Biomedical subjects
Publications and source records attributed to J Ricke.
We report a case of glossopharyngeal neuralgia with vascular compression. High-resolution MRI at 3 tesla demonstrated the posterior inferior cerebellar artery to be closely related to the rootlets of the left glossopharyngeal nerve in a patient who suffered attacks of burning sensation in the left side of the throat. The MRI findings were confirmed at curative surgery.
PURPOSE: Implementation of a self-designed, web-based digital image archive incorporating the existing DICOM infrastructure to assure distribution of digital pictures and reports and to optimize work flow. Assessment after three years. MATERIALS AND METHODS: Open-source software was used to guarantee highest reliability and cost effectiveness. In view of rapidly increasing capacity and decreasing costs of hard discs (HDs), HDs were preferred over slower and expensive magneto-optical disk (MOD) or tape storage systems. The number of installed servers increased from one to 12. By installing HDs with increased capacities, the number of servers should be kept constant. Entry and access of data were analyzed over two 4-month periods (after 1.5 and 2 years of continuous operations). RESULTS: Our digital image archive was found to be very reliable, cost effective and suitable for its designated tasks. As judged from the measured access volume, the average utilization of the system increased by 160 %. In the period from January to April 2002, the users accessed 239.8 gigabyte of the stored 873.7 gigabyte image data (27 %). The volume of the stored data added 20%, mainly due to an increase in cross-section imaging. CONCLUSION: The challenge of developing a digital image archive with limited financial resources resulted in a practicable and expandable solution. The utilization, number of active users and volume of transferred data have increased significantly. Our concept of utilizing HDs for image storage proved to be successful.
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The use of telemedicine is becoming indispensable for a continuous and economical delivery of a high quality of care. However, data protection requirements have to be considered. For the selection of solutions, vendor-independent components based on standards are a prerequisite for a seamless integration into the existing, often heterogeneous, IT infrastructure. The "Internet protocol" TCP/IP and the DICOM standard with it's new security extensions form the basis for an internationally standardized and accepted procedure for a secure interchange of radiological images beyond platform boundaries.
PURPOSE: Evaluation of the continuity and energy distribution of a laser system for laser-induced thermo therapy. MATERIAL AND METHODS: For evaluation of the continuity of laser optical devices, laser generating units and optical fibers of three different manufactures (Dornier, Hüttinger, Somatex), we used the equipment to generate a laser beam of 25 Watt for 60 minutes. Measurements of the applied energy were done sequentially with two MY Test (Fa. Hüttinger) units. We also performed two in vitro ablations of animal liver tissue with different fiber optics [Mikrodom A 13-0540, Microflexx REF A 13-0561 (Hüttinger), Diffusor-Tip H-6111-T 3, Diffusor H-6111-T 4 (Dornier), Somaflex-Diffusor (Somatex)] over 20 minutes at- an energy flow of 25 J per second. We then evaluated the geometry of coagulation. RESULTS: The different equipment used for our tests showed differences of a maximum of 10 %. Some components did not work properly in certain configurations even though the manufacturer assured it would. We saw significant differences in the ablation characteristics of the different fiber optics, especially in axial and frontal directions. CONCLUSION: Knowledge of the different characteristics in energy distribution and ablation characteristics are an important factor in performing a successful laser-induced thermo therapy.
PURPOSE: To evaluate different concepts of the application of a portable CT (PCT) directly in a patient's ICU room versus in a specially designed interventional suite (IS). METHODS: 13 patients with maximum ICU treatment were examined by PCT and assessed with regard to their health status by ICU scores (TISS 28, MODS). Only patients with a therapeutic intervention scoring system 28 (TISS 28) value of 40 or greater were included in the study. A TISS 28 value of 40 or more characterizes a patient requiring maximal ICU treatment. Patients were examined by PCT either in the patient's room or in the IS on the ICU. Scanning time and personnel resource expense were determined. The multiple organ dysfunction score (MODS) was utilized for patient characterization. RESULTS: An average of 1.4 hours was needed to perform a PCT scan in the interventional room. A minimum of 4.5 hours or up to a maximum of 7.2 hours were required to perform a bedside scan in the patient's room. There is a noticeable difference between patients with respect to TISS 28. Patients examined by bedside CT were more acutely ill than the others by reason of MODS (8 - 18 patient-room group vs. 3 - 12 IS group). CONCLUSIONS: PCT performed on an ICU assures optimal treatment of patients during CT examination. Portable CT had more time exposure and required more personnel resources than examination in the IS. All PCT examinations performed directly in the patient's room demonstrated the diagnostic value and had direct therapeutic consequences.
