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Biomedical subjects

A Bossuyt

Publications and source records attributed to A Bossuyt.

At least 19 recordsLinked to original sources

Effect of exercise induced hyperlactatemia on the biodistribution and metabolism of iodine-123-15(p-iodophenyl)-3-R,S-methyl pentadecanoic acid in normal volunteers.

We have evaluated the biodistribution and metabolism of iodine-123-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) in the presence of increased lactate levels induced by short-term heavy exercise. Five healthy male subjects received 159 MBq (+/- 13 MBq) 123I-BMIPP at rest and a week later after they performed a maximal exercise test using a bicycle ergometer. Planar and tomographic images were obtained with a dual-head gamma camera up to 4 h after administration of the tracer. Multiple blood samples were taken at different time points for blood clearance, substrate concentration measurements and for HPLC analysis of metabolites. The exercise test did not alter plasma glucose and non-esterified fatty acid concentrations, but blood lactate increased from 1.12 mmol/l at rest to 9.26 mmol/l with maximal exercise. After exercise, BMIPP showed a significantly faster plasma clearance than at rest and the production of PIPA, the end metabolite of BMIPP oxidation, was reduced. Activity in the heart was similar after exercise and at rest on planar images 15 min after injection (4.83 +/- 0.50% ID vs 4.80 +/- 0.43% ID, P = NS), although the myocardium-to-cavity activity ratio, as determined on the SPET images 20 min after tracer injection, was slightly increased after the exercise test (4.20 +/- 0.63 vs 3.78 +/- 1.34 at rest, P = NS). Significantly increased activity was observed in a leg muscle region of interest after exercise (4.98 +/- 0.50% ID vs 3.93 +/- 0.44% ID at rest, P = 0.02). Between early and late images, tracer washout from the myocardium increased from 20.72% at rest to 36.72% after exercise (P < 0.05), but was unchanged for liver and leg muscles. The metabolic and physiological alterations induced by exercise do not degrade image quality of BMIPP scintigraphy. On the contrary, exercise-induced hyperlactatemia seems to enhance myocardium-to-cavity activity ratios on SPET images, although this effect does not reach statistical significance in this small group of normal subjects. These findings further support the robustness of BMIPP SPET in varied metabolic environments.

Adult↗

Interest of the ordered subsets expectation maximization (OS-EM) algorithm in pinhole single-photon emission tomography reconstruction: a phantom study.

Pinhole single-photon emission tomography (SPET) has been proposed to improve the trade-off between sensitivity and resolution for small organs located in close proximity to the pinhole aperture. This technique is hampered by artefacts in the non-central slices. These artefacts are caused by truncation and by the fact that the pinhole SPET data collected in a circular orbit do not contain sufficient information for exact reconstruction. The ordered subsets expectation maximization (OS-EM) algorithm is a potential solution to these problems. In this study a three-dimensional OS-EM algorithm was implemented for data acquired on a single-head gamma camera equipped with a pinhole collimator (PH OS-EM). The aim of this study was to compare the PH OS-EM algorithm with the filtered back-projection algorithm of Feldkamp, Davis and Kress (FDK) and with the conventional parallel-hole geometry as a whole, using a line source phantom, Picker's thyroid phantom and a phantom mimicking the human cervical column. Correction for the angular dependency of the sensitivity in the pinhole geometry was based on a uniform flood acquisition. The projection data were shifted according to the measured centre of rotation. No correction was made for attenuation, scatter or distance-dependent camera resolution. The resolution measured with the line source phantom showed a significant improvement with PH OS-EM as compared with FDK, especially in the axial direction. Using Picker's thyroid phantom, one iteration with eight subsets was sufficient to obtain images with similar noise levels in uniform regions of interest to those obtained with the FDK algorithm. With these parameters the reconstruction time was 2.5 times longer than for the FDK method. Furthermore, there was a reduction in the artefacts caused by the circular orbit SPET acquisition. The images obtained from the phantom mimicking the human cervical column indicated that the improvement in image quality with PH OS-EM is relevant for future clinical use and that the improvements obtained using the OS-EM algorithm are more significant for the pinhole geometry than for the conventional parallel-hole geometry. We conclude that PH OS-EM is a practical and promising alternative for pinhole SPET reconstruction.

