localization of invasive diagnosis procedures was recorded in order to assess usefulness of FDG-PET/CT. Results : FDG-PET/CT showed a different pattern in FUO and asymptomatic viremic patients. Reactive HIV lymph nodes in asymptomatic viremic patients were mostly peripheral with mean SUVmax of 6.5. In patients with FUO and underlying focal pathologies, hypermetabolic lymph nodes were central with mean SUVmax of 11.6. Presence of central lymph nodes with high FDG uptake in had a 100% specificity for focal pathology, even in viremic patients and absence of these had 100% negative predictive value. Lymph node biopsy in central hypermetabolic areas allowed identifying underlying disease in all FUO patients. For peripheral lymph nodes, a ROC curve was built in order to define the best cut-off of SUVmax for biopsy: SUVmax of 6-8 showed a sensitivity of 62.5% and specificity of 75%. Lymph nodes with SUVmax

Study objective: To investigate whether topographic analysis of EEG mapping and technetium-99m ( 99m Tc) hexamethylpropylenamine oxide (HMPAO) brain single-photon emission computed tomography (SPECT) can detect cerebral anomalies in the acute phase of carbon monoxide poisoning. Design: Twelve patients aged 18 to 55 years with severe carbon monoxide poisoning and no history of neurologic disorder were evaluated. Either nasal (5 patients) or hyperbaric (7 patients) oxygen therapy was administered. Criteria for hyperbaric oxygen therapy were blood CO of more than 20%, loss of consciousness, pregnancy, or signs of cardiac injury. After oxygen treatment, all patients had a blood CO value of 0% and no patient had persistent acute signs of toxicity. Patients then were investigated by confentional EEG, EEG mapping, and 99m Tc HMPAO brain SPECT. These procedures were performed on the day of admission. Participants: After nasal (5 patients) or hyperbaric (7 patients) oxygen therapy was administered, 12 adults with severe carbon monoxide poisoning were evaluated. AI studies were performed on the day of admission. Measurements: Conventional EEG, EEG mapping, and 99m Tc HMPAO brain SPECT. Results: While classic EEG was normal in 9 of 12 patients and showed diffuse anomalies in 3, EEG mapping and 99m Tc HMPAO brain SPECT demonstrated unilateral or bilateral regional anomalies in 8 of 12 patients. Anomalies were localized in temporo-parieto-occipital areas, the watershed areas of the major cerebral arteries, or in temporal cortex. Conclusion: These preliminary results suggest that EEG mapping and 99m Tc HMPAO brain SPECT can be complementary tools to diagnose early regional cerebral anomalies in carbon monoxide-poisoned patients.

Acquisitions of 360 degrees are usually performed for bone single photon emission computed tomography (SPECT). However, the spine is a peripheral and median structure, it therefore seemed interesting to compare the 360 degrees and the posterior 180 degrees SPECT images. In a phantom study and in 25 adult patients, the 360 degrees SPECT images were compared with the posterior 180 degrees images obtained during the same acquisition: the posterior 180 degrees images are at least equivalent to the 360 degrees images. With a reduction in the examination time, SPECT could become easier to perform, especially in patients suffering from back pain.

Until recently, renogram, performed in children with pelvi-ureteric junction stenosis detected antenatally, has not been able to predict the probability of function improvement after surgery or the risk of function deterioration in case of conservative attitude. Recently, Schlotmann et al. have suggested that cortical transit might have this predictive role. The aim of this study, focused on those kidneys with severely impaired cortical transit, was to verify this statement.All renograms performed in children during a 3-year period (n=729) were retrospectively reviewed and 19 pediatric patients were selected based on an antenatally detected unilateral pelvi-ureteric junction syndrome, the existence of at least two renograms during the follow-up and a severe cortical transit impairment, visually defined. Twenty-six pairs of data could be analyzed and allowed comparing preoperative and postoperative differential renal function (DRF), and the DRF changes during the conservative management.Among the 16 patients who underwent pyeloplasty, 10 showed a significant DRF improvement. Among the 10 patients with conservative follow-up, four showed a significant DRF deterioration.Severely impaired cortical transit seems to be a valuable marker of those patients who could benefit from a pyeloplasty, either because of the high probability of postoperative DRF improvement, or because of DRF deterioration in case of an conservative approach. However, a normal cortical transit, as defined in this study, does not exclude the risk of DRF deterioration. Alternatively, the design of this study does not allow excluding the fact that DRF might improve after pyeloplasty despite a normal cortical transit.

