[Current reporting in radiology : what will happen tomorrow?]. / Befundung in der Radiologie heute : Was kommt morgen?

CLINICAL/METHODICAL ISSUE: Reporting in radiology faces considerable changes in the near future that will be influenced by a broader understanding of the task and increasing technological possibilities. STANDARD RADIOLOGICAL METHODS: Until now a radiological report could be regarded as a text phrased by a radiologist after viewing imaging data. METHODICAL INNOVATIONS: New solutions will be accessed by advances in visualization of large datasets, in extracting, analyzing, and communicating metadata as well as by improved integration and interpretation of clinical information. PERFORMANCE: Virtual reality, texture analysis, growing networks, semantic annotation, data mining and context based presentation have the potential to extensively change the everyday working routine. ACHIEVEMENTS: Although many of these developments are still in a laboratory phase, the impact on the process of reporting can already be predicted. PRACTICAL RECOMMENDATIONS: As the leading community in information analysis and technology, radiology as a subject should strive to lead and shape these impending changes.

[Structured reporting in radiology]. / Strukturierte Befundung in der Radiologie.

The radiology report plays a key role in the radiological procedure and is used both for documentation of internal procedures as well as in a variety of communication processes within and outside the radiology department. Due to the various communication processes the question arises whether and how the report should be structured. The first stage of such a structured report implies a thematic structure only. This corresponds to the current practice in Germany whereby the reports are structured according to the X-ray act. In the second stage a structure of the contents is added, which is usually implemented by selecting predefined text modules. In the third stage the wording of the text modules is selected from controlled vocabularies, such as the RadLex which allows complete encoding of the report. Templates like this are provided by the Radiological Society of North America (RSNA) reporting initiative and are available to the general public. As advantages of structured reports of levels 2 and 3 it is expected that they provide a better structure and greater clarity of the findings to the referring physician. By using predefined blocks of text a higher degree of completeness and a shorter reporting time is expected. These benefits have been tested in several studies but have not yet yielded clear results. Within a radiology department the structured reports are communicated according to the integrating the healthcare enterprise (IHE) controlled reporting workflow as DICOM structured reports and outside radiology departments the reports are exchanged as CDA objects using HL7 standards.

[Negative-pressure pulmonary edema after general anaesthesia. Imaging diagnostic procedure]. / Unterdrucklungenödem nach Allgemeinanästhesie. Bildgebende Diagnostik im Verlauf.

Negative-pressure pulmonary edema is not a rare complication, e.g. in general anaesthesia and the diagnosis is made predominantly by clinical findings. When clinical findings are not clear radiology is necessary. This case report with detailed radiologic diagnostics, including follow-up, shows which radiologic signs are important for the clinical assessment to obtain a precise diagnosis and to start an adequate therapy.

[Value of diffusion-weighted imaging for diagnosing vertebral metastases due to prostate cancer in comparison to other primary tumors]. / Stellenwert der Diffusionsbildgebung in der Diagnostik von Wirbelkörpermetastasen des Prostatakarzinoms im Vergleich zu anderen Primärtumoren.

PURPOSE: Several publications have reported that the apparent diffusion coefficient is generally lower in metastatically affected vertebrae. Therefore, metastases are represented in diffusion-weighted images by increased signal intensity in comparison to unaffected vertebrae. However, there were indications that metastases due to prostate cancer may differ from this. Therefore, the contrast behavior of vertebral metastases due to prostate cancer or tumors with another histology are to be systematically studied using diffusion-weighted images. The present study is intended to examine whether the two groups differed and whether possible differences depended on the degree of sclerosis. MATERIALS AND METHOD: In a retrospective study the vertebral metastases of patients with prostate cancer (n = 18) were compared to those of patients with tumors of another histology (n = 20). A steady-state free precession sequence was used for the diffusion-weighted imaging. Additionally, a T1 weighted sequence before and after administration of contrast agent as well as a fat suppressed T2 weighted sequence were performed. The contrast behavior of the metastases was evaluated for all four sequences and was compared to that of the unaffected parts of the vertebra. RESULTS: In 18 patients of the tumor group, the vertebral metastases showed positive contrast in the diffusion-weighted images, and 2 had minimally negative contrast up to - 0.04. In the prostate cancer group, the contrast was positive in 9 patients and negative in 9. 6 of the metastases with negative contrast had an osteoblastic metastasization, 1 had an osteolysis, and 1 had a normal finding in the conventional X-ray image. Between the tumor group and the prostate cancer group, the medians of the contrasts were not significantly different (p = 0.054). CONCLUSION: In general, the metastatically affected vertebrae appear hyperintense in the diffusion-weighted images. This observation is only true for some vertebral metastases due to prostate cancer. The cause for this seems to be the degree of sclerosis of the metastases. Thus, it cannot be generally deduced from the hypointensity in diffusion-weighted images that a lesion is benign.