In 1998 and 1999, a delphi consensus procedure was performed to establish guidelines for standardised diagnostic imaging of neuroendocrine tumours. The procedure included four consecutive workshops of a European group of experts in neuroendocrine tumours as well as feedback given by specialists from the departments of radiology, nuclear medicine, surgery and internal medicine of the according home institutions. Diverging approaches among the centres, which became apparent during the discussion, reflect a lack of controlled studies specifically for rare subgroups of neuroendocrine tumours. This paper summarises the standards for diagnostic imaging as developed during the delphi process. In particular, the diagnostic workflows as well as the technical properties of different imaging modalities are described in detail.
PURPOSE: To evaluate the diagnostic accuracy, complications, and therapeutic impact of CT-guided percutaneous core biopsies of pulmonary lesions. MATERIAL AND METHODS: Seventy-nine patients underwent diagnostic CT-guided percutaneous core biopsies of pulmonary lesions between July 1995 and March 1999. Evaluation included corresponding clinical data, pathologic results, and therapeutic consequences. RESULTS: There were 29 benign and 50 malignant lesions. Percutaneous core biopsy had an overall diagnostic accuracy of 95%. For malignant lesions, core biopsy was positive in 48 patients (sensitivity 96%), and for benign lesions, in 27 (sensitivity 93%). There were no false-positive findings. Pneumothoraces were observed in 19 patients (24%) and 4 of them required a chest drain (5%). There were no hematothoraces or major bleeding complications; however, postinterventional local hemorrhages were observed in 23 patients (29%). No hemoptysis was noted. CONCLUSION: Percutaneous core biopsies of pulmonary lesions offer excellent diagnostic accuracy for both benign and malignant pulmonary lesions at a low complication rate.
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The latest dramatic progress in the technologies of the computer industry is likely to increasingly influence the oncologist's daily routine. Besides well known and established telemedical services such as videoconferencing, the most influential trends are the spread of digital hospital infrastructures with unlimited, secured access to all relevant patient information. This article seeks to summarise the most imminent influences of telemedical developments on the future of the oncologist: the effects of telemedical services and electronic infrastructures on clinical workflow and on medical quality management. In addition, the history of telemedicine, recent technologies and the performance of electronic patient records are described.
RATIONALE AND OBJECTIVES: To assess the vascularization of neuroendocrine tumors by stimulated acoustic emission (SAE) of SH U 508A during the blood pool phase in comparison with contrast-enhanced Doppler sonography. METHODS: Thirty-six patients with neuroendocrine tumors received contrast-enhanced Doppler sonography and 21, an additional SAE. To classify tumor perfusion on Doppler sonography, a 4-step rating score was introduced: (1) no vessels (hypoperfusion); (2) one feeding or central vessel (hypoperfusion); (3) some vessels (hyperperfusion); and (4) disseminated vessels (hyperperfusion). In 36 patients, 1 pancreatic primary tumor, 33 liver metastases, 1 splenic metastasis, and 1 lymph node metastasis were examined. Results were correlated with biphasic spiral CT (n = 35) and angiography (n = 2). RESULTS: Arterial-phase CT and digital subtraction angiography revealed 18 hyper- and 18 hypoperfused lesions. Contrast-enhanced Doppler correctly classified 15 of 18 patients (83%) with hyperperfused lesions as well as 16 of 18 (89%) hypoperfused tumors by applying the rating score. SAE correctly identified 4 of 9 hyperperfused lesions (44%), 2 were isoperfused compared with normal liver tissue (22%), and 3 were hypoperfused (33%). Of 12 hypoperfused lesions, 11 were classified correctly (92%), and 1 showed isoperfusion. Hence, the positive and negative predictive values for SAE were 80% and 69%, respectively. For contrast-enhanced Doppler sonography, positive and negative predictive values were 88% and 84%, respectively. CONCLUSIONS: Blood pool SAE failed to determine subtle tumor perfusion correctly. The rating score for contrast-enhanced Doppler sonography characterized tumor perfusion with high accuracy. The use of a contrast agent significantly improved perfusion characterization.
