Time-resolved imaging of contrast kinetics three-dimensional (3D) magnetic resonance venography in patients with pelvic congestion syndrome.

The purpose of this study was to assess the role of magnetic resonance venography (MRV) with time-resolved imaging of contrast kinetics (TRICKS) in dynamically evaluating ovarian vein dilation, reflux and direction of flow in patients with suspected pelvic congestion syndrome (PCS). The hypotheses tested were: (i) That conspicuity scores of the ovarian veins across three raters was greater using TRICKS MRV compared with T2W or T(2)* imaging; (ii) That three key MR variables (ovarian vein diameter, timing and grade of reflux) correlated across all raters. We carried out a retrospective study of 13 patients undergoing T2W and TRICKS MRI and pelvic sonography (n = 4) or catheter venography (n = 5). Three observers rated conspicuity, vessel diameter, timing and grade of ovarian vein reflux for T(2)/T2*W and TRICKS MRI. The mean left ovarian diameter for all patients with reflux was 7.9 mm (range 2.2-12 mm). There was high inter-observer agreement for ovarian vein diameter for both sequences. TRICKS showed significantly greater conspicuity than T(2)/T2*W imaging (TRICKS: T(2)/T2* mean (SD) = 7.80 (3.20):5.50 (1.97), F (1,12) = 5.80, p < 0.05). TRICKS MRV demonstrated high inter-observer correlation for timing and grade of reflux (r (36) = 0.77,0.71,0.79, p < 0.01). TRICKS MRA/V was significantly degraded by breathing artefact in two patients. We conclude that TRICKS MRV accurately and dynamically demonstrates ovarian vein reflux in patients with PCS but requires quiet respiration. TRICKS MRV has better image conspicuity than T(2)/T2*W imaging and sufficient temporal resolution to distinguish between Grade I, II and III reflux.

ExAblate magnetic resonance-guided focused ultrasound system in multiple body applications.

Focused ultrasound surgery (FUS) is a completely noninvasive method of thermally destroying a target tissue while sparing adjacent tissues and organs. Treatment is relatively painless and can be carried out under conscious sedation on an out-patient basis. The combination of magnetic resonance guidance with FUS (MRgFUS) provides the ability to plan and monitor treatments in near real-time, further increasing the safety profile of MRgFUS. This technology provides a very personalized treatment, adjusted to the individual patient anatomy, pathology and treatment response, hence it meets the needs of patients, as well as of physicians. MRgFUS has been used extensively in the successful treatment of uterine fibroids, and has been shown to be an effective treatment in the breast and in bone metastases in smaller scale studies. It shows great potential in the treatment of prostate and liver tumors, as well as in the brain and facet joints.

Conservative management of diabetic forefoot ulceration complicated by underlying osteomyelitis: the benefits of magnetic resonance imaging.

AIMS: To assess efficacy of conservative management of neuropathic forefoot ulcers with underlying osteomyelitis in subjects with diabetes when magnetic resonance imaging (MRI) is used to confirm or establish diagnosis and to guide antibiotic duration. METHODS: A retrospective cohort study over 6 years assessing rates of ulcer healing, relapse and amputation. Antibiotics were continued for 3-month cycles with interval MRI: if the lesion had healed and bone signal change resolved or improved, antibiotics were discontinued; if the lesion had not healed or there was no difference in bone signal change, antibiotics were continued for a further 3-month cycle; clinical or radiological deterioration resulted in endoluminal or open vascular surgical intervention where appropriate, or digital or more proximal amputation. RESULTS: There were 53 episodes in 47 subjects (mean +/- sd age 62 +/- 13 years, duration of diabetes 19 +/- 13 years, glycated haemoglobin 8.4 +/- 1.6%; six with Type 1 diabetes and seven with end-stage renal failure). Successful healing without relapse was achieved in 40 episodes (75%) [median (range) duration of antibiotics 6 (3-12) months and follow-up post-cessation of antibiotics 15 (3-58) months]. Relapse occurred in six episodes (13%) at 31 (2-38) months post-cessation of antibiotics. There were one major (2%) and eight minor (15%) amputations. Five subjects have died (11%), all without foot ulcers. CONCLUSIONS: High rates of healing and low rates of amputation were achieved. The use of MRI was associated with long courses of antibiotics, but particularly low relapse rate.

Cost-effectiveness of magnetic resonance-guided focused ultrasound surgery for treatment of uterine fibroids.

