Preprocedural Magnetic Resonance Research Articles

Abstract 18343: B-type Natriuretic Peptide (BNP) Levels Correlate With Indices of Left Ventricular Function and Predict Outcomes Following Transcatheter Aortic Valve Implantation (TAVI): A Cardiovascular Magnetic Resonance Imaging Study

Background: High levels of B-type natriuretic peptide (BNP) have been shown to predict outcomes following transcatheter aortic valve implantation (TAVI). However, the relationship between pre-procedural BNP levels and magnetic resonance imaging (MRI) parameters of cardiac function has not previously been described in patients with severe aortic stenosis undergoing TAVI. Methods: 108 patients underwent cardiac MRI and had measurements of BNP taken prior to TAVI. MRI was performed using a 1.5T scanner; steady-state free precession sequences were used for aