Novel Focal Therapeutic Hypothermia Device for Treatment of Acute Neurologic Injury: Large Animal Safety and Efficacy Trial.

Objective Therapeutic hypothermia is a potentially powerful and controversial clinical tool for neuroprotection following acute neurologic pathology, particularly vascular injury. Indeed, therapeutic hypothermia remains a standard of care for postcardiac arrest ischemia and acute neonatal hypoxic-ischemic encephalopathy, improving both survival and outcomes. Although therapeutic hypothermia remains promising for cellular and systems-based neuronal protection in other neurologic injury states, the systemic side effects have limited clinical utility, confounded analysis of potential neurologic benefits, and precluded the completion of meaningful clinical trials. Methods To address such limitations, we developed and tested a novel, minimally invasive, neurocritical care device that employs continuous circulation of cold saline through the pharyngeal region to deliver focal cerebrovascular cooling. We conducted a preclinical safety and efficacy trial in six adult porcine animals to assess the validity and functionality of the NeuroSave device, and assess cooling potential following middle cerebral artery occlusion ( n = 2). Results NeuroSave consistently lowered brain parenchymal temperature by a median of 9°C relative to core temperature within 60 minutes of initiation, including in ischemic cerebral parenchyma. The core body temperature experienced a maximal reduction of 2°C, or 5% of body temperature, with no associated adverse effects identified. Conclusion The present study uses a large animal preclinical model to demonstrate the safety and efficacy of a novel, noninvasive device for the induction of robust and systemically safe hypothermia within the brain.

Uterine and Fibroid Imaging Analysis from the FIRSTT Study.

Background: Women with uterine fibroids often seek uterine-preserving treatments, rather than hysterectomy. Imaging-defined endpoints following nonsurgical treatments for fibroids are limited. Materials and Methods: Fibroid Interventions: Reducing Symptoms Today and Tomorrow (FIRSTT), a randomized controlled trial of uterine artery embolization (UAE) versus magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS), enrolled premenopausal women with symptomatic uterine fibroids. In this subanalysis, we report imaging results up to 36 months after UAE or MRgFUS. Magnetic resonance imaging (MRI) was performed at baseline for all women and during the 36 months after treatment if they did not meet other study endpoints. The main outcome of this subanalysis was fibroid volume reduction (defined both in terms of total fibroid load and volume of the largest fibroid), uterine volume reduction, and nonperfused volume. Results: During 2010-2014, 25 of the 37 women who were randomized and treated at Mayo Clinic had a 24-month follow-up MRI (11 UAE; 14 MRgFUS); among these women, 15 (7 UAE and 8 MRgFUS) had a 36-month follow-up MRI. Average age for the cohort was 44.1 (standard deviation, SD = 4.4) years. Nine patients had a second fibroid procedure by 36 months (seven in the MRgFUS arm and two in UAE arm). Median total fibroid load reduction was ∼50% in both treatment arms at both 24- and 36-month follow-up. Volume of the largest fibroid decreased more in the MRgFUS arm, whereas uterine volume decreased more in the UAE arm (neither reached statistical significance). At 24 months, median nonperfused volume was higher in the UAE arm (92%) than the MRgFUS arm (10%). Conclusions: Similar fibroid volume reduction was seen for the MRgFUS and UAE treatments in this comparative effectiveness study. Nonperfused volume 24 months after the procedure was higher in the UAE arm than in the MRgFUS arm. Clinical Trial Registration Number: NCT00995878, clinicaltrials.gov.

Body Interventional MRI for Diagnostic and Interventional Radiologists: Current Practice and Future Prospects.

Clinical use of MRI for guidance during interventional procedures emerged shortly after the introduction of clinical diagnostic MRI in the late 1980s. However, early applications of interventional MRI (iMRI) were limited owing to the lack of dedicated iMRI magnets, pulse sequences, and equipment. During the 3 decades that followed, technologic advancements in iMRI magnets that balance bore access and field strength, combined with the development of rapid MRI pulse sequences, surface coils, and commercially available MR-conditional devices, led to the rapid expansion of clinical iMRI applications, particularly in the field of body iMRI. iMRI offers several advantages, including superior soft-tissue resolution, ease of multiplanar imaging, lack of ionizing radiation, and capability to re-image the same section. Disadvantages include longer examination times, lack of MR-conditional equipment, less operator familiarity, and increased cost. Nonetheless, MRI guidance is particularly advantageous when the disease is best visualized with MRI and/or when superior soft-tissue contrast is needed for treatment monitoring. Safety in the iMRI environment is paramount and requires close collaboration among interventional radiologists, MR physicists, and all other iMRI team members. The implementation of risk-limiting measures for personnel and equipment in MR zones III and IV is key. Various commercially available MR-conditional needles, wires, and biopsy and ablation devices are now available throughout the world, depending on the local regulatory status. As such, there has been tremendous growth in the clinical applications of body iMRI, including localization of difficult lesions, biopsy, sclerotherapy, and cryoablation and thermal ablation of malignant and nonmalignant soft-tissue neoplasms. Online supplemental material is available for this article. ©RSNA, 2021.

