Orwik

Fully automated 3D basal ganglia activity measurement in dopamine transporter scintigraphy (Spectalyzer).

OBJECTIVES: Semiquantitative evaluation of tracer uptake in basal ganglia is superior to visual assessment of images in dopamine transporter (DAT) scintigraphy especially in follow-up of the patients. Manual drawing of regions of interest (ROIs) in t... expand abstractwo-dimensional (2D) transaxial slices of the single photon emission computed tomography (SPECT) datasets leads to a large inter- and intra-reader variability, while being time consuming. Our aim was to investigate a technique that extracts 3D ROIs in a fully automated fashion and thus might provide reproducible user-independent results allowing better follow-up control and large-scale clinical studies. METHODS: The highest activity of 123IFP-CIT is expected in the basal ganglia. The proposed method (Spectalyzer) uses the following steps to localize this maximum and extract the ROIs in 3D: (1) Dithers the SPECT volume to obtain a 3D volume with binary only. (2) Models the obtained point distributions as two multivariate Gaussian distributions and estimated their parameters using the expectation maximization algorithm. (3) Using the original SPECT activity values, thresholding is performed using a fixed percentage of maximum activity as a parameter to obtain the 3D ROIs. (4) A reference volume in the occipital region is automatically found based on the location of the two ROIs. (5) From the 3D ROIs, statistical information like mean and median activity and the volume is extracted, relative to the activity in the reference region. The resulting values are compared with values from manual 2D ROIs. Further validation is performed by means of an anthropomorphic striatal phantom. RESULTS: The method was evaluated on 12 SPECT volumes including anthropomorphic striatal phantoms. In all cases the two basal-ganglia were successfully localized and the 3D ROIs estimated, with perfect reproducibility. The obtained values for the mean activity showed the same trend with the values obtained manually and also with the results of the 2D semiautomatic software, but without the substantial inter- and intra-reader variations. CONCLUSIONS: The proposed method is successful in finding the 3D ROIs and performing the subsequent measurements automatically. It is proposed as an automatic reproducible approach for semiquantitative analysis of DAT scintigraphy. collapse abstract

Amyloid PET and MRI in Alzheimer's disease and mild cognitive impairment.

The neurodegenerative disorder Alzheimer's disease (AD) is the most common form of dementia. It is characterized by progressive impairment of cognitive functions and behavior. To distinguish clinically AD from other forms of dementia is an ongoing ch... expand abstractallenge. In addition, although mild cognitive impairment (MCI) is recognized as a risk factor for dementia, it remains a challenge to predict on an individual level who will convert to become demented. Amyloid beta (Abeta) is one of the crucial pathological findings in AD. Recently, amyloid tracers for PET imaging have been developed successfully which may offer the unique possibility for measuring fibrillar Abeta load in the living brain. Therefore, in the near future positron emission tomography (PET) may become an important tool for in vivo amyloid imaging contributing to early (differential) diagnosis as well as evaluation of treatment response in AD. Moreover, Abeta may play a role in prediction the conversion of MCI to AD. In this paper we review the recent development of the molecular imaging technique PET and its different radiopharmaceuticals on the trail for imaging amyloid in AD and the conversion of MCI to AD. collapse abstract

SPECTCT.

Interatrial 18F-FDG uptake mimicking malignancy.

Successful treatment of a patient with lymphocyte-predominant Hodgkin's lymphoma with yttrium-90-ibritumomab tiuxetan.

Lymphocyte-predominant Hodgkin's lymphoma (LPHL) is known to be radiosensitive, and radiotherapy often forms part of the treatment of patients with stage III or IV LPHL. In addition, as LPHL is thought to arise from a germinal centre B-cell, and LPHL... expand abstract cells express the B-cell marker CD20 there is a rationale for using anti-CD20 therapies for the treatment of LPHL. We report a 42-yr-old man with stage III B LPLH who underwent successful treatment of LPHL with (90)Y-ibritumomab tiuxetan. To our knowledge, this is the first report on the use of an anti-CD20 radiolabeled antibody for the treatment of LPHL. collapse abstract

"Wispino" protocol for 18FDG-PET scanning of myocardium.