Contrast venography, the accepted gold standard for the diagnosis of venous thrombosis of the leg, is a painful and invasive procedure with late side effects. There is controversy in literature reports about the sensitivity of 99Tcm-macroaggregated albumin (MAA) phlebography: indeed, using 99Tcm-MAA, poor results are obtained when one has to detect calf vein thrombosis. As with other isotopic procedures requiring a pedal injection of the tracer, the use of an injectable solution of 81Krm is a nonspecific method, based upon the abnormality in flow in the deep venous system which results from a deep venous thrombosis. However, when compared with 99Tcm-MAA, 81Krm offers theoretical advantages for phlebographic studies of the lower limbs. In this work 24 patients were studied both with contrast phlebography and with 81Krm. Although 81Krm provided images of high quality, there was a lack of sensitivity below the knee, where false negative results were observed. This could be explained by the fact that the radionuclide venographic procedures usually visualize only one or, in some cases, two of the three deep veins of the calf. Moreover, accurate differentiation between superficial and deep veins in the calf often appears difficult, even using a tourniquet.

Patients often ask for the results after a radioisotope procedure, which can make nuclear medicine physicians feel uncomfortable. In Belgium, nuclear medicine physicians are not supposed to disclose results directly to patients, but to send them to the referring physician. We undertook this work to determine the official rules and practical attitudes in other countries. An introductory letter and a questionnaire were sent to 103 eminent nuclear medicine specialists from 37 countries. Seventy responses (32 countries) were received. Official rules seemed to exist in only seven countries. Most of the respondents indicated that their attitude depended on the clinical situation and the results of the test. Many respondents emphasized that, while in some situations the results should be communicated directly to patients in order to initiate treatment rapidly, in other situations, such as cancer, the referring physician was better suited to disclose the results. The advantages and drawbacks of different attitudes are discussed. Practically and universally applicable rules are difficult to establish, but choosing one solution remains preferable to no standardized attitude at all. An official body, including the medical community, representatives of the population and legal experts, should define an official rule which should be widely communicated, stressing its advantages and drawbacks. In practice, all nuclear medicine physicians would have to do would be to stick to the rule.

Objectives: Osteopenia and osteoporosis are more frequent in HIV-infected patients. Whether antiretroviral therapy induces a bone mineral density (BMD) loss remains controversial and few data are available in women. This cross-sectional study of 89 pre-menopausal HIV-infected women evaluates the relationship between BMD and antiretroviral treatment. Methods: Three groups of women were compared: women never treated (n = 37), women treated with nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors and never treated with protease inhibitor (PI) (n = 25) and women treated with a PI-containing regimen (n = 27). Their lumbar spine and hip BMD was measured by dual-energy X-ray absorptiometry. We assessed also demographic parameters, body mass index (BMI), habits, history of HIV infection and treatment, lipodystrophy and metabolic and hormonal parameters. Results: 83% were African women. Mean age was 37 years. Median duration of HIV treatment was 3.5 years. The overall prevalence of osteopenia/porosis was 31.5%. No difference was found between the three groups. Using logistic regression, low BMI was the only factor associated with osteopenia/porosis. Conclusion: Osteopenia/porosis was highly prevalent among these HIV-infected pre-menopausal women, mainly of African origin. BMD loss was not associated with antiretroviral therapy (containing PI or not) but was associated with a low BMI. © 2009 Elsevier Ireland Ltd. All rights reserved.

This study was performed to investigate the interobserver reproducibility of the interpretation of Tc-labelled white blood cell scans combined or not with other nuclear medicine procedures.Twenty nuclear medicine physicians working in Belgium received clinical data and scintigraphic images from 10 patients suspected of suffering from various infectious diseases. They had to choose, for each patient, one answer among 'high probability', 'intermediate probability' and 'low probability' of infection. In a first step the level of agreement, defined as the highest percentage obtained among the three proposed answers, was calculated for each case; complete agreement was arbitrarily defined when 80% or more of the observers gave the same answer. In a second step, a numerical score was given for each answer and for each observer. The scores were defined as 0 for the 'low probability' answer, 1 for the 'intermediate probability' and 2 for the 'high probability' answer. The scores of each observer were summed up allowing obtaining of a cumulated score for each observer; observers were thereafter classified as a function of their own cumulated score.An agreement of 80% or more was observed only in three patients. The cumulated scores of the observers were between 4 and 16, demonstrating that some observers were more sensitive than others.Interobserver reproducibility in the interpretation of the white blood cell scan was poor; several factors could explain these results, the most frequent being both the poor specificity of the labelled white blood cell scan and different concepts in interpreting combined nuclear medicine procedures in several situations. As observers received the anonymized overall results, this study may have a favourable impact on continuing education in medical imaging.

