[Prostate carcinoma]

Prostate cancer is the most common malignancy in men in Europe, North America, and in some African states. Early diagnosis in an asymptomatic stage is possible through the combination of digitorectal examination, PSA serum testing, and systematic biopsy. However, general screening is so far not recommended by the Urologic Societies, because the efficiency is not yet proved. Imaging is also not recommended for first-line screening. Novel functional methods of transrectal ultrasound (TRUS) and endorectal MRI can improve accuracy of tumor detection to more than 90% and can be used for TRUS- and now also MRI-guided biopsy leading to two- to threefold higher tumor detection rates. There is general agreement that all men over 50 years of age should be informed about the possibilities, benefits, and risks of the available methods for early tumor detection.

[Cost considerations for whole-body MRI and PET/CT as part of oncologic staging]

PURPOSE

The aim of this study was to evaluate and discuss economic aspects of whole-body MRI and PET/CT in oncologic staging. Considerations from the perspective of the health care system, the radiologist, and the patients are presented.

MATERIALS AND METHODS

Costs of both whole-body techniques are compared with the conventional radiologic diagnostic recommendations of the AWFM (Arbeitsgemeinschaft Wissenschaftlich Medizinischer Fachgesellschaften) in oncologic staging of the five most frequent tumor entities. Temporal and monetary aspects are calculated. Invasive, endoscopic, and endosonographic techniques are regarded as essential and cannot be replaced by other techniques. Thus only the minimal potential for cost reduction is quantified.

RESULTS

In the German system there is no cipher to correctly balance whole-body MRI and PET/CT. Using the frequently applied ciphers 5700-5730 and 5378, 5489 (factor 1.0) total costs were 440.45 euros, and adding the cipher for additional series 545.37 euros (60 min examination time) for whole-body MRI and 774.74 euros (879.66 euros) (60/90 min examination time) for whole-body PET/CT. Using the common factor 1.8 costs were 981.66 and 1583.38 euros. On the basis of a simple full cost analysis total costs of whole-body PET/CT were higher than of whole-body MRI by a factor of about 2.0 (about 1123 vs 575 euros). There were substantial monetary and temporal differences between tumor entities. In extended bronchial carcinoma 375.32 euros and 55 min can be saved using whole-body MRI in comparison to conventional recommended techniques and using whole-body PET/CT 88.14 euros and 45 min. In tumor entities of lower stages with thus less essential radiologic diagnostics the potential for cost reduction is substantially lower.

CONCLUSION

Whole-body imaging techniques make it possible to reduce the number of necessary separate radiologic examinations and thus time in oncologic staging. A substantial reduction of health care costs seems to be possible in many tumor entities but differences between different tumor entities are decisive.

[MR aspect of the prostate in CPPS patients (chronic pelvic pain syndrome)]

PURPOSE

To describe typical morphological patterns of abacterial prostatitis using magnetic resonance imagine (MRI) in chronic pelvic pain syndrome patients including spectroscopy.

MATERIALS AND METHODS

18 patients (age range between 25 and 67 years, average 46.2 years) with recurrent chronic pelvic pain syndrome for at least 3 months were evaluated clinically in the urological department and included if there were no suspicious findings from endorectal digital palpation and if their PSA values were < 5 ng/ml. A retrospective analysis of these 18 patients with 30 contrast-enhanced MRI investigations with endorectal coils in 28 of 30 cases was performed with a 1.5T MRI. T 2w signal intensity (SI) and spectroscopy data (9 / 18 patients) were acquired for the normal peripheral zone, the central zone, for the peripheral zone suspected of inflammation and for the muscle including SI ratios for the unaltered and the suspicious inflammatory peripheral zone.

RESULTS

Typical MR patterns of signal alterations suspected of inflammation of CPPS patients were able to be detected as T 2w hypointense triangular, stringy (n = 12, 66.6 %) contrast-enhancing signal alterations without a nodular shape with well circumscribed margins of the capsula and without pericapsular signal alterations. In 6 patients changes also had a triangular but more homogeneous aspect (33.3 %). Three patients had an additional periurethral uptake (16.6 %). T 2w SI measurements and T 2w SI ratios showed much lower values for the peripheral zone suspected of inflammation as compared to the normal peripheral zone of the prostate (277.29 STD 77.5 to 432.9 STD 112.02 and 4.94 STD 1.47 to 7.58 STD 2.01 respectively). The spectroscopic analysis of the signal alterations suspected of inflammation showed normal Cholin+Creatin/Citrate SI ratio values in 3 patients (SI < 0.5), ratios suspected of low grade cancer in 3 patients (SI 0.5 and < 0.7) and ratios suspected of intermediate grade prostate cancer in 3 patients (SI > 0.7 and < 3.0).