Algorithms↗

Electromagnetic diathermia: a lymphoscintigraphic and light reflection rheographic study of leg lymphatic and venous dynamics in healthy subjects.

Because electromagnetic diathermia (ED) has been reported to reduce lymphedema, we opted to examine the effects of ED on leg venous and lymph dynamics in healthy subjects. To examine lymph flow, we performed lymphangioscintigraphy (LAS) in 10 subjects without leg edema and used static images at the injection site and at the inguinal region for "control data." Later, we applied ED (2450 MHz, 200W) and then repeated the LAS using the same dosage and volume. Differences between the first and second sessions were examined using two way ANOVA and the differences between the scores with or without ED were analyzed by a Student's t-test. To examine venous flow, we first tested the left lower leg of 15 healthy subjects on two occasions using light reflection rheography (LRR). Venous refill time was recorded after each individual performed 10 dorsiflexions with the left foot on three occasions with an interval of 3 minutes between each recording. Thereafter, 20 minutes ED (2450 MHz, 200 W) was applied and using the same protocol venous refill time was recorded and repeated after an interval of one week. The 20% level and the declination angle of the refill time was determined and differences between the experimental and control groups analyzed by ANOVA. The results between the first and second sessions were consistent and reproducible with or without the electromagnetic application, with no change of radiotracer transport from the injection site or arrival at the inguinal nodes. There was also a high correlation between the scores for the 50% level and declination angle (r = 0.97) after LRR. Thus, after ED there was an accelerated venous refill time. In conclusion, after ED there was no increase in lymph flow but there was accelerated venous return.

Adult↗

Quantification of 99Tcm-HMPAO brain SPET in two series of healthy volunteers using different triple-headed SPET configurations: normal databases and methodological considerations.

We evaluated the methodological issues underlying the assessment of normal confidence intervals, as used in clinically based region-of-interest (ROI) semi-quantification of 99Tcm-HMPAO brain SPET. At two different centres equipped with high-resolution, triple-headed gamma cameras, HMPAO SPET scans were performed on two groups of 24 and 15 healthy volunteers respectively. Together with an operator-defined analysis (ODA), a semi-automated analysis (SAA) was conducted on the normal datasets in one centre. Tests of intra- and inter-observer variability were performed. Repeat scans were performed within 72 h after the first to analyse short-term regional inter-study variations. The overall regional uptake showed significant differences in most regions between both normal datasets. Intra-observer and inter-observer reproducibility were on average within 4% for the ODA, while for the SAA it was less than 1%. Inter-study variations were excellent for both centres, ranging from -4% to +3% for most regions studied. The variability in clinical brain perfusion studies largely depends on the reproducibility of the data analysis technique. A semi-automated approach shows clear advantages over an entirely operator-defined approach. Intra-subject repeat studies show enough stability for use as reliable baseline measurements in the construction of a normal database or to allow activation studies with high sensitivity.

Adult↗

Rapid gastric emptying of a liquid meal in long-term Type 2 diabetes mellitus.

Both delayed and accelerated gastric emptying rate (GER) have been reported in patients with diabetes mellitus. Delayed GER has been attributed to autonomic neuropathy in established diabetes but rapid GER was demonstrated in early Type 2 diabetes. The aim of the study was to investigate rapid gastric emptying in a group of people with long-duration Type 2 diabetes. GER of a radiolabelled liquid meal was studied scintigraphically in 20 Type 2 patients with a mean (+/-SEM) duration of diabetes 13 (+/-1) years. The 50% emptying time (t50) for the liquid meal was shorter in diabetic patients (29.6+/-2.1 min) than in controls (39.2+/-1.9 min; p<0.0005). Accelerated emptying (t50 value below the shortest t50 of controls) was evidenced in 14/20 patients and delayed emptying (t50 value exceeding the upper t50 of controls) in none. Patients with accelerated GER were comparable for BMI, diabetes duration, HbA1c and fasting glycaemia to those with normal GER. Rapid GER for liquids was found in the presence or absence of autonomic neuropathy. Seven of the patients with rapid emptying of the liquid meal were reassessed using a solid meal. Only one patient demonstrated rapid emptying of the solid meal, which was normal in 3 and delayed in 3 patients. In conclusion, accelerated GER can be found in long-term Type 2 diabetes but there is no concordance between GER of a liquid and a solid meal.

