[New design concept to improve medical application software]. / Neues Design-Konzept zur Verbesserung der medizinischen Anwendersoftware.

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. 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).

Distributed nuclear medicine applications using World Wide Web and Java technology.

At present, medical applications applying World Wide Web (WWW) technology are mainly used to view static images and to retrieve some information. The Java platform is a relative new way of computing, especially designed for network computing and distributed applications which enables interactive connection between user and information via the WWW. The Java 2 Software Development Kit (SDK) including Java2D API, Java Remote Method Invocation (RMI) technology, Object Serialization and the Java Advanced Imaging (JAI) extension was used to achieve a robust, platform independent and network centric solution. Medical image processing software based on this technology is presented and adequate performance capability of Java is demonstrated by an iterative reconstruction algorithm for single photon emission computerized tomography (SPECT).

A Jini service to reconstruct tomographic data.

Distributed computing that uses dynamic networks will change the way we work and communicate thanks to the interaction of devices and services, that are automatically added and removed from the network as needed. The Jini technology, which is built atop the Java programming language, provides a homogenous view of the network and extends the ability of code to migrate in Java. This software design model simplifies the configuration and access to hardware devices and software services in a network. Thus, it becomes possible to execute new services without pre-installing software on client machines. This new programming paradigm is especially important in medical applications, where the reliable transmission of information is essential. This paper demonstrates how single photon emission computerized tomography data can be iteratively reconstructed using a Jini service.

Reoperation as treatment of relapse after subtotal thyroidectomy in Graves' disease.

BACKGROUND AND METHODS: In Graves' disease radioiodine is the recommended treatment for relapses after subtotal thyroidectomy. If patients reject radioiodine, hyperthyroidism is managed with antithyroid drugs; surgery is generally not considered as an alternative. Here we retrospectively analyzed 30 consecutive patients with Graves' disease who had recurrent hyperthyroidism after subtotal thyroidectomy. RESULTS: On relapse after the first operation, the patients were initially treated by medication; 25 opted for definitive treatment (19 for reoperation and 6 for radioiodine). Operations consisted of 10 unilateral and 8 bilateral resections (total or near-total with capsular remnants of < 1 g) and 1 transsternal approach (because of dystopic intrathoracic thyroid tissue). The decision between a unilateral and a bilateral reintervention was based on the ultrasonographic determination of remnant volumes. These size estimates were valid because they were significantly correlated to the weight of the resected remnants (r = 0.92, slope = 0.95). Eighteen of the 19 patients were adequately treated by this approach. Unilateral resection was performed in 1 patient with a remaining contralateral remnant of 5.4 mL; this patient had a second relapse. The complication rate was low (2 cases of transient recurrent nerve injury and 1 of transient hypocalcemia). CONCLUSION: Provided that no contraindication is present, reoperation is safe, effective, and expeditious in recurrent hyperthyroidism. Because the likelihood of a recurrence depends on the total remnant size, the goal is to keep it below 2 g. Preoperative ultrasonography can effectively guide the decision between a unilateral and a bilateral resection.

Possible effect of calcitonin deficiency on bone mass after subtotal thyroidectomy.

Bone mass is purportedly reduced by an excess of endogenous or exogenous thyroid hormone or perhaps by calcitonin deficiency. Patients who have undergone thyroidectomy could be subject to all of these effects. In the present study we tried to demonstrate, whether lack of calcitonin following thyroidectomy has a significant influence on bone density. We measured thyroid hormone levels, TSH and calcitonin and assessed the bone mass in the hip and lumbar spine of 55 patients (32 f, 23 m), who had undergone a subtotal thyroidectomy between 1938 and 1996 on the reason of a non-toxic goitre. TSH levels were suppressed in 16 patients. Serum concentration of total calcium, intact PTH, osteocalcin were normal in all subjects. The mean fasting calcitonin level was in the patient group 2.09 +/- 0.7 pg/ml and in the control group, age matched healthy volunteers, 2.8 +/- 1.2 pg/ml. However, the serum level of calcitonin was not significantly lower than in the control group. 43 patients had an osteopenia or osteoporosis. The interpretation of the results in this study is hampered by the fact, that in women results may be influenced by involutional osteoporosis. Therefore we focus on the potential for osteoporosis among the 23 men. The results of our study indicates, that there is a significant reduction in bone mass in male after thyroidectomy, no matter whether T4 therapy is given or not, and whether TSH is suppressed or in a normal range.

