Bone mineral density among premenopausal women with early breast cancer in a randomized trial of adjuvant endocrine therapy

PURPOSE

To examine the effects on bone mineral density of 2 years of treatment with a luteinizing hormone-releasing hormone (LHRH) agonist alone or in combination with tamoxifen or tamoxifen alone in premenopausal breast cancer.

PATIENTS AND METHODS

We recruited 89 women from two centers in Stockholm participating in a randomized multicenter trial of three different endocrine approaches in the adjuvant setting (Zoladex in Premenopausal Patients Trial). The women were assigned to receive the LHRH agonist goserelin with or without tamoxifen, tamoxifen alone, or no endocrine therapy. The treatment was given for 2 years. We measured total-body bone density before start of treatment and at 12, 24, and 36 months.

RESULTS

After 2 years of treatment, there was a significant loss of bone mineral density (mean change, -5%; P <.001) in the women receiving goserelin alone. The combined goserelin and tamoxifen treatment, as well as tamoxifen alone, resulted in a lesser but statistically significant decline in bone mineral density (mean change, -1.4%; P =.02; and -1.5%; P <.001). One year after cessation of treatment, the goserelin group alone showed a partial recovery from bone loss (mean change, 1.5%; P =.02).

CONCLUSION

Two years of ovarian ablation from goserelin treatment caused a significant reduction in bone mineral density but there was a partial recovery from the bone loss 1 year after cessation of treatment. The addition of tamoxifen seems to partially counteract the demineralizing effects of goserelin.

Peripheral administration of GLP-2 to humans has no effect on gastric emptying or satiety

Glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) are secreted in parallel to the circulation after a meal. Intravenous (IV) GLP-1 has an inhibitory effect on gastric emptying, hunger and food intake in man. In rodents, central administration of GLP-2 increases satiety similar to GLP-1. The aim of the present study was to assess the effect of IV administered GLP-2 on gastric emptying and feelings of hunger in human volunteers. In eight (five men) healthy subjects (age 31.1+/-2.9 years and BMI 24.1+/-1.0 kg m(-2)), scintigraphic solid gastric emptying, hunger ratings (VAS) and plasma concentrations of GLP-2 were studied during infusion of saline or GLP-2 (0.75 and 2.25 pmol kg(-1) min(-1)) for a total of 180 min. Concentrations of GLP-2 were elevated to a maximum of 50 and 110 pmol l(-1) for 0.75 and 2.25 pmol kg(-1) min(-1) infusion of GLP-2, respectively. There was no effect of GLP-2 on either the lag phase (29.5+/-4.4, 26.0+/-5.2 and 21.2+/-3.6 min for saline, GLP-2 0.75 or 2.25 pmol kg(-1) min(-1), respectively) or the half emptying time (84.5+/-6.1, 89.5+/-17.8 and 85.0+/-7.0 min for saline, GLP-2 0.75 or 2.25 pmol kg(-1) min(-1), respectively). The change in hunger rating after the meal to 180 min was also unaffected by infusion of GLP-2. GLP-2 does not seem to mediate the ileal brake mechanism.

Sentinel node scintigraphy in breast cancer using a dual tracer technique

AIM

In order to depict the anatomy and improve the localization, sentinel node scintigraphy in breast cancer was combined with intravenous administration of pertechnetate. As this may reduce the detectability of weak 'hot spots', the number of lymph nodes detected at scintigraphy and at surgery in one group of patients was compared with that obtained in another group that had not received pertechnetate.

PATIENTS AND METHODS

The number of 'hot spots' at frontal and lateral views in 47 female patients at scintigraphy performed 2-3 h after subcutaneous injection of radiocolloid together with 25 MBq pertechnetate i.v. was compared in retrospect with that of 41 female patients who had not received pertechnetate. The number of lymph nodes detected at surgery using a hand-held gamma probe together with blue dye in the two groups was also compared. The washout kinetics of pertechnetate was studied in 10 patients.

RESULTS

There was no difference in the number of detected lymph nodes at any comparison. The kinetics study revealed a decreasing activity with time after correction for physical decay.

CONCLUSION

Administration of a 25 MBq pertechnetate i.v. in order to improve the anatomical localization at sentinel node scintigraphy in breast cancer does not reduce the detectability of radioactive lymph nodes.

Regulation of regional lung perfusion by nitric oxide

Improved oxygenation has previously been shown in patients with acute lung injury when ventilated in prone position. We hypothesized that this was due to higher regional production of nitric oxide in dorsocaudal lung regions. We measured nitric oxide synthase mRNA expression and nitric oxide production by citrulline assay in ventral and dorsal lung tissue from patients. In volunteers, regional lung perfusion in prone and supine postures was assessed by single photon emission computed tomography using (99m)Tc macroaggregated albumin before and after inhibition of nitric oxide synthase by N(G)-monomethyl-L-arginine infusion. Nitric oxide synthase mRNA expression and nitric oxide production were significantly higher in dorsal compared with ventral lung regions. In supine posture, lung perfusion was shifted to ventral parts during nitric oxide synthase inhibition, whereas in the prone posture lung perfusion remained unchanged. Our results suggest a role for endogenous nitric oxide in regulation of regional pulmonary perfusion.

Blood Pool Scintigraphy of the Skull in Relation to Head-Down Tilt Provocation in Patients With Chronic Tension-Type Headache and Controls

OBJECTIVE

To investigate the mechanisms behind the increase of chronic tension-type headache during head-down tilt.

BACKGROUND

The pathophysiology of chronic tension-type headache is unknown.

DESIGN AND METHODS

Ten patients suffering from chronic tension-type headache and 10 age- and sex-matched controls were studied with respect to pain intensity and alterations in cranial blood volume using planar scintigraphy and radiolabeled autologous erythrocytes before, during, and after head-down tilt, a procedure known to increase chronic tension-type headache.

RESULTS

Four of 8 patients with chronic tension-type headache studied had increased cerebrospinal fluid pressure. During head-down tilt, the pain increased significantly in the group with chronic tension-type headache (P <.001) while the procedure did not cause headache in the controls. Blood volume significantly increased extracranially and decreased intracranially in both groups during head-down tilt. The extracranial nasal blood volume was significantly related to the pain experienced by the patients with chronic tension-type headache before and during head-down tilt.

CONCLUSIONS

Although the changes in blood volume and, presumably, the increase of intracranial pressure were similar in the patients with chronic tension-type headache and the controls, only the patients experienced pain and pain increase during head-down tilt. This indicates that the pre-head-down tilt conditions must be different in the 2 groups and should be related to increased cerebrospinal fluid pressure/intracranial venous pressure in patients with chronic tension-type headache compared with controls. A difference in central mechanisms may, however, also be of importance for the difference in headache provocation in the 2 groups during head-down tilt.