Blood Glucose↗

Iodine-123 alpha-methyl-l-tyrosine single-photon emission tomography for the visualization of head and neck squamous cell carcinomas.

The uptake of iodine-123 alpha-methyl-l-tyrosine (IMT) in the primary tumours and metastatic lymph nodes of squamous cell carcinoma of the head and neck was examined with single-photon emission tomography (SPET). Eleven patients with biopsy-proven carcinomas were studied prior to any therapeutic action. The evaluation of cervical lymph node involvement was based on the findings of physical examination, computed tomography and magnetic resonance imaging, and in six patients on the histological data relating to tissue samples obtained by fine-needle lymph node aspiration or surgical intervention. SPET imaging was performed 10 min after the injection of 130-170 MBq IMT using a triple-head gamma camera equipped with medium-energy collimators. High-quality IMT SPET depicted the primary tumour in 10 of 11 patients (sensitivity: 91%). Tumours located in the larynx were visualized more clearly than those located in the mouth or oropharynx. The mean tumour-to-background ratio was 2.35 (range: 1.6-3.1) for laryngeal tumours and 1.67 (range: 1.2-2.2) for mouth and oropharyngeal tumours. Metastatic cervical lymph nodes were involved to various degrees in 8 of the 11 patients. Among these eight patients there were 16 sites, nine of which were detected by IMT SPET (sensitivity: 56%). If the IMT SPET findings were recorded per side of the neck, the sensitivity was 64%. Five of the seven missed metastatic lymph nodes were smaller than 15 mm. The mean tumour-to-background ratio of the scintigraphically visualized lymph nodes was 1.81+/-0.51 (range: 1.39-2.77). Asymmetric physiological submandibular salivary gland IMT uptake led to false-positive lymph node assessment in three patients. This study indicates the potential use of IMT SPET as a metabolic imaging modality in patients with head and neck squamous cell carcinoma.

Adult↗

123I-5-I-R91150, a new single-photon emission tomography ligand for 5-HT2A receptors: influence of age and gender in healthy subjects.

5-HT2A receptors have been implicated in the pathophysiology of mood disorders and in the therapeutic effect of the so-called atypical antipsychotics. Recently, a new radioiodinated ligand with high affinity and selectivity for serotonin 5-HT2A receptors, 123iodinated 4-amino-N-1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl] 5-iodo-2-methoxybenzamide (123I-5-I-R91150), has been developed and has been shown to be suitable for single-photon emission tomography (SPET) imaging. In this study the influence of age and gender on the ligand binding was investigated in normal volunteers. One hundred and fifty MBq of 123I-5-I-R91150 was administered to 26 normal volunteers (13 females and 13 males) with an age range of 23-60 years. SPET imaging was performed with a triple-headed gamma camera. For semi-quantitative analysis, ratios of ligand binding in different regions of interest to the binding in the cerebellum were calculated. Mean ratios of 1.7 were obtained. No gender difference was demonstrated. 5-HT2A binding was shown to decline with age. Over an age range of 40 years a reduction in ligand binding of 42% +/- 7% was found. These results are in agreement w in vitro and positron emission tomography findings of a decline in 5-HT2A receptor binding with age. The findings confirm the suitability of 123I-5-I-R91150 for SPET imaging of 5-HT2A receptors, and highlight the necessity for age-matched controls in clinical studies.

Adult↗

The influence of cold and compression on lymph flow at the ankle.

OBJECTIVE: To investigate the effects of cold application with different temperatures on lymph flow in healthy persons and to examine the effects of the combination of cold and compression on lymph vessels. PARTICIPANTS: Thirty-nine healthy persons were included in the study, and each served as his or her own control. INTERVENTION: Water bags (1 degree, 15 degrees, and 32 degrees) with or without 25 mm Hg pressure were applied to the experimental legs for 30 minutes. Cold, pressure, or both were administered by an Aircast-Cryo-cuff (Aircast Europe GMBH, Rosenheim, Germany). MAIN OUTCOME MEASURES: Skin temperature was measured with a TESTO 901 (Testoterm GMBH, Leuven, Belgium) precision thermometer. Lymph flow was recorded continuously using lymphoscintigraphy. MANOVA with repeated measures was used for data analysis. RESULTS: As expected, skin temperature dropped relative to the temperature of the water. The migration of the tracer was comparable in both ankles during the first 30 minutes of the experiment (rest). When the water bag was applied, lymph flow increased significantly (p < 0.01). The application of water of 1 degree C without pressure influenced lymph evacuation significantly differently from the other temperatures. The application of pressure of 25 mm Hg influenced lymph evacuation significantly at 1 degree C and 32 degrees C. CONCLUSION: These results indicate that lymph evacuation at the ankle is influenced significantly when cold water is applied with or without pressure. When pressure is added to the application of water of 32 degrees C, lymph flow will also increase significantly, indicating the importance of pressure in lymph evacuation.