The goal of this study was to evaluate the inter-observer reproducibility in reporting on renal drainage obtained during 99mTc MAG3 renography in children, when already processed data are offered to the observers. Because web site facilities were used for communication, 57 observers from five continents participated in the study. Twenty-three renograms, including furosemide stimulation and posterect postmicturition views, covering various patterns of drainage, were submitted to the observers. Images, curves and quantitative parameters were provided. Good or almost good drainage, partial drainage and poor or no drainage were the three possible responses for each kidney. An important bias was observed among the observers, some of them more systematically reporting the drainage as being good, while others had a general tendency to consider the drainage as poor. This resulted in rather poor inter-observer reproducibility, as for more than half of the kidneys, less than 80% of the observers agreed on one of the three responses. Analysis of the individual cases identified some obvious causes of discrepancy: the absence of a clear limit between partial and good or almost good drainage, the fact of including or neglecting the effect of micturition and change of patient’s position, the underestimation of drainage in the case of a flat renographic curve, and the difficulties of interpretation in the case of a small, not well functioning kidney. There is an urgent need for better standardisation in estimating the quality of drainage.

Summary Objective When using radioiodine for hyperthyroidism there is no consensus regarding the administration of fixed or calculated doses. Guidelines do not specify the preferable approach or the parameters to use to calculate the dose. Therefore, the dose might be quite different with regard to the chosen procedure. This study was undertaken to evaluate the variability of the amount of radioiodine administered in Belgium in various cases of hyperthyroidism. Design and patients Twenty-one Belgian nuclear medicine physicians received summarized clinical files from 10 patients suffering from overt hyperthyroidism (n = 7) or subclinical hyperthyroidism (n = 3). Five patients had homogeneous goiters, one had multinodular goiter, and four had hot nodule. Participants had to determine the radioiodine dose (millicuries, mCi) they would give in each case. Results Proposed doses varied between 2 mCi and 25 mCi. Mean proposed dose for nodular disease was 10·71 mCi; it was 6·79 mCi for homogeneous goiter. For individual cases, a difference between the lowest and the highest dose of more than 17 mCi was observed in more than 50% of the cases. Conclusions We believe that more precise guidelines are mandatory, underlying uncertainties, controversies but recommending however, as minimal and maximal doses to administer, as well as clinical and biological parameters, if any, to be taken into account in order to modulate these doses.

Normal (51)Cr-ethylenediaminetetraacetic acid (EDTA) clearance values as a function of age were published a number of years ago. These values were based on data from children with a normal left to right ratio and a normal appearance on DMSA scintigraphy, despite the presence of an acute renal infection. At that time, the authors were unaware that hyperfiltration is a common phenomenon in patients with acute renal infection and that their normal values could have been significantly overestimated. The present work therefore aimed to re-appraise these normal values.In a first step, in order to verify the previous results, the same type of population was selected, namely patients with present or past urinary tract infection but normal images and a normal left to right ratio on DMSA scintigraphy. In a second step, the selection was based on patients who had had no recent urinary tract infection. In both series, a single blood sample method was used for the evaluation of (51)Cr-EDTA clearance.In the first group of patients, the results obtained were almost identical to those previously published. In the second group of patients, the results were significantly lower: after 2 years of age, the mean GFR value was 104 ml/min/1.73 m(2) (10th and 90th percentiles 81 and 135 ml/min/1.73 m(2), respectively), compared with 117 ml/min/1.73 m(2) in the first group.The data of the second group are probably more representative of the true normal GFR values and can be applied to the entire paediatric population.

The aim of this study was to assess the reproducibility of a number of simplified clearance methods using chromium-51 ethylenediamine tetraacetic acid (51Cr-EDTA) and to compare these with the multiple blood sample technique. Twenty-four healthy volunteers were enrolled into the study. The test was performed twice, 1 week apart and under similar physiological conditions. After intravenous injection of the tracer, 13 blood samples were taken between 5 and 240 min. The reference clearance was calculated after adapting a bi-exponential fit on the whole plasma disappearance curve. Simplified methods included the slope intercept method using different combinations of blood samples (2 and 4 h; 2, 3 and 4 h; 1.5, 2, 3 and 4 h; 1.5, 2 and 3 h) and several single clearance methods (Constable 3 h; Groth 3 h; Groth 4 h). The standard deviation of the differences between the first and second measurements were similar for all methods, confirming the comparable reproducibility of these methods.