Principal component and volume of interest analyses in depressed patients imaged by 99mTc-HMPAO SPET: a methodological comparison

Previous regional cerebral blood flow (rCBF) studies on patients with unipolar major depressive disorder (MDD) have analysed clusters of voxels or single regions and yielded conflicting results, showing either higher or lower rCBF in MDD as compared to normal controls (CTR). The aim of this study was to assess rCBF distribution changes in 68 MDD patients, investigating the data set with both volume of interest (VOI) analysis and principal component analysis (PCA). The rCBF distribution in 68 MDD and 66 CTR, at rest, was compared. Technetium-99m d, l-hexamethylpropylene amine oxime single-photon emission tomography was performed and the uptake in 27 VOIs, bilaterally, was assessed using a standardising brain atlas. Data were then grouped into factors by means of PCA performed on rCBF of all 134 subjects and based on all 54 VOIs. VOI analysis showed a significant group x VOI x hemisphere interaction ( P<0.001). rCBF in eight VOIs (in the prefrontal, temporal, occipital and central structures) differed significantly between groups at the P<0.05 level. PCA identified 11 anatomo-functional regions that interacted with groups ( P<0.001). As compared to CTR, MDD rCBF was relatively higher in right associative temporo-parietal-occipital cortex ( P<0.01) and bilaterally in prefrontal ( P<0.005) and frontal cortex ( P<0.025), anterior temporal cortex and central structures ( P<0.05 and P<0.001 respectively). Higher rCBF in a selected group of MDD as compared to CTR at rest was found using PCA in five clusters of regions sharing close anatomical and functional relationships. At the single VOI level, all eight regions showing group differences were included in such clusters. PCA is a data-driven method for recasting VOIs to be used for group evaluation and comparison. The appearance of significant differences absent at the VOI level emphasises the value of analysing the relationships among brain regions for the investigation of psychiatric disease.

Physiological evaluation of a new quantitative SPECT method measuring regional ventilation and perfusion

We have developed a new quantitative single-photon-emission computed tomography (SPECT) method that uses (113m)In-labeled albumin macroaggregates and Technegas ((99m)Tc) to estimate the distributions of regional ventilation and perfusion for the whole lung. The multiple inert-gas elimination technique (MIGET) and whole lung respiratory gas exchange were used as physiological evaluations of the SPECT method. Regional ventilation and perfusion were estimated by SPECT in nine healthy volunteers during awake, spontaneous breathing. Radiotracers were administered with subjects sitting upright, and SPECT images were acquired with subjects supine. Whole lung gas exchange of MIGET gases and arterial Po(2) and Pco(2) gases was predicted from estimates of regional ventilation and perfusion. We found a good agreement between measured and SPECT-predicted exchange of MIGET and respiratory gases. Correlations (r(2)) between SPECT-predicted and measured inert-gas excretions and retentions were 0.99. The method offers a new tool for measuring regional ventilation and perfusion in humans.

A new approach for improving diagnostic accuracy in Alzheimer?s disease and frontal lobe dementia utilising the intrinsic properties of the SPET dataset

Alzheimer's disease (AD) and frontal lobe dementia (FLD) show characteristic patterns of regional cerebral blood flow (rCBF). However, these patterns may overlap with those observed in the aging brain in elderly normal individuals. The aim of this study was to develop a new method for better classification and recognition of AD and FLD cases as compared with normal controls. Forty-six patients with AD, 7 patients with FLD and 34 normal controls (CTR) were included in the study. rCBF was assessed by technetium-99m hexamethylpropylene amine oxime and a three-headed single-photon emission tomography (SPET) camera. A brain atlas was used to define volumes of interest (VOIs) corresponding to the brain lobes. In addition to conventional image processing methods, based on count density/voxel, the new approach also analysed other intrinsic properties of the data by means of gradient computation steps. Hereby, five factors were assessed and tested separately: the mean count density/voxel and its histogram, the mean gradient and its histogram, and the gradient angle co-occurrence matrix. A feature vector concatenating single features was also created and tested. Preliminary feature discrimination was performed using a two-sided t-test and a K-means clustering was then used to classify the image sets into categories. Finally, five-dimensional co-occurrence matrices combining the different intrinsic properties were computed for each VOI, and their ability to recognise the group to which each individual scan belonged was investigated. For correct classification of the AD-CTR groups, the gradient histogram in the parieto-temporal lobes was the most useful single feature (accuracy 91%). FLD and CTR were better classified by the count density/voxel histogram (frontal and occipital lobes) and by the mean gradient (frontal, temporal and parietal lobes, accuracy 98%). For AD and FLD the count density/voxel histogram in the frontal, parietal and occipital lobes classified the groups with the highest accuracy (85%). The concatenated joint feature correctly classified 96% of the AD-CTR, 98% of the FLD-CTR and 94% of the AD-FLD cases. 5D co-occurrence matrices correctly recognised 98% of the AD-CTR cases, 100% of the FLD-CTR cases and 98% of the AD-FLD cases. The proposed approach classified and diagnosed AD and FLD patients with higher accuracy than conventional analytical methods used for rCBF-SPET. This was achieved by extracting from the SPET data the intrinsic information content in each of the selected VOIs.

Visualisation of the normal adrenals at SPET examination with 111In-pentetreotide

On single-photon emission tomography (SPET) examinations with indium-111 pentetreotide, we have often observed a small "hot" spot close to the upper portion of the left kidney. While it was initially believed that this represented a tumour in the tail of the pancreas or in the left adrenal, we now understand that it represents normal adrenal uptake. Since the adrenals have not been described as normally visualised, this uptake may interfere with the interpretation of the examination. We have studied how often the normal adrenals are visualised at such examinations. One hundred consecutive clinical (111)In-pentetreotide examinations in adults including SPET of the abdomen and with normal findings were studied. All examinations with a hot spot attributable to the adrenals were, when available, compared with computed tomography (CT) or magnetic resonance imaging (MRI) of the abdomen performed on clinical grounds within 3 months before or at any time after the scintigraphy. In 11 patients both adrenals were visualised. In 27 patients only the left and in one only the right adrenal was visualised. CT or MRI examinations were available for comparison in 25 of these 39 patients. Two of these showed a pathological finding in the left adrenal. A conservative interpretation is that the normal adrenal is visualised on one or both sides in at least one-quarter of adults at SPET examination with (111)In-pentetreotide.

Early assessment of neoadjuvant chemotherapy by FEC-courses of locally advanced breast cancer using 99mTc-MIBI

PURPOSE

Response assessment at neoadjuvant (preoperative) chemotherapy of locally advanced breast cancer using clinical examination and mammography is insensitive. Mammoscintigraphy with 99mTc-MIBI was studied for the prediction of response at such therapy before finishing the chemotherapy cycles.

MATERIAL AND METHODS

Chemotherapy was given as repeated courses of 5-fluorouracil, epirubicin and cyclophosphamide (FEC). In 1 patient group (n = 23), the tumor uptake relative to surrounding breast tissue and lung tissue at SPECT examination after finishing neoadjuvant chemotherapy was compared with the examination made before chemotherapy. In another group (n = 30), a similar comparison after the first therapy cycle (mean 19 days) with a baseline examination was made. Histologic examination of the resected tumors was made.

RESULTS

After finishing chemotherapy, there was a strong reduction of the relative tumor activity, while there was no correlation with therapy effect as assessed by histology. After one therapy course, there was no significant reduction of the relative tumor uptake.

CONCLUSION

Scintigraphy with 99mTc-MIBI demonstrated the response after finished neoadjuvant chemotherapy of breast cancer using FEC-courses. It cannot be used to predict a therapy response after one therapy course.

Growth hormone treatment improves body composition in adults with Prader-Willi syndrome

OBJECTIVE

Low growth hormone (GH) secretion and hypogonadism are common in patients with Prader-Willi syndrome (PWS). In this study we present the effects of GH treatment on body composition and metabolism in adults with PWS.

PATIENTS AND MEASUREMENTS

Nineteen patients with clinical PWS were recruited, 13 had PWS genotype. They were randomised to treatment with placebo or GH (Genotropin, Pharmacia Corporation, Sweden) 0.8 IU (0.2 mg) daily for 1 month and then 1.6 IU (0.5 mg) daily for 5 months. Thereafter patients received open label treatment so that all had 12 months of active GH treatment. Doses were individually titrated to keep serum IGF-I within the normal range for age. Body composition using dual energy X-ray absorptiometry (DXA), metabolic and endocrinological parameters, including oral glucose tolerance test (OGTT), were studied every 6 months. Seventeen patients, nine men and eight women, 17-32 years of age, with a mean body mass index (BMI) of 35 +/- 3.2 kg/m2 completed the study.

