Effect of Drinking Oxygenated Water Assessed by in vivo MRI Relaxometry.

GRANT SUPPORT: This project was funded by the Research Council of Norway. BACKGROUND: Oxygen uptake through the gastrointestinal tract after oral administration of oxygenated water in humans is not well studied and is debated in the literature. Due to the paramagnetic properties of oxygen and deoxyhemoglobin, MRI as a technique might be able to detect changes in relaxometry values caused by increased oxygen levels in the blood. PURPOSE: To assess whether oxygen dissolved in water is absorbed from the gastrointestinal tract and transported into the bloodstream after oral administration. STUDY TYPE: A randomized, double-blinded, placebo-controlled crossover trial. POPULATION/SUBJECTS: Thirty healthy male volunteers age 20-35. FIELD STRENGTH/SEQUENCE: 3T/Modified Look-Locker inversion recovery (MOLLI) T1 -mapping and multi fast field echo (mFFE) T2 *-mapping. ASSESSMENT: Each volunteer was scanned in two separate sessions. T1 and T2 * maps were acquired repeatedly covering the hepatic portal vein (HPV) and vena cava inferior (VCI, control vein) before and after intake of oxygenated or control water. Assessments were done by placing a region of interest in the HPV and VCI. STATISTICAL TEST: A mixed linear model was performed to the compare control vs. oxygen group. RESULTS: Drinking caused a mean 1.6% 95% CI (1.1-2.0% P < 0.001) increase in T1 of HPV blood and water oxygenation attributed another 0.70% 95% confidence interval (CI) (0.07-1.3% P = 0.028) increase. Oxygenation did not change T1 in VCI blood. Mean T2 * increased 9.6% 95% CI (1.7-17.5% P = 0.017) after ingestion of oxygenated water and 1.2% 95% CI (-4.3-6.8% P = 0.661) after ingestion of control water. The corresponding changes in VCI blood were not significant. DATA CONCLUSION: Ingestion of water caused changes in T1 and T2 * of HPV blood compatible with dilution due to water absorption. The effects were enhanced by oxygen. Assessment of oxygen enrichment of HPV blood was not possible due to the dilution effect. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:720-728.

Determination of oxygen r1 at 3 Tesla using samples with a concentration range of dissolved oxygen.

OBJECTIVE: To investigate the sensitivity of modified Look-Locker inversion recovery (MOLLI) to measure changes in dissolved oxygen (DO) concentrations in water samples and to calculate sequence-specific relaxivity (r1m) and limit of detection (LOD). MATERIALS AND METHODS: Ten water samples with a range of DO concentrations were scanned at 3 T using two variations of MOLLI schemes. Using linear regression the r1 of DO was estimated from the measured DO concentrations and T1 relaxation rates (R1). The results were combined with previously reported values on in vivo stability measures of the MOLLI sequences and used to estimate a LOD. RESULTS: DO concentrations ranged from 0.5 to 21.6 mg L-1. A linear correlation between DO and R1 was obtained with both MOLLI sequences, with an average correlation coefficient (R2) 0.9 and an average estimated r1 ([Formula: see text]) of 4.45 × 10-3 s-1 mg-1 L. Estimated LOD was ≈ 10 mg L-1. CONCLUSION: MOLLI T1-mapping sequences may be used for detecting dissolved oxygen in vivo at 3 T with an [Formula: see text] in the range 4.18-4.8 × 10-3 s-1 mg-1 L and a corresponding LOD for dissolved oxygen of approximately 10 mg L-1. MOLLI-based T1 mapping may be a useful non-invasive tool for quantification of in vivo changes of DO concentration during oxygen challenges.

Needle tip tracking for ultrasound-guided peripheral nerve block procedures-An observer blinded, randomised, controlled, crossover study on a phantom model.