Adolescent↗

Effect of oral glucose loading on the biodistribution of BMIPP in normal volunteers.

UNLABELLED: We have evaluated whether myocardial uptake of the fatty acid analog 123I-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) is dependent on the dietary state. METHODS: We compared the biodistribution of 150 MBq of 123I-BMIPP in six healthy volunteers in two states: after at least 12 hr of fasting and after oral glucose loading (75 g) 60 min before tracer administration, followed by a meal enriched in carbohydrates and protein. Planar and tomographic acquisitions were performed over a 4-hr time period after tracer injection; data were corrected for radioactive decay and injected dose. Radioactivity was measured in blood samples drawn at several points. RESULTS: Significant increases of glycemia and insulinemia and a significant drop in plasma nonesterified acids were documented after glucose loading. Half-time values for plasma radioactivity were significantly shorter in the glucose-loaded state than in the fasted state (4.3 +/- 1.4 min compared to 6.3 +/- 1.3 min, p < 0.05). Activity in the heart and liver tended to be higher in the glucose-loaded state than in the fasted state. SPECT images at 0.5 hr after tracer injection demonstrated that the myocardial wall-to-cavity ratio was higher after glucose than in the fasted state (2.53 +/- 0.59 compared to 2.11 +/- 0.21, p = 0.15). Washout from the liver between 1 and 4 hr after injection increased from 18.6% +/- 4.4% in the fasted study to 24.1% +/- 2.4% after glucose (p = 0.04). Washout from the myocardium between 0.5 and 3.5 hr after injection increased from 13.1% +/- 8.8% in the fasted study to 24.0% +/- 3.7% after glucose (p = 0.05). CONCLUSION: These results indicate that fasting before BMIPP scintigraphy is not mandatory to obtain adequate SPECT images. At the tire when SPECT is usually performed, glucose loading may provide improved ratios between myocardial and blood pool activity.

Administration, Oral↗

Cerebral blood flow related to induction of a depressed mood within and out of the realm of attention in normal volunteers.

The effects of a depressed mood on regional cerebral blood flow (rCBF) were measured after a mood-induction procedure (MIP) in normal volunteers. The MIPs were administered 'within the realm of attention' and 'out of the realm of attention'. A modified Velten procedure, which consisted of tape-recorded self-referent depressive statements, was used for mood induction. For the induction out of the realm of attention, a combination of dichotic listening and subliminal stimulation was used. A neutral induction procedure served as a control condition. CBF was measured with Tc-99m HMPAO single photon emission computed tomography (SPECT) with regard to 14 healthy female students. Scores on mood rating scales showed negative changes after both MIPs. Statistical analyses revealed lateralized changes in rCBF in the thalamus. Decreased thalamic CBF in the right hemisphere was demonstrated after both MIPs compared with the neutral induction condition. Moreover, hippocampal rCBF increased significantly, but only after induction out of the realm of attention. These findings suggest both hippocampal and thalamic involvement in the regulation of mood experience.

Adult↗

Fascial Tc-99m MDP uptake in eosinophilic fasciitis as demonstrated by SPECT.

BACKGROUND: The presence of bone-seeking radiopharmaceutical uptake in extraskeletal tissues of the lower or upper extremities may indirectly reflect the presence of active inflammatory lesions in patients in whom systemic disease is suspected. MATERIALS AND METHODS: The authors present the case of a 26-year-old woman who had mixed signs of scleroderma and cosinophilic fasciitis, in whom misleading findings on planar bone scintigraphy suggested diffuse muscular tracer uptake in the lower extremities. RESULTS: However, using additional SPECT imaging of the pelvis and thighs, it was shown that the soft tissue radioactivity was clearly restricted to the fascia overlying the muscles. The fascial localization of the inflammation was confirmed by biopsy. CONCLUSION: SPECT imaging was proven useful in indicating the exact localization of an active inflammatory process in the muscle fascia.