RESULTS

Compared to placebo, GH treatment increased IGF-I (P < 0.01) levels and decreased body fat (P = 0.04). When all patients recieved GH treatment a mean reduction in body fat of 2.5% (P < 0.01) concomitant with a mean increase in lean body mass of 2.2 kg (P < 0.05) was seen. Significant changes in body composition were only seen in the patients with the PWS genotype. Lipid profiles were normal in most patients before treatment and did not change. OGTT was impaired in five patients at 12 months, but two of these patients increased in fat mass. Insulin levels were unchanged. According to homeostasis model assessment (HOMA), insulin resistance did not change. Side-effects attributed to water retention occurred in three patients, one of whom had to be given increased diuretic therapy.

CONCLUSION

This study shows beneficial effects of GH treatment on body composition in adult PWS patients without significant side-effects. Consequently, further studies are encouraged.

Alterations of rCBF and mitochondrial dysfunction in major depressive disorder: a case report

OBJECTIVE

A mitochondrial disease might be considered when depressive disorder is associated with diabetes mellitus or other symptoms commonly found in mitochondrial disease. Scattered regional cerebral blood flow (rCBF) decreases and increases have been reported in depressive and mitochondrial disorders. A 61-year-old male patient with early adult onset of depressive disorder and a slowly developing multiorgan syndrome including diabetes mellitus was investigated.

METHOD

99mTc-HMPAO rCBF SPECT and muscle biopsy to assess mitochondrial functions were performed in the patient.

RESULTS

Alterations of rCBF were found in the patient, with the most pronounced decreases in the left dorsolateral frontal and inferior parietal lobes, and the most pronounced increases in the bilateral superior parietal lobes. Muscle biopsy revealed myopathy and decrease of mitochondrial adenosine triphosphate production rates (MAPRs).

CONCLUSION

The MAPRs decreases support the suspicion of mitochondrial dysfunction in the patient. A subgroup of depressed patients may have mitochondrial dysfunctions.

No effect of drains on the postoperative hematoma volume in hip replacement surgery: a randomized study using scintigraphy

In a prospective randomized study we used erythrocyte scintigraphy to evaluate whether drainage reduced the hematoma volume after total hip arthroplasty. 12 patients were left without drains and 10 patients had two drains inserted, one below the fascia and one subcutaneously. We used tomographic registration (SPECT) to calculate the volume of the hematoma (erythrocytes) about 22 hours after surgery and found that drainage did not reduce the volume, but increased the need for blood transfusion.

Metabolic profile and body composition in adults with Prader-Willi syndrome and severe obesity

Previous investigations of adults with the Prader-Willi syndrome (PWS) are few and have demonstrated severe obesity with increased morbidity and mortality in cardiovascular disease. It is, thus, important to identify risk factors and, if possible, start prevention. We studied the clinical, genetic, endocrinological, and metabolic findings in 19 adult PWS patients (10 men; mean age, 25 yr). The PWS karyotype was demonstrated in 13 patients. The mean body mass index was 35.6 kg/m(2), and total body fat was increased. Two thirds were biochemically hypogonadal. Fifty percent had severe GH deficiency (GHD). Four were hypertensive. One patient had heart failure and diabetes. Impaired glucose tolerance was seen in 4 patients, elevated homeostasis model assessment index in 9 patients, and modest dyslipidemia in 7. IGF-binding protein-1 correlated negatively with insulin levels. Four patients had osteoporosis, and 11 had osteopenia. There was no significant difference between the group with the PWS karyotype and the group without the karyotype in age, body mass index, waist/hip ratio, percent body fat, insulin values, homeostasis model assessment index, or lipid profile, except for lipoprotein(a), which was significantly higher in the group with the negative karyotype. IGF-I and lumbar spine bone mineral density were significantly lower in patients with genetic alteration, indicating a more severe GHD. The risk factors found in this study predicting cardiovascular disease are interpreted as secondary to GHD. These findings point to the importance of evaluating treatment of GHD in adults with PWS.

Gastric emptying and duodeno-gastro-oesophageal reflux in gastro-oesophageal reflux disease

BACKGROUND

Previous studies present conflicting results regarding relationship between gastric emptying and gastro-oesophageal reflux disease. Reflux of duodenal content to oesophagus is generally considered to be associated with more severe disease.

AIM

To assess presence of a gastric emptying disorder in persons with reflux of duodenal contents to oesophagus and to identify any correlation with gastric emptying and oesophageal motility.

METHODOLOGY

A total of 15 subjects with (B+) and 15 subjects without (B-) bile reflux to oesophagus determined by 24-hour bilirubin monitoring were studied with scintigraphic solid gastric emptying and 24-hour oesophageal manometry.

RESULTS

There was no difference in lag phase [median 23.7 (range 10.8-44.0) vs 24.6 (8.1-40.1) min], half emptying time [74.6 (48.0-93.6) vs 82.8 (54.4-153.9) min] or emptying rate [0.89 (0.59-1.34) vs 0.83 (0.36-1. 15)%/min] for B- and B+ subjects, respectively. In addition, there was no difference in emptying rate of gastric fundus between B- and B+ subjects. Subjects with bile reflux had less effective oesophageal contractions of oesophageal body [9.4(3.3-37)%] compared to subjects without bile reflux [32(19-47)%, p = 0.002]. However, there was no correlation between oesophageal motility and gastric emptying.

CONCLUSION

Results suggest that a gastric emptying disorder is a less likely contributing cause of bile reflux to the oesophagus, but bile reflux is associated with less effective oesophageal motility.

A novel quantitative dual-isotope method for simultaneous ventilation and perfusion lung SPET

A quantitative dual-isotope single-photon emission tomography (SPET) technique for the assessment of lung ventilation (V) and perfusion (Q) using, respectively, technetium-99m labelled Technegas (140 keV) and indium-113m labelled macro-aggregated albumin (392 keV), is presented, validated and clinically tested in a healthy volunteer. In order to assess V, Q and V/Q distributions in quantitative terms, algorithms which correct for down scattering, photon scattering and attenuation, as well as an organ outline algorithm, were implemented. Scatter and down-scatter correction were made in the spatial domain by pixel-wise image subtraction of projection-dependent global scattering factors obtained from the energy domain. The attenuation correction was based on an iterative projection/back-projection method. All studies were made on a three-headed SPET system (Trionix) with medium-energy parallel-hole collimators. The set of input data for quantification was based on SPET acquisition of emission data in four separate energy windows, the associated cumulative energy spectra and transmission data. The attenuation correction routine as well as the edge detection algorithm utilized data from (99m)Tc transmission tomography. Attenuation data for (113m)In were obtained by linear scaling of the (99m)Tc attenuation maps. The correction algorithms were experimentally validated with a stack phantom system and applied on a healthy volunteer. The mean difference between the corrected SPET data of the dense stack lung phantom and those obtained from the corresponding scatter- and attenuation-"free" version was only 1.9% for (99m)Tc and 0.9% for (113m)In. The estimated fractional V/Q distribution in the 3-D lung phantom volume had its peak at V/Q=1, with a width (FWHM) of 0.31 due to noise, particularly in the (113m)In images, and to partial volume effects. For a healthy volunteer, the corresponding values were 0.9 and 0.35, respectively. This method allows accurate assessment of radionuclide distribution on a regional basis. For basic lung physiology and clinical practice, the method allows assessment of the global frequency functions of the V, Q and V/Q distributions.