An artificial neural net and error backpropagation to reconstruct single photon emission computerized tomography data.

At present, algorithms used in nuclear medicine to reconstruct single photon emission computerized tomography (SPECT) data are usually based on one of two principles: filtered backprojection and iterative methods. In this paper a different algorithm, applying an artificial neural network (multilayer perception) and error backpropagation as training method are used to reconstruct transaxial slices from SPECT data. The algorithm was implemented on an Elscint XPERT workstation (i486, 50 MHz), used as a routine digital image processing tool in our departments. Reconstruction time for a 64 x 64 matrix is approximately 45 s/transaxial slice. The algorithm has been validated by a mathematical model and tested on heart and Jaszczak phantoms. Phantom studies and very first clinical results ((111)In octreotide SPECT, 99mTc MDP bone SPECT) show in comparison with filtered backprojection an enhancement in image quality.

Bone scintigraphy in screening of torture survivors.

BACKGROUND: In most developed countries, survivors of physical torture inflicted for political, religious, or ethnic reasons face ever more stringent review when seeking asylum. In Austria, asylum seekers are required by immigration authorities to undergo medical examination as part of the review. Bone scintigraphy can detect bone lesions that are not detectable clinically or radiologically. We assessed the value of bone scintigraphy as corroboration of alleged injuries. METHODS: Human-rights organisations referred 25 asylum seekers to us from countries where torture is practised. We included patients who claimed to have been beaten by the security forces in their home country because of political or religious conviction or ethnic origin. Injuries had been inflicted 4 months to 5 years earlier. The patients (three women, 22 men) from 12 countries were categorised retrospectively into two groups: group A (n=12), tortured with blows from hard objects, and group B (n=13), tortured with blows from fists and kicks. We also used a control group of 25 individuals with the same age and sex distribution from the same countries who had no history of torture. FINDINGS: In group A, bone scans showed abnormalities in the area of alleged injury in all patients, whereas radiography was positive in only five patients. In group B, bone scans in the alleged areas of damage were positive in seven patients, but radiography yielded no positive outcomes. Among the controls there was one abnormal scan due to a known coxarthrosis. INTERPRETATION: Our preliminary results suggest that bone scintigraphy is a sensitive, non-invasive tool to document trauma some years after the actual injury.

The incidence of hyperthyroidism in Austria from 1987 to 1995 before and after an increase in salt iodization in 1990.

