[MR-guided core biopsy of the shoulder: possibilities and experience with a vertically open 0.5T system]

PURPOSE

The availability of open whole body MRI magnets and MR-compatible instrumentarium were essential conditions for the progression of interventional MRI. The advantages of an MR-guided biopsy at the musculoskeletal system are the visualization of the puncture site of a representative area for tumor histology, the absence of exposure to radiation and the free selection of imaging planes. The purpose of the study was the development of a new technique of a secure MR-guided biopsy of intraosseus lesions in the humeral head.

MATERIAL AND METHODS

MR-guided core biopsy of a intraosseus lesion of the humeral head was performed in five male patients on a vertical open, whole body MRI magnet (SIGNA SP/i 0.5T, GE Medical Systems). The technique using interactive MRI and the MR-compatible instrumentarium are described.

RESULTS

A secure core biopsy could be obtained from a representative area for tumor histology in all cases. No complications occurred, especially no nerve or vessel lesion, no rotator cuff lesion and no intra-articular contamination of the shoulder joint were observed.

CONCLUSION

A new technique is presented to obtain MR-guided core biopsies of intraosseous lesions of the humeral head. Furthermore, clinical indications of this technique are described.

Pediatric MR-guided interventions

MRI guided interventions are a relatively new but steadily growing field within surgery in pediatric age. Besides the advantages of MRI, such as multiplanar capability and excellent soft tissue contrast and spatial resolution, particularly relevant for the pediatric population is the lack of ionizing radiation. There is meanwhile a group of well defined diagnostic or therapeutic indications for applying MR imaging during pediatric interventions. Aim of this review is to give an overview about indications of MR-guided procedures in children as well as the advantages and disadvantages of MR-guided interventions. We also briefly discuss interventional MR-systems and MR-compatible devices. It is our opinion that MR-guidance for pediatric interventions is a promising technique at the beginning of its development.

Computerized CT-Based 3D Visualization Technique in Living Related Liver Transplantation

INTRODUCTION

For living donor liver transplantation (LDLT) accurate diagnostic workup is essential. Multiple imaging approaches are currently used. Problems arise in the assessment of vascular and bile duct anatomy, liver graft volume, and vascular territories involved. A 3D visualization system that improves anatomic assessment, allows interactive surgery planning, and acts as an intraoperative guide with enhanced precision is required. Refinements in computed tomography (CT) technology with the introduction of multidetector-row CT scanners and implementation of mathematical methods on computerized digital data has enabled CT-based 3D visualizations.

MATERIALS AND METHODS

Sixteen LDLT candidates and three LDLT recipients were assessed by multislice CT examination. Image processing of the digital raw data for 3D visualization included segmentation and calculation of center lines. A hierarchical mathematical model representing the vascular and biliary tree was created. This allowed calculation of individual vascular territories.

RESULTS

3D CT-based visualization in LDLT facilitates diagnostic workup with high accuracy for analyses of vascular and bile duct variants, volumetry, and assessment of the optimal surgical splitting line of the living donor liver. Resultant areas of either arterial devascularization or venous congestion can be displayed and quantified preoperatively. The diagnostic method is of major impact on patient selection and directly influences intraoperative surgical guidance. The currently practiced "multiple imaging approach" approach, especially with regard to invasive diagnostics, can be avoided in the future.