Objective: This work was undertaken to identify scintigraphic patterns obtained in patients suspected of having reflex sympathetic dystrophy (RSD), now often referred to as complex regional pain syndrome, whose interpretations could be difficult. Methods: Ten patients had bone scans because of clinical suspicion of RSD in the lower legs. They were selected retrospectively to have a wide sample of scintigraphic patterns. The radionuclide images and a multiple-choice questionnaire were presented as a PowerPoint file that was sent electronically on the Internet to 54 Belgian nuclear medicine physicians. They had to determine whether the images were in favor of the diagnosis of RSD. Results: Twenty-eight answers (52%) were received. There was near-complete interobserver agreement for perfectly normal scans, for scans showing diffuse uptake with enhancement of periarticular activity, and for scans showing only focal hyperactivity at the site of previous trauma. Results were more discordant when the hyperactivity was mild and when there was a diffuse hypoactivity, with or without focal hyperactivity. Conclusion: This study shows that using very simple methodology, it is possible to identify some scintigraphic patterns in which there is disagreement among observers and whose interpretations vary. As the results are returned to the participants, they can compare their own interpretations with those of their peers. This aspect could be useful in continuing education in medical imaging.

Summary Objective: A drop of split renal function often constitutes a criterion for pyeloplasty in hydronephrosis since it is considered as representing deterioration of the affected kidney. The aim of this work was to determine, in a selected population of patients with a drop of split function of at least 5%, if the evolution of single kidney glomerular filtration rate (SKGFR) was parallel to the one of split renal function. Methods: From a large data basis, we found retrospectively only 29 children (10 below and 19 above two years of age at first examination) having had at least two Tc-99m mertiatide (Tc-99m MAG3) renographic explorations for various urological diseases, with a decrease of split function of at least 5% between the two examinations. Evolution of split function was compared to evolution of SKGFR obtained by means of the combination of Tc-99m MAG3 split function and overall glomerular filtration rate as given by the chromium Cr 51 ethylenediamine tetraacetic acid (EDTA) clearance. Results: For the group above two years of age, SKGFR increased or remained stable in 63% of the cases, while in the children less than 2 years of age, a decrease of SKGFR was never observed, according to the maturation of overall GFR in this age group. Thus, the decrease of split function was not necessarily associated with a similar decrease of SKGFR. Conclusion: In patients with unilateral or bilateral urological disorders, deterioration of split renal function does not necessary correspond to a loss of function of the affected kidney. SKGFR often modifies the interpretation of split function.

The objectives of this study were 2-fold: first, to investigate the robustness of the normalized residual activity (NORA), a parameter that has recently been proposed for the estimation of renal emptying during renography; and second, to define the usual values of NORA in 2 categories of kidneys-those with a normal renogram and those that are dilated but definitely unobstructed.NORA was defined as the renal activity at a given moment (end of renogram, end of furosemide acquisition, image after micturition) divided by the renal activity between 1 and 2 min. Two variables that might influence the results of NORA were evaluated: the choice of background correction, and an error in the estimation of the 1- to 2-min renal activity. To estimate the values of NORA in usual clinical conditions, 2 sets of data were analyzed: normal kidneys with a normal renogram pattern, and dilated but definitely unobstructed kidneys.Using a perirenal or a subrenal background correction, NORA was, on average, 67% or 83%, respectively, of the value obtained without background correction. The use of a renal activity of 1 min 20 s to 2 min 20 s instead of a 1- to 2-min activity resulted in a systematic 10%-15% underestimation of NORA. The 90th percentile values of NORA were, in the normal group, 0.70 at 20 min, 0.23 at the end of the furosemide test, and 0.10 after micturition. In the kidneys that had undergone surgery, the 90th percentile values were 3.92 at 20 min, 2.91 at the end of the furosemide test, and 1.99 after micturition. A good correlation was observed between NORA and output efficiency.If adequately standardized, NORA is a robust and simple parameter that allows evaluation of renal emptying at any time of the acquisition. One should be aware of the fact that high NORA values, corresponding to poor renal emptying, may be observed in the operated unobstructed kidneys, even after micturition.

