Statisch-dynamische MR-Urographie Vergleich mit Ausscheidungsurographie und Szintigraphie bei experimentell induzierter Harntransportstörung (HTS)

Purpose. To assess the diagnostic value of combined static-dynamic MR urography (MRU) for the functional-morphological evaluation of experimentally induced urinary tract obstruction. Methods: Static-dynamic MRU – combination study with a respiratory-triggered 3D-IR-TSE sequence and a dynamic 2D-FFE sequence after Gd-DTPA and furosemide – was obtained in comparison with ^99mTc-MAG3 diuretic renal scintigraphy (DRS), excretory urography (EU) and ultrasound (US) in 29 healthy piglets and in 20 piglets with surgically induced ureteric stenosis (total of 50 postoperative examination blocks). Results: MRU allowed complete depiction of the urinary tract in all controls, in operated piglets the stenosis was always correctly identified. Quality of MRU was superior to EU in 36 of 43 comparative studies. Calculation of single kidney function from parenchymal renograms, and assessment of urinary excretion from whole-kidney renograms resulted in a highly significant agreement of MRU with DRS. Conclusion: Static-dynamic MR urography allows excellent depiction of experimentally induced urinary tract obstruction, and reliable assessment of individual renal function and urinary excretion. Two advantages of the method stand out, it does not require radiation and it permits a functional-morphological correlation.     

Molekulare Bildgebung in der Magnetresonanztomographie und der Nuklearmedizin

The identification of genetic and biochemical changes allows a more conclusive characterization and classification of disease. Up to now this information is mostly obtained through in vitro analysis after resection or biopsy by immunohistopathology and molecular biology. There is a definite need for non-invasive detection and repeated monitoring of such changes in experimental research as well as in clinical trials. Therefore, it is necessary to develop radiological imaging techniques that not only visualize morphologic and physiologic alterations, but track genetic and biochemical processes. This short review reports some of the various ongoing research projects that address this problem and provide some very promising approaches.     

Reconstruction methods in postprocessing of CT- and MR-angiography of the aorta

The aim of the study was to investigate the use of 2D and 3D reconstructions in examinations of the aorta with CT and MRI. Postprocessing of 5 data sets including 2D MPR reconstructions, 3D MIP reconstructions and 3D volume rendering reconstructions acquired with contrast enhanced CTA and 5 data sets acquired with contrast enhanced MRA were performed. The luminal diameter, the length of the aneurysm and the detection of dissection was assessed for the reconstructions and the source images. Aneurysms and dissections of the aorta were correctly identified on source images. 2D MPR reconstructions and source images allow for a clear and easy image analysis including cases with high signal intensity or density of surrounding tissue and complex anatomical structures. The diameter and length of pathological findings can be determined correctly wit 2D MPR reconstructions, even when the vessel orientation is not exactly inplane or throughplane in relation to the source images. MIP reconstructions are suitable for contrast enhanced MRA data sets with high C/N ratio and volume rendering reconstructions are suitable for contrast enhanced CTA data sets, where calcifications and bone have also high density. For 3D visualization of large volumes MIP reconstructions are the method of choice for MRA and volume rendering reconstructions for CTA, respectively. In addition, 2D MPR can be necessary to determine the diameter and length of pathological findings.     

Verbesserung der Diagnostik von Lebermetastasen mit der Multi-Detektor-CT

The introduction of multidetector computed tomography in clinical routine creates a new dimension of increased spatial and temporal resolution in CT scanning. On the basis of the very short acquisition time, the whole liver can now be scanned within one breathhold. Multidetector-CT allows the examination of the liver with nearly isotropic data sets. This is the prerequisite for the optimal assessment of very small liver lesions in all planes and excellent enhancement of liver lesions in defined organic perfusion phases. The speed of multidetector-CT can either be used to reduce the time to cover a given volume, or to use narrower beam collimation to increase the resolution of details along the z-axis and to reduce volume averaging. We report our clinical experiences in hepatic multidetector-CT examinations and optimized examination protocols in the assessment of hepatic metastases. Multidetector-CT and the use of interactive multiplanar reconstructions improve the detection and characterization of liver metastases. However, new problems in data management may arise from the large amount of data generated by multidetector-CT.     

Transarterielle Chemoembolisation (TACE) von Lebermetastasen – Ein palliativer Therapieansatz

Metastatic involvement of the liver determines the treatment. Hepatic artery chemoembolization (TACE) represents a safe palliative treatment for patients with unresectable liver metastases. Technical treatment, indication and results of the TACE are reported. The results of TACE depend on primary cancer, size and vascularisation of the hepatic tumors. Our results with out patient treatment of 245 patients prove that TACE results in a extremely low rate of side effects. Combination of TACE with local ablative treatment may present potentially curative treatment option for unresectable tumors.     