Using Black Bone Magnetic Resonance Imaging for Fibula Free Flap Surgical Planning: A Means to Reduce Radiation Exposure with Accurate Surgical Outcomes.

SUMMARY: Advances in virtual surgical planning and three-dimensionally-printed guides have enabled increased precision in vascularized free fibula flap reconstruction of the mandible and valuable preoperative planning. However, virtual surgical planning currently requires high-resolution computed tomographic scans, exposing patients to ionizing radiation. The aim of this study was to determine whether black bone magnetic resonance imaging can be used for accurate surgical planning and three-dimensionally-printed guide creation, thus reducing patient radiation exposure. This study included 10 cadaver heads and 10 cadaver lower extremities. A mock fibula free flap for mandible reconstruction was performed. Five operations were planned with guides created using black bone magnetic resonance imaging, whereas the other five were planned and performed using guides created with computed tomographic scan data. All specimens underwent a postoperative computed tomographic scan, and three-dimensional reconstruction of scans was performed and surgical accuracy to the planned surgery was assessed. Guides created from black bone magnetic resonance imaging demonstrated high accuracy to the surgical plan. There was no statistically significant difference in postoperative deviation from the plan when black bone magnetic resonance imaging versus computed tomographic scanning was used for virtual surgical planning and guide creation. Both modalities led to a postoperative positive or negative deviation from the virtual plan within 0.8 mm. This study demonstrates that virtual surgical planning and three-dimensionally-printed guide creation for free fibula flaps for mandible reconstruction can be performed using black bone magnetic resonance imaging with comparable accuracy to computed tomographic scanning. This could reduce radiation exposure for patients and enable a more streamlined imaging process for head and neck cancer patients.

Experimental Investigation of Cryoneedle Heating during MR-Guided Cryoablation in Ex Vivo Tissue Samples at 1.5-Tesla.

PURPOSE: To investigate cryoneedle heating risks during magnetic resonance (MR)-guided cryoablation and potential strategies to mitigate these risks. MATERIALS AND METHODS: Ex vivo experiments were performed on a 1.5-Tesla (T) MR scanner using an MR conditional cryoablation system on porcine tissue phantoms. Cryoneedles were placed inside the tissue phantom either with or without an angiocatheter. Typical cryoneedle geometric configurations (including gas supply line) encountered in clinical procedures with low to high expected heating risks were investigated. Up to 4 fiber optic temperature sensors were attached to the cryoneedle/angiocatheter to measure the MR-induced cryoneedle heating at different locations during MR with different estimated specific absorption rates (SARs). The impact of cryoneedle heating on cryoablation treatment was studied by comparing temperature changes during 10-min freeze-thaw cycles with and without MR. RESULTS: Rapid temperature increases of >100 °C in < 2 minutes were observed during MR with a SAR of 2.1 W/kg. The temperature changes during a typical freeze-thaw cycle were also affected by cryoneedle heating when MR was used to monitor the ice-ball evolution. The observed cryoneedle heating was affected by multiple factors; including cryoneedle geometric configurations, sequence SAR, whether an angiocatheter was used, and whether the cryoneedle was connected to the rest of the cryoablation system. CONCLUSIONS: The ex vivo experiments demonstrated that MR could induce significant cryoneedle heating risks. Furthermore, MR-induced cryoneedle heating can affect temperatures in the ice-ball evolution during the freeze-thaw cycle. Several practical strategies to reduce the cryoneedle heating have been proposed.

Comparison of Clinical Performance Between Two Generations of Magnetic Resonance-guided Focused Ultrasound Systems in Treatments of Uterine Leiomyomas.

