MR-guided focused ultrasound (MRgFUS) ablation for the treatment of nonspinal osteoid osteoma: a prospective multicenter evaluation

BACKGROUND

Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel imaging-guided surgical technique that allows the performance of noninvasive and radiation-free ablation. Presently, computed tomography (CT)-guided radiofrequency ablation, a minimally invasive percutaneous technique, is the standard for treating symptomatic osteoid osteomas. The purpose of this study was to evaluate the use of MRgFUS ablation for the treatment of nonspinal osteoid osteomas in terms of technical success, complications, and clinical success through one year of follow-up.

METHODS

In this prospective multicenter study, thirty consecutive patients with a nonspinal osteoid osteoma were enrolled between May 2010 and April 2012 at three different university centers; twenty-nine of the patients were treated with use of MRgFUS. Lesions had been previously diagnosed on the basis of imaging, including dynamic contrast-enhanced MR. The mean number of sonications and energy deposition were determined. Technical success was evaluated through an assessment of complications immediately after treatment. Clinical success was determined on the basis of pain reduction as measured with a visual analog scale (VAS), recurrence, and long-term complications through twelve months.

RESULTS

Technical success of MRgFUS was observed for all twenty-nine patients. The mean number of sonications (and standard deviation) was 7 ± 3, and the mean delivered acoustic energy was 1180 ± 736 J. At the twelve-month follow-up, complete clinical success was observed in twenty-six (90%) of the twenty-nine patients (95% confidence interval [CI] = 84 to 95; mean VAS, 0 ± 0 points). Partial success was observed in three (10%) of the twenty-nine patients (95% CI = 5 to 16; mean VAS score, 5 ± 0 points); two of these patients subsequently underwent CT-guided radiofrequency ablation, and one underwent open surgery. Pain score values showed a significant reduction (p < 0.001) between baseline (mean VAS score, 8 ± 1 points) and post treatment (mean VAS score, 1 ± 2 points). No complications were observed.

CONCLUSIONS

MRgFUS may be an effective and safe alternative approach in the treatment of nonspinal osteoid osteoma. A complete clinical success rate of 90% was demonstrated without adverse events. MRgFUS is totally noninvasive and eliminates radiation exposure.

Multisite phosphorylation of c-Jun at threonine 91/93/95 triggers the onset of c-Jun pro-apoptotic activity in cerebellar granule neurons

Cerebellar granule cell (CGC) apoptosis by trophic/potassium (TK) deprivation is a model of election to study the interplay of pro-apoptotic and pro-survival signaling pathways in neuronal cell death. In this model, the c-Jun N-terminal kinase (JNK) induces pro-apoptotic genes through the c-Jun/activator protein 1 (AP-1) transcription factor. On the other side, a survival pathway initiated by lithium leads to repression of pro-apoptotic c-Jun/AP-1 target genes without interfering with JNK activity. Yet, the mechanism by which lithium inhibits c-Jun activity remains to be elucidated. Here, we used this model system to study the regulation and function of site-specific c-Jun phosphorylation at the S63 and T91/T93 JNK sites in neuronal cell death. We found that TK-deprivation led to c-Jun multiphosphorylation at all three JNK sites. However, immunofluorescence analysis of c-Jun phosphorylation at single cell level revealed that the S63 site was phosphorylated in all c-Jun-expressing cells, whereas the response of T91/T93 phosphorylation was more sensitive, mirroring the switch-like apoptotic response of CGCs. Conversely, lithium prevented T91T93 phosphorylation and cell death without affecting the S63 site, suggesting that T91T93 phosphorylation triggers c-Jun pro-apoptotic activity. Accordingly, a c-Jun mutant lacking the T95 priming site for T91/93 phosphorylation protected CGCs from apoptosis, whereas it was able to induce neurite outgrowth in PC12 cells. Vice versa, a c-Jun mutant bearing aspartate substitution of T95 overwhelmed lithium-mediate protection of CGCs from TK-deprivation, validating that inhibition of T91/T93/T95 phosphorylation underlies the effect of lithium on cell death. Mass spectrometry analysis confirmed multiphosphorylation of c-Jun at T91/T93/T95 in cells. Moreover, JNK phosphorylated recombinant c-Jun at T91/T93 in a T95-dependent manner. On the basis of our results, we propose that T91/T93/T95 multiphosphorylation of c-Jun functions as a sensitivity amplifier of the JNK cascade, setting the threshold for c-Jun pro-apoptotic activity in neuronal cells.