BACKGROUND: The Onvision needle tip tracking (NTT) is a new technology consisting of a needle with an ultrasound sensor close to the needle tip and a console for computerised signal processing. The aim of the study was to evaluate NTT technology during ultrasound-guided simulated peripheral nerve block procedures in a porcine phantom model. METHODS: Forty anaesthesiologists performed in-plane and out-of-plane simulated nerve blocks with and without NTT guidance. The primary outcome measure was procedure time. Secondary outcomes were hand movements and the path length travelled by the hands measured by motion analysis, precision of the needle tip related to the target structure, success rates and violations of the target structure, and the participants confidence whether their procedure would be successful or not. RESULTS: Procedure time was reduced from 66.7 (SD = 47.5) seconds to 43.8 (SD = 29.2) seconds when NTT was used for out-of-plane procedures (P = 0.002). The number of hand movements of the probe hand was 13.9 (SD = 30.2) with NTT and 22.8 (SD = 30.0) without NTT (P = 0.019). No significant differences were registered during the performance of in-plane procedures. The participants confidence in a presumed block success was increased with both in-plane procedures (8.50 (SD = 1.18) with NTT vs 7.65 (SD = 1.96), P = 0.004) and out-of-plane procedures (8.50 (SD = 1.09) vs 7.10 (SD = 1.89), P = 0.0001). CONCLUSIONS: The new NTT technology significantly reduced the procedure time and the number of hand movements for ultrasound-guided out-of-plane PNB procedures. No significant differences were found for the in-plane procedures.

Can we ablate liver lesions close to large portal and hepatic veins with MR-guided HIFU? An experimental study in a porcine model.

OBJECTIVES: Invasive treatment of tumors adjacent to large hepatic vessels is a continuous clinical challenge. The primary aim of this study was to examine the feasibility of ablating liver tissue adjacent to large hepatic and portal veins with magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU). The secondary aim was to compare sonication data for ablations performed adjacent to hepatic veins (HV) versus portal veins (PV). MATERIALS AND METHODS: MRgHIFU ablations were performed in six male land swine under general anesthesia. Ablation cells of either 4 or 8 mm diameter were planned in clusters (two/animal) adjacent either to HV (n = 6) or to PV (n = 6), with diameter ≥ 5 mm. Ablations were made using 200 W and 1.2 MHz. Post-procedure evaluation was made on contrast-enhanced MRI (T1w CE-MRI), histopathology, and ablation data from the HIFU system. RESULTS: A total of 153 ablations in 81 cells and 12 clusters were performed. There were visible lesions with non-perfused volumes in all animals on T1w CE-MRI images. Histopathology showed hemorrhage and necrosis in all 12 clusters, with a median shortest distance to vessel wall of 0.4 mm (range 0-2.7 mm). Edema and endothelial swelling were observed without vessel wall rupture. In 8-mm ablations (n = 125), heat sink was detected more often for HV (43%) than for PV (19%; p = 0.04). CONCLUSIONS: Ablations yielding coagulative necrosis of liver tissue can be performed adjacent to large hepatic vessels while keeping the vessel walls intact. This indicates that perivascular tumor ablation in the liver is feasible using MRgHIFU. KEY POINTS: • High-intensity focused ultrasound ablation is a non-invasive treatment modality that can be used for treatment of liver tumors. • This study shows that ablations of liver tissue can be performed adjacent to large hepatic vessels in an experimental setting. • Liver tumors close to large vessels can potentially be treated using this modality.

Precision of T1-relaxation time measurements in the hepatic portal vein: influence of measurement technique and sequence parameters.

OBJECTIVE: To investigate the effects of a range of parameter settings on T1 measurement stability in the portal vein using the T1-mapping sequences Look-Locker (LL) and Modified Look-Locker inversion recovery (MOLLI). MATERIALS AND METHODS: Ten different versions of LL and MOLLI sequences were tested and compared to a reference sequence provided by the MR manufacturer. Ten healthy volunteers were imaged multiple times on two separate scan days at 3T. The mean T1 values and coefficient of variation (CoV) were calculated for each of the ten sequences and compared to the reference sequence. RESULTS: Six of the tested sequences had T1 values close to the reference sequence; among those, three sequences achieved lower CoV than the reference sequence. Lowest CoV was achieved using a non-triggered LL sequence with 5 beat readout and a 45o flip angle (mean T1 1733 ms ± 89 ms, CoV 1.3% ± 0.58%). CONCLUSION: T1-measurements in the hepatic portal vein can be performed with high precision using either MOLLI or LL sequences provided that LL sampling duration is sufficiently long and flip angle sufficiently high. The advantage of constant timing outweighed the advantage of ECG-triggering.