Wert und Bedeutung der digitalen Vollfeldmammographie im Rahmen eines Mammographie-Screenings

To evaluate the digital technique for screening mammography various experimental studies and clinical examinations were performed by using direct full-field digital mammography (FFDM). The findings concerning the detectability and characterization of microcalcifications and soft tissue masses as well as the radiation exposure were compared to the state-of-the-art conventional screen-film mammography (SFM). The results of these studies revealed a high performance of the digital images, which are at least equivalent to the conventional images, whereas digital spot views were significantly superior to conventional ones particularly in the detection of microcalcifications. This was especially true, when the potential of post-processing was used. In addition, the sensitivity of FFDM should be increased, if computer-aided-diagnosis (CAD) is available. Furthermore, the patient radiation dose can be significantly reduced. Additional advantages are quick and easy handling, efficient data transfer and digital archiving. Thus, FFDM will become an important tool in screening mammography.     

Ultrasound anatomy of the shoulder joint during the growth period

AIM OF STUDY: It is the aim of this investigation to describe the normal ultrasonographical appearance of the glenohumeral joint in childhood. METHODS: Ultrasound investigation was performed in 20 healthy children aged between 6 weeks and 19 years (median: 6 years) using 12 MHz linear probes. A dynamic examination of both shoulders was carried out. Probe positions according to standard planes were used, and attention was paid to visualise the growth regions. RESULTS: Ultrasound images of the periarticular soft tissue in children do not differ markedly from those in adults. However, there are basic structural differences of the epiphyseal and apophyseal regions. In the newborn period the proximal humeral epiphysis mainly consists of cartilage and changes to the adult shape after the appearance of three secondary ossification centers and growth plates. Interestingly, the chondral buds of the acromion or coracoid process offer additional imaging facilities for ultrasound examination in children. CONCLUSIONS: Ultrasound examination of the glenohumeral joint in children offers a more precise evaluation when compared to adults, due to the presence of additional ultrasonographical "windows" and depiction of parts of the humeral epiphysis. This imaging technique is well tolerated by children.     

Benign bone-forming tumors

Benign bone-forming tumors include osteomas, enostomas, osteoid osteomas, and osteoblastomas. These lesions are often characterized by typical imaging findings on radiographs, CT and MR imaging studies. Radiologic findings and additional clinical information allow for a specific diagnosis in most cases. This review article emphasizes the radiological patterns of benign bone-forming tumors as well as their epidemiological, clinical, and pathological characteristics. In addition, minimally invasive interventional procedures for the therapy of osteoid osteoma are reviewed.     

“Open approach”– der “Fortschritt” zurück an den Beginn der Septorhinoplastik

Looking back at 150 years of the development of septorhinoplasty--50 of which I have experienced myself--one can conclude that recent developments go back to the nineteenth century. In the era of "minimal invasive surgery" the "open approach" to septorhinoplasty should no longer be indicated. The sublabial approach in the sense of minimal invasive surgery is recommended.     

Abhängigkeit des uni- und bilateralen Riechvermögens von der nasalen Strömung bei Patienten mit chronischer Rhinosinusitis

OBJECTIVE: Olfactory dysfunction is a common finding in patients with chronic rhinosinusitis (CRS). The aim of this study was to investigate the relationship between olfaction and nasal flow as determined by active anterior rhinomanometry (AAR). METHODS: Thirty patients with CRS were included in this series. Patients' histories and subjective assessments of olfaction were documented with questionnaires. Smell tests, assessments of olfaction, AAR, and results of rhinoscopy were recorded, including odor identification, discrimination and thresholds measured with the "Sniffin' Sticks"-test. RESULTS: CRS influenced olfactory performances variably in the different tests: 10% of the patients had pathologic rates of odor discrimination, compared with 34% in odor identification and 73% in thresholds. Statistical analyses (using Spearman's test) indicated a significant correlation between nasal airflow and odor identification screening (r29 = 0.56, P < 0.01) and n-butanol-threshold (r29 = 0.44, P < 0.05), respectively. CONCLUSION: Olfactory performance in CRS was correlated to several parameters of nasal airflow measured with AAR. The n-butanol threshold test revealed the most frequent pathological results and may best be used for detecting olfactory disorders. However, because a number of factors may influence olfactory dysfunction in CRS, our findings must be evaluated in a lager series.