RATIONALE AND OBJECTIVES: To evaluate the sensitivity of contrast-enhanced MRI in the preoperative detection of abnormal parathyroid glands in patients with clinical evidence of hyperparathyroidism. METHODS: Twenty-eight patients with biochemical evidence of hyperparathyroidism underwent contrast-enhanced preoperative MRI of the parathyroid glands. Two blinded readers assessed the MR images by consensus, and MR results were subsequently correlated with those from surgery (location, diameter, weight) and histopathology. RESULTS: MRI depicted 32 of 39 surgically proved abnormal parathyroid glands (sensitivity 82%; 95% confidence interval, 66%-92%), and 1 of 114 (0.9%) was incorrectly considered abnormal. All ectopic glands were correctly identified (2 mediastinal, 1 submandibular). Sensitivity was superior for adenomas but less for hyperplasia (adenomas 87%; 95% confidence interval, 67%-97%; hyperplasia 75%; 95% confidence interval, 47%-92%). Among all lesions, atypical signal characteristics on MRI were observed in 34% of lesions (9% hyperintense signals on T2- and T1-weighted images; 25% isointense signals on T2- and T1-weighted images), with improved lesion detection after contrast administration in 17% of lesions. CONCLUSIONS: MRI of the parathyroid glands presented a sensitive imaging modality, thus demonstrating its high potential to preoperatively detect abnormal glands. Moreover, in a minor proportion of patients with atypical parathyroid lesion characteristics, contrast administration may increase lesion detectability.
We report a 58-year-old female patient with the suspected diagnosis of ovarian cancer. Upon surgical exploration, examination of the appendix revealed the histological diagnosis of primary mucinous adenocarcinoma. This is an unusual consideration in the differential diagnosis of the ovarian cancer. We discuss the diagnosis, classification and treatment of the cancer of the appendix in relation to ovarian cancer.
PURPOSE: To give recommendations for diagnostic imaging workflow in suspected neuroendocrine tumours. MATERIALS AND METHODS: Recommendations for imaging workflow were elaborated by consensus of researchers in neuroendocrine tumours. RESULTS: Workflow charts are presented for: (1) nonfunctional and functional endocrine tumours of the pancreas (except insulinoma); (2) insulinoma; (3) ECL cell tumour; (4) assessment of unknown primaries in functional and nonfunctional neuroendocrine tumours of the gut; (5) assessment of metastases in functional and nonfunctional neuroendocrine tumours of the gut. CONCLUSIONS: The workflow charts facilitate diagnosis of neuroendocrine tumours as well as the design of controlled studies.
OBJECTIVE: To design, implement and evaluate a PC-based medical viewing application including image postprocessing for DICOM images for use within an existing hospital infrastructure. MATERIAL AND METHODS: A user-friendly DICOM compliant viewing application including image postprocessing (spatial frequency and contrast enhancement) and HL7 communication ability was designed and implemented on PC basis to run under Windows OS. To assess its quality compared to high-end workstations, an ROC analysis was performed. RESULTS: The use of image postprocessing on a PC significantly improved the perception of low-contrast details in computed radiographs. Review at a radiological workstation was superior to review at a PC with image postprocessing.