Signal Enhancement of the Dentate Nucleus at Unenhanced MR Imaging after Very High Cumulative Doses of the Macrocyclic Gadolinium-based Contrast Agent Gadobutrol: An Observational Study.

Purpose To test for measurable visual enhancement of the dentate nucleus (DN) on unenhanced T1-weighted magnetic resonance (MR) images in a cohort of patients with a primary brain tumor who had not received linear gadolinium-based contrast agents (GBCAs) but had received many injections of macrocyclic GBCAs. Materials and Methods Seventeen patients with high-grade gliomas who had received 10-44 administrations of the macrocyclic GBCA gadobutrol (0.1 mmol/kg of body weight) were retrospectively included in this regional ethics committee-approved study. Two neuroradiologists inspected T1-weighted MR images with optimized window settings to visualize small differences in contrast at the baseline and at the last examination for the presence of visual DN signal enhancement. Signal intensity (SI) in the DN was normalized to the SI of the pons, and a one-sample t test was used to test for differences between baseline normalized SI (nSI) in the DN (nSIDN) and the average change in nSIDN of all postbaseline MR imaging sessions (ΔnSIDNavg) or the change in nSIDN from baseline to the last MR imaging session (ΔnSIDN). Linear and quadratic correlation analyses were used to examine the association between the number of macrocyclic GBCA administrations and ΔnSIDN or ΔnSIDNavg. Results The mean ± standard deviation number of macrocyclic GBCA administrations was 22.2 ± 10.6 administered throughout 706 days ± 454. Visually appreciable signal enhancement was observed in two patients who had received 37 and 44 macrocyclic GBCA injections. Mean ΔnSIDN was greater than zero (0.03 ± 0.05; P = .016), and there was a significant linear association between the number of macrocyclic GBCA injections and ΔnSIDN (r = 0.69, P = .002) and ΔnSIDNavg (r = 0.77, P < .001). Conclusion A small but statistically significant dose-dependent T1-weighted signal enhancement was observed in the DN after multiple macrocyclic GBCA injections. Visually appreciable enhancement in the DN was observed on contrast-optimized images in two patients who had received 37 and 44 standard doses of macrocyclic GBCAs. © RSNA, 2017 Online supplemental material is available for this article.

Semiautomated Magnetic Resonance Imaging Assessment of Carotid Plaque Lipid Content.

BACKGROUND: The composition of a carotid plaque is important for plaque vulnerability and stroke risk. The main aim of this study was to assess the potential of semiautomated segmentation of carotid plaque magnetic resonance imaging (MRI) in the assessment of the size of the lipid-rich necrotic core (LRNC). METHODS: Thirty-four consecutive patients with carotid stenosis of 70% or higher, who were scheduled for carotid endarterectomy, underwent a clinical neurological examination, Color duplex ultrasound, 3-T MRI with an 8-channel carotid coil, and blood tests. All examinations were performed less than 24 hours prior to surgery and plaques were assessed histologically immediately following endarterectomy. Plaques were defined as symptomatic when associated with ipsilateral cerebral ischemic symptoms within 30 days prior to inclusion. The level of agreement between the size of the LRNC and calcification on MRI to the histological estimation of the same tissue components, plaque echolucency on ultrasound, and symptoms was assessed. RESULTS: The size of the LRNC on MRI was significantly correlated to the percentage amount of lipid per plaque on histological assessment (P = .010, r = .5), and to echogenicity on ultrasound with echolucent plaques having larger LRNC than echogenic plaques (P = .001, r = -.7). CONCLUSIONS: In this study, we found that semiautomated MRI assessments of the percentage LRNC in carotid plaques were significantly correlated to the percentage LRNC per plaque on histological assessment, and to echogenicity on ultrasound with echolucent plaques having larger LRNC than echogenic plaques.

Rehabilitation of Executive Functions in Patients with Chronic Acquired Brain Injury with Goal Management Training, External Cuing, and Emotional Regulation: A Randomized Controlled Trial.