Differences in resting state regional cerebral blood flow assessed with 99mTc-HMPAO SPECT and brain atlas matching between depressed patients with and without tinnitus

An increased occurrence of major depressive disorder has been reported in tinnitus patients, and of tinnitus in depressive patients. Involvement of several Brodmann areas (BAs) has been reported in tinnitus perception. The aim of this study was to assess the regional cerebral blood flow (rCBF) changes in depressed patients with and without tinnitus. The rCBF distribution at rest was compared among 45 patients with a lifetime prevalence of major depressive disorder, of whom 27 had severe tinnitus, and 26 normal healthy subjects. 99mTc-hexamethylenepropylene amine oxime (99mTc-HMPAO) single photon emission computed tomography (SPECT), using a three-headed gamma camera, was performed and the uptake in 34 functional sub-volumes of the brain bilaterally was assessed by a computerized brain atlas. Decreased rCBF in right frontal lobe BA 45 (P<0.05), the left parietal lobe BA 39 (P<0.00) and the left visual association cortex BA 18 (P<0.05) was found in tinnitus patients compared with non-tinnitus patients. The proportion of tinnitus patients with pronounced rCBF alterations in one or more of the temporal lobe BAs 41+21+22 was increased compared to gender matched controls (P<0.00) and patients without tinnitus (P<0.05). Positive correlations were found between trait anxiety scales from the Karolinska Scales of Personality and rCBF in tinnitus patients only in three limbic BAs (P<0.01), and inverse correlations in non-tinnitus patients only in five BAs subserving auditory perception and processing (P<0.05). rCBF differences between healthy controls and depressed patients with and without tinnitus were found in this study. The rCBF alterations were distributed in the cortex and were particularly specific in the auditory cortex. These findings suggest that taking audiological symptoms into account may yield more consistent results between rCBF studies of depression.

[Scintigraphic assessment of the small intestine transit. Diagnostic investigation of dysmotility with 99mTc-HIDA]

Symptoms from the gastro-intestinal tract are common and often difficult to evaluate. Specialised examination techniques are available only at a limited number of clinics. A technique based on biliary scintigraphy when measuring the transit of contents through the small intestine has been developed. The investigation is simple to perform and convenient for the patient. It can be carried out at any clinic equipped with a gamma camera. 30 healthy individuals were examined in order to obtain reference values. 23 patients were examined with scintigraphy in combination with upper gastrointestinal manometry, 10 of whom had abdominal pain and neurogenic or myogenic pseudoobstruction disclosed by manometry. In another 4 patients, slow transit and pain prevailed in conjunction with normal manometric findings. Rapid transit and diarrhoea was found in 3 patients with various abberations on manometry. Of the remaining patients, 4 had slow transit and diarrhoea with intestinal neuropathy and pseudoobstruction, and 2 had slow transit along with endocrinopathies (diabetes, pituitary insufficiency).

Scintigraphy of the small intestine: a simplified standard for study of transit with reference to normal values

Evaluation of small bowel transit, which should preferably be performed using non-invasive techniques, is complex owing to the anatomical position of the small bowel. In order to avoid any influence of the gastric emptying rate on scintigraphic results, we have used (99m)Tc-HIDA, an intravenous tracer that is excreted in bile and thereby delivered directly into the duodenum. Thirty healthy subjects were studied after an overnight fast. Immediately after administration of 120 MBq (99m)Tc-HIDA, dynamic 1-min image acquisitions were begun. The duodenum and caecum were easily identified on the digitised images. Small bowel transit time was determined from the difference in the arrival times of the radiopharmaceutical in the proximal duodenum and caecum, as assessed by evaluation of the count rate against background activity (Scint 1) and by the visual appearance of activity (Scint 2). Hydrogen breath test was performed simultaneously to evaluate scintigraphic transit. Scintigraphic transit tests were also performed in 23 patients with motility disorders who had undergone manometry of the small bowel. In healthy subjects, the transit time of (99m)Tc-HIDA was 77.9+/-31.1 min (Scint 1) or 79.3+/-30.9 min (Scint 2) and the lactulose transit time was 100.1+/-43.4 min. Seventeen of the 23 patients had a dysmotility pattern verified by manometry, and in 14 of these patients, (99m)Tc-HIDA transit was prolonged. (99m)Tc-HIDA small bowel transit is a readily available method for the detection of transit abnormalities in the clinical setting. The method is clinically feasible and the transit time of (99m)Tc-HIDA shows a good correlation with results of the hydrogen breath test (lactulose transit time) in healthy volunteers.

Regional cerebral blood flow as assessed by principal component analysis and (99m)Tc-HMPAO SPET in healthy subjects at rest: normal distribution and effect of age and gender

The increasing implementation of standardisation techniques in brain research and clinical diagnosis has highlighted the importance of reliable baseline data from normal control subjects for inter-subject analysis. In this context, knowledge of the regional cerebral blood flow (rCBF) distribution in normal ageing is a factor of the utmost importance. In the present study, rCBF was investigated in 50 healthy volunteers (25 men, 25 women), aged 31-78 years, who were examined at rest by means of single-photon emission tomography (SPET) using technetium-99m d, l-hexamethylpropylene amine oxime (HMPAO). After normalising the CBF data, 27 left and 27 right volumes of interest (VOIs) were selected and automatically outlined by standardisation software (computerised brain atlas). The heavy load of flow data thus obtained was reduced in number and grouped in factors by means of principal component analysis (PCA). PCA extracted 12 components explaining 81% of the variance and including the vast majority of cortical and subcortical regions. Analysis of variance and regression analyses were performed for rCBF, age and gender before PCA was applied and subsequently for each single extracted factor. There was a significantly higher CBF on the right side than on the left side ( P<0.001). In the overall analysis, a significant decrease was found in CBF ( P=0.05) with increasing age, and this decrease was particularly evident in the left hemisphere ( P=0.006). When gender was specifically analysed, CBF was found to decrease significantly with increasing age in females ( P=0.037) but not in males. Furthermore, a significant decrease in rCBF with increasing age was found in the brain vertex ( P=0.05), left frontotemporal cortex ( P=0.012) and temporocingulate cortex ( P=0.003). By contrast, relative rCBF in central structures increased with age ( P=0.001). The ability of standardisation software and PCA to identify functionally connected brain regions might contribute to a better understanding of the relationships between rCBF at rest, anatomically defined brain structures, ageing and gender.

Localization of sentinel nodes in head and neck tumours by combined lymphoscintigraphy and bone scintigraphy

Sentinel node scintigraphy in tumours of the head and neck region was combined with bone scintigraphy to provide anatomical landmarks in order to better locate the lymph node uptake. 99Tc(m)-nanocolloid (40 MBq) was injected in the peritumour region 1 h after the administration of bone-seeking 99Tc(m)-methylene diphosphonate (200 MBq). After 5 min, A-P and lateral projections of the head and neck region were acquired. In all the 26 patients examined, the surrounding anatomy was clearly depicted. In 23 patients, the lymphatic drainage was identified within 30 min. In these patients, all hot spots appearing outside the deposited activity could be located according to the neck region classification system of the Memorial Sloan-Kettering Hospital. No lymphatic drainage was visualized in the remaining three patients. The injection of bone-seeking activity 1 h before deposition of the radiocolloid provided images visualizing soft tissues as well as skeletal structures, thus improving the topical diagnosis. Correlation with the results of surgery was not performed. The administration of a small amount of bone-seeking activity prior to sentinel node scintigraphy of head and neck tumours improves the anatomical localization of the lymph node activity.