[Comparison of time-oriented cost accounting catalogs to control a department of radiology]. / Vergleich zeitorientierter Leistungskataloge zum Controlling einer radiologischen Abteilung.

PURPOSE: Within a hospital, the radiology department has taken over the role of a cost center. Cost accounting can be applied to analyze the costs for the performance of services. By assigning the expenditures of resources to the service, the cash value can directly be distributed to the costs of equipment, material and rooms. Time-oriented catalogs of services are predefined to calculate the number of the employees for a radiology department. Using our own survey of time data, we examined whether such catalogs correctly represent the time consumed in a radiology department. Only services relevant for the turnover were compared. MATERIALS AND METHODS: For 96 primary radiological services defined by the score-oriented German fee catalog for physicians (Gebuhrenordnung fur Arzte), a ranking list was made for the annual procedures in descending frequency order. According to the Pareto principle, the 11 services with the highest frequency were chosen and the time consumed for the technical and medical services was collected over a period of 2 months. This survey was compared with the time-oriented catalogs TARMED and EBM 2000plus. RESULTS: The included 11 relevant radiological services represented 80.3 % of the annual procedures of our radiology department. When comparing the technical services between the time-oriented catalogs and our own survey, TARMED gives a better description of the time consumed in 7 of the 11 services and EMB 2000plus in 3 services. When comparing the medical services, TARMED gives a better description of the time consumed in 6 of the 11 services and EBM 2000plus in 4 services. When averaging all the radiological services, TARMED overestimates the current number of physicians necessary for primary reading by a factor of 10.0 % and EBM 2000plus by a factor of 2.6 %. CONCLUSION: As to the time spent on performing the relevant radiological services, TARMED is slightly superior to describe the radiology department of a hospital than EBM 2000plus. For calculating the number of physicians necessary for primary reading, EBM 2000plus is superior to TARMED.

[Computer simulation of a clinical magnet resonance tomography scanner for training purposes]. / Computersimulation eines klinischen Magnetresonanztomographen für Ausbildungszwecke.

PURPOSE: The idea for this project was born by the necessity to offer medical students an easy approach to the theoretical basics of magnetic resonance imaging. The aim was to simulate the features and functions of such a scanner on a commercially available computer by means of a computer program. MATERIALS AND METHODS: The simulation was programmed in pure Java under the GNU General Public License and is freely available for a commercially available computer with Windows, Macintosh or Linux operating system. The graphic user interface is oriented to a real scanner. In an external program parameter, images for the proton density and the relaxation times T1 and T2 are calculated on the basis of clinical examinations. From this, the image calculation is carried out in the simulation program pixel by pixel on the basis of a pulse sequence chosen and modified by the user. The images can be stored and printed. In addition, it is possible to display and modify k-space images. RESULTS: Seven classes of pulse sequences are implemented and up to 14 relevant sequence parameters, such as repetition time and echo time, can be altered. Aliasing and motion artifacts can be simulated. As the image calculation only takes a few seconds, interactive working is possible. CONCLUSION: The simulation has been used in the university education for more than 1 year, successfully illustrating the dependence of the MR images on the measuring parameters. This should facititate the approach of students to the understanding MR imaging in the future.

[Development of a secure and cost-effective infrastructure for the access of arbitrary web-based image distribution systems]. / Entwicklung einer sicheren und kostengünstigen Infrastruktur zum Zugriff auf beliebige webbasierte Bildverteilungssysteme.

PURPOSE: To build an infrastructure that enables radiologists on-call and external users a teleradiological access to the HTML-based image distribution system inside the hospital via internet. In addition, no investment costs should arise on the user side and the image data should be sent renamed using cryptographic techniques. MATERIALS AND METHODS: A pure HTML-based system manages the image distribution inside the hospital, with an open source project extending this system through a secure gateway outside the firewall of the hospital. The gateway handles the communication between the external users and the HTML server within the network of the hospital. A second firewall is installed between the gateway and the external users and builds up a virtual private network (VPN). A connection between the gateway and the external user is only acknowledged if the computers involved authenticate each other via certificates and the external users authenticate via a multi-stage password system. All data are transferred encrypted. External users get only access to images that have been renamed to a pseudonym by means of automated processing before. RESULTS: With an ADSL internet access, external users achieve an image load frequency of 0.4 CT images per second. More than 90 % of the delay during image transfer results from security checks within the firewalls. Data passing the gateway induce no measurable delay. CONCLUSION: Project goals were realized by means of an infrastructure that works vendor independently with any HTML-based image distribution systems. The requirements of data security were realized using state-of-the-art web techniques. Adequate access and transfer speed lead to a widespread acceptance of the system on the part of external users.