PURPOSE: To evaluate contrast-enhanced, fat-saturated spin echo sequences for the detection of peritoneal carcinosis with MRI. MATERIALS AND METHODS: 61 patients, 35 with and 26 without peritoneal carcinosis, were examined with abdominal MRI. Fat-saturated, T1-weighted spin echo sequences were performed before and after administration of Gd-DTPA. In addition, 22 patients with peritoneal carcinosis were examined with contrast-enhanced abdominal CT. RESULTS: 32 of 35 patients with peritoneal carcinosis demonstrated contrast enhancement of the visceral and 30 of 35 enhancement of the parietal peritoneum (91 and 86%, respectively). Wall thickening of the intestine or parietal peritoneum were noted in 21 and 20 of 35 patients (60 and 57%, respectively), ascites in 18 of 35 patients (51%). False positive contrast enhancement of the peritoneum was noted in 4 of 26 patients (15%). In the direct comparison of MRI and CT, 22 of 22 patients versus 7 of 22 patients showed contrast enhancement of the visceral peritoneum (100 and 32%, respectively). For other signs of peritoneal carcinosis (e.g., ascites, peritoneal seedings), no differences in diagnostic reliability were demonstrated. CONCLUSIONS: The use of fat-saturated, spin echo sequences facilitates the diagnosis of peritoneal carcinosis by artifact reduction and improved detection of peritoneal contrast enhancement. MRI with fat-saturated sequences was superior to CT.
UNLABELLED: The aim of this study was two-fold: to compare 67Ga scintigraphy with MRI (a) for the staging of malignant lymphoma of the bone and (b) with regard to accuracy in detecting residual disease after first-line chemotherapy for restaging. METHODS: Twenty-one patients with 36 malignant osseous lesions were examined, including 7 patients with primary or multifocal osseous lymphoma and 14 patients with malignant lymphoma and simultaneous or secondary involvement of the bone. After first-line therapy, MRI and 67Ga scintigraphy were performed on 13 patients. The remission status based on all clinical and radiological findings during the follow-up was used as the gold standard. RESULTS: The osseous lesions were located on the axial skeleton in 64% of patients and on the appendicular skeleton in 36%. 67Ga scintigraphy detected 77% of the osseous lesions examined by MRI. For restaging after first-line therapy, MRI had a sensitivity of 90% and a specificity of 80% when dynamic MRI information was included. There were several false-positive results as a result of the pathologic increase in signal intensity ratios of reactive hematopoietic regions after chemotherapy. For 67Ga scintigraphy, a sensitivity of 70% and a specificity of 93% were calculated. CONCLUSION: These data show that monitoring malignant lymphoma of the bone still presents diagnostic problems. Given the high sensitivity of MRI and the high specificity of 67Ga scintigraphy but the limited specificity of MRI and sensitivity of 67Ga scintigraphy, both methods are valuable but should be used as complementary diagnostic tools.
INTRODUCTION: An ROC analysis was carried out in order to determine the reliability of digital luminescence radiography review at a PC and this was compared with a radiological work station and with X-ray film on a viewing box. MATERIAL AND METHOD: 54 chest images obtained by digital luminescence radiography were selected, 31 of these contained small pulmonary nodules. In order to evaluate critical detail, five images of a phantom showing round foci were used. Five radiologists examined these, using a Siemens Magic View work station, a PC with proprietary software (ViewMed) and X-ray films on a viewing box. Image processing of the work station used the standard clinical application. ViewMed performs linear scaling of grey levels to 8 Bit. The results were examined statistically by means of a t-test. RESULTS: As far as the chest images were concerned there was no significant difference in the diagnostic value of these methods. There was, however, a highly significant loss of diagnostic information with respect to the round focus phantom when using the PC compared with the other methods. CONCLUSION: In the configuration in which it was used, the PC should not be relied on as a primary means of examination since critical details cannot always be seen. In routine use these play a subordinate role and there was no significant diagnostic loss where the chest images were concerned. We expect that by improvements in the frequency and contrast processing the PC accuracy will be considerably increased.