Adult↗

Visualizing ocular melanoma using iodine-123-N-(2-diethylaminoethyl)4-iodobenzamide SPECT.

UNLABELLED: Radiolabeled benzamides have recently been introduced for the detection of melanoma. We evaluated the potential clinical applicability of 123I-N-(2-diethylaminoethyl) 4-iodobenzamide ([123I]IDAB) for SPECT imaging of ocular melanoma. METHODS: Fourteen patients were studied, 10 with or suspected of malignant ocular melanoma and four with ocular naevi. All patients underwent SPECT imaging of the head and whole-body scintigraphy 4-5 hr after injection of 170 MBq [123I]IDAB. RESULTS: A definite tracer hyperfixation was observed in the pathological eye in 9 of 10 (90%) patients with ocular melanoma. The pathological-to-normal eye ratio averaged 1.46 (range 1.07-2.86). The melanoma nature of the scintigraphic lesions was confirmed after enucleation in eight cases and by clinical evolution in two. A false-negative scan was reported in a patient with a small and hypochromic lesion. In patients with ocular naevi, no false-positive scintigrams were documented. CONCLUSION: Iodine-123-IDAB scintigraphy may contribute significantly to decide about enucleation in cases where some doubt persists with conventional techniques.

Benzamides↗

Low back pain and nuclear medicine.

Low back pain (LBP) is a major cause of disability in many patients during some time of their lives. In this article the role of nuclear medicine, and more in particular the role of single photon emission tomography (SPECT), in the investigation of LBP is discussed by reviewing the literature. Because of the improved anatomical localization of lesions in the vertebral body when up-to-date SPECT is used, this technique is a powerful imaging modality in patients with LBP. Bone scintigraphy therefore can contribute significantly in the diagnosis of patients with LBP. In cases where conventional radiological techniques fail to elucidate the cause of LBP performing a bone scintigraphy with SPECT should strongly be recommended.

Diagnosis, Differential↗

Optimal collimator choice for sequential iodine-123 and technetium-99m imaging.

Dual-isotope studies with technetium-99m and iodine-123 may be useful for various organs, including brain and myocardium. For the images obtained with each of the tracers to be comparable, it is important that activity ratios (activity in one part of the image/reference activity in the image) are preserved by the imaging method. We have used a Rollo phantom to study how collimator response affects such ratios. All investigations were performed with 123I(p,5n) and on a Siemens Orbiter 3700 camera fitted with either a low-energy high-resolution (LEHR) or a medium-energy (ME) collimator. Images were made of a Rollo phantom filled with an aqueous solution of either 99Tc or 123I, and placed on the collimator surface with 8 cm of methyl-methacrylate interposed. Count densities were measured in ROIs drawn in each cell of the phantom, and normalised to the maximal ROI value in the image. The mean square error (MSE) was used to assess how well the ratios of count densities approximated the known activity ratios based on the dimensions of the cells of the phantom. For 99mTc, regardless of the collimator used, the count density ratios approximated the activity ratios fairly well (LEHR: MSE=0.008; ME: MSE=0.020). For 123I, count density ratios obtained with the LEHR were consistently higher than activity ratios (MSE=0. 235), whereas the differences between the measured and the theoretical values were less with the ME collimator (MSE=0.013). Contrast fidelity of the 123I images obtained with the LEHR collimator could be improved with Jaszczak scatter correction with k=1, but this led to unfavourable signal-to-noise ratios. For sequential 99mTc/123I studies with extended sources, ME is to be preferred because of its higher contrast accuracy. Spatial resolution is less for the ME than for the LEHR collimator (FWHM with scatter: LEHR/99mTc=6.9 mm, LEHR/123I=7.4 mm, ME/99mTc= 10.1 mm, ME/123I=11.1 mm), but remains similar for both tracers when the ME is used.

Gamma Cameras↗

Left ventricular ejection fraction from gated SPET myocardial perfusion studies: a method based on the radial distribution of count rate density across the myocardial wall.