Rectal nitric oxide assessment in children with Crohn disease and ulcerative colitis. Indicator of ileocaecal and colorectal affection

BACKGROUND

Nitric oxide (NO) production is increased in inflammatory bowel disease (IBD). Measurements of luminal NO in Crohn disease and ulcerative colitis have revealed that levels are increased during active disease. We aim to evaluate whether rectal measurements of NO can reveal active disease of the colon as well as ileum.

METHODS

Sixteen children with active Crohn disease in the ileocaecal or colorectal regions of the gut and 6 children with active ulcerative colitis were compared to a group of 14 healthy children. Gaseous samples for analysis of luminal NO were collected using a Foley catheter inserted into rectum. The balloon of the catheter was filled with NO-free air and incubated for 10 min. After aspiration, samples were analysed using chemiluminescence. Values are expressed as median and range.

RESULTS

In healthy children, rectal NO values were 60 (0-275) ppb. In children with Crohn disease of the colorectal region, NO concentrations were 5,675 (300-49,350) ppb (P < 0.001), while those with Crohn disease of the ileocaecal region had NO levels of 2,625 (300-15,000) ppb (P < 0.01). In children with ulcerative colitis, NO values of 5,500 (950-34,000) ppb were found (P < 0.001).

CONCLUSION

Rectal NO levels are greatly increased in children with IBD. Highest values were found in patients with colorectal engagement, but rectal NO was increased also in ileocaecal disease. Rectal sampling of luminal NO is a simple and minimally invasive method and should be considered a diagnostic tool for intestinal inflammatory activity in children regardless of primary disease location.

Severe oral mucositis after therapeutic administration of [131I]MIBG in a child with neuroblastoma

OBJECTIVE

The purpose of this report is to document a newly encountered oral side effect of targeted radiotherapy with iodine 131-metaiodobenzylguanidine ([(131)I]MIBG) in the treatment of neuroblastoma.

STUDY DESIGN

A 14-month-old girl was diagnosed with stage 4 neuroblastoma. After completion of chemotherapy, the tumor showed no signs of regression; treatment with 3700 MBq [(131)I]MIBG was therefore decided on, 8 months after diagnosis.

RESULTS

Fourteen days after infusion of MIBG, severe oral mucositis was diagnosed, with a generalized erythema involving the mucous membranes of the hard and soft palate, buccal mucosa, and upper and lower lips. The gingiva exhibited a general linear erythema.

CONCLUSIONS

Visualization of the salivary glands on [(123)I]MIBG images suggests that accumulation of radiolabeled MIBG in the salivary glands may be related to sympathetic innervation.

Mapping pathological (99m)Tc-d,l-hexamethylpropylene amine oxime uptake in Alzheimer's disease and frontal lobe dementia with SPECT

Seventeen patients with probable Alzheimer's disease (AD), 7 patients with frontal lobe dementia (FLD) and 19 control subjects (NOR) were examined by (99m)Tc-d,l- hexamethylpropylene amine oxime ((99m)Tc-HMPAO) SPECT. Images were standardised in the same 3D space and averaged within each group. After normalisation, the three sets of images were analysed in all cerebral lobes, hippocampus, thalamus and basal ganglia. In AD, the (99m)Tc-HMPAO uptake values were significantly reduced, as compared to NOR, in the parietal, temporal and insular lobes. In patients with FLD, the uptake was altered in all lobes with the exception of the parietal lobe. The uptake in the nucleus caudatus decreased significantly in both AD and FLD as compared to NOR. The uptake in the anterior cingulate cortex was significantly reduced in FLD. Subtraction images highlighted all significantly decreased areas. In conclusion, standardising SPECT in a common space and subtracting data from a control group improves the visual interpretation of images. In this study, the typical temporo-parietal and fronto-parietal (99m)Tc-HMPAO uptake reductions were found in AD and FLD, respectively. The uptake in the nucleus caudatus was found to decrease significantly in AD and FLD and the one in the anterior cingulate cortex was reduced in FLD.

High continuous positive airway pressure level induces ventilation/perfusion mismatch in the prone position

OBJECTIVE

Gas exchange in patients with adult respiratory distress syndrome is influenced by posture. The combined effect of continuous positive airway pressure and posture has not been investigated. We studied the effect of normal spontaneous breathing, and that of continuous positive airway pressure, on ventilation/perfusion distributions in healthy volunteers while they were in supine and prone positions.

SETTING

Nuclear medicine department in a university hospital.

DESIGN

Experimental study.

SUBJECTS

Sixteen healthy volunteers.

INTERVENTIONS

In the supine or prone position, the subjects inhaled a technetium-labeled aerosol (technetium-99m diethylenetriamine pentaacetic acid) through a tight-fitting mask. Single photon emission computed tomography images of the lungs were obtained. The subjects then received an intravenous injection of technetium-99m-labeled macroaggregates of albumin, and an identical single photon emission computed tomography imaging was performed. In the group that received continuous positive airway pressure, an end-expiratory pressure of 10 cm H2O was applied during both inhalation and injection.

MEASUREMENTS AND MAIN RESULTS

During spontaneous breathing, ventilation/perfusion distribution assessed by regression analysis was uniform (i.e., not significantly different from zero) both in supine and prone positions, with a slope of -1.5 +/- 3.5%/cm supine and 1.5 +/- 3.5%/cm prone. During continuous positive airway pressure breathing in the supine position, ventilation/perfusion had a slope of -3.4 +/- 2.4 compared with 8.3 +/- 1.1%/cm in the prone position according to analysis of spatial resolution.

CONCLUSION

There was a less favorable ventilation/perfusion ratio in the prone position when the subjects were exposed to continuous positive airway pressure of 10 cm H2O.

Specific or superfluous? Doubtful clinical value of granulocyte scintigraphy in osteomyelitis in children

To study the clinical usefulness of granulocyte scintigraphy, eight children with clinical, laboratory and/or radiologic findings strongly suggestive of osteomyelitis were prospectively evaluated. Comparison was made with bone scintigraphy and magnetic resonance imaging. In adults, granulocyte scintigraphy is highly infection specific, although nonspecific findings (i.e. photopenic lesions) may also occur. Granulocyte scintigraphy was positive in one patient, false-negative in two and demonstrated nonspecific photopenic lesions in five children (62%). In conclusion, there appears to be little place for granulocyte scintigraphy in routine investigation of suspected ostoemyelitis in children.

GLP-1 inhibits gastric emptying of water but does not influence plasma

BACKGROUND

Glucagon-like peptide-1 (GLP-1) has been shown to inhibit gastric emptying of a caloric load but the effect on a non-caloric load is unknown.

METHODS

Seven healthy men were studied after an over-night fast. Thirty min before the intake of 330 ml radioactively labeled water either GLP-1 (0.75 pmol/kg/min) or saline was administered intravenously and continued for 75 min. Scintigraphic gastric emptying was performed for 45 min and plasma samples were obtained for analysis of vasopressin, sodium, osmolality, GLP-1, insulin, and glucose. In addition, electric field stimulation of human gastric muscle strips was done.

RESULTS

The median (range) percent water retained in the stomach, 45 min after intake of water, was 96% (68%-98%) and 12% (2%-42%) (P = 0.02) during infusion of GLP-1 and saline, respectively. Additionally, GLP-1 did not affect basal tone or contractile response of gastric muscle strips to electric field stimulation or acetylcholine (ACh). There was no change in plasma concentrations of vasopressin, sodium, or plasma osmolality during GLP-1 compared to saline infusion.