OBJECTIVE: To estimate the cost-effectiveness of a treatment strategy for symptomatic uterine fibroids, which starts with Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) as compared with current practice comprising uterine artery embolisation, myomectomy and hysterectomy. DESIGN: Cost-utility analysis based on a Markov model. SETTING: National Health Service (NHS) Trusts in England and Wales. POPULATION: Women for whom surgical treatment for uterine fibroids is being considered. METHODS: The parameters of the Markov model of the treatment of uterine fibroids are drawn from a series of clinical studies of MRgFUS, and from the clinical effectiveness literature. Health-related quality of life is measured using the 6D. Costs are estimated from the perspective of the NHS. The impact of uncertainty is examined using deterministic and probabilistic sensitivity analysis. MAIN OUTCOME MEASURES: Incremental cost-effectiveness measured by cost per quality-adjusted life-year (QALY) gained. RESULTS: The base-case results imply a cost saving and a small QALY gain per woman as a result of an MRgFUS treatment strategy. The cost per QALY gained is sensitive to cost of MRgFUS relative to other treatments, the age of the woman and the nonperfused volume relative to the total fibroids volume. CONCLUSIONS: A treatment strategy for symptomatic uterine fibroids starting with MRgFUS is likely to be cost-effective.

Magnetic resonance guided focused ultrasound surgery of uterine fibroids--the tissue effects of GnRH agonist pre-treatment.

OBJECTIVE: The purpose of this study was to determine the ablative effect of magnetic resonance guided focused ultrasound (MRgFUS) on fibroid tissue following the administration of gonadotrophin releasing hormone (GnRH) agonist. STUDY DESIGN: Fifty women with clinically symptomatic uterine fibroids were treated. Those with uterine diameter of 10 cm or greater were given 3 months pre-treatment with GnRH agonists. Data regarding number of ultrasound sonications, Joules of energy delivered and volume of thermal destruction was recorded. RESULTS: Twenty-seven subjects were given GnRH agonist therapy before MRgFUS and 23 women underwent MRgFUS without pre-treatment. All patients in both study groups completed MR guided FUS as an outpatient procedure with no device related adverse events reported. In the group of women who received GnRH agonists, the volume of ablation was significantly larger than that in the control group (0.06 cm3 versus 0.03 cm3, P<0.05), per Joule of energy applied. CONCLUSION: The use of GnRH agonists potentiates the thermal effects of MRgFUS in women undergoing treatment of uterine fibroids.

MR-guided laser thermal ablation of primary and secondary liver tumours.

AIM: To test the hypothesis that magnetic resonance (MR)-guided hepatic tumour ablation is (i) safe and feasible, (ii) is associated with favourable patient survival, and (iii) decreases viable tumour. MATERIALS AND METHODS: One hundred and twenty-five MR-guided laser thermal ablations (LTA) were performed on 35 patients with hepatocellular carcinoma (HCC, n=19), hepatic metastases (n=11, mainly colorectal) and carcinoid liver tumours (n=5). RESULTS: Mean overall survival was 14.8 months (HCCs 14.6 months, metastases 15.2 months). Near real-time T1-weighted colourized thermal maps correlated moderately with follow-up gadolinium-enhanced MR imaging in predicting ablated tumour area (Pearson correlation coefficient=0.5). There was a significant difference in percentage enhancing pre- and post-LTA (Wilcoxon signed ranks test=0.0001). An average of 50.7% of tumour was ablated by each treatment. In patients with multiple liver tumours ablated tumours grew significantly less than untreated tumours (108%compared with 196% growth, follow-up period 5.8 months, WSRTp=0.07). CONCLUSION: MR- guided LTA of primary and secondary liver tumours is safe, feasible, and significantly decreased amount of enhancing or viable tumour. MR-guided LTA produces a better survival in patients with HCC than would be expected in untreated patients, and has a mean survival in patients with metastases at least equal to the longest median survival in untreated patients.

Magnetic resonance imaging-guided laser thermal ablation of renal tumours.

OBJECTIVE: To test the hypothesis that magnetic resonance imaging (MRI)-guided laser thermal ablation (LTA) of inoperable renal tumours is a safe, tolerable and potentially effective treatment. PATIENTS AND METHODS: Nine patients (aged 56-81 years) with malignant renal tumours underwent percutaneous LTA under MRI guidance in a 0.5 T open magnet. Real-time colour thermal mapping was used to monitor tumour ablation, and the follow-up was with gadolinium-enhanced MRI at 6 weeks and (where appropriate) 3-4 months after the procedure. Tumour volume and percentage tumour enhancement before and after ablation were compared. The percentage of tumour ablated on real-time T1-weighted thermal maps was compared with that on gadolinium-enhanced follow-up MRI. RESULTS: The mean (range) follow-up was 16.9 (3-32) months after the first ablation. The mean tumour size did not change significantly, but the mean percentage of viable tumour decreased significantly from 73.7% before to 29.5% after ablation (P = 0.012, Wilcoxon signed-ranks test). Thermal maps correlated moderately well with follow-up MRI in predicting the extent of tumour ablation (Pearson correlation coefficient 0.55). There were two minor and one major complication. CONCLUSION: In this pilot study of patients unsuitable for surgery, MRI-guided LTA of renal tumours was safe, feasible (being well tolerated by the patient) and significantly reduced enhancing tumour volume by a mean of 45%.