OBJECTIVES: The aim of this study was to evaluate the impact of technology improvements on the outcomes of magnetic resonance-guided focused ultrasound (MRgFUS) treatments of symptomatic uterine leiomyomas (uterine fibroids). The study compared ablation volumes and incidence of adverse events in patient groups treated with two generations of MRgFUS systems from a single vendor. METHODS: The present study describes the results of a retrospective comparative study of two groups of women with symptomatic uterine leiomyomas who were clinically treated with MRgFUS at a single institution. Group 1 (n = 130) was treated using the first-generation system between March 2005 and December 2009. Group 2 (n = 71) was treated using the second-generation between December 2013 and September 2019. RESULTS: The second-generation MRgFUS system resulted in significantly improved nonperfused volume ratios in both dark and bright T2 fibroid categories compared with the first-generation system (dark - 80% versus46 %, p = 0.00002 and bright - 46% versus 32%, p = 0.001). There have been no recorded hospital admissions, no skins burns, and no reported major adverse events since the introduction of this second-generation ExAblate 2100 system with advanced safety and treatment planning features. CONCLUSION: This study has demonstrated that improvements to current MRgFUS technology resulted in significantly increased efficacy and patient safety of clinical treatments of patients with symptomatic uterine leiomyomas.

Improved MR-thermometry during hepatic microwave ablation by correcting for intermittent electromagnetic interference artifacts.

MRI-guided microwave ablation (MWA) is a minimally invasive treatment for localized cancer. MR thermometry has been shown to be able to provide vital information for monitoring the procedure in real-time. However, MRI during active MWA can suffer from image quality degradation due to intermittent electromagnetic interference (EMI). A novel approach to correct for EMI-contaminated images is presented here to improve MR thermometry during clinical hepatic MWA. The method was applied to MR-thermometry images acquired during four MR-guided hepatic MWA treatments using a commercially available MRI-configured microwave generator system. During the treatments MR thermometry data acquisition was synchronized to respiratory cycle to minimize the impact of motion. EMI was detected and corrected using uncontaminated k-space data from nearby frames in k-space. Substantially improved temperature and thermal damage maps have been obtained and the treatment zone can be better visualized. Our ex vivo tissue sample study shows the correction introduced minimal errors to the temperature maps and thermal damage maps.

Rectal wall saline displacement for improved margin during MRI-guided cryoablation of primary and recurrent prostate cancer.

PURPOSE: To describe safety, efficacy, and added oncologic margin of saline displacement of the rectal wall during MRI-guided cryoablation of primary and recurrent prostate cancer. METHODS: A retrospective review was conducted for patients who underwent MRI-guided cryoablation with saline displacement of the rectal wall for treatment of primary and recurrent prostate cancer over a 2-year period. Saline displacement was used when the distance from the edge of the ablation area to the rectal wall was insufficient to provide at least a 5-mm treatment margin. Pre- and post-ablation rectal wall displacement distances as well as ablative zone margins were assessed with MRI. Saline displacement distance was measured from the rectal wall to the edge of the lesion for focal lesion ablation and from the edge of the prostate for hemi-gland ablation. Immediate and intermediate-term complications were assessed. RESULTS: Saline displacement was used in 25 patients undergoing MRI-guided cryoablation. Twenty-one patients underwent salvage cryoablation, while four patients had it as primary treatment for prostate cancer. Median pre- and post- saline displacement rectal wall displacement distances were 6.0 and 11.2 mm, respectively (P < 0.0001). Median-added oncologic margin achieved by saline displacement was 4.6 mm (range 0.6-26.5). Median follow-up was 14 months (range 5-29). There were no intra-procedural complications and 3 patients experienced minor (Clavien-Dindo grade I) complications. One rectal complication occurred in a patient undergoing salvage cryotherapy with a history of extensive pelvic surgery and radiation. CONCLUSIONS: Saline infusion at the time of MRI- guided cryoablation for prostate cancer resulted in increased distances between the target lesion and rectum. This is a useful technique in providing an added oncologic margin when treating lesions close to the rectal wall.

Magnetic Resonance-Guided Prostate Ablation.