Between 1963 and 1990, Austria had iodized salt prophylaxis of endemic goitre with 10 mg KI (7.5 mg I) per kg. This was obviously insufficient, as urinary iodine excretion ranged from 42 to 78 microg I per g of creatinine and goitre in adults remained in the endemic range of 15%-30%. Therefore salt iodization was doubled in 1990. The aim of this study was to assess the annual incidence of different types of hyperthyroidism (HT) before and after this increase in salt iodization. The incidence of HT was recorded in 14 nuclear medicine centres from 1987 to 1995. In five additional centres data were available from 1992 onwards. Data prior to 1992 were documented retrospectively, while those after 1992 were recorded prospectively. The 14 centres drew patients from an area with a population of approximately 4.23 million while all 19 institutes were estimated to cover an area with a population of 5.4 million (the total population of Austria is 7.86 million). A total of 414232 persons were examined for the first time in the participating centres. HT and the type of HT were defined by clinical examination, serum TSH, thyroid hormone levels in blood, ultrasonography, scintigraphy and serum autoantibody titres. HT was classified into immunogenic HT (Graves' or Basedow's disease, GD) and HT with intrinsic thyroid autonomy (uni-, multinodular or disseminated Plummers' disease, PD). HT was also divided into overt (o) or subclinical (sc) disease. The following data were calculated: annual incidence per 100000 and the relative risk (RR) for HT with 95% confidence intervals (CI). In addition, linear trends were calculated for each type of HT by means of logistic regressions. In the 19 centres a total of 47834 patients with HT were registered from 1987 to 1995. PD accounted for 75% of all cases of HT and GD for 19%, while other types of HT were present in 6%. From 1987 to 1989 (time period T0), the annual incidence of oPD was 30.5 (95% CI 29.6-31.5) per 100000. The RR compared to the baseline period T0 was highest in 1992 (1.37; 1.3-1.45) and decreased to 1.17 (1.1-1.24) in 1995. The annual incidence of scPD in T0 was 27.4 (26.5-28.3) per 100000. The RR was highest in 1991 (1.64; 1.56-1.73) and was 1.60 (1. 51-1.69) in 1995. In oPD and scPD a higher RR was observed in persons older than 50 years of age, particularly in men. The incidence of oGD in T0 was 10.4 (9.8-10.9) per 100000; the maximum RR increased to 2.19 (2.01-2.38) in 1993 and decreased to 1.95 (1.78-2.13) in 1995. The incidence of scGD was 1.9 (1.6-2.1) in T0. The maximum RR was observed in 1994 (2.47; 2.04-3.0) and it was still 2.26 (1.85-2.77) in 1995. The increased incidence of oGD and scGD was evenly distributed in all ages and both sexes. The time course of different types of HT following the increase in salt iodization could be divided into two phases: an increase in the incidences of HT with peaks after 1-4 years and a subsequent decrease, the only exception being scGD. The effect was more pronounced in GD than in PD. PD showed an age and gender dependency over time, while GD did not.

Elevated serum neopterin levels in atherosclerosis.

Plasma levels of neopterin were determined in patients with different clinical stages of atherosclerosis. Non-hospitalized patients with atherosclerosis had serum and plasma neopterin levels within the normal range of the assay (6 +/- 2 nM). These values were not significantly different from those reported for healthy blood donors (5 +/- 2 nM). In contrast, about 50% (29 out of 61) of hospitalized patients undergoing conservative or surgical therapy had neopterin plasma levels, which exceeded the normal range (greater than 10 nM) up to 10-fold. The two groups differ on a significance level of P less than 0.01. For further evaluation hospitalized patients were subgrouped according to neopterin levels. In the subgroup with elevated neopterin levels patients with higher Frederickson types of atherosclerosis were overrepresented compared to patients with normal neopterin levels. Type 4 differed significantly from patients without pathological changes of lipoprotein (P less than 0.05). Only 3 patients suffered from minimal skin necrosis, two of them had elevated neopterin levels. Significantly more patients with peripheral artery occlusions had elevated neopterin levels than patients with occlusions of central arteries (P less than 0.05). All other criteria used for comparison (sex, age, smoking, antioxidant status, diabetes, hypertension, adipositas, hyperuricemia) did not vary significantly in both subgroups. These data indicate that neopterin plasma levels might be a valuable parameter in activity staging and therapeutic follow up of atherosclerotic patients. Additionally, an involvement of the nonspecific immune system in atherogenesis is suggested by the increased plasma neopterin concentrations.

[Rational informative nuclear medicine diagnosis for cardiology]. / Rationell informative nuklearmedizinische Diagnostik für die Kardiologie.

A combined program in SYMA has been developed. It gives parameters for the left ventricle (LV) as well as for the right ventricle (RV); it also can be used as a basis for more specific details. We tried indeed to get more informations with less costs and time. Studying 163 patients (the mean age was 62 years) we have seen that ejection fraction (EF), wallmotion (WM) and CINE data show good results even in more complex events. From different points of view positive and negative aspects were discussed mainly concerning the role of nuclear medicine in clinic al cardiology. Typical samples have been shown. Final results are built up by two components; primarily the number of theoretical ideas are very helpful but otherwise practical experiences perfect the whole impression.