Abstract Magnetic resonance imaging (MRI) has excellent soft tissue contrast, which can be enhanced by different contrast agents, multiplanar imaging capability and high temporal and spatial resolution. Even blood vessels can be easily visualised, and MRI parameters are sensitive to temperature. Therefore, MRI has the greatest potential for guiding and monitoring interventional and surgical procedures. The aim of this study was to design and evaluate new solutions for MR-guided procedures and surgery, to develop the technique and to assess the feasibility of MR-guided nerve root infiltration, bone biopsy and sacroiliac (SI) joint arthrography. The possibilities for versatile use of MR scanners were studied with a setup where an MR scanner with a 0,23 T open magnet was installed in a full-scale operating room (OR) to allow diagnostic MRI examinations, research, radiological interventions and neurosurgical operations to be performed in the same facility. All of the 144 MR-guided radiological interventions and neurosurgical operations performed in Oulu University Hospital between February 1999 and September 2000 were included in the study. The studied setup was a functionally feasible solution for combined neurosurgical and radiological use. To further improve MR-guided interventions, a new user interface was developed and preliminary tested with simulated clinical experiments. The new user interface seemed to be easily adobted by radiologists for interventional procedures. MR-guided nerve root infiltrations were studied by using MRI guidance on 34 consequent patients referred for first sacral root infiltration. Needle placement into the first sacral nerve root sheath was successful in 34 of the 35 (97%) cases, and the average duration of the procedure was 32 minutes. Bone biopsies were performed using a bone biopsy set designed in our institution to be connected to an optical tracking system. The feasibility of this new guiding system was evaluated with biopsies from five different anatomical areas. The bone biopsy system was successfully applied to all patients and provided a safe and accurate guidance method for all phases of the procedure. Twenty patients with low back pain suspected to arise from the SI joint underwent MR-guided SI joint arthrography. The procedure was successfully performed in all cases. The needle guiding with optical tracking inside the soft tissues proved to be accurate enough for successful procedures. In conclusion, versatile use of MR scanners for diagnostic imaging, radiological procedures and neurosurgery is feasible if planned properly. The prototype of a new user interface for MR-guided procedures allows radiologist to fully control the MR-scanner during the procedure. MRI is a suitable and accurate guidance method for musculoskeletal interventions.

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Radiologic technologists who transition into the role of clinical instructor are usually expert practitioners but may lack knowledge of best practices regarding student instruction and evaluation. The purpose of this phenomenological qualitative study was to investigate how CIs experience the transition from practitioner to educator and what knowledge or education of best practices of instruction and evaluation they bring to the position. This study consisted of interviews with radiography CIs from one associate degree radiography program in the southeastern part of the United States. While some CIs felt prepared to transition into the CI role, none of them had previously had education regarding instruction. They were provided support as they transitioned, but little formal orientation or training. The results of this study should challenge radiography programs to implement or strengthen current orientation programs for new CIs who are critical to student success.

Abstract The purpose of the present study was to implement a unique low-field open magnetic resonance scanner for perioperative imaging in neurosurgery. A paradigm was created for joint intraoperative/interventional MRI, including premises, surgical practice and an operational model. The feasibility of the paradigm was tested in clinical work. The joint use of the facilities between the Departments of Neurosurgery and Diagnostic Radiology was found to enhance the economic rationale and provide for perioperative imaging. It was also found to be organizationally viable in the long run. Intraoperative MRI was implemented and studied in connection with neuronavigation and other intraoperative instruments, tools and imaging modalities. The unique shut down possibility of the magnet enabled staged operating-imaging practice, use of non-MRI-compatible instruments and devices, multimodal imaging with navigation, and avoidance of safety risks associated with operating in magnetic fringe fields. Two dynamic contrast enhanced MR imaging sequences, which used undersampled projection reconstruction, were implemented in the low-field scanner. The applicability of these imaging sequences to follow contrast enhancement of meningiomas was studied in laboratory experiments and in two patient cases. The laboratory experiments showed a nearly linear response in signal intensity to the concentration of gadopentetate dimeglumine in purified water up to 1.25 mM. The patient cases showed results consistent with an earlier study performed at high-field strength. The potential of low-field MRI study including dynamic contrast enhanced imaging to predict surgical and histopathologic characteristics of meningiomas was studied in a series of 21 patients. Dynamic contrast enhanced imaging could be used to evaluate microvessel densities of meningiomas. Surgical bleeding, blood loss during operation, progesterone receptor expression and collagen content were statistically best correlated to the relative intensity of meningioma on FLAIR images. Tissue hardness correlated best with relative intensity on T2-weighted images.

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