In 2019, the American Cancer Society (ACS) estimates that 174,650 new cases of prostate cancer will be diagnosed and 31,620 will die due to the prostate cancer in the United States. Prostate cancer is often managed with aggressive curative intent standard therapies including radiotherapy or surgery. Regardless of how expertly done, these standard therapies often bring significant risk and morbidity to the patient's quality of life with potential impact on sexual, urinary, and bowel functions. Additionally, improved screening programs, using prostatic-specific antigen and transrectal ultrasound-guided systematic biopsy, have identified increasing numbers of low-risk, low-grade "localized" prostate cancer. The potential, localized, and indolent nature of many prostate cancers presents a difficult decision of when to intervene, especially within the context of the possible comorbidities of aggressive standard treatments. Active surveillance has been increasingly instituted to balance cancer control versus treatment side effects; however, many patients are not comfortable with this option. Although active debate continues on the suitability of either focal or regional therapy for the low- or intermediate-risk prostate cancer patients, no large consensus has been achieved on the adequate management approach. Some of the largest unresolved issues are prostate cancer multifocality, limitations of current biopsy strategies, suboptimal staging by accepted imaging modalities, less than robust prediction models for indolent prostate cancers, and safety and efficiency of the established curative therapies following focal therapy for prostate cancer. In spite of these restrictions, focal therapy continues to confront the current paradigm of therapy for low- and even intermediate-risk disease. It has been proposed that early detection and proper characterization may play a role in preventing the development of metastatic disease. There is level-1 evidence supporting detection and subsequent aggressive treatment of intermediate- and high-risk prostate cancer. Therefore, accurate assessment of cancer risk (i.e., grade and stage) using imaging and targeted biopsy is critical. Advances in prostate imaging with MRI and PET are changing the workup for these patients, and advances in MR-guided biopsy and therapy are propelling prostate treatment solutions forward faster than ever.

FIRSTT study: randomized controlled trial of uterine artery embolization vs focused ultrasound surgery.

BACKGROUND: Uterine leiomyomas (fibroid tumors) cause considerable symptoms in 30-50% of women and are the leading cause of hysterectomy in the United States. Women with uterine fibroid tumors often seek uterine-preserving treatments, but comparative effectiveness trials are lacking. OBJECTIVE: The purpose of this study was to report treatment effectiveness and ovarian function after uterine artery embolization vs magnetic resonance imaging-guided focused ultrasound surgery from the Fibroid Interventions: Reducing Symptoms Today and Tomorrow study. STUDY DESIGN: The Fibroid Interventions: Reducing Symptoms Today and Tomorrow study, which is a randomized controlled trial of uterine artery embolization vs magnetic resonance imaging-guided focused ultrasound surgery, enrolled premenopausal women with symptomatic uterine fibroid tumors; women who declined randomization were enrolled in a parallel observational cohort. A comprehensive cohort design was used for outcomes analysis. Our target enrollment was 220 women, of which we achieved 41% (n=91) in the randomized and parallel arms of the trial. Primary outcome was reintervention for uterine fibroid tumors within 36 months. Secondary outcomes were change in serum anti-Müllerian hormone levels and standardized measures of fibroid symptoms, quality of life, pain, and sexual function. RESULTS: From 2010-2014, 83 women (mean age, 44.4 years) were treated in the comprehensive cohort design (43 for magnetic resonance imaging-guided focused ultrasound surgery [27 randomized]; 40 for uterine artery embolization [22 randomized]); baseline clinical and uterine characteristics were similar between treatment arms, except for higher fibroid load in the uterine artery embolization arm. The risk of reintervention was higher with magnetic resonance imaging-guided focused ultrasound surgery than uterine artery embolization (hazard ratio, 2.81; 95% confidence interval, 1.01-7.79). Uterine artery embolization showed a significantly greater absolute decrease in anti-Müllerian hormone levels at 24 months compared with magnetic resonance imaging-guided focused ultrasound surgery. Quality of life and pain scores improved in both arms but to a greater extent in the uterine artery embolization arm. Higher pretreatment anti-Müllerian hormone level and younger age at treatment increased the overall risk of reintervention. CONCLUSION: Our study demonstrates a lower reintervention rate and greater improvement in symptoms after uterine artery embolization, although some of the effectiveness may come through impairment of ovarian reserve. Both pretreatment anti-Müllerian hormone level and age are associated with risk of reintervention. CLINICAL TRIAL REGISTRATION NUMBER: NCT00995878, clinicaltrials.gov.

Targeted Prostate Biopsy and MR-Guided Therapy for Prostate Cancer.

In 2018, the American Cancer Society (ACS) estimates that 164,690 new cases of prostate cancer will be diagnosed and 29,430 will die due to the prostate cancer in the United States (Siegel et al., CA Cancer J Clin 67:7-30, 2018). Many men with prostate cancer are often managed with aggressive therapy including radiotherapy or surgery. No matter how expertly done, these therapies carry significant risk and morbidity to the patient's health related quality of life with impact on sexual, urinary and bowel function (Potosky et al., J Natl Cancer Inst 96:1358-1367, 2004). A recent meta-analysis of 19 studies reviewing the use of surgery and radiation for prostate cancer demonstrated patients who received radiation were more likely to die from their disease as compared to surgery (Wallis et al., Eur Urol 70:21-30, 2016). Furthermore, screening programs using prostatic specific antigen (PSA) and transrectal ultrasound (TRUS) guided systematic biopsy have identified increasing numbers of low risk, low grade "localized" prostate cancer. This indolent nature of many prostate cancers presents a difficult decision of when to intervene given the possible comorbidities of aggressive treatment. Active surveillance has been increasingly instituted in order to balance cancer control versus treatment side effects (Jemal et al., CA Cancer J Clin 56:106-130, 2006). Although active debate continues on the suitability of focal or regional therapy for these low or intermediate risk prostate cancer patients, many unresolved issues remain which complicate this approach of management. Some of the largest unresolved issues are: prostate cancer multifocality, limitations of current biopsy strategies, suboptimal staging by accepted imaging modalities, less than robust prediction models for indolent prostate cancers and whether established curative therapies can be safely and effectively used following focal therapy for prostate cancer. In spite of these restrictions focal therapy continues to confront the current paradigm of therapy for low and even intermediate risk disease (Onik, Tech Vasc Interv Radiol 10:149-158, 2017). It has been proposed that early detection and proper characterization may play a role in preventing the development of metastatic disease (Vickers et al., BMJ 346:f2023, 2013). There is Level 1 evidence supporting detection and subsequent aggressive treatment of intermediate and high-risk prostate cancer (Bill-Axelson et al., N Engl J Med 370:932-942, 2014). Therefore accurate assessment of cancer risk (i.e. grade and stage) using imaging and targeted biopsy is critical. Advances in prostate imaging with MRI have been accompanied with advances in MR guided therapy propelling prostate treatment solutions forward faster than ever.

Laser ablation for mesial temporal epilepsy: a multi-site, single institutional series.

OBJECTIVEAlthough it is still early in its application, laser interstitial thermal therapy (LiTT) has increasingly been employed as a surgical option for patients with mesial temporal lobe epilepsy. This study aimed to describe mesial temporal lobe ablation volumes and seizure outcomes following LiTT across the Mayo Clinic's 3 epilepsy surgery centers.METHODSThis was a multi-site, single-institution, retrospective review of seizure outcomes and ablation volumes following LiTT for medically intractable mesial temporal lobe epilepsy between October 2011 and October 2015. Pre-ablation and post-ablation follow-up volumes of the hippocampus were measured using FreeSurfer, and the volume of ablated tissue was also measured on intraoperative MRI using a supervised spline-based edge detection algorithm. To determine seizure outcomes, results were compared between those patients who were seizure free and those who continued to experience seizures.RESULTSThere were 23 patients who underwent mesial temporal LiTT within the study period. Fifteen patients (65%) had left-sided procedures. The median follow-up was 34 months (range 12-70 months). The mean ablation volume was 6888 mm3. Median hippocampal ablation was 65%, with a median amygdala ablation of 43%. At last follow-up, 11 (48%) of these patients were seizure free. There was no correlation between ablation volume and seizure freedom (p = 0.69). There was also no correlation between percent ablation of the amygdala (p = 0.28) or hippocampus (p = 0.82) and seizure outcomes. Twelve patients underwent formal testing with computational visual fields. Visual field changes were seen in 67% of patients who underwent testing. Comparing the 5 patients with clinically noticeable visual field deficits to the rest of the cohort showed no significant difference in ablation volume between those patients with visual field deficits and those without (p = 0.94). There were 11 patients with follow-up neuropsychological testing. Within this group, verbal learning retention was 76% in the patients with left-sided procedures and 89% in those with right-sided procedures.CONCLUSIONSIn this study, there was no significant correlation between the ablation volume after LiTT and seizure outcomes. Visual field deficits were common in formally tested patients, much as in patients treated with open temporal lobectomy. Further studies are required to determine the role of amygdalohippocampal ablation.

MR-Guided Prostate Interventions.

Prostate cancer is the most commonly diagnosed noncutaneous cancer and second leading cause of death in men. Many patients with clinically organ-confined prostate cancer undergo definitive treatment of the whole gland, including radical prostatectomy, radiation therapy, and cryosurgery. Active surveillance is a growing alternative option for patients with documented low-volume and low-grade prostate cancer. However, many patients are wanting a less morbid focal treatment alternative. With recent advances in software and hardware of magnetic resonance imaging (MRI), multiparametric MRI of the prostate has been shown to improve the accuracy in detecting and characterizing clinically significant prostate cancer. Targeted biopsy is increasingly utilized to improve the yield of MR detected, clinically significant prostate cancer and to decrease in detection of indolent prostate cancer. MR-guided targeted biopsy techniques include cognitive MR fusion transrectal ultrasound (TRUS) biopsy, in-bore transrectal targeted biopsy using robotic transrectal device, and in-bore direct MR-guided transperineal biopsy with a software based transperineal grid template. In addition, advances in MR-compatible thermal ablation technology allow accurate focal or regional delivery of thermal ablative energy to the biopsy-proved, MRI-detected tumor. MR-guided ablative treatment options include cryoablation, laser ablation, and high-intensity focused ultrasound with real-time or near simultaneous monitoring of the ablation zone. We present a contemporary review of MR-guided techniques for prostatic interventions.