CONCLUSIONS

We saw typical MR patterns in CPPS patients. However, spectroscopy can mimic findings of cancer so that the knowledge of typical morphological patterns and a solid clinical evaluation play a major role in the diagnosis of CPPS.

Image quality improvement of composed whole-spine MR images by applying a modified homomorphic filter--first results in cases of multiple myeloma

To establish a modified homomorphic filter (BiFiC) for post-processing of composed MR images in clinical routine and to evaluate it in special regards to image quality and diagnostic safety. Twenty-three whole-spine examinations were post-processed with the filter. Qualitative image evaluation included documentation of lesions and their visualization at original and post-processed images. Variations of signal intensities were calculated pixel by pixel and visualized by color-coded maps. Quantitative data evaluation was conducted by region-by-region analysis with standardized regions of interests. The BiFiC filter could be implemented successfully on the scanner's software platform and used within clinical routine. Color-coded maps could demonstrate that the BiFiC filter improves the signal uniformity in all cases, including images with metallic artifacts caused by implants. The subjective image quality of the post-processed images was improved in 22 out of the 23 MR examinations; in one case it was rated as equal. All pathologies were visualized on post-processed images without the need of additional contrast adjustments. The implemented BiFiC filter significantly improves image signal homogeneity. The algorithm can consequently be integrated into clinical routine as an automatic image post-processing step.

[Whole body MRI--diagnostic strategy of the future?]

Whole body magnetic resonance imaging (MRI) opens new opportunities in diagnostic radiology as systemic disease entities can be examined with high sensitivity. This can lead to a change of paradigm, so that not only organ-related but rather disease-specific MRI examination protocols can be applied which focus on the underlying pathophysiology of the disease. Whole body MRI has already been successfully used for several oncological and non-oncological indications. In addition, whole body MRI has broadened the discussion regarding its use for secondary prevention. Compared to computed tomography, MRI does not use radiation. Although whole body MRI is still in an early stage, the enormous medical and economical potential can be envisioned.

Comparison of 11C-choline-PET/CT and whole body-MRI for staging of prostate cancer

Aim of this study was to compare the diagnostic accuracy of positron emission tomography and computed tomography with (11)C-Choline (Cho-PET/CT) and whole body magnetic resonance imaging (WB-MRI) for diagnostic work-up of prostate cancer.

PATIENTS, METHODS

We evaluated retrospectively 42 patients with untreated prostate cancer (n = 17), or increasing levels of prostate-specific antigen (PSA) after curative therapy (n = 25) who had been investigated by both Cho-PET/CT and WB-MRI. MRI, CT, and PET images were separately analyzed by experienced radiologists or nuclear medicine experts, followed by consensus reading. Validation was established by histology, follow-up, or consensus reading.

RESULTS

88/103 detected lesions were considered as malignant: 44 bone metastases, 22 local tumor, 15 lymph node metastases, 3 lung, and 3 brain metastases. One further lesion was located in the adrenal gland, which was a second tumor. Overall sensitivity, specificity and accuracy for Cho-PET/CT were 96.6%, 76.5%, and 93.3%, resp., and for WB-MRI 78.4%, 94.1%, and 81.0%, resp. 3 vertebral metastases had initially been missed by Cho-PET/CT and were found retrospectively. MRI identified 2 bone metastases and 1 lymph node metastasis after being informed about the results of Cho-PET/CT.

CONCLUSIONS

Cho-PET/CT and WB-MRI both presented high accuracy in the detection of bone and lymph node metastases. The strength of MRI is excellent image quality providing detailed anatomical information whereas the advantage of Cho-PET/CT is high image contrast of pathological foci.

[Generating statements at whole-body imaging with a workflow-optimized software tool--first experiences with multireader analysis]

INTRODUCTION

Due to technical innovations in sectional diagram methods, whole-body imaging has increased in importance for clinical radiology, particularly for the diagnosis of systemic tumor disease. Large numbers of images have to be evaluated in increasingly shorter time periods. The aim was to create and evaluate a new software tool to assist and automate the process of diagnosing whole-body datasets.

MATERIAL AND METHODS

Thirteen whole-body datasets were evaluated by 3 readers using the conventional system and the new software tool. The times for loading the datasets, examining 5 different regions (head, neck, thorax, abdomen and pelvis/skeletal system) and retrieving a relevant finding for demonstration were acquired. Additionally a Student T-Test was performed. For qualitative analysis the 3 readers used a scale from 0 - 4 (0 = bad, 4 = very good) to assess dataset loading convenience, lesion location assistance, and ease of use. Additionally a kappa value was calculated.