Executive dysfunction is a common consequence of acquired brain injury (ABI), causing significant disability in daily life. This randomized controlled trial investigated the efficacy of Goal Management Training (GMT) in improving executive functioning in patients with chronic ABI. Seventy patients with a verified ABI and executive dysfunction were randomly allocated to GMT (n=33) or a psycho-educative active control condition, Brain Health Workshop (BHW) (n=37). In addition, all participants received external cueing by text messages. Neuropsychological tests and self-reported questionnaires of executive functioning were administered pre-intervention, immediately after intervention, and at 6 months follow-up. Assessors were blinded to group allocation. Questionnaire measures indicated significant improvement of everyday executive functioning in the GMT group, with effects lasting at least 6 months post-treatment. Both groups improved on the majority of the applied neuropsychological tests. However, improved performance on tests demanding executive attention was most prominent in the GMT group. The results indicate that GMT combined with external cueing is an effective metacognitive strategy training method, ameliorating executive dysfunction in daily life for patients with chronic ABI. The strongest effects were seen on self-report measures of executive functions 6 months post-treatment, suggesting that strategies learned in GMT were applied and consolidated in everyday life after the end of training. Furthermore, these findings show that executive dysfunction can be improved years after the ABI.

Cochlear implantees: Analysis of behavioral and objective measures for a clinical population of various age groups.

INTRODUCTION: As of 2014 more than 1200 patients have received a cochlear implant (CI) at Oslo University Hospital (OUS) and approximately half of them have been children. The data obtained from these patients have been used to develop a comprehensive database for a systematic analysis of several objective measurements and programming measurements. During the past 10 years, we have used an objective measurements protocol for our CI surgeries. Our intra-operative protocol includes: Evoked Compound Action Potentials (ECAP), visually observed Electrically evoked Stapedius Reflex Threshold (ESRT), and electrode impedances. Post-operative (Post-OP) programming sessions typically begin 4-6 weeks after surgery and continue on a scheduled basis. The initial programming data include threshold levels (T-levels) and comfortable levels (C-levels) for the different patient age groups. In this study, we compared initial stimulation levels and stimulation levels after at least 1 year of CI with objective measurements obtained intra-operatively. METHOD: This study focused on the development of a comprehensive database of detailed intra-operative objective measures and post-OP programming measurements from a group of 296 CI patients who received the same type of CI and electrode configuration (Cochlear Corporation CI with Contour electrode). This group included 92 bilateral CI patients. Measurements from 388 CI devices were studied. Patients were divided into 5 different age groups at the age of implantation: 0-2, 2-5, 5-10, 10-20, and above 20 years in order to investigate age-related differences in programming levels and objective measurements. For the comparison analysis we used T- and C-levels obtained after the last day of initial programming and also after at least 1 year implant use. These programming levels were then correlated with some of the intra-operative objective measurements. RESULTS: T-levels were found to be the lowest for the youngest patient group and increased with age. C-levels varied within age groups and frequency range. Patients above 20 years of age had the highest comfort levels in the low to mid-frequencies (electrodes 22-8) and the lowest comfort levels in the high-frequency range (electrodes 1-7). Correlation coefficients between intra-operative objective measurements and programming levels were found to be in the range of no correlation to moderate correlation. Adult patients had the most significant correlation coefficients between ECAP thresholds and T-levels in the low frequencies. The younger patients aged 10-20 years and 5-10 years had more significant correlations in the higher frequency channels compared to the other age groups. Intra-operative visually observed ESRTs and electrode impedances were not significantly correlated with initial or stable programming levels for the children or adults. CONCLUSION: Analyzing initial and follow-up mapping levels from previous patients is very important for a CI Center in terms of quality control. The mean T/C-levels reported in this study can provide guidance to our programming audiologists and help them determine the initial programming levels to be stored in the speech processor, especially for very young patients. Unfortunately intra-operative objective measures in our study, such as ECAP, ESRT, and electrode impedances did not provide statistically significant correlations that may help to predict the programming T- and C-levels for all patients. However, we have observed cases where the intra-operative objective measures of ESRT and TECAP profiles were very similar to an individual's MAP profile. It was not possible, however, to determine why some patients did not have an objective measures profile that was similar to their programming levels profile.

