[Successful therapy of metastatic basal cell carcinoma with vismodegib]. / Erfolgreiche Therapie eines metastasierten Basalzellkarzinoms mit Vismodegib.

A 71-year-old man presented with giant basal cell carcinoma on the abdomen which had metastasized. He was treated with oral vismodegib. Both the primary ulcerated tumor on the abdomen and the metastases responded. Vismodegib was well tolerated without significant side effects. The tumor recurred promptly after vismodegib was discontinued, and then was resistant to therapy when vismodegib was re-administered.

Effect of degeneration on gene expression of chondrogenic and inflammatory marker genes of intervertebral disc cells: a preliminary study.

AIM: New techniques for biological repair in the treatment of degenerative disc disease (DDD) have been developed recently. The question arises whether it is possible to find a predictive marker to identify a patient population which could benefit from this new treatment option. Standard magnetic resonance imaging (MRI) fails to differentiate between pathologic painful and asymptomatic aging discs. Neurological symptoms contribute to identifying the pathological level. In this preliminary translational research study we analysed the gene expression of structure proteins and inflammatory mediators as well as histological features of lumbar intervertebral discs in symptomatic patients with various signs of degeneration in the MRI. METHODS: Specimens of intervertebral disc tissue were obtained from 20 patients undergoing lumbar nucleotomy. Preoperatively, a group selection based on four pre-defined MRI-criteria was performed: Group 1 (mild signs of degeneration), group 2 (moderate), group 3 (moderate-severe), group 4 (severe). RESULTS: An increase of the expression of structural proteins and inflammatory markers could be observed in MRI-groups 2 and 3. Gene expression of collagen type I and II and aggrecan went along with levels of cyclooxygenase-2 (COX-2) and (fibroblast growth factor-2) FGF-2 expression. Histological examination showed signs of granulation tissue in only 35% of cases, but no differences between the groups. CONCLUSION: Our findings implicate that the gene expression of structural proteins might correlate with the appearance of inflammatory mediators in symptomatic patients with moderate disc changes in the MRI in this preliminary clinical subset. The assessment of cell activity and protein expression in a larger number of patients could be next step to support and supplement the present data.

[The balanced scorecard--applications in a radiology department]. / Die Balanced Scorecard--Anwendungsmöglichkeiten in der Radiologie.

The balanced scorecard (BSC) represents a comprehensive management tool for organizations with the aim to focus all activities on a chosen strategy. Targets for various perspectives of the environment such as the customer, financial, process, and potential perspective are linked with concrete measures, and cause-effect relationships between the objectives are analyzed. This article shows that the BSC can also be used for the comprehensive control of a radiology department and thus provides a meaningful contribution in organizing the various diagnostic and treatment services, the management of complex clinical environment and can be of help with the tasks in research and teaching.

Magnetic resonance imaging of orbital tumors.

This contribution provides an overview of diseases of eye and orbit and their appearance on magnetic resonance imaging. In recent years the diagnosis of eye and orbit pathology has profited significantly from increasingly sophisticated technical developments in the field of tomographic methods. Due to the small size of the examination area the improvement in spatial resolution and soft tissue contrast leads to an increase in image quality. In most clinical questions concerning eye and orbit pathologies magnetic resonance imaging is superior to computed tomography and should be early performed.

Thermography as potential real-time technique to assess changes in flow distribution in hemofiltration.

Flow distributions are critical determinants in the function of hemofilters. Despite their importance, however, flow distributions cannot currently be measured in filters during experimental or clinical applications. Here, we demonstrate that the thermal conduction properties of extracorporeal circuits may provide a tool to overcome this limitation. More specifically, we show that thermography provides an indirect approach to visualize differences in regional perfusion rates through temperature profiles on the filter surface. Thermograms were recorded using a TVS700 system (Ca. Goratec) during recirculating in vitro hemofiltration of porcine blood. Different test protocols were executed to characterize the contribution of thermal conduction and convection to the measurable changes in the temperature at the surface of the filter housing. For comparison and validation, these experiments were supplemented by computer tomography (CT) of filters after dye injection. Thermography enabled real-time visualization of the flow distributions in a hemofilter. Moreover, 'point' trends taken from different regions of the filter provided quantitative information about changes of flow distributions in response to changing experimental conditions. Our preliminary data suggest that thermography is a promising new approach for assessing the principles and time-related changes in flow distributions in hemofiltration. As expected, resolution is lower than that in CT measurements and further studies will be necessary to determine the smallest temperature gradient that still identifies differences in regional perfusion rates. Given its potential to develop into an inexpensive tool for the 'bedside' level monitoring of flow distributions during clinical studies, further investigation of thermography is highly desirable.