Assessing traumatic brain injuries using EEG power spectral analysis and instantaneous phase

Although mild traumatic brain injury (mTBI) occurs commonly, little is known about how multiple mTBI incidents accumulate over time to produce serious morbidity or how the extent of injury can be quantified. This work presents a rat model that uses deceleration-induced brain trauma and an implantable EEG system for recording injury-induced changes in brain activity. Specifically, we present an analysis method to assess and quantify mTBI by combining information derived from EEG power spectral analysis and EEG phase shifts. We found that in different frequency bands, both EEG power spectra and the instantaneous phases of the two EEG channels before the impact were different from those measured after the impact. This study shows that EEG analysis can be used as a tool to identify and assess brain related injuries.

Quality of Life, Wishes, and Needs in Women with Gestational Diabetes: Italian DAWN Pregnancy Study

The DAWN (Diabetes Attitudes, Wishes and Needs) study is a survey promoted by the International Diabetes Federation to recognize the perceptions and attitudes of people suffering from diabetes mellitus. In this context, we evaluated the quality of life of Italian and immigrant women with gestational diabetes mellitus (GDM). Information was gathered using a structured questionnaire for patients' self-compilation. In a 3-month period, a 51-item questionnaire was submitted to 198 Italians and 88 immigrants (from 27 different foreign nationalities). Italian women were older and had higher education than the immigrants. 60% of the Italians and 38% of the immigrants had a family history of diabetes mellitus. In both groups, the diagnosis of GDM caused anxiety; one-third of women feared their child could contract diabetes at delivery and/or have congenital malformations. Some women had trouble in following treatment regimens: the major concern being dietary advice and blood glucose testing. Most women were satisfied (34%) or highly satisfied (60%) with the quality of care, although the degree of cooperation between diabetes specialists and gynaecologists was considered sometimes unsatisfactory. In order to optimize maternal and foetal outcomes, educational projects and improved communication between patients and the healthcare provider team are recommended.

A comparison between SSMF and large-A(eff) Pure-Silica core fiber for ultra long-haul 100G transmission

We compare the transmission performance of 112-Gb/s POLMUX-QPSK modulation over large-A(eff) Pure-Silica core fiber and SSMF using EDFA-only amplification. The higher nonlinear threshold of the large-A(eff) Pure-Silica core fiber allows for a 55% increase in transmission distance. By using back-propagation an additional 10% increase is observed. In case spans with equal length for both fiber types and two splices per span only would have been used, resulting in a lower span loss for the large-A(eff) Pure-Silica core fiber, the total increase grows to 85%.

Low-dose contrast-enhanced time-resolved MR angiography at 3T: diagnostic accuracy for treatment planning and follow-up of vascular malformations

AIM

To assess the accuracy of low-dose contrast-enhanced time-resolved 3T magnetic resonance angiography (MRA) for the morphological and functional assessment of vascular malformations (VM), and to evaluate its diagnostic potential for the depiction of treatment-induced changes.

MATERIALS AND METHODS

Twenty-five patients with known VM underwent MRA to evaluate the location and extent of lesions and their haemodynamic characteristics. Three-dimensional (3D) T1-weighted time-resolved sequences were acquired following the administration of 0.05mmol/kg of gadobenate dimeglumine. VM were classified according to their morphology and haemodynamic characteristics. All patients thereafter underwent conventional angiography to confirm the diagnosis and to treat the lesions (embolization or sclerotherapy). Follow-up MRA was performed 30 days after treatment to assess morphological and functional changes. A visual analogue scale (VAS) was used to clinically assess the severity of symptoms before and after therapy.

