[Objectivity, reproducibility and validity of 3D ultrasound in dermatology]. / Objektivität, Reproduzierbarkeit und Validität der 3D-Sonographie in der Dermatologie.

Recently it has become possible to visualize the three-dimensional (3D) architecture of sonographic structures using high-resolution ultrasound above 20 MHz (Dermascan C, Denmark; DUB 20, Germany). We studied the objectivity, reproducibility, and validity of these two 3D analysis systems on 22 skin tumors. To validate both systems, we compared the sonometric and histometric volume in 4 tumors. The objectivity was calculated by repeated evaluation of the volume on the same serial B-scan sections at 3-month intervals. The two-dimensional B-scans and 3D images exhibited similar characteristics. Volumetric evaluations were reproducible with both systems (variation coefficient < or = 9.9%), when the applicator was oriented longitudinal to the body axis. By changing the orientation, the coefficient increased up to 58.1% (DUB 20). Sonometric and histometric volumes of a phantom model and of the tumors exhibited small deviations in the Dermascan C (< or = 8.1%) and in some tumors large deviations in the DUB 20 (< or = 93.1%). We can conclude that the 3D sonography is a reproducible method, which can be used to evaluate the volume of skin tumors and metastases under chemotherapy or radiotherapy. We suggest in particular to use the in-vivo tumor volume as a prognostic parameter for the malignant melanoma.

[History of high frequency sonography]. / Geschichte der hochfrequenten Sonographie.

The development of high frequency sonography (< 20MHz) has gained increasing importance since the last decade. In this field A-mode-scanner were used firstly in the measurement of skin thickness. 1987 the first commercial available 20 MHz B-scanning system was introduced. These systems provided the possibility of correlating the ultrasound images with the micromorphological findings in histology. With these correlations we were able to interpret ultrasound phenomena and in conclusion we were able to measure tumour thicknesses with direct impact on the therapeutic regimen. In inflammatory skin diseases the role of high frequency ultrasound in follow up investigations of morphea and systemic sclerosis must be underlined. We believe that in this field the technique is the "golden standard". In other inflammatory diseases (e.g. psoriasis) or wound healing ultrasound is mainly used for scientific purposes. The investigation of intraepidermal structures and differential diagnosis is only possible with higher frequencies than 20 MHz. Therefore we developed 50 and 100 MHz in vivo scanning systems. With resolution up to 11 microns (100 MHz) we hope to answer open questions in the future. Ultrasound microscopy is widely used for scientific evaluation of tissue morphology in vitro (resolution < 1 micron). Computer-based three-dimensional reconstructions provide additional information (e.g. tumour volume or tumour surface). These parameters are well suited to follow up the effect of systemic or local therapies on skin metastases of different cancers. However, also the tumour volume of the primary tumour (in vivo) might be of great interest as a prognostic parameter in future.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer assisted insulin dosage adjustment--perspectives for diabetes control.

Pocket computers provide the physician's (expert's) advice at home and by that may increase the number of self-adapting diabetics and alleviate documentation and evaluation of therapy data. By a more complex quantitative approach metabolic control may be improved beyond the range which is attained by optimal intensified education, as clinical trials showed. By their reproducible measures a learning process seems to be induced in the patients. Risks like hyperinsulinisation may be overcome by watch dog functions and suitable algorithms. In addition to these patient-oriented functions the automatic data acquisition may be used for secondary PC-assisted data interpretation and more complex advice at the physicians office. For compliance reasons the system concept has to be user-friendly considering size, easy handling and compensating for the loss of a written log book by adequate display.