Low immediate postoperative serum-cortisol nadir predicts the short-term, but not long-term, remission after pituitary surgery for Cushing's disease.

BACKGROUND: Cushing's disease is an ACTH-producing pituitary adenoma, and the primary treatment is microscopic or endoscopic transsphenoidal selective adenectomy. The aims of the present study were to evaluate whether the early postoperative S-cortisol level can serve as a prognostic marker for short- and long-term remission, and retrospectively review our own short and long term results after surgery for Cushing's disease. METHODS: This single centre, retrospective study consists of 19 consecutive patients with Cushing's disease who underwent transsphenoidal surgery. S-cortisol was measured every 6 h after the operation without any glucocorticoid replacement. We have follow-up on all patients, with a mean follow-up of 68 months. RESULTS: At the three-month follow-up, 16 patients (84 %) were in remission; at 12 months, 18 (95 %) were in remission and at the final follow-up (mean 68 months), 13 (68 %) were in remission. Five-years recurrence rate was 26 %. The mean postoperative S-cortisol nadir was significantly lower in the group of patients in remission than in the non-remission group at 3 months, but there was no difference between those in long-term remission compared to those in long-term non-remission. The optimal cut-off value for classifying 3-month remission was 74 nmol/l. CONCLUSION: We achieved a 95 % 1-year remission rate with transsphenoidal surgery for Cushing's disease in this series of consecutive patients. However, the 5-year recurrence rate was 26 %, showing the need for regular clinical and biochemical controls in this patient group. The mean postoperative serum-cortisol nadir was significantly lower in patients in remission at 3 months compared to patients not in remission at 3 months, but a low postoperative S-cortisol did not predict long-term remission.

Thermal fixation of swine liver tissue after magnetic resonance-guided high-intensity focused ultrasound ablation.

The aim of this study was to investigate experimental conditions for efficient and controlled in vivo liver tissue ablation by magnetic resonance (MR)-guided high-intensity focused ultrasound (HIFU) in a swine model, with the ultimate goal of improving clinical treatment outcome. Histological changes were examined both acutely (four animals) and 1 wk after treatment (five animals). Effects of acoustic power and multiple sonication cycles were investigated. There was good correlation between target size and observed ablation size by thermal dose calculation, post-procedural MR imaging and histopathology, when temperature at the focal point was kept below 90°C. Structural histopathology investigations revealed tissue thermal fixation in ablated regions. In the presence of cavitation, mechanical tissue destruction occurred, resulting in an ablation larger than the target. Complete extra-corporeal MR-guided HIFU ablation in the liver is feasible using high acoustic power. Nearby large vessels were preserved, which makes MR-guided HIFU promising for the ablation of liver tumors adjacent to large veins.

Catheter tip tracking for MR-guided interventions using discrete Kalman filter and mean shift localization.

PURPOSE: This paper presents and evaluates stochastic computer algorithms used to automatically detect and track marked catheter tip during MR-guided catheterization. The algorithms developed employ extraction and matching of regional features of the catheter tip to perform the localization. METHOD: To perform the tracking, a probability map that indicates the possible locations of the catheter tip in the MR images is first generated. This map is generated from the similarity to a given marker template. The method to assess the similarity between the marker template image and the different positions on each MR frame is based on speeded-up robust features extracted from the gradient image. The probability map is then used in two different stochastic localization frameworks mean shift (MS) localization and Kalman filter (KF) to track the position of the catheter using pairs of orthogonal projection of 2D MR images. The algorithm developed was tested on catheter tip marked with LC resonant circuit (of size 2 mm x 2 cm) tuned to the Larmor frequency of the MRI scanner and for different image resolutions (1, 3, 5 and 7 mm squared pixel). RESULTS: The tracking performance was very robust for the two algorithms MS and KF with image resolution as low as 3 mm where the localization error was about 1 mm for KF and 0.9 mm for MS. For the 5-mm resolution images, the error was 2.2 mm for both KF and MS, and for the 7-mm resolution images, the error was 3.6 and 3.7 mm for KF and MS, respectively. CONCLUSION: Both KF and MS gave comparable results when it comes to accuracy for the different image resolutions. The results showed that the two tracking algorithms tracked the catheter tip with high robustness for image resolution of 3 mm and with acceptable reliability for image resolution as poor as 5 mm with the resonant marker configuration used.