PET-CT is only one option.

CT attenuation correction is clinically superior to supine-prone MPS.

Case report: Gluteal injection site granulomas: false positive finding on FDG-PET in patients with non-small cell lung cancer.

Positron-emission-tomography (PET) with fludeoxyglucose F-18 ([(18)F] fluoro-2-deoxy-D-glucose, FDG) has become an established imaging modality in patients with lung cancer for mediastinal lymph node staging and the detection of extrathoracic metasta... expand abstractses. However, tracer accumulations are not limited to malignant tissue but are also found in muscles and benign inflammatory processes. We report on two patients with lung cancer in whom FDG-PET revealed suspicious tracer accumulations in the buttock. Ultrasound (US) revealed a hyperechogenic nodule with poorly defined margins in both patients. On specific inquiry both patients reported on repeated "intramuscular" gluteal injections. Histology after US guided biopsy showed an accumulation of macrophages within fibrous tissue, compatible with injection site granulomas. The reported cases underline that (18)F-FDG may accumulate in benign, ancillary processes that have to be distinguished from distant metastases. Tracer accumulation in the buttocks may be highly suggestive of injection site granulomas, especially if the patient reports on "intramuscular" injections. In this setting, US is a widely available modality to distinguish metastasis from adipose tissue necrosis. collapse abstract

Sweet nuclear medicine phantoms for scintigraphic sentinel lymph node detection: a cooking recipe.

Scintimammography with a pinhole collimator.

Medical aspects of objectifying torture sequels

Migration, civil wars and other conflicts in various regions of the world have led to a drastic increase in the number of displaced persons and refugees. Associated with this development is an increase in the number of torture victims seeking asylum.... expand abstract This means that the medical personnel is increasingly confronted with the evaluation and therapy of torture victims. The methods of verification of sequels of torture are of utmost importance in the work-up of treatment centres for survivors of torture. Since each organ can be affected by torture, a multidisciplinary cooperation is mandatory for the examination of torture victims. In this paper we shall discuss some aspects concerning the diagnosis of injuries caused by torture which are essential for interviewing and examining torture victims in order to objectify sequels of torture. collapse abstract

New approaches in nuclear medicine for early diagnosis of Alzheimer's disease.

Dementia, Alzheimer's disease (AD) being the most common cause of it, is a major and growing medical and social problem, particularly in the advanced age, with the highest rate in the population over 75 y. Recent sophisticated therapeutic measures re... expand abstractquire more sensitive diagnostic tests to recognize early stages of the disease. In this paper, the current neuronuclear imaging literature is reviewed with regard to early and differential diagnosis of dementia. Functional imaging with single photon emission computed tomography (SPECT) and positron emission tomography (PET) could provide the clinician with additional information complementary to morphological assessments, thus contributing to achieve a more adequate diagnosis, and also with information regarding prodromal stages of AD. collapse abstract

Positron emission tomography is not useful in detecting metastasis in the sentinel lymph node in patients with primary malignant melanoma stage I and II.

The most powerful predictor for recurrence and survival in patients with primary malignant melanoma is the presence or absence of lymph node metastases. In the present study, 18-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) findings we... expand abstractre compared with histopathological results of sentinel lymph node biopsy (SNB). The purpose was to determine the value of FDG-PET in predicting regional lymph node involvement in patients with primary malignant melanoma stage I and II. Forty-eight consecutive patients with primary cutaneous melanoma stage I (Breslow thickness > 1 mm) and II underwent FDG-PET scans, preoperative lymphoscintigraphy, and SNB. The FDG-PET and SNB results were interpreted independently of each other and then compared. Of the 48 patients included in the study, eight (16.7%) had a positive SNB. PET was positive in only one patient with a positive SNB, yielding a sensitivity of 13%. All other positive sentinel nodes could not be detected by metabolic FDG-PET imaging. Our study revealed that FDG-PET is obviously not an adequate screening test for subclinical and sonographically inconspicuous lymph node metastases in patients with malignant melanoma stage I and II. The low sensitivity is probably due to the small size of metastatic deposits in sentinel nodes. Therefore, SNB remains the technique of choice for evaluating the histological status of lymph node basins in patients with early-stage cutaneous melanoma. collapse abstract