RESULTS

Based on haemodynamic characteristics, VM were classified as predominantly arterial [4 (16%)], artero-venous [19 (76%)] or venous [2 (8%)]. Twenty-three (92%) lesions were classified as high-flow VM and two (8%) as low-flow VM. Intralesional thrombosis was present in 17 (68%) lesions before therapy and in 10 lesions (40%) after therapy. The median VAS scores were 5±1 before treatment and 4±2 after treatment. Very good correlation (Spearman's correlation coefficient: rho=0.87; p=0.000) was noted between the reduction of lesion size on follow-up MRA and pain relief as assessed by VAS.

CONCLUSION

Low-dose contrast-enhanced time-resolved 3T MRA can be used to define morphological and functional aspects of VM accurately during treatment planning and follow-up, and can identify post-therapy changes that positively correlate with treatment outcome.

Malignant tumours of the small intestine: a review of histopathology, multidetector CT and MRI aspects

Small bowel neoplasms, including adenocarcinoma, carcinoid tumour, lymphoma and gastrointestinal stromal tumours, represent a small percentage of gastrointestinal cancers, yet are among those with the poorest prognosis compared with other gastrointestinal malignancies. Unclear clinical scenarios and difficult radiological diagnosis often delay treatment with negative effects on patient survival. Recently, multidetector CT (MDCT) and MRI have been introduced as feasible and accurate diagnostic techniques for the identification and staging of small bowel neoplasms. These techniques are gradually replacing conventional barium radiography as the tool of choice. However, the inherent technical and physiological challenges of small bowel imaging require a familiarity with patient preparation and scan protocols. Adequate knowledge of the histopathology and natural evolution of small bowel neoplasms is also important for differential diagnosis. The aim of this article is to review MDCT and MRI protocols for the evaluation of small bowel tumours and to provide a concise yet comprehensive guide to the most relevant imaging features relative to histopathology.

Diagnostic performance of 64-MDCT and 1.5-T MRI with high-resolution sequences in the T staging of gastric cancer: a comparative analysis with histopathology

PURPOSE

This study was undertaken to compare the accuracy of magnetic resonance (MR) imaging and 64-slice multidetector computed tomography (64-MDCT) in the T staging of gastric carcinoma in comparison with histopathology.

MATERIALS AND METHODS

Forty patients with an endoscopic diagnosis of gastric carcinoma underwent preoperative MR imaging and 64-MDCT, both of which were performed after i.v. injection of scopolamine and water distension of the stomach. In the MR imaging protocol, we acquired T2-weighted turbo spin-echo (TSE) sequences, true fast imaging steady-state free precession (true-FISP) and gadolinium-enhanced T1-weighted volumetric interpolated breath-hold examination (VIBE) 3D sequences. Contrastenhanced CT scans were obtained in the arterial and venous phases. Two groups of radiologists independently reviewed the MR and 64-MDCT images. The results were compared with pathology findings.

RESULTS

In the evaluation of T stage, 64-MDCT had 82.5% and MR imaging had 80% sensitivity. Accuracy of MR imaging was slightly higher than that of 64-MDCT in identifying T1 lesions (50% vs 37.5%), whereas the accuracy of 64-MDCT was higher in differentiating T2 lesions (81.2% vs 68.7%). The accuracy of MR imaging and 64-MDCT did not differ significantly in the evaluation of T3-T4 lesions (p>0.05). Understaging was observed in 20% of cases with MR imaging and in 17.5% with 64-MDCT.

CONCLUSIONS

MR imaging and 64-MDCT accuracy levels did not differ in advanced stages of disease, whereas MR imaging was superior in identifying early stages of gastric cancer and can be considered a valid alternative to MDCT in clinical practice.