[Standardizing the radiologic report -- norm DIN 6827-5]. / Standardisierung des radiologischen Befundberichtes -- Norm DIN 6827-5.

PURPOSE: According to the current German "Rules and Regulation for the Application of X-rays" (RöV), a radiological report has to be issued whenever a person undergoes an examination involving x-rays. Since the RöV is not specific as to its contents, the German Radiology Standards Committee (NAR) has developed a standard for the reports. The scope of this reporting standard was expanded beyond x-ray procedures to all imaging modalities. MATERIALS AND METHODS: The radiologic report describes the type of examination performed on the patient. Following the "DICOM Structured Report" information model, the report is structured in form of a document tree. The report must be archived in printed form or digitally. RESULTS: The report is thematically divided into six sections. Within each section, the data are condensed to the smallest still meaningful information unit. For each entry, it is stated whether it is obligatory or optional. CONCLUSION: The reports according to the standards of the NAR comply with the RöV. Standards prescribing a structure can be used as guide for uniform reporting, as appropriate for printed reports. By consistently following the DICOM standards, future international standards for medical contents can be integrated into radiologic reports.

Recovery of motor functions following hemiparetic stroke: a clinical and magnetic resonance-morphometric study.

Predictors for the degree of clinical recovery after stroke are still poorly defined. In this study we tried to assess the predictive value of clinical data and of lesion size for motor recovery after ischemic stroke. In 52 hemiparetic patients we monitored the course of clinical recovery by a dedicated score of sensorimotor hand function after their first stroke. The course of the lesion size was measured in proton density magnetic resonance images. Three groups of patients were identified. Patients with moderate initial motor deficit recovered almost completely within 9 days (17/17, group 1). From the patients with severe initial motor deficit, about equal numbers recovered (16/35, group 2) or remained severely impaired during the entire observation period of more than 6 months (19/35, group 3). There was no correlation between changes of lesion size and motor deficit. Logistic regression of probability of good clinical outcome on initial lesion size, initial motor score and subcortical versus cortical location of lesion showed that only the initial motor score was predictive (p = 0.006). A relative improvement of the initial motor score of about 20% in the first 4 weeks after stroke appeared to be a relevant cut point for good outcome. The data indicate that patients with mild initial motor deficits recover well, whereas severely affected patients may differ in outcome. Since lesion size was not correlated with outcome the amount of spared residual function appeared as major determinant for the capacity for motor recovery.

Comparison of cerebral blood volume measurements using the T1 and T2* methods in normal human brains and brain tumors.

PURPOSE: Regional cerebral blood volume (rCBV) can be determined after bolus injection of a contrast agent by utilizing the susceptibility effect (T2* method) or the relaxation effect (T1 method). The aim of this study was to apply both methods in groups of normal subjects and tumor patients and to compare the results. METHOD: CBVs in different brain areas were determined from groups of 18 normal subjects and 21 patients with different histologically classified tumors. Measurements were performed using GE sequences on a 1.5 T scanner without echo planar imaging capability. As a measure of quality of a single examination, the temporal behavior of the contrast agent bolus was characterized using parameters such as rise time, peak value, fall time, and full width at half-maximum of the concentration-time curves. RESULTS: The quality of the T2* measurements was inferior to that obtained with the T1 method. A mean CBV value of 4.1 + 1.1 vol% averaged over the entire brain area was found in the normal collective with the T1 method. The value obtained with the T2* method was 2.6 +/- 1.1 vol%. Similar underestimations of the CBV values were also found using the T2* method when evaluating regions of interest in tumor patients. CONCLUSION: Both methods are able to determine rCBV in routine clinical studies. If the goal is to obtain quick, qualitative multislice information, the T2* method is adequate. For quantitative evaluations, however, the T1 method should be preferred.

Effect of partial volume correction on muscarinic cholinergic receptor imaging with single-photon emission tomography in patients with temporal lobe epilepsy.

Animal experiments and preliminary results in humans have indicated alterations of hippocampal muscarinic acetylcholine receptors (mAChR) in temporal lobe epilepsy. Patients with temporal lobe epilepsy often present with a reduction in hippocampal volume. The aim of this study was to investigate the influence of hippocampal atrophy on the quantification of mAChR with single photon emission tomography (SPET) in patients with temporal lobe epilepsy. Cerebral uptake of the muscarinic cholinergic antagonist [123I]4-iododexetimide (IDex) was investigated by SPET in patients suffering from temporal lobe epilepsy of unilateral (n=6) or predominantly unilateral (n=1) onset. Regions of interest were drawn on co-registered magnetic resonance images. Hippocampal volume was determined in these regions and was used to correct the SPET results for partial volume effects. A ratio of hippocampal IDex binding on the affected side to that on the unaffected side was used to detect changes in muscarinic cholinergic receptor density. Before partial volume correction a decrease in hippocampal IDex binding on the focus side was found in each patient. After partial volume no convincing differences remained. Our results indicate that the reduction in hippocampal IDex binding in patients with epilepsy is due to a decrease in hippocampal volume rather than to a decrease in receptor concentration.

[Dependence of axis deviation in the esophagram on computerized tomography determined wall thickness and its value in assessing depth of invasion of esophageal carcinoma]. / Abhängigkeit der Achsdeformierungen im Osophagogramm von der computertomographisch bestimmten Wanddicke und deren Wertigkeit bei der Beurteilung der Invasionstiefe des Osophaguskarzinoms.

PURPOSE: In this study we compared the abnormalities of the esophageal axis seen in the esophagogram with the thickness of the esophageal wall measured by computed tomography. We have investigated, how exactly both methods assess the local tumor invasion according to the TNM criteria and whether there is a relation between the esophageal axis and the wall thickness. METHODS: In a retrospective study we examined the esophagograms of 65 tumor patients. Computed tomography examinations were available in 40 cases. Using a graphical method the wall thickness was transferred to the esophagograms under consideration of the different scales of the images. RESULTS: There is no correlation between the different types of distortion of the esophageal axis and the wall thickness in computed tomography. However, it can be demonstrated that the distortion results from specific fixation effects with the surrounding tissue. CONCLUSIONS: Both radiological methods cannot determinate the tumor invasion correctly.

1H T1 and T2 measurements of the MR imaging contrast agents Gd-DTPA and Gd-DTPA BMA at 1.5T.

We report in vitro T1 and T2 relaxation studies for the open-chain complexes Gd-DTPA and Gd-DTPA BMA. Measurements were performed on phantoms containing aqueous and plasma solutions of different concentrations by MR imaging in a 1.5T superconducting whole-body scanner. Longitudinal relaxation times T1 were evaluated from serial turbo-FLASH experiments for concentrations less than 1 mM, whereas for larger concentrations the values were obtained from a standard inversion recovery (IR) sequence. Transverse relaxation times T2 were determined using multi-echo spin-echo MRI protocols. The T1 and T2 relaxivities of the nonionic Gd-DTPA BMA are similar to those of the Gd-DTPA. The temperature dependencies of the relaxivities were determined over a temperature interval ranging from 21 to 50 degrees C and were found to be slightly different for the two contrast agents. In the case of Gd-DTPA BMA a larger deviation of the expected temperature behavior of the relaxivities was observed as compared with Gd-DTPA. Deviations from a strictly linear dependence of relaxation times on temperature were found at lower concentrations in aqueous solutions. In plasma solutions a high T1/T2 ratio was observed for low concentrations, which decreased monotonically with increasing concentrations.

An efficient and robust PC program to calculate MR based regional cerebral blood volume maps.

In addition to morphological and anatomical information, functional information is increasingly used in clinical routine to assess pathological alterations of the brain. In addition to nuclear-medical methods there is a growing interest in using magnetic resonance imaging (MRI) to investigate tissue perfusion of the brain. The method employed is based on the indicator-dilution method after bolus injection of a contrast agent. In this paper we present the implementation of an efficient algorithm to calculate quantitatively the regional cerebral blood volume (rCBV). Computation requires about 1 min on a Macintosh Quadra 660AV. The results are represented as parameter images that allow global overall visual inspection as well as quantitative local evaluation by means of user-defined regions of interest.

[Value of the esophagogram in preoperative assessment of esophageal carcinoma]. / Stellenwert des Osophagogramms bei der präoperativen Einschätzung des Osophaguskarzinoms.

PURPOSE: In this study we utilized barium swallows exhaustively in each patient. After that we compare the results with the intraoperative findings. The goal is to select those criteria which contribute to the preoperative clinical staging of esophageal carcinoma. METHODS: In a retrospective study we examined the esophagograms of 65 tumor patients. We evaluated the location and length of the tumor, the deformation of the esophageal axis, stenosis, dilatation, and the radiological type of the tumor. All characteristics were correlated with the pathologically determined TNM-criteria, the stage of the tumor, and the palliative or curative type of resection. RESULTS: We found the following significant correlations: localisation/T-criterion, radiological type/T-and M-criteria, stenosis/type of resection, deformation of the axis, stenosis and radiological type/tumor stage. CONCLUSION: In the sense of a checklist the stenosis, the deformation of the esophageal axis and the radiological type of the tumor should be carefully evaluated and included in the report. With these data, the clinical stage of the tumor can be estimated.