Metabolic impairment of brain metabolism in patients with Lewy body dementia.

A reliable assessment of dementia is essential for a differentiated treatment. Recent studies have demonstrated a poor accuracy of clinical criteria for diagnosis of Lewy body dementia. Diffuse Lewy body disease (LBD) is the second most common cause ... expand abstractof senile degenerative dementia and is characterized histologically by the occurrence of Lewy bodies in allocortical, neocortical and subcortical structures. Seven male patients (mean age 81 years) with clinically suspected diffuse LBD were investigated with 18F-fluorodeoxyglucose (FDG)-PET using a Siemens ECAT-ART PET-scanner. The 18F-FDG-PET showed a diffuse glucose hypometabolism in the entire cerebral cortex with relative sparing of the primary sensory-motor cortex in all patients. This diffuse metabolic impairment in the entire cortex with relative sparing of central region seems to be a typical pattern for LBD, distinct from Alzheimer's disease. collapse abstract

Expression of somatostatin receptors in inflammatory lesions and diagnostic value of somatostatin receptor scintigraphy in patients with ANCA-associated small vessel vasculitis.

OBJECTIVE: To assess the usefulness of somatostatin receptor (SSTR) scintigraphy for the evaluation of disease activity in the upper and lower respiratory tract in ANCA-associated vasculitis (AASV). METHODS: Thirty-two consecutive patients with AASV ... expand abstractwere subjected to SSTR scintigraphy as part of their initial diagnostic evaluation and follow-up. The presence of SSTRs in inflammatory lesions was evaluated with immunohistochemistry in selected cases. RESULTS: In AASV, specificity of SSTR scintigraphy for active vs non-active disease was 96% for pulmonary disease and 100% for ear, nose and throat (ENT) involvement, while sensitivity was 86% and 68%, respectively. Absence of previously present tracer accumulation characterized treatment responders, and treatment resistance was reflected by repeated positive scintigraphy. We could demonstrate the expression of SSTRs in lung and mucosal biopsies obtained from patients with active Wegener's granulomatosis and with microscopic polyangiitis. CONCLUSION: SSTR scintigraphy is useful for the assessment of AASV, indicating disease activity, disease extent and treatment efficacy. SSTRs are expressed in both granulomatous as well as non-granulomatous AASV. collapse abstract

New design concept to improve medical application software

Up to now, there has been no software model available that adequately addresses the growing importance of flexibility in using different information tools. Based on Java, Jini technology provides distributed and therefore robust software architecture... expand abstract. In case of an application crash, Jini is able to minimize the damage by adding functions that reverse the effects of the crash. Owing to increasing user mobility, it is necessary to be able to receive location-independent information. The growing use of powerful telecommunications suggests the application of 'wireless application protocol' (WAP) mobile telephones also for medical purposes. This paper presents the application of these new software trends (Jini and wireless application protocol). collapse abstract

Effect of rocaltrol on bone mass in patients with pulmonary disease treated with corticosteroids.