CONCLUSION

GLP-1 has a profound inhibitory effect on the gastric emptying of water in man, but no short-term effect on water homeostasis. No effect was seen on contractility of gastric muscle strips suggesting an indirect action on gastric emptying.

Dynamic 99Tcm-HIDA SPET: non-invasive measuring of intrahepatic bile flow. Description of the method and a study in primary sclerosing cholangitis

In this study dynamic 99Tcm-HIDA single photon emission tomography (SPET) was performed in patients with primary sclerosing cholangitis and normal test subjects. The method offers the possibility of functional analysis of individual liver segments. After injection of 120 MBq of 99Tcm-HIDA, 12 consecutive SPET examinations were performed at 6-min intervals. The segmental borders of liver segments as seen on computed tomography or magnetic resonance examinations were superimposed on the scintigraphic images allowing placement of regions of interest (ROIs) in specific liver segments. Sampling from the same ROIs in consecutive SPET images enabled creation of time-activity curves for individual liver segments. A range of normal values was created by quantitative analysis of normal volunteer studies. Results of the studies in patients correlated well with cholangiographic extent of disease, liver function tests and histological stage. The technique may have particular value in diseases that affect the liver in a nonhomogenous or segmental fashion. Giving an indication of bile clearance from individual liver segments, it can quantify the functional importance of radiologically detected strictures. Percutaneous liver biopsy can be directed to the worst affected parts of the liver, making biopsy more representative. Sequential studies may allow monitoring of disease progression, aiding in selection and timing of therapeutic procedures.

Absence of somatostatin receptor expression in vivo is correlated to di- or tetraploid 1p36-deleted neuroblastomas

BACKGROUND

Poor prognosis in childhood neuroblastoma is associated with deletions of chromosome region 1p36 and di/tetraploid DNA content.

PROCEDURE

Forty-six patients with histopathologically proven neuroblastoma were investigated for in vivo expression of somatostatin receptors (SR) by 111In-pentetreotide scintigraphy. All tumors were analyzed for cytometric DNA content and chromosome 1p36 integrity.

RESULTS

SR expression was detected in 28 tumors (61%) and correlated with young age, localized clinical stage, and favorable outcome. Fourteen tumors showed deletion at chromosome 1p36, thirteen of which did not show SR expression (P< 0.001). A triploid DNA content was correlated with the presence of SR (23 of 25, P< 0.001). No tumor with deletion of chromosome 1p36 and di/tetra DNA content showed SR expression (chi2 = 29.88, d.o.f. = 2, P < 0.001).

CONCLUSIONS

We conclude that SR expression is related to genetic features of prognostic significance. This may be assessed with a minimally invasive scintigraphic method.

Combined (111)In-pentetreotide scintigraphy and (123)I-mIBG scintigraphy in neuroblastoma provides prognostic information

BACKGROUND

High-affinity somatostatin receptors (SRs) have been characterized in neuroblastomas and may be used as target structures for in vivo detection of SR.

PROCEDURE

Eighty-eight children with histologically proven neuroblastoma were investigated at diagnosis or relapse by (123)I-mIBG and (111)In-pentetreotide scintigraphy. All tumors were investigated for MYCN copy number, chromosome 1p36 status, and 68/88 also for DNA content, followed for a median follow-up of 35 months (range 1-88 months).

RESULTS

SR expression was detected in 56/88 tumors and (123)I-mIBG showed positivity in 83/88. (111)In-pentetreotide was less sensitive in detecting tumor tissue than was (123)I-mIBG (64% vs. 94%, P = 0.005). Survival (SUR) and event-free survival probability (EFS) according to Kaplan-Meier was significantly better for children with positive SR scintigraphy than for the children with a negative SR scan (SUR: 90% vs. 48% at 4 years log rank P < 0.003, EFS: 83% vs. 39% at 4 years, log rank P < 0.0002).

CONCLUSIONS

(123)I-mIBG scintigraphy remains the best scintigraphic method for detecting neuroblastoma tumor tissue, whereas additional SR scintigraphy is able to provide significant prognostic information with a minimum of invasiveness.

Detection of Langerhans cell histiocytosis lesions with somatostatin analogue scintigraphy--a preliminary report

BACKGROUND

Langerhans cell histiocytosis (LCH) is a disease where granulomatous lesions occur in various organs of the body. The etiology and pathogenesis remain unknown. Inflammatory destructive activity give rise to a wide range of clinical symptoms, including fractures, skin lesions, pulmonary fibrosis, endocrinopathies, and central nervous system deterioration. Since disease activity may ultimately lead to fibrosis and organ damage, it is important to have diagnostic tools to detect disease activity early.

PROCEDURE

The present study was undertaken in order to evaluate whether somatostatin analogue scintigraphy ((111)In-pentetreotide or OctreoScan could be used in detecting LCH granulomas and to compare this method with the radiologic methods used today in LCH diagnosis and follow-up. The somatostatin analogue octreotide used here binds to the cell membrane of activated lymphocytes expressing somatostatin receptors.

RESULTS

In five out of six children studied, LCH lesions detected by other means were also detected with (111)In-pentetreotide. It can be speculated that the lesion in the remaining patient was not active at the time of investigation. In addition, in two of the patients signs of disease activity not previously known were revealed.

CONCLUSION

(111)In-pentetreotide can be used to detect active LCH lesions. Since the biologically active somatostatin analogue decreases inflammatory activity, this may also be of therapeutic value in selected patients with LCH. More studies are needed to evaluate the diagnostic and potential therapeutic usefulness of this radionuclide.

Added value of CEA scintigraphy in the detection of recurrence of rectal carcinoma

PURPOSE

To explore the diagnostic value of immunoscintigraphy compared to CT and/or MR imaging in the diagnosis of local recurrence (LR) of rectal cancer.

MATERIAL AND METHODS

Forty-six patients suspected of having LR of rectal cancer were retrospectively studied. Carcinoembryonic antigen (CEA) scintigraphy findings were compared to CT and/or MR in all patients, and with data from surgery and morphology (31 patients), biopsy (7 cases) and follow-up (8 patients).

RESULTS

CEA scintigraphy was not complementary to CT and/or MR in the detection of LR. Two false-positive and 14 false-negative diagnoses of LR occurred with CEA scintigraphy. Distant metastases including metastatic lymph nodes were found by this method in only 7 of 27 patients with proven metastases. CT/MR were able to demonstrate these metastases in 21 of 27 patients.

CONCLUSION

Accuracy and sensitivity of CEA scintigraphy in the detection of LR and distant metastases is lower than that of CT and/or MR. However, CEA scintigraphy seems to have a high specificity and could therefore be used in patients with a strong clinical suspicion of LR but negative CT/MR investigations. Available diagnostic methods have limitations in differentiating between benign, post-treatment changes and LR of rectal cancer and in staging of malignant disease.

