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H Jacobsson

Publications and source records attributed to H Jacobsson.

At least 37 records · Page 2Linked to original sources
PubMed2000

[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.

Adult↗
PubMed2000

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.

Child↗
PubMed2000

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.

3-Iodobenzylguanidine↗
PubMed2000

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.

Adolescent↗
PubMed2000

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.

Brain↗
PubMed2000

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.

Abstracting and Indexing↗
PubMed2000

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.

Adolescent↗
PubMed2000

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.

Adult↗
PubMed2000

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.

Adult↗
PubMed2000

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.

Acute Disease↗
PubMed2000

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.

Acetaminophen↗
PubMed2000

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.

Adult↗
PubMed2000

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.

Adult↗
PubMed2000

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.

Acute Disease↗
PubMed1999

In vivo dynamic distribution of 131I-glucagon-like peptide-1 (7-36) amide in the rat studied by gamma camera.

The in vivo distribution of glucagon-like peptide-1 (7-36) amide (GLP-1) was studied in a rat model using radiolabeled GLP-1 (131I-GLP-1) depicted by a gamma-camera. The dynamic scan showed a rapid clearance from the blood circulation after an intravenous (i.v.) injection of 131I-GLP-1. After 10 min, the major part of the radioactivity was accumulated in the kidneys, whereas about 9% (of the blood value) was found in the brain. The pharmacokinetic study using 125I-GLP-1 demonstrated a rapid elimination from plasma, with a half-life of 3.3 +/- 0.6 min, a clearance of 117 +/- 15 mL/min, and a distribution volume of 557 +/- 61 mL. The elimination half-lives for the intact 125I-GLP-1 in lungs and kidneys were determined to 3.7 and 3.9 min, respectively. The metabolite GLP-1 (9-36) amide was followed in blood, lung, and kidney. All other organs assumed to contain low molecular weight fragments of GLP-1. The present study suggest that GLP-1 and/or its labeled metabolites cross the blood-brain barrier. Also the kidney plays an essential role in GLP-1 elimination after an i.v. administration, which can be of clinical interest especially in patients with kidney insufficiency who are treated with GLP-1.

Animals↗
PubMed1999

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.

Animals↗