Global network modulation during thalamic stimulation for Tourette syndrome.

Background and objectives: Deep brain stimulation (DBS) of the thalamus is a promising therapeutic alternative for treating medically refractory Tourette syndrome (TS). However, few human studies have examined its mechanism of action. Therefore, the networks that mediate the therapeutic effects of thalamic DBS remain poorly understood. Methods: Five participants diagnosed with severe medically refractory TS underwent bilateral thalamic DBS stereotactic surgery. Intraoperative fMRI characterized the blood oxygen level-dependent (BOLD) response evoked by thalamic DBS and determined whether the therapeutic effectiveness of thalamic DBS, as assessed using the Modified Rush Video Rating Scale test, would correlate with evoked BOLD responses in motor and limbic cortical and subcortical regions. Results: Our results reveal that thalamic stimulation in TS participants has wide-ranging effects that impact the frontostriatal, limbic, and motor networks. Thalamic stimulation induced suppression of motor and insula networks correlated with motor tic reduction, while suppression of frontal and parietal networks correlated with vocal tic reduction. These regions mapped closely to major regions of interest (ROI) identified in a nonhuman primate model of TS. Conclusions: Overall, these findings suggest that a critical factor in TS treatment should involve modulation of both frontostriatal and motor networks, rather than be treated as a focal disorder of the brain. Using the novel combination of DBS-evoked tic reduction and fMRI in human subjects, we provide new insights into the basal ganglia-cerebellar-thalamo-cortical network-level mechanisms that influence the effects of thalamic DBS. Future translational research should identify whether these network changes are cause or effect of TS symptoms.

Using Black Bone Magnetic Resonance Imaging in Craniofacial Virtual Surgical Planning: A Comparative Cadaver Study.

BACKGROUND: The use of magnetic resonance imaging (MRI) for virtual surgical planning has not yet been described. In the United States, over 600,000 computed tomographic (CT) scans are performed annually on children, who are at higher risk than adults of developing cancer caused by ionizing radiation. The aim of this study was to demonstrate whether three-dimensionally-printed craniofacial surgical guides created from "black bone" MRI are comparable in accuracy to those created from CT scans. METHODS: A mock craniosynostosis surgery translocating four calvarial segments was virtually planned and performed in 10 cadavers. For five specimens, planning was performed and three-dimensionally-printed guides were created using black bone MRI scans. Five specimens underwent standard planning using CT scans. Reconstructed skulls underwent CT scans and three-dimensional reconstruction. Accuracy was compared to that of virtually planned surgeries. RESULTS: The preoperative black bone MRI scan had an average deviation from the preoperative CT scan of 1.37 mm. There was no statistically significant difference in the fit accuracy of MRI versus CT-created guides. Average deviation of postoperative anatomy from preoperative plan was within 1.5 mm for guides created from either scanning modality, with no statistically significant difference in accuracy between the two methods. Planned versus postoperative skull volume was not statistically significantly different when MRI versus CT was used. CONCLUSIONS: This study demonstrates that virtual surgical planning and three-dimensional craniofacial surgical guide creation can be performed using black bone MRI with accuracy comparable to that of CT. This could dramatically reduce radiation exposure of craniofacial reconstruction patients.

Safety of Laser Interstitial Thermal Therapy in Patients With Pacemakers.