Routine bone scintigraphy is of limited value in the clinical assessment of untreated patients with Hodgkin's disease

The aim of this retrospective study was to evaluate the role of routinely performed bone scintigraphy in the clinical assessment of patients with previously untreated Hodgkin's disease (HD). One-hundred and eighty-three patients with a median age of 31 yrs (range 16-85) with newly diagnosed HD underwent bone scintigraphy between 1972 and 1995. Bone scintigraphies and skeletal X-ray examinations of patients with any pathological scintigraphic finding were reassessed. Initially HD bone involvement could be excluded in 173 (95%) of the patients. Among the remaining ten patients, two had diffuse increased tracer uptake but X-rays were normal. One of these patients was classified as normal with regard to HD bone involvement. A bone marrow scintigraphy examination and regression of changes following therapy supported primary osseous involvement in the other patient. Five patients had focal scintigraphic abnormalities but skeletal X-rays remained negative; three of these five patients reported pain in the scintigraphically affected areas, and therefore the suspicion of bone involvement was strong. The remaining three patients had focal findings both on bone scintigraphy and skeletal X-ray examination and were considered as having osseous HD involvement. All seven patients judged to have HD bone involvement were planned to receive combination chemotherapy up-front, irrespective of the scintigraphic findings. In this series of 183 patients bone involvement was detected in seven patients based on bone scintigraphy/symptoms (n=3), bone marrow scintigraphy/symptoms (n=1), and bone scintigraphy/X-ray examination (n=3). The decision to give multiagent chemotherapy to all patients was not influenced by scintigraphic findings. Therefore, routine bone scintigraphy seems to be of limited value in the clinical assessment of untreated patients with HD.

Nationwide standardisation and evaluation of scintigraphic gastric emptying: reference values and comparisons between subgroups in a multicentre trial

By means of a standardised procedure, reference values for scintigraphic gastric emptying were established. The influence of gender, age, menstrual cycle, body mass index (BMI) and smoking habits was also evaluated. Eight centres recruited 20 healthy subjects each. The meal consisted of a technetium-99m labelled omelet (1,300 kJ) and of 150 ml unlabelled soft drink. Geometric means of frontal and dorsal acquisitions were utilised in a linear fit model for determination of the linear emptying rate, and by using the intercepts of the regression line with the 90% and 50% levels, the lag phase and half-emptying time, respectively, were defined. All individuals showed an initial lag phase and subsequent linear emptying. Because of a longer lag phase and a slower linear emptying rate, premenopausal women had a slower gastric emptying than postmenopausal women and men of all ages. The gastric emptying rate increased with age in the women, mainly due to a shortened lag phase, while the emptying rate remained almost unchanged with age in the males. There were no significant differences in results between the centres. The menstrual cycle, BMI and smoking habits did not affect emptying. In conclusion, the fact that the results showed a slower gastric emptying rate in younger women compared with older women and men indicates that it is necessary to use separate reference values for fertile females.

[Examination of gastric emptying with gamma camera. Clinically useful, uniform method now established]

Although more than 30 years have passed since the introduction of scintigraphic testing of gastric emptying there has been no well-defined standard. Eight Swedish hospitals have established a nationally standardized method for scintigraphic testing of gastric emptying of solids. 160 healthy subjects participated. The meal consisted of a 99mTc-labeled omelet (1300 kJ) and 150 ml unlabeled soft drink (290 kJ). There were no differences in calculated variables between the centers. Premenopausal women showed slower emptying than postmenopausals and men of any age, making separate reference values for younger women necessary.

Gastric emptying: comparison of scintigraphic, polyethylene glycol dilution, and paracetamol tracer assessment techniques

BACKGROUND

The method of choice for studying gastric emptying is dependent on several factors. The aim of the present study was to assess the concordance between solid gastric emptying, using a scintigraphic technique as gold standard, and gastric emptying as measured with parcetamol tracer and polyethylene glycol (PEG) dilution.

METHODS

Two groups of seven male volunteers with similar ages and weights were studied, one for scintigraphic (310-kcal omelette with 12-15 MBq 99mTc-labeled macroaggregated albumin) and paracetamol (1.5 g dissolved in water and administered concomitantly with the omelette) and one for the marker dilution study (PEG 4000 dissolved in a 310-kcal meal).

RESULTS

The gastric half-emptying time (T50) was shorter in the PEG study than in the scintigraphic test (47.5 (37.5-62) versus 68.1 (43.6-89.4), median (range) (P < 0.05), respectively), whereas there was no significant difference between the T50 for gastric emptying as assessed with the scintigraphic and paracetamol tracer methods. No difference in gastric emptying rate using PEG dilution or paracetamol tracer was obtained.

CONCLUSIONS

In summary, this study shows that scintigraphic, paracetamol tracer, and PEG dilution methods can all be used to assess gastric emptying. The use of the paracetamol tracer technique offers a relatively inexpensive technique that yields a good approximation of gastric emptying as verified by the scintigraphic emptying of a solid meal.

Effects of acute hypobaric hypoxia on regional cerebral blood flow distribution: a single photon emission computed tomography study in humans

Single Photon Emission Computed Tomography (SPECT) and radiopharmaceutical stabilizing agents allowed us to investigate regional cerebral blood flow (CBF) distribution in six resting healthy subjects during acute laboratory hypobaric hypoxic conditions. In the hypobaric experiment stabilized 99mTc-D, L-hexamethyl-propylene amine oxime was injected 40 min after reaching hypoxic conditions corresponding to an altitude of 5500 m above sea level. Arterial blood sample was taken after five additional minutes. Mean arterial oxygen pressure and haemoglobin saturation were 28 mmHg and 56%, respectively. The control experiment was performed similarly, apart from barometric pressure and blood gas analysis. We analysed CBF distribution in 12 regions of functional interest bilaterally in frontal, parietal, temporal, occipital cortex, in the hippocampus, in the basal ganglia and other central structures of brain. No overall effect of hypoxia on normalized regional CBF distribution in the considered regions was found. Motor cortex (Brodmann 4) and basal ganglia were the only regions in which hypobaric hypoxia significantly increased relative distribution of the radiopharmaceutical [F(1,5)=18.30; P < 0.008 and F(1,5)=10.85; P < 0.022, respectively]. Despite severe hypoxia, we did not observe any major regional CBF redistribution. We found a small relative increase in blood flow to the motor cortex and the basal ganglia, at rest after 40 min of hypobaric hypoxia, suggesting a preferential compensatory mechanism of these functional regions of brain.

Diclofenac treatment prolongs renal transit time in acute ureteral obstruction: a renographic study

OBJECTIVE

Prostaglandin inhibitors, mostly diclofenac, are currently first-choice therapy for ureteral colic, their main action being reduction of intrapelvic pressure and diuresis. We hypothesized that diclofenac, by increasing tubular reabsorption, can delay excretion of contrast medium and give a false impression of severe obstruction.

METHODS

Gamma camera renography was performed with 50 MBq (99)Tc(m)-MAG3 before and with 150 MBq 30 min after intramuscular injection of 75 mg diclofenac in 10 patients with acute ureteral colic. The time to maximum isotope activity in each kidney, T(max), was compared with T(max) in 10 control patients, who did not receive diclofenac but underwent two identical renographies.

RESULTS

T(max) was significantly delayed after diclofenac, from 353 s at baseline to >1,200 s on the stone side, and from 225 to 465 s on the healthy side. Without diclofenac there was no T(max) retardation between the two renographies.

CONCLUSION

Diclofenac treatment can lead to overestimation in ureteral stone disease, by delaying renal excretion bilaterally, but predominantly on the side of calculus.