The aim of this study was to evaluate the effect of calcitriol on bone mass in patients with corticosteroid induced osteoporosis. Thirty-seven patients (26 females, 11 males, mean age 66.4 years) with pulmonary disease under long-term treatment with ... expand abstractcorticosteroids (5-10 mg prednisolone daily) and osteopenia/osteoporosis verified by dual-energy x-ray absorptiometry (DEXA) measurement were enrolled into the study. Rocaltrol was prescribed to 30/37 of the patients, the rest of the patients (6 females, 1 male) served as controls. In the treatment group, there was a slight increase of bone mass in the hip and lumbar vertebrae (L1-L4), whereas the control group showed a decrease of bone mass (change rate of bone mass in patients +0.8% and +1.0%, respectively, vs. -1.9% and -0.3%, respectively, in the control group). The preliminary results of our study suggest a beneficial role for the treatment of corticosteroid induced osteoporosis with Rocaltrol, which is well-tolerated by patients and cost-efficient in patient management. collapse abstract

Sentinel lymph node detection with large human serum albumin colloid particles in breast cancer.

Detection of metastatic involvement of lymph nodes is essential for management and prognostic evaluation in breast cancer patients. The success of lymphatic mapping depends on identifying the sentinel lymph node(s) draining the primary tumour. Howeve... expand abstractr, when mapping is performed with a radiocolloidal agent, the number of hot lymph nodes varies with the agent and its size, among other factors. In this study, we evaluated prospectively the detection rate of sentinel lymph nodes in breast cancer when injecting large particles (100-600 nm) of human serum albumin colloids (Senti-Scint). In 128 consecutive breast cancer patients without palpable lymph nodes, pre-operative static lymphoscintigraphic mapping of the breast was performed after subcutaneous injection of 15 MBq of the radiocolloid. Lymphoscintigrahic results were compared with intra-operative surgical gamma detection probe and blue dye mapping data. Pre-operative lymphoscintigraphy and surgical gamma detection probe both correctly detected 203 sentinel lymph nodes in 122/128 patients (95%), while blue dye mapping showed only 183 sentinel lymph nodes in 82% of the patients. Only one or two sentinel lymph nodes were identified in each patient, which allowed the surgeon easily to find the sentinel lymph node(s) intra-operatively. In conclusion, lymphoscintigraphy with large particles of human serum albumin colloids is a helpful and reliable procedure for the surgical management of breast cancer. collapse abstract

The life of refugees.

Determination of therapy management in rectal carcinoma by staging with 18-FDG-PET

The curative treatment of carcinoma of the rectum in the early stage of the disease is radical local surgery. If there is a solitary liver metastasis, resection is also a curative treatment. This report describes a female patient with rectal carcinom... expand abstracta, in whom a solitary liver metastasis in the left lobe was diagnosed only by FDG-PET and verified at surgery. This case report demonstrates the potential role of FDG-PET even for primary staging in detecting occult hepatic and extrahepatic metastases, thus significantly influencing the therapeutic management and prognosis of these patients. collapse abstract

Regional cerebral blood flow in patients suffering from post-traumatic stress disorder.

OBJECTIVE: The aim of the study was to determine whether regional cerebral blood flow in survivors of torture suffering from post-traumatic stress disorder (PTSD) differed significantly from that in healthy controls. METHOD: We examined the cerebral ... expand abstractregional distribution of 99m-technetium-hexamethylpropyleneamineoxime (HMPAO) using single photon emission computed tomography (SPECT) in 8 patients and in 8 healthy controls. A semi-quantitative analysis was performed in which symmetrical regions of interest (ROI) were drawn in all subjects. RESULTS: Regional blood flow was markedly more heterogeneous in patients suffering from PTSD than in healthy controls. The differences are significant. CONCLUSION: Severe psychological trauma induced by torture can cause neurobiologic alterations that may contribute, even years after the original trauma, to a number of complaints commonly expressed by patients suffering from PTSD. collapse abstract

Diagnosis of recurrent astrocytoma with fludeoxyglucose F18 PET scanning.

Optimized mammary lymphoscintigraphy using larger colloid particles.

Implementing a Java-based image and report distribution system in a non-picture archiving and communication environment.