The aim of this study was to evaluate a simple parameter describing renal output, namely NORA (normalized residual activity). We first compared, in a simulated model, different parameters of transit to an ideal standard; we then compared, in a clinical study, NORA and output efficiency. 123I-hippurate, 99Tcm-DTPA and 99Tcm-MAG3 plasma curves, each with two levels of renal clearance, were convoluted by means of different types of simulated retention functions, with different mean transit times. On the reconstructed renograms, several parameters reflecting renal transit were determined and compared with mean transit time. In a second step, in 33 patients, we compared output efficiency and NORA (i.e. the residual renal activity), normalized by the renal activity at 2 min. These two parameters were calculated at the end of the renogram, at the end of the frusemide test and after the micturition phase. In the simulated model, both output efficiency and NORA were only slightly influenced by the level of overall renal function. In the clinical study, a good correlation was found between output efficiency and NORA, whatever part of the study considered (renogram, frusemide test, post-voiding image). NORA is a simple and reliable parameter that allows quantification of renal output; it is almost independent of the level of renal function and can be used whatever the timing of the frusemide injection.

(51)Cr ethylene diamine tetraacetic acid ((51)Cr EDTA) clearance is nowadays considered as an accurate and reproducible method for measuring glomerular filtration rate (GFR) in children. Normal values in function of age, corrected for body surface area, have been recently updated. However, much criticism has been expressed about the validity of body surface area correction. The aim of the present paper was to present the normal GFR values, not corrected for body surface area, with the associated percentile curves.For that purpose, the same patients as in the previous paper were selected, namely those with no recent urinary tract infection, having a normal left to right (99m)Tc MAG3 uptake ratio and a normal kidney morphology on the early parenchymal images. A single blood sample method was used for (51)Cr EDTA clearance measurement.Clearance values, not corrected for body surface area, increased progressively up to the adolescence.The percentile curves were determined and allow, for a single patient, to estimate accurately the level of non-corrected clearance and the evolution with time, whatever the age.

A 57-year-old man with chronic respiratory disease related to bullous emphysema located mainly in the right upper lobe developed recurrent hemoptysis. Because bacteriological as well as cytologic studies were negative, it was thought that the hemoptysis was related to bullous disease. The patient developed polyarthralgias and a bone scan showed extraskeletal intrathoracic Tc-99m diphosphonate accumulations, which corresponded to bleeding sites shown on a thoracic CT scan. According to the authors, this report may be the first in which extraosseous uptake of a bone imaging agent identified intrapulmonary bleeding.

The aim of this study was to evaluate the variability of the Patlak-Rutland slope as applied to the renal clearance method. We analysed the 99 Tc m -mercaptoacetyltriglycine renograms of 17 non-selected patients (both children and adults, number of kidneys = 34) with a single kidney glomerular filtration rate of 6-73 ml min -1 1.73 m -2 . The acquisition time for the renograms was 20 min with a frame duration of 20 s. First, correction for background activity was introduced using the perirenal area and the size ratio between the kidney and the perirenal area. The Patlak plot was then applied. The first two points were systematically rejected and a series of linear fits calculated from the experimental points, starting from the third point (i.e. 1 min). The final point of the fit never exceeded the time of the peak of the renogram minus one minute (T max - 1) and was always less than 5 min. Although simple visual inspection of the slopes would suggest that the experimental points were distributed accurately along a straight line, it appeared that the slope was strongly dependent on the number of points used for the determination of the fit. As a second step, we restricted the number of points for fitting to the time interval between 1 min and 2 min 40 s. This procedure appeared to show that the Patlak methodology is reliable, giving rise to only small variations in slope, depending on the number of points chosen. However, even in this narrow time interval, significant errors can be made, either because of the very early escape of the radionuclide or because of statistical noise (e.g. in renal failure the signal-to-noise ratio is unfavourable). Therefore, it is advisable, when using this methodology, to restrict the fitting procedure to the second minute of the study and to check visually that this fixed time interval gives rise to a slope that is well adapted to the Patlak plot.