[Appearance of orbital diseases on MRI]. / Orbitaerkrankungen und ihr Erscheinungsbild in der MRT.

We provide an overview of diseases of the orbit and their MR imaging appearance. Over recent years MRI has become established in the diagnosis of orbit diseases. There is a selection of different surface coils for examination. The choice of surface coil depends on the clinical question and the anatomical region under consideration. In addition, the significance of the different sequences and the value of contrast medium administration are discussed.

[Ultrasound contrast agents for liver diagnostics]. / Ultraschallkontrastmittel in der Leberdiagnostik.

Ultrasound contrast agents have achieved a high level of acceptance in diagnostics of liver tumors. Contrast-enhanced ultrasound can, on the one hand, be used for detection of liver tumors, e.g., during the search for metastases in tumor staging, and, on the other hand, for tumor characterization. The dispersion behavior of the ultrasound contrast agent plays a decisive role in the characterization and the enhancement patterns correspond to a large extent to those already known from contrast-enhanced computed tomography. Contrast-enhanced ultrasound can also be employed for monitoring ablative tumor therapies, visualization of vessels difficult to depict, and measurement of the so-called liver transit time.

[Morphometric analysis of the temporomandibular joint with MRI in 320 joints]. / Morphometrische Analyse des Kiefergelenkes anhand von 320 Gelenken mit der MRT.

PURPOSE: To compare several morphometric parameters in MRI with the functional status of the articular disc in a large patient group suffering from internal derangement (ID) of the temporomandibular joint (TMJ). MATERIALS AND METHODS: In a retrospective study, 320 analyzable high resolution MRI examinations of the TMJs obtained in a 1.5 T unit were evaluated in 184 patients with clinically suspected ID. The analysis included the anatomical structures and a number of morphometric parameters previously described in the literature. The parameters were compared with the position of the articular disc. RESULTS: The disc position was categorized as "normal" (NDP, 21.9 %, n = 70), "anterior displacement with reduction on opening" (AMR, 51.6 %, n = 165) and "anterior displacement without reduction on opening" (AOR, 26.6 %, n = 85). With increasing disc displacement, significant configurational changes of the disc were observed. Disc displacement was associated with changes of the condyle consisting of increasing deformity and other degenerative changes. A large tuberculum and marked inclination of the eminence can be seen as predisposition for the development of ID. With increasing severity of the ID, the position of the condyle moved from a centric position of the condylar center to an excentric (dorsal and cranial) position. CONCLUSION: MRI demonstrated that increasing disc displacement is associated with changes of the disc, condyles and condylar position in the fossa.

Value of image fusion using single photon emission computed tomography with integrated low dose computed tomography in comparison with a retrospective voxel-based method in neuroendocrine tumours.

The objective was the evaluation of single photon emission computed tomography (SPECT) with integrated low dose computed tomography (CT) in comparison with a retrospective fusion of SPECT and high-resolution CT and a side-by-side analysis for lesion localisation in patients with neuroendocrine tumours. Twenty-seven patients were examined by multidetector CT. Additionally, as part of somatostatin receptor scintigraphy (SRS), an integrated SPECT-CT was performed. SPECT and CT data were fused using software with a registration algorithm based on normalised mutual information. The reliability of the topographic assignment of lesions in SPECT-CT, retrospective fusion and side-by-side analysis was evaluated by two blinded readers. Two patients were not enrolled in the final analysis because of misregistrations in the retrospective fusion. Eighty-seven foci were included in the analysis. For the anatomical assignment of foci, SPECT-CT and retrospective fusion revealed overall accuracies of 91 and 94% (side-by-side analysis 86%). The correct identification of foci as lymph node manifestations (n=25) was more accurate by retrospective fusion (88%) than from SPECT-CT images (76%) or by side-by-side analysis (60%). Both modalities of image fusion appear to be well suited for the localisation of SRS foci and are superior to side-by-side analysis of non-fused images especially concerning lymph node manifestations.