Left ventricular ejection fraction (LVEF) can be derived from gated single-photon emission tomographic (SPET) myocardial perfusion studies using either manual or edge detection techniques. In the presence of severe perfusion defects, however, difficulties may be encountered. In this article a method based on the assumption that the average position of the myocardial wall can be localized by means of statistical analysis of the distribution count density, and not on edge detection, is used to measure LVEF. SPET myocardial perfusion images, gated in eight time bins, were recorded in 50 patients 60 min after the injection of 925 MBq technetium-99m tetrofosmin. Masking of non-myocardial structures and thresholding resulted in images in which only myocardial walls had significant non-zero values. The distance of the wall relative to the centre of the cavity was calculated in the three-dimentional space as the first moment of the count rate distribution along radii originating in the centre of the cavity. LVEF was calculated using, for each time bin, the sum of the cube of all distances as an estimate of the cavity volume. The method required minimal operator interventions and was successful in all patients, including those with severe perfusion defects. Intraobserver and interobserver variability was excellent, with regression coefficients of 0.97 and standard deviations of 4.5% and 4.7%, respectively. For 30 patients, the measurements were validated against planar equilibrium radionuclide angiography (ERNA) that was obtained within an interval of 1 week. LVEF ranged from 12% to 88%. Agreement between the two methods was excellent (LVEFERNA=1.05+0.92 LVEFGSPET, r=0.93, P=0.023, SEE=7.06). The Bland-Altman analysis did not show any apparent trend in the differences between ERNA and gated SPET over a wide range of ejection fractions. The standard deviation of the differences was 3. 1%. In addition no relationship was found between the two methods and the severity of perfusion defects. In conclusion, accurate measurements of LVEF are obtained from gated SPET perfusion images using a method based on statistical analysis of the count rate density. This method did not deteriorate even in the presence of severe perfusion defects and could therefore be used in following patients after myocardial infarction.

Aged↗

Technetium-99m hexamethylpropylene amine oxime single-photon emission tomography of regional cerebral blood flow in insulin-dependent diabetes.

The study was performed to investigate subclinical abnormalities in regional cerebral blood flow (rCBF) in patients with insulin-dependent diabetes mellitus (IDDM) and to correlate them with patients characteristics. After intravenous injection of technetium-99m hexamethylpropylene amine oxime (HMPAO), tracer uptake of the prefrontal, frontal and parieto-occipital zones was measured with a triple-head single-photon emission tomography (SPET) camera system in 35 IDDM patients outside an episode of hypoglycaemia. Tracer uptake values in 16 age- and sex-matched healthy volunteers served as reference values. Compared with healthy subjects, increased tracer uptake of both prefrontal regions and the left frontal region could be shown in diabetes. Tracer uptake was negatively correlated with the duration of diabetes in all investigated regions. In diabetic patients with a disease duration of more than 5 years (n=26), stepwise regression analysis revealed a significant positive correlation between their HbA1c levels and tracer uptake. Long-term diabetic patients with reduced (pre)frontal tracer uptake (n=8) had lower HbA1c levels than those without (8.4%+/-0.2% vs 9.3%+/-0.3%, P<0.05) and tended to have more frequently a history of hypoglycaemic coma (6/8 vs 6/18, P=0.06). It can be concluded that duration of diabetes contributes to subclinical changes in basal rCBF in IDDM as detected with HMPAO SPET of the brain. The positive correlation between the presence of regional hypoperfusion and lower HbA1c levels in long-term diabetic patients may be interpreted in the light of a presumed higher incidence of hypoglycaemia as metabolic control improves.

Adult↗

Comparison of 99m Tc HMPAO SPECT scan between chronic fatigue syndrome, major depression and healthy controls: an exploratory study of clinical correlates of regional cerebral blood flow.

An explorative analysis of the relationship between symptomatology and cerebral blood flow in the chronic fatigue syndrome (CFS) as assessed with 99mTc HMPAO SPECT scan reveals statistically significant positive correlations between frontal blood flow on the one hand and objectively and subjectively assessed cognitive impairment, self-rating of physical activity limitations and total score on Hamilton Depression Rating Scale on the other. A pathophysiological role of frontal blood flow in the cognitive impairment and physical activity limitations in CFS is hypothesized. A comparison of cerebral blood flow between CFS, major depression (MD) and healthy controls (HC) has been performed. A lower superofrontal perfusion index is demonstrated in MD as compared with both CFS and HC. There is neither a global nor a marked regional hypoperfusion in CFS compared with HC. Asymmetry (R > L) of tracer uptake at parietotemporal level is demonstrated in CFS as compared with MD.

Adult↗