Percutaneous closure of catheter enterotomy: feasibility determination in vivo.

AIM: To determine whether a catheter enterotomy can be percutaneously sealed with a commercially available vascular closure implant. MATERIAL AND METHODS: The study was performed using a porcine model of small intestinal obstruction. Preliminary experiments were performed to allow an informed choice between two of the most promising commercially available alternatives: A multipronged metal clip (StarClose®) and a resorbable anchored polymer plate (FemoSeal®). Thereafter closure of seven enterotomies was attempted with the most suitable implant. The deployment procedure was subjectively analyzed. The sealed enterotomies were visually evaluated and hydrostatically tested. RESULTS: StarClose was rejected for formal assessment because it was both difficult to deploy and could not ensure a watertight seal. The conventional method for deploying FemoSeal was found to be inappropriate for percutaneously closing enterotomies. However an improvised accessory allowed all seven enterotomies to be successfully sealed with the implant using a modified procedure that involved only one additional step. After closure, six of the seven enterotomies tolerated intraluminal pressure up to 65 mm Hg. CONCLUSION: FemoSeal has the potential to serve as an implant for percutaneous closure of catheter enterotomies if the deployment tool can be appropriately modified.

Volumetric ablation of uterine fibroids using Sonalleve high-intensity focused ultrasound in a 3 Tesla scanner--first clinical assessment.

INTRODUCTION: The purpose of this study was to evaluate the feasibility and safety of the Sonalleve high-intensity focused ultrasound (HIFU; Philips Healthcare, Vantaa, Finland) system in ablating uterine fibroids in a 3T magnet. MATERIAL AND METHODS: Seven women were included in this study. Treatment was performed according to the manufacturer's recommendation. Technical data describing the HIFU procedures were collected. On MR images at baseline, immediately and 30 days after ablation, we evaluated the volumes of the uterus, the dominant fibroid and the ablation zone. The Uterine Fibroid Symptom and Quality of Life (UFS-QOL) questionnaire was used to assess potential clinical response. RESULTS: The procedure was technically feasible in all patients. The median number of sonications performed during each procedure was 20 (range 2-27) per patient, the maximum temperature in all sonication cells was about 68°C. The median procedure time was 156 minutes (range 95-164). The non-perfused volume after treatment ranged from 1 to 27 ml and was unchanged or decreased in all but one patient at 30 days follow-up. There were no major adverse events. DISCUSSION: In our 3T magnet the system was able to heat tissue and induce areas of non-enhancement within uterine fibroids without major complications. Clinical benefit remains to be proven.

Iterative reconstruction reduces abdominal CT dose.

OBJECTIVE: In medical imaging, lowering radiation dose from computed tomography scanning, without reducing diagnostic performance is a desired achievement. Iterative image reconstruction may be one tool to achieve dose reduction. This study reports the diagnostic performance using a blending of 50% statistical iterative reconstruction (ASIR) and filtered back projection reconstruction (FBP) compared to standard FBP image reconstruction at different dose levels for liver phantom examinations. METHODS: An anthropomorphic liver phantom was scanned at 250, 185, 155, 140, 120 and 100 mAs, on a 64-slice GE Lightspeed VCT scanner. All scans were reconstructed with ASIR and FBP. Four readers evaluated independently on a 5-point scale 21 images, each containing 32 test sectors. In total 672 areas were assessed. ROC analysis was used to evaluate the differences. RESULTS: There was a difference in AUC between the 250 mAs FBP images and the 120 and 100 mAs FBP images. ASIR reconstruction gave a significantly higher diagnostic performance compared to standard reconstruction at 100 mAs. CONCLUSION: A blending of 50-90% ASIR and FBP may improve image quality of low dose CT examinations of the liver, and thus give a potential for reducing radiation dose.

Improved infarction rates in fibroids after the introduction of contrast-enhanced ultrasound during uterine artery embolization.