The aim of this paper was to determine the reproducibility (precision) of technetium-99m mercaptoacetyltriglycine (MAG3) clearance and to compare it with that of chromium-51 ethylenediamine tetra-acetic acid (EDTA). Twelve young volunteers (aged between 21 and 34 years), without any history of medical problems, were enrolled in this study. The test was performed twice, at an interval of 8 days and under similar physiological conditions. After the intravenous injection of both tracers, 15 blood samples were taken between 3 and 240 min. A biexponential fit was adapted to the plasma disappearance curves (5- to 120-min samples for 99mTc-MAG3 and 10- to 240-min samples for 51Cr-EDTA); the clearances were calculated according to Sapirstein and corrected for body surface area. The mean clearance values were 110 (range 85-130) and 226 (range 109-319)ml/min/1.73 m2, respectively, for 51Cr-EDTA and 99mTc-MAG3. For 51Cr-EDTA clearance, the mean difference between the first and the second measurement was -2.1% of the mean of the two successive values (SD: 8.4%). In ten cases, the difference was less than 12%; in two cases, the differences were 15% and 18%, respectively. For 99mTc-MAG3 clearance, the mean difference between the first and the second measurement was -20% of the mean of the two successive values (SD: 25%). In six cases, the difference was less than 12%; in four cases, between 15% and 40%; and in two cases, more than 60%. Methodological factors (impurities contained in the commercial kit, variable protein binding) as well as physiological factors (pH of urine, sodium load, stress) may explain the lack of precision of the 99mTc-MAG3 clearance. It is concluded that changes in 99mTc-MAG3 plasma clearance should be interpreted with care in daily routine.

Fifteen patients who had bilateral mediofrontal hypoactivity and 30 control subjects without this SPECT anomaly underwent Tc-99m HMPAO brain SPECT imaging. Bilateral mediofrontal hypoactivity was found in various neurologic disorders, including subcortical arteriosclerotic encephalopathy, lacunar state, chronic alcoholism, progressive nonvascular dementia, carbon monoxide poisoning, and diabetes mellitus. This SPECT abnormality was, however, specifically associated with three clinical signs: motor disabilities predominating in the lower limbs, urinary incontinence, and akinetic mutism.

Major sources of errors in the gamma-camera methods for the calculation of renal clearance are the accuracy of background correction for obtaining the true renal time-activity curve and the validity of the externally recorded pre-cordial activity as an estimate of the plasmatic time-activity curve. With technetium 99m mercaptoacetyltriglycine (99mTc-MAG3), because of its high protein plasma binding, one could expect minimal extravascular diffusion and hence a more accurate externally detected plasmatic curve. The high extraction rate should reduce the influence of the background, but, on the other hand, the effect of hepatobiliary excretion on the calculation of renal clearance might be significant. Our results suggest that the hepatobiliary excretion of 99mTc-MAG3 does not influence the gamma-camera renal clearance determination, even in patients with low renal function. However, the pre-cordial curve does not reflect accurately the plasmatic disappearance curve; its calibration with a single plasma sample taken at the 20th min is responsible for significant errors, probably because of an unfavourable ratio between the intravascular and extravascular activities at the 20th min.

The outlook for children with cerebral palsy is determined by the severity of motor problems and the presence of associated disabilities, in which early detection remains a medical challenge. The authors studied 13 children (aged 13 months to 12 years) with cerebral palsy by means of single photon emission computed tomography (SPECT) of the brain with technetium-99m hexamethylpropyleneamineoxime (HMPAO). In all children with hemiplegia, SPECT demonstrated hypoperfusion in the hemisphere contralateral to the motor deficit. SPECT demonstrated normal findings in patients with mild diplegia; bilateral hypoperfusion in the superior motor cortex in patients with moderate di- or tetraplegia; and bilateral reduction of perfusion in the superior motor, inferior motor, prefrontal, and parietal cortices in patients with severe di- or tetraplegia. Results suggest that Tc-99m HMPAO SPECT of the brain is a valuable complementary tool for thorough neurologic assessment in cerebral palsy.

Extrahepatosplenic intraabdominal Tc-99m colloid uptake has been described in rare pathological conditions. This phenomenon was observed in a large abdominal tumor which, on pathological examination, corresponded to a benign hepatic adenoma; to the authors' knowledge, extrahepatic uptake has not yet been described in hepatic adenoma.

A hard swelling located on the top of the skull developed progressively in a 27-year-old woman who had been treated previously for ovarian dysgerminoma. Bone scintigraphy showed an unusual pattern, consisting of a well-circumscribed area of intensely increased uptake that seemed superimposed on the skull. Results of a CT scan were inconclusive. Biopsy of the lesion revealed a benign osseous angioma.

A 69-year-old woman with degenerative joint disease and right hand pain after trauma underwent Tc-99m MDP bone imaging. Anterior thoracic imaging showed two areas of intense uptake along the chest wall. These symmetric accumulations were related to Tc-99m MDP uptake in the calcified tissue around breast prostheses. The patient had undergone reconstructive breast surgery 30 years earlier.