BACKGROUND AND IMPORTANCE: Laser interstitial thermal therapy (LiTT) has increasingly been used as a treatment option for medically refractory epilepsy, tumors, and radiation necrosis. The use of LiTT requires intraoperative magnetic resonance (MR) thermography. This can become an issue in patients with other implanted therapeutic devices such as pacemakers and vagal nerve stimulators due to concerns regarding increases in the specific absorption rate (SAR). This is a technical case report demonstrating a successfully and safely performed LiTT in a 1.5-T magnetic resonance imaging (MRI) in a patient with a pacemaker for mesial temporal sclerosis. CLINICAL PRESENTATION: An 83-yr-old gentleman who had an implanted cardiac pacemaker presented with medically intractable epilepsy and was confirmed to have mesial temporal sclerosis on imaging. Video electroencephalography demonstrated concordant ipsilateral seizures and semiology. He underwent LiTT for ablation of the mesial temporal lobe. This was performed with the below described protocol with a cardiology nurse monitoring the patient's cardiac condition and a physicist monitoring SAR, and MR imaging quality without any adverse events. CONCLUSION: This study reports on a protocol of cardiac and MR SAR to safely perform MR-guided LiTT in the setting of traditional pacemakers in patients who are not pacemaker dependent.

Uterine fibroids: correlations between MRI appearance and stiffness via magnetic resonance elastography.

RATIONALE AND OBJECTIVES: Magnetic resonance elastography has proven to be a valuable tool in the diagnosis of liver fibrosis, breast and cervical cancer, but its application in uterine fibroids requires further characterization. The aim of the present study was to examine the relationship between uterine fibroid stiffness by MRE and MR imaging characteristics. MATERIALS AND METHODS: An IRB-approved, HIPAA compliant review was performed of prospectively collected pelvic MRI and 2D-MRE data in patients with symptomatic uterine fibroids (N = 102). T1 and T2 weighted pelvic MRI with gadolinium enhancement were performed. In a small patient subset, fibroid stiffness was assessed by both 2D and 3D MRE. Fibroid stiffness by modality or imaging characteristics was analyzed using one-way analysis of variance followed by Student t test. RESULTS: Four fibroid groups were identified based on T2 appearance: Isointense (N = 7), bright (N = 6), dark with minimal heterogeneity (N = 69), and dark with substantial heterogeneity (N = 20). Mean fibroid stiffness was 4.81 ± 2.12 kPa. Comparison of fibroid stiffness by T2 signal intensity showed that T2 bright fibroids were significantly less stiff than fibroids appearing T2 dark with minimal heterogeneity (mean stiffness difference = 2.38 kPa; p < 0.05) and T2 dark fibroids with substantial heterogeneity were significantly less stiff than T2 dark fibroids with minimal heterogeneity (mean difference = 1.25 kPa; p < 0.05). There was no significant association between fibroid stiffness and T1 signal characteristics or gadolinium enhancement. There was no significant difference in stiffness values obtained by either 2D vs. 3D MRE. CONCLUSIONS: These data suggest differences in fibroid stiffness are associated with different T2 imaging characteristics with less stiff fibroids being T2 bright and more stiff fibroids being T2 dark. Further studies are needed to determine if fibroid stiffness by MRE may serve as an imaging biomarker to help predict MR-guided treatment response.

Whole-Gland Prostate Cancer Cryoablation with Magnetic Resonance Imaging Guidance: One-Year Follow-Up.

PURPOSE: Patients who develop prostate cancer after prior abdominal perineal resection are poor surgical candidates, and have limited treatment options. Therefore, our goal is to present results from a single institutional experience of four patients who underwent whole gland MRI-guided cryoablation with a history complicated by prior abdominoperineal resection. MATERIALS AND METHODS: Four MRI-guided cryoablative treatments (mean age 64, range 59-69 years) for primary and locally recurrent prostate adenocarcinoma were retrospectively reviewed in patients with prior abdominal perineal resection for colorectal cancer (3) and juvenile polyposis (1). Average prostate volume prior to ablation was 23 cc, with an average PSA of 5.6 ng/mL. For each gland, 7-10 cryoprobes were placed approximately 0.5 cm apart in the prostate gland under MRI guidance by a transperineal approach with 3-4 freeze-thaw cycles performed. Each patient had follow up imaging and PSA measurements out to 12 months post ablation. RESULTS: All four patient's PSA dropped below 0.1 ng/mL at 3-6 month post-ablation and remained at these levels at 12 months. Three of the 4 patients had PSA measurements to 33 months post-ablation, with no evidence of recurrence. No patient developed urinary incontinence due to the whole gland cryoablation. CONCLUSION: With all four patients in our study having undetectable PSAs 12 months post ablation, and with no patient developing urinary incontinence due to the cryoablation, MRI-guided cryoablation appears to be a promising treatment option in patients who are poor surgical candidates due to prior pelvic surgery and/or radiation.

Periprocedural outcomes comparing fibroid embolization and focused ultrasound: a randomized controlled trial and comprehensive cohort analysis.