What is the message of a meeting? Analysis and comparison of the 2458 abstracts of the EANM/WCNMB congress in Berlin and the SNM meeting in Toronto in 1998. European Association of Nuclear Medicine/World Federation of Nuclear Medicine and Biology, and the Society of Nuclear Medicine

The abstracts of the joint congress of EANM/WCNMB in Berlin 1998 and of the 45th Annual Meeting of the Society of Nuclear Medicine in Toronto 1998 have been analysed and compared in terms of comprehensibility, composition, questions at issue, methods, patient/subject number, type of conclusion and duplication of information between the meetings. All 1362 and 1096 abstracts, respectively, were analysed from the abstract books with regard to ten "hard" and four "soft" variables. The dominant topics were new radiopharmaceuticals, methods of synthesis, examination methods, evaluation of examinations, investigation algorithms, technical devices and novel use of radiopharmaceuticals. In addition to these topics, there were numerous reports about established radiopharmaceuticals and techniques, often without a specific merit mentioned. There were also many abstracts with questions outside nuclear medicine, but using such techniques. Few papers reported negative findings or dealt with quality assurance, dosimetry, and cost-effectiveness. Many of the conclusions contained hyperbole. Some abstracts were very extensive and detailed. Sixty-seven contributions conveyed identical information at both meetings. Structured and/or paragraphed abstracts promote clarity and reduce the number of lines that need to be read in order to comprehend the background and aim of the abstract. Such contributions were more frequent at the EANM/WCNMB congress while the SNM meeting covered a wider field with a greater representation of radiophysics, instrumentation, and computer evaluations.

A novel phantom design for emission tomography enabling scatter- and attenuation-"free" single-photon emission tomography imaging

A newly designed technique for experimental single-photon emission tomography (SPET) and positron emission tomography (PET) data acquisition with minor disturbing effects from scatter and attenuation has been developed. In principle, the method is based on discrete sampling of the radioactivity distribution in 3D objects by means of equidistant 2D planes. The starting point is a set of digitised 2D sections representing the radioactivity distribution of the 3D object. Having a radioactivity-related grey scale, the 2D images are printed on paper sheets using radioactive ink. The radioactive sheets can be shaped to the outline of the object and stacked into a 3D structure with air or some arbitrary dense material in between. For this work, equidistantly spaced transverse images of a uniform cylindrical phantom and of the digitised Hoffman rCBF phantom were selected and printed out on paper sheets. The uniform radioactivity sheets were imaged on the surface of a low-energy ultra-high-resolution collimator (4 mm full-width at half-maximum) of a three-headed SPET camera. The reproducibility was 0.7% and the uniformity was 1.2%. Each rCBF sheet, containing between 8.3 and 80 MBq of 99mTcO4- depending on size, was first imaged on the collimator and then stacked into a 3D structure with constant 12 mm air spacing between the slices. SPET was performed with the sheets perpendicular to the central axis of the camera. The total weight of the stacked rCBF phantom in air was 63 g, giving a scatter contribution comparable to that of a point source in air. The overall attenuation losses were <20%. A second SPET study was performed with 12-mm polystyrene plates in between the radioactive sheets. With polystyrene plates, the total phantom weight was 2300 g, giving a scatter and attenuation magnitude similar to that of a patient study. With the proposed technique, it is possible to obtain "ideal" experimental images (essentially built up by primary photons) for comparison with "real" images degraded by photon scattering and attenuation losses. The method can serve as a tool for experimental validation and intercomparison of attenuation and scatter correction methods. Moreover, the large flexibility of this phantom design will allow investigations of arbitrary activity distributions and autoradiography or other imaging techniques such as PET, x-ray computed tomography or magnetic resonance imaging.

A comparison of 99Tcm-MDP and 99Tcm-MIBI in the detection of breast cancer

In this study, we made an intra-individual comparison of the uptake of 99Tcm-MDP and 99Tcm-MIBI in breast cancer. Twenty women with large breast masses (one dimension > or = 3 cm on mammography) underwent SPET in the supine position with both agents. All transverse sections demonstrating tumour activity were added together and the net (total) tumour uptake in a region of interest was compared to that of surrounding tissue activity (background). We also evaluated maximum tumour uptake versus background activity. Tumour uptake was observed in all examinations. In contrast to MIBI, eight MDP examinations showed increased uptake in normal breast parenchyma in addition to tumour uptake. There was no significant difference in net tumour uptake between the two tracers and non-parenchymal (indifferent) background activity, but the maximum tumour activity of MIBI was significantly higher than that of MDP. In the eight MDP examinations with parenchymal activity, mammograms were required to identify tumour uptake correctly. In conclusion, MDP may provide similar images to MIBI in postmenopausal women not receiving hormone replacement therapy. For other patients, MIBI gives better tumour depiction.

Uptake of 111In-pentetreotide and 99mTc-labeled autologous granulocytes in Kimura's disease

Uptake of 111In-pentetreotide (OctreoScan) and 99mTc-labeled autologous granulocytes by the lesions of a 37-year-old female from Thailand with Kimura's disease is described. This is a benign chronic inflammatory condition that is endemic in Asians. It is characterized by adenopathy and subcutaneous nodules mostly affecting the head and neck area or the salivary glands. Although these examinations have previously not been described in Kimura's disease, uptake of the radiopharmaceuticals in the lesions can be expected from their histological appearance. With increasing medical, social and economic interactions with Asia, it is important to recognize this cause of adenopathy, including its appearance at various nuclear medicine examinations.

Reproducibility and repeatability of 99Tcm-HMPAO rCBF SPET in normal subjects at rest using brain atlas matching

The aim of this study was to assess regional cerebral blood flow (rCBF) in normal subjects at rest using 99Tcm-HMPAO single photon emission tomography (SPET). Analysis of reproducibility and repeatability was performed both before and after normalization of flow data. Six healthy volunteers were examined, three times each, according to a routine rCBF protocol. A computerized brain atlas was used to evaluate flow data in eight selected regions. The overall reproducibility of rCBF was evaluated from two scans performed at an average interval of 3 months. Repeatability was evaluated from two scans, 3 h apart and without re-injection of 99Tcm-HMPAO. For the normalized (relative) flow data, the reproducibility was +/- 1.3% and the repeatability +/- 2.2% (i.e. methodological errors dominate). For the non-normalized flow data, the corresponding values were +/- 14.8% and +/- 5.9%. rCBF SPET with 99Tcm-HMPAO is highly reproducible provided that the flow data are normalized. The variation in flow between individuals at one point in time and 3 months later was less than +/- 5% for all brain regions.

Malignant human renin producing paraganglionoma-localization with 123I-MIBG and treatment with 131I-MIBG

A 22-year-old woman presenting severe hypertension and hypokalaemia is described. Initial evaluation showed a large tumour localized at the position of the left adrenal gland. Subsequent surgery temporarily relieved all signs and symptoms caused by the tumour. The symptoms relapsed after a 2-year disease-free interval. At re-evaluation, the tumour was shown to produce an uncontrolled secretion of renin, thus triggering aldosterone-dependent hypertension. This report describes the diagnosis, treatment and clinical course of this unique patient with a malignant paraganglionoma of adrenal origin.

Biodistribution of liposomal 131I-VIP in rat using gamma camera

Vasoactive intestinal peptide (VIP), a 28 amino-acid peptide was labeled with 131I and encapsulated into liposomes. 131I-VIP or liposomal 131I-VIP was administered intravenously into the rats. The distribution was studied by a gamma camera and established by counting the radioactivity in the removed organs. The elimination half-life for the liposomal 131I-VIP in both blood and lungs was significantly longer (5.29 and 9.28 min, respectively) than that obtained after the administration of 131I-VIP (0.62 and 3.18 min, respectively). Dynamic scans using a gamma camera after the administration of liposomal 131I-VIP showed a higher uptake of the liposomal form into the lungs compared with 131I-VIP. The lack of VIP in asthmatics has been shown in previous studies. However, the clinical investigations using VIP were disappointing most probably due to the rapid degradation of the peptide in the bronchial tract. This in fact is supported by our previous study, in which we demonstrated that VIP had a half-life of 0.45 min in blood. We conclude that the encapsulation of VIP in liposomes prolongs its elimination half-life in plasma and enhances its uptake in lungs. This observation may increase the clinical use of VIP in both diagnostic and therapy.