[Digital knowledge in the coat pocket -- hand-held personal digital assistants in radiology]. / Digitales Wissen in der Kitteltasche -- Taschencomputer (Handhelds) in der Radiologie.

The personal digital assistant (PDA) enables the independent access to large data in a pocket-sized format. The applications for hand-held computers are growing steadily and can support almost any kind of problem. An overview of the available hardware and software is provided and evaluated. Furthermore, the use of the PDA in the clinical daily routine is described. In view of the numerous software programs available in radiology, the range of software solutions for radiologists is presented. Despite the high acquisition cost, the PDA has already become the digital assistant for the radiologist. After a short time of getting used to the PDA, nobody wants to miss it at work or at home. New technical features and available software programs will continuously increase the integration of the PDA into the medical workflow in the near future.

[Clinical use of digital retrospective image fusion of CT, MRI, FDG-PET and SPECT -- fields of indications and results]. / Klinischer Einsatz der digitalen retrospektiven Bildfusion von CT, MRT, FDG-PET und SPECT -- Anwendungsgebiete und Ergebnisse.

PURPOSE: To evaluate the feasibility and the clinical benefits of retrospective digital image fusion (PET, SPECT, CT and MRI). MATERIALS AND METHODS: In a prospective study, a total of 273 image fusions were performed and evaluated. The underlying image acquisitions (CT, MRI, SPECT and PET) were performed in a way appropriate for the respective clinical question and anatomical region. Image fusion was executed with a software program developed during this study. The results of the image fusion procedure were evaluated in terms of technical feasibility, clinical objective, and therapeutic impact. RESULTS: The most frequent combinations of modalities were CT/PET (n = 156) and MRI/PET (n = 59), followed by MRI/SPECT (n = 28), CT/SPECT (n = 22) and CT/MRI (n = 8). The clinical questions included following regions (more than one region per case possible): neurocranium (n = 42), neck (n = 13), lung and mediastinum (n = 24), abdomen (n = 181), and pelvis (n = 65). In 92.6 % of all cases (n = 253), image fusion was technically successful. Image fusion was able to improve sensitivity and specificity of the single modality, or to add important diagnostic information. Image fusion was problematic in cases of different body positions between the two imaging modalities or different positions of mobile organs. In 37.9 % of the cases, image fusion added clinically relevant information compared to the single modality. CONCLUSION: For clinical questions concerning liver, pancreas, rectum, neck, or neurocranium, image fusion is a reliable method suitable for routine clinical application. Organ motion still limits its feasibility and routine use in other areas (e. g., thorax).

[Characterization of hepatic tumors with contrast-enhanced ultrasound and digital grey-scale analysis]. / Charakterisierung von Lebertumoren durch kontrastverstärkte Sonographie und digitale Graustufenbestimmung.

PURPOSE: The characterization of different liver tumors is of therapeutic and prognostic relevance and has been the purpose of several studies. Although ultrasound offers the opportunity to detect hepatic tumors without ionizing radiation, its previous techniques did not lead toward a definitive differentiation of different tumor entities. The purpose of this study was the clinical evaluation of contrast enhanced ultrasound followed by quantitative digital analysis in patients with focal hepatic tumors. MATERIALS AND METHODS: In a prospective study, 50 patients (18 females, 32 males, age 28 to 83 years, mean age 59.4 years) with liver tumors previously detected by CT (n = 47) or MRI (n = 3) were examined by ultrasound of the upper abdomen using conventional technique and phase inversion technique after intravenous application of sulfur-based contrast enhancer SonoVue. At scheduled intervals after application of the contrast enhancer, a digital image was stored and the characteristic signal course of each lesion determined semiquantitatively. The gold standard was either resection (n = 17), percutaneous needle biopsy (n = 19) or the clinical course (n = 14). RESULTS: While the percentage of tumors correctly characterized by CT/MRI amounted to 78 %, the percentage increased from 60 % using conventional ultrasound to 86 % using contrast enhanced ultrasound including grey-scale analysis. Typical graphs were achieved for different tumor entities on digital grey-scale analysis. The optimal intervals for the differentiation of particular entities were 20 and 100 seconds after injection. CONCLUSION: Quantification of contrast enhanced ultrasound is an addition to the previous diagnostic procedure in hepatic tumors. It offers the possibility of an investigator-independent characterization of lesions and should be evaluated in further studies.