Clinical outcomes following percutaneous magnetic resonance image guided laser ablation of symptomatic uterine fibroids.

BACKGROUND: Fibroids are common benign tumours of the uterus. Percutaneous magnetic resonance (MR) image guided laser ablation provides a minimally invasive, day-case alternative to surgery for the treatment of symptomatic fibroids. METHODS: Women with symptomatic fibroids wishing to avoid surgery were treated with laser ablation. MR thermal mapping ensured that maximal safe energy was applied. Fibroid volume was measured at 3 and 12 months, menstrual blood loss was recorded before and after treatment and a menorrhagia outcomes questionnaire (MOQ) was used to assess satisfaction. RESULTS: A total of 66 patients was treated. There was a significant (P < 0.001) reduction in mean fibroid volume of 31%. This was 41% at 1 year follow-up (P < 0.001). Measured menstrual blood loss in eight patients complaining of excessive bleeding was reduced (P = 0.012). The MOQ total outcome score was not as good as that seen in hysterectomy patients (P = 0.02) but the quality of life/satisfaction score was similar (P = 0.06). CONCLUSION: We have used objective and subjective outcome measures to determine the efficacy of MR guided laser ablation for fibroids. Based on this limited study we are encouraged that this procedure may represent a minimally invasive alternative therapy for fibroids.

Hepatocellular adenoma: diagnostic difficulties and novel imaging techniques.

We report the case of a 30-year-old eastern European female who presented with right upper quadrant pain. Clinical examination was unremarkable and liver function tests were normal. CT identified a 5 cm lesion in segment V of the liver, which was of homogeneous low density with no calcification or significant enhancement. MRI showed the lesion to be hypointense to liver on T(1) weighted sequences and isointense on T(2) weighted sequences. Rapid arterial enhancement with gadolinium-DTPA faded without leaving a definite central scar. Ultrasound showed the lesion to be echogenic with minimal vascularity. Administration of a liver-specific microbubble contrast agent showed low uptake relative to the surrounding liver. Phosphorus-31 MR spectroscopy, localized to the lesion itself, revealed a markedly increased phosphomonoester resonance with a decreased phosphodiester resonance, compatible with increased cell turnover. Biopsy confirmed the lesion to be a hepatocellular adenoma. The diagnosis of a hepatic adenoma is difficult with tissue diagnosis the gold standard, but it may be suggested by a combination of imaging modalities. We have described two new imaging techniques not previously described in characterization of hepatic adenomata, namely ultrasound with contrast agent and MR spectroscopy.

The trunk muscles of elite oarsmen.

OBJECTIVES: To investigate the trunk strength of elite rowers and the impact of low back pain on these measures in order to determine if asymmetries or weakness were present. METHODS: Twenty two elite rowers were recruited: 13 reported previous low back pain, five current low back pain, and the remainder had no history of low back pain. All subjects were scanned during simulated rowing in an interventional open magnetic resonance imaging scanner. In each simulated rowing position, axial scans were obtained at the level of the L4-5 and L5-S1 disc interspace to determine the cross sectional area of the posterior trunk muscles. RESULTS: Considerable differences were observed between the three groups of rowers. In contrast with expectations and previous literature, the trunk muscles of rowers with low back pain had significantly larger cross sectional areas (p<0.001). No left/right asymmetries were observed and no differences between oarside and non-oarside in terms of muscle cross sectional area. CONCLUSION: These findings suggest that low back pain in rowers does not arise as a result of muscle weakness.

Ablative therapy for liver tumours.

Established ablative therapies for the treatment of primary and secondary liver tumours, including percutaneous ethanol injection, cryotherapy, and radiofrequency ablation, are discussed. Newer techniques such as magnetic resonance imaging guided laser interstitial thermal therapy of liver tumours has produced a median survival rate of 40.8 months after treatment. The merits of this newly emerging technique are discussed, together with future developments, such as focused ultrasound therapy, which holds the promise of non-invasive thermoablation treatment on an outpatient basis.