BACKGROUND: Uterine fibroids are a common problem for reproductive-aged women, yet little comparative effectiveness research is available to guide treatment choice. Uterine artery embolization and magnetic resonance imaging-guided focused ultrasound surgery are minimally invasive therapies approved by the US Food and Drug Administration for treating symptomatic uterine fibroids. The Fibroid Interventions: Reducing Symptoms Today and Tomorrow study is the first randomized controlled trial to compare these 2 fibroid treatments. OBJECTIVE: The objective of the study was to summarize treatment parameters and compare recovery trajectory and adverse events in the first 6 weeks after treatment. STUDY DESIGN: Premenopausal women with symptomatic uterine fibroids seen at 3 US academic medical centers were enrolled in the randomized controlled trial (n = 57). Women meeting identical criteria who declined randomization but agreed to study participation were enrolled in a nonrandomized parallel cohort (n = 34). The 2 treatment groups were analyzed by using a comprehensive cohort design. All women undergoing focused ultrasound and uterine artery embolization received the same postprocedure prescriptions, instructions, and symptom diaries for comparison of recovery in the first 6 weeks. Return to work and normal activities, medication use, symptoms, and adverse events were captured with postprocedure diaries. Data were analyzed using the Wilcoxon rank sum test or χ2 test. Multivariable regression was used to adjust for baseline pain levels and fibroid load when comparing opioid medication, adverse events, and recovery time between treatment groups because these factors varied at baseline between groups and could affect outcomes. Adverse events were also collected. RESULTS: Of 83 women in the comprehensive cohort design who underwent treatment, 75 completed postprocedure diaries. Focused ultrasound surgery was a longer procedure than embolization (mean [SD], 405 [146] vs 139 [44] min; P <.001). Of women undergoing focused ultrasound (n = 43), 23 (53%) underwent 2 treatment days. Immediate self-rated postprocedure pain was higher after uterine artery embolization than focused ultrasound (median [interquartile range], 5 [1-7] vs 1 [1-4]; P = .002). Compared with those having focused ultrasound (n = 39), women undergoing embolization (n = 36) were more likely to use outpatient opioid (75% vs 21%; P < .001) and nonsteroidal antiinflammatory medications (97% vs 67%; P < .001) and to have a longer median (interquartile range) recovery time (days off work, 8 [6-14] vs 4 [2-7]; P < .001; days until return to normal, 15 [10-29] vs 10 [10-15]; P = .02). There were no significant differences in the incidence or severity of adverse events between treatment arms; 86% of adverse events (42 of 49) required only observation or nominal treatment, and no events caused permanent sequelae or death. After adjustment for baseline pain and uterine fibroid load, uterine artery embolization was still significantly associated with higher opioid use and longer time to return to work and normal activities (P < .001 for each). Results were similar when restricted to the randomized controlled trial. CONCLUSION: Women undergoing uterine artery embolization have longer recovery times and use more prescription medications, but women undergoing focused ultrasound have longer treatment times. These findings were independent of baseline pain levels and fibroid load.

The Impact of Mirth-Inducing Ventral Striatal Deep Brain Stimulation on Functional and Effective Connectivity.

Deep brain stimulation (DBS) of the ventral capsule/ventral striatum (VC/VS) is an investigational therapy for treatment-resistant obsessive-compulsive disorder. The ability of VC/VS DBS to evoke spontaneous mirth in patients, often accompanied by smiling and laughter, is clinically well documented. However, the neural correlates of DBS-evoked mirth remain poorly characterized. Patients undergoing VC/VS DBS surgery underwent intraoperative evaluation in which mirth-inducing and non-mirth-inducing stimulation localizations were identified. Using dynamic causal modeling (DCM) for fMRI, the effect of mirth-inducing DBS on functional and effective connectivity among established nodes in limbic cortico-striato-thalamo-cortical (CSTC) circuitry was investigated. Both mirth-inducing and non-mirth-inducing VC/VS DBS consistently resulted (conjunction, global null, family-wise error-corrected P < 0.05) in activation of amygdala, ventral striatum, and mediodorsal thalamus. However, only mirth-inducing DBS resulted in functional inhibition of anterior cingulate cortex. Dynamic causal modeling revealed that mirth-inducing DBS enhanced effective connectivity from anterior cingulate to ventral striatum, while attenuating connectivity from thalamus to ventral striatum relative to non-mirth-inducing stimulation. These results suggest that DBS-evoked mood elevation is accompanied by distinct patterns of limbic thalamocortical connectivity. Using the novel combination of DBS-evoked mood alteration and functional MRI in human subjects, we provide new insights into the network-level mechanisms that influence affect.