[Virtual MR endoscopy of the ventricles prior to neurosurgical interventional endoscopy -- evaluation of different presentation techniques]. / Virtuelle MR-Ventrikelendoskopie vor neurochirurgischer interventioneller Endoskopie -- Evaluierung verschiedener Darstellungstechniken.

PURPOSE: In the past, virtual endoscopies have been performed for planning of endoscopic interventions or for diagnostic purposes in various organ systems with increasing frequency. This study evaluates the ability of virtual ventricular endoscopy to depict anatomical structures and the use for planning of real endoscopy. MATERIALS AND METHODS: In a prospective study, 4 volunteers and 8 patients were examined with MRI. In 3 of the patients endoscopy was performed by our neurosurgeons thereafter. The calculation of the virtual endoscopy was based on 1 mm sagittal T2-weighted images. Comparison of surface rendering and volume rendering was made by means of video sequencing of individual views, and these were compared with the intraoperative endoscopic videos concerning the depictability of anatomical landmarks. RESULTS: The reconstructions using volume rendering were more significant and easier to calculate than those based on surface rendering. Virtual endoscopy in the transparent mode allowed visualization of hazardous structures outside the ventricular system such as the basilar artery tip. Transparent 3D images of the ventricles gave a good overview on the depicted structures and enabled a better orientation during the virtual camera flight than surface rendered views. CONCLUSION: MR-based virtual endoscopy of the ventricular system can be obtained on the basis of surface- and volume-rendered views of sagittal T2-weighted thin sections. Preoperative utilization of this method simplifies the planning of endoscopy by visualization of anatomical structures.

[Differential diagnosis of intraconal orbital masses using high-resolution MRI with surface coils in 78 patients]. / Differenzialdiagnostik intrakonaler orbitaler Raumforderungen unter Verwendung der hochauflösenden MRT mit Oberflächenspulen anhand von 78 Patienten.

PURPOSE: Over the last decade, MRI has become the standard procedure for the diagnosis of orbital masses. Purpose of the study was to evaluate criteria for differential diagnosis for intraconal masses on MRI in a large patient group. MATERIAL AND METHODS: In a retrospective study, MR examinations of 78 patients with intraconal masses were evaluated. All examinations were performed using surface coils for high spatial resolution. Signal behavior on T2-WI and T1-WI before and after contrast application as well as further tumor characteristics (i. e., shape, size, position, delineation and infiltration) were evaluated. Every diagnosis was proven by histopathological results from extirpation (n = 18) or biopsy (n = 22), or confirmed by other imaging modalities (n = 13) or clinical course (n = 25). RESULTS: Different tumor characteristics are helpful in the differentiation between cavernous hemangioma, lymphangioma, varices, AV malformations and solid tumors. Due to overlapping in the imaging appearance, the differentiation between inflammatory pseudotumor, lymphoma and orbital metastasis was more difficult. CONCLUSION: While high resolution MRI using surface coils allows differentiation between the typical vascular tumors, the differentiation between solid tumors is more difficult. Thus, a histopathologic verification of the diagnosis is necessary in solid tumors.

MRI after magnetic drug targeting in patients with advanced solid malignant tumors.