BACKGROUND: In order to achieve sustained symptom control and minimize the risk of recurrence, uterine artery embolization (UAE) should aim at complete infarction of all fibroids. PURPOSE: To retrospectively evaluate the infarction rate of uterine fibroids in patients that had undergone uterine artery embolization (UAE) after the introduction of contrast-enhanced ultrasound (CEUS) during UAE procedures at our institution. MATERIAL AND METHODS: Thirty patients treated with UAE between February 2006 and August 2009 were included. MR images obtained before, at 3 months, and 12 months after the procedure were reviewed. We evaluated volume changes in dominant fibroids as well as the infarction rate of all fibroids in each patient. Clinical results were evaluated by reviewing the medical records. The study was approved by the institutional review board. RESULTS: CEUS was technically successfully performed during the UAE procedure in all patients. In five cases the endpoint of embolization was adjusted based on findings at CEUS. The mean volume shrinkage of dominant fibroids was 39.8% after 3 months and 59.8% after 12 months. There was complete infarction of all fibroid tissue in 97% of patients at 3 months and 96% at 12 months. No major complications were observed. CONCLUSION: After the introduction of CEUS during UAE procedures in our institution, high infarction rates were achieved.

Intra-operative MRI facilitates tumour resection during trans-sphenoidal surgery for pituitary adenomas.

BACKGROUND: During trans-sphenoidal microsurgical resection of pituitary adenomas, the extent of resection may be difficult to assess, especially when extensive suprasellar and parasellar growth has occurred. In this prospective study, we investigated whether intra-operative magnetic resonance imaging (iMRI) can facilitate tumour resection. METHODS: Twenty patients with macroadenomas, (16 non-functioning, three growth-hormone secreting and one pharmaco-resistant prolactinoma) were selected for surgery in the iMRI. The mean tumour diameter was 27 mm (range 11-41). The mean parasellar grade, according to the Knosp classification, was 2.3. Pre-operative coronal and sagittal T1-weighted and T2-weighted images were obtained. The trans-sphenoidal tumour resection was performed at the edge of the tunnel of a Signa SP 0.5-Tesla MRI. The surgeon aimed at a radical tumour resection that was followed by a peri-operative MRI scan. When a residual tumour was visualised and deemed resectable, an extended resection was performed, followed by another MRI scan. This procedure was repeated until the imaging results were satisfactory. In all patients, we were able to obtain images to assess the extent of resection and to classify the resection as either total or subtotal. RESULTS: After primary resection, eight out of 20 cases were classified as total resections. A second resection was performed in 11 of 12 cases classified as subtotal resections, and in four of these, total resection was achieved. A third resection was performed in three of the remaining seven cases with subtotal resections, but we did not achieve total resection in any of these cases. Therefore, the use of iMRI increased the number of patients with total resection from 8/20 (40%) to 12/20 (60%). The only observed complication was a transient spinal fluid leakage. CONCLUSION: Intra-operative MRI during trans-sphenoidal microsurgery is useful in selected patients for a safe and more complete resection.

Long-term follow-up of patients operated with the symmetry proximal connector device.

OBJECTIVE: : The Symmetry proximal connector device was introduced as a facilitator for construction of proximal anastomosis in coronary bypass surgery. Use of the connector made it unnecessary to clamp the ascending aorta. Early results were promising, but a controlled study performed in our center demonstrated poor angiographic patency of saphenous veins attached with the connector. The objective of this study was to investigate long-term clinical results in patients operated with connector or traditional suture technique. METHODS: : At a minimum of 5 years after surgery, medical records of 46 patients who had undergone off-pump coronary bypass with Symmetry (n = 23) or traditional suture (n = 23) were examined, and the patients were interviewed personally by phone. Patients were asked about the presence of angina pectoris, hospital admission for cardiac conditions, or the need for new interventions. The Norwegian population registry was used to document survival status. RESULTS: : Two control patients and five Symmetry patients died during the observation period (P = 0.414). Seven Symmetry and one control patient required reintervention (P = 0.015). Of the patients who were interviewed, 8 of 19 Symmetry patients suffered from angina and none of 20 control patients (P = 0.003). CONCLUSIONS: : Patients who were operated with the Symmetry connector device have a high chance of having cardiac ischemia in the intermediate to long term after surgery, despite of relatively frequent reintervention. Patients operated with this connector requires close clinical follow-up.