Biomedical subjects

C Stroszczynski

Publications and source records attributed to C Stroszczynski.

57 records · Page 4Linked to original sources

PubMedDate not supplied

Malignant biliary obstruction: value of imaging findings.

This review focuses on the clinical impact of different modalities to image primary and secondary malignant biliary obstruction. The detection and staging of cancers of the pancreatic and biliary tract are best accomplished with endoscopic ultrasound, contrast-enhanced computed tomography, and magnetic resonance cholangiopancreatography. Three-dimensional ultrasound is a new noninvasive method that may be used increasingly as an initial test to select patients who require further diagnostic evaluation by magnetic resonance cholangiopancreatography or therapeutic endoscopic retrograde cholangiopancreatography. All-in-one computed tomography including three-dimensional reconstructions of the biliary tree may be competitive against all-in-one magnetic resonance imaging for diagnosis and staging of pancreatic tumors. Magnetic resonance cholangiopancreatography is excellent for identifying the presence and the level of biliary obstruction. With newer diagnostic imaging technologies emerging, endoscopic retrograde cholangiopancreatography is evolving into a predominantly therapeutic procedure.

Bile Duct Neoplasms↗

PubMedDate not supplied

Use of semiflexible applicators for radiofrequency ablation of liver tumors.

PURPOSE: To evaluate the feasibility and potential advantages of the radiofrequency ablation of liver tumors using new MRI-compatible semiflexible applicators in a closed-bore high-field MRI scanner. METHODS: We treated 8 patients with 12 malignant liver tumors of different origin (5 colorectal carcinoma, 2 cholangiocellular carcinoma, 1 breast cancer) under MRI guidance. Radiofrequency ablation (RFA) was performed using 5 cm Rita Starburst Semi-Flex applicators (Rita Medical Systems, Milwaukee, WI, USA) which are suitable for MR- and CT-guided interventions and a 150 W RF generator. All interventions were performed in a closed-bore 1.5 T high-field MRI scanner for MRI-guided RFA using fast T1-weighted gradient echo sequences and T2-weighted ultra-turbo spin echo sequences. Control and follow-up MRI examinations were performed on the next day, at 6 weeks, and every 3 months after RFA. Control MRI were performed as double-contrast MRI examinations (enhancement with iron oxide and gadopentetate dimeglumine). All interventions were performed with the patient under local anesthesia and analgo-sedation. RESULTS: The mean diameter of the treated hepatic tumors was 2.4 cm (+/-0.6 cm, range 1.0-3.2 cm). The mean diameter of induced necrosis was 3.1 cm (+/-0.4 cm). We achieved complete ablation in all patients. Follow-up examinations over a duration of 7 months (+/-1.3 months, range 4-9 month) showed a local control rate of 100% in this group of patients. All interventions were performed without major complications; only 2 subcapsular hematomas were documented. CONCLUSION: RFA of liver tumors using semiflexible applicators in closed-bore 1.5 T scanner systems is feasible. These applicators might simplify the RFA of liver tumors under MRI control. The stiff distal part of the applicator facilitates its repositioning.

Aged↗

PubMedDate not supplied

Shortcomings of low-cost imaging systems for viewing computed radiographs.

OBJECTIVE: To assess potential advantages of a new PC-based viewing tool featuring image post-processing for viewing computed radiographs on low-cost hardware (PC) with a common display card and color monitor, and to evaluate the effect of using color versus monochrome monitors. MATERIALS AND METHODS: Computed radiographs of a statistical phantom were viewed on a PC, with and without post-processing (spatial frequency and contrast processing), employing a monochrome or a color monitor. Findings were compared with the viewing on a radiological Workstation and evaluated with ROC analysis. RESULTS: Image post-processing improved the perception of low-contrast details significantly irrespective of the monitor used. No significant difference in perception was observed between monochrome and color monitors. The review at the radiological Workstation was superior to the review done using the PC with image processing. CONCLUSION: Lower quality hardware (graphic card and monitor) used in low cost PCs negatively affects perception of low-contrast details in computed radiographs. In this situation, it is highly recommended to use spatial frequency and contrast processing. No significant quality gain has been observed for the high-end monochrome monitor compared to the color display. However, the color monitor was affected stronger by high ambient illumination.

Humans↗