The purpose of this study was to evaluate the ability of MRI to detect magnetic particle uptake into advanced solid malignant tumors and to document the extension of these tumors, carried out in the context of magnetic drug targeting. In a prospective phase I trial, 11 patients were examined with MRI before and after magnetic drug targeting. The sequence protocol included T1-WI and T2-WI in several planes, followed by quantitative and qualitative evaluation of the signal intensities and tumor extensions. In nine patients, a signal decrease was observed in the early follow-up (2-7 days after therapy) on the T2-weighted images; two patients did not show a signal change. The signal changes in T1-WI were less distinct. In late follow-up (4-6 weeks after therapy), signal within nine tumors reached their initially normal level on both T1-WI and T2-WI; two tumors showed a slight signal decrease on T2-WI and a slight signal increase on T1-WI. Within the surveillance period, tumor remission in 3 out of 11 patients was observed, and in 5 patients tumor growth had stopped. The remaining three patients showed significant tumor growth. There was no statistically significant correlation between signal change and response. MRI is a suitable method to detect magnetite particles, deposited at the tumor site via magnetic drug targeting. MRI is therefore eligible to control the success of MDT and to assess the tumor size after the end of therapy.

Preoperative localization of parathyroid glands. Use of MRI, scintigraphy, and image fusion.

AIM: Minimally invasive resection of hyperfunctional parathyroid glands is an alternative to open surgery. However, it requires a precise preoperative localization. This study evaluated the diagnostic use of magnetic resonance (MR) imaging, parathyroid scintigraphy, and consecutive image fusion. PATIENTS, METHODS: 17 patients (9 women, 8 men; age: 29-72 years; mean: 51.2 years) with primary hyperparathyroidism were included. Examination by MRI used unenhanced T1- and T2-weighted sequences as well as contrast-enhanced T1-weighted sequences. (99m)Tc-MIBI scintigraphy consisted of planar and SPECT (single photon emission tomography) imaging techniques. In order to improve the anatomical localization of a scintigraphic focus, SPECT-data were fused with the corresponding MR-data using a modified version of the Express 5.0 software (Advanced Visual Systems, Waltham, MA). Results of image fusion were then compared to histopathology. RESULTS: In 14/17 patients, a single parathyroid adenoma was found. There were 3 cases with hyperplastic glands. MRI detected 10 (71%), scintigraphy 12 (86%) adenomas. Both modalities detected 1/3 patients with hyperplasia. Image fusion improved the anatomical assignment of the 13 scintigraphic foci in five patients and was helpful in the interpretation of inconclusive MR-findings in two patients. CONCLUSIONS: Both MRI and (99m)Tc-MIBI scintigraphy sensitively detect parathyroid adenomas but are less reliable in case of hyperplastic glands. In case of a scintigraphic focus, image fusion considerably improves its topographic assignment. Furthermore, it facilitates the evaluation of inconclusive MRI findings.

Diagnosis of neuroendocrine tumours by retrospective image fusion: is there a benefit?

This study evaluated the use of image fusion in the preoperative staging of neuroendocrine tumors (NET) of the pancreas and the gastrointestinal tract (GIT). Thirty-eight patients suffering from a metastasized NET with location of the primary in the pancreas ( n=15) or the GIT ( n=23) were examined by somatostatin receptor scintigraphy (SRS) and computed tomography (CT). Consecutive image registration and fusion were performed using custom-built software integrated in AVS/Express (Advanced Visual Systems, Waltham, MA, USA). Registration was performed by a voxel-based algorithm based on normalized mutual information. Image fusion was feasible in 36/38 patients. A total of 87 foci were assigned to anatomical regions (e.g. gut, pancreas, liver, lymph node or others) by two independent observers in both SRS and SRS/CT fusion images. The assignments used a binary ranking system (1="definite", 0="not definite"). These results were then retrospectively compared to the classification of the foci, based on postoperative histology or clinical follow-up. Imaging by SRS allowed a definite anatomical assignment in 57% (50/87) and 61% (53/87) of all lesions in the case of observers A and B, respectively. Image fusion improved the topographic assignment to 91% (79/87) and to 93% (81/87). The number classified as "definite" by both observers increased from 54% (47/87) to 86% (77/87). The increase in definite assignments was highly significant for both observers ( P<0.0001 for each). In the case of foci classified as liver metastases, image fusion allowed improved assignment to the corresponding liver segment from 45% (18/40) to 98% (39/40) and from 58% (23/40) to 100% (40/40) by observers A and B, respectively. Furthermore, the improved assignment of foci classified as lesions by image fusion was relevant for therapy in 7/36 patients (19%). Therefore, the image fusion technique presented herein appears to be a very useful method for clinical routine.