RESULTS

The average loading time was 39.7 s (+/- 5.5) with the conventional system and 6.5 s (+/- 1.4) (p < 0.01) with the new software tool. For the different regions (conventional system/new software tool), the time reduction for readers 1, 2, and 3 were as follows: in the head region 35.9 % (p < 0.01)/49.9 % (p < 0.01)/54.3 % (p < 0,01), in the neck region 48.5 % (p < 0.01)/52.6 % (p < 0.01)/59.4 % (p < 0.05), in the thorax region 59.1 % (p < 0.01)/56.2 % (p < 0.05)/62.1 % (p < 0.05), in the abdominal region 61.9 % (p < 0.01)/62.7 % (p < 0.05)/47.9 % (p < 0.01) and in the pelvis region 73.1 % (p < 0.01)/63.7 % (p < 0.05)/55 % (p < 0.01), respectively. 148.2 s (+/- 94.8) compared to 2.5 s (+/- 0.5) were required to retrieve a previously described finding (p < 0.01). With and without the new software tool the same number of metastases was found (p < 0.01, k > 0.9). The qualitative analysis showed a significant advantage with respect to convenience (p < 0.01, k > 0.9).

CONCLUSION

Use of the new software can achieve a significant time savings when working with whole-body datasets with a constant quality of findings and a significant advantage with respect to convenience. As a result, the problem of evaluating examinations with thousands of images can be approached systematically.

Interdisziplinäre Untersuchungen zur Verbesserung der Behandlungsqualität des Prostatakarzinoms

BACKGROUND

After sufficient oncological treatment of prostate cancer the life quality becomes most important. A multi disciplinary research network aims to optimize the diagnostics and the resulting treatment of prostate cancer.

METHODS

Main characteristics of the interdisciplinary cooperation are the interlocked individual projects. A major research field is investigation of the whole mounted prostate sections to study the peripheral nerves and the comparison of histological tumor locations with the MRI. Using serial sections of prostate specimens, three-dimensional computer-animated models are created illustrating the tumors histological and immunohistochemical distributions. For nodal staging, a new methodology is investigated to demonstrate single tumor cells in lymphatic tissue lysates. A retrospective evaluation of life quality including the functional outcome is performed by using questionnaire surveys.

RESULTS

Anatomical studies gave new insights into the exact localizations of peripheral nerves which may lead to an improvement of the surgical approach in nerve-sparing radical prostatectomy. For the preoperative planning the MRI imaging might need a different interpretation in relation to the topographic location. Studies using molecular markers and their relation and distribution patterns gave new insights regarding interpretation of histological biopsy results concerning the tumor extension. Numerical quantification of tumor cells in each lymph node demonstrated micro metastases in histological negative nodes contributing to the nodal staging. A close connection of the nerve-sparing technique was demonstrated with quality of life aspects and functional results.

CONCLUSION

An interdisciplinary approach is mandatory for translational prostate cancer research. As a result, individualized diagnostic and therapeutic approaches improve oncological results and at the same time provide the best quality of life in these patients.

Dynamische Magnetresonanz-Nephrografie und -Urografie bei Kindern mit Harnwegserkrankungen

PURPOSE

To evaluate an improved method of dynamic magnetic resonance (MR) nephrography with short acquisition time and compensation of breathing motion for assessment of renal excretion and split renal function in children with anomalies of the urinary tract.

MATERIALS AND METHODS

A protocol for dynamic MR nephrography was implemented using a T1-weighted navigator-gated TurboFLASH sequence (TR/TE 498 ms/1.25 ms, saturation recovery time 300 ms, flip angle 8 degrees ). After bolus injection of 0.05 mmol/kg gadolinium dimeglumine (Gd-DTPA), split renal function was determined from the contrast-medium excretion. In 20 patients (ages between 3 months and 14 years), dynamic MR nephrography and MAG3 radionuclide scintigraphy as the gold standard were performed.

RESULTS

In all children, T1-weighted images were able to be recorded over 40 minutes at a nearly identical diaphragm position using the TurboFLASH sequence, thus allowing for exact region-of-interest analysis of the excretion and split renal function. The course of the contrast-medium concentration was able to be measured in the renal pelvis with good accuracy due to the high spatial resolution and the lack of breathing artifacts. Excellent correlation to the MAG3 scintigraphy was demonstrated for the excretion and split renal function (correlation coefficient: 0.975).

CONCLUSION

Dynamic MR nephrography allows for reliable assessment of renal function in children with anomalies of the urinary tract with higher spatial resolution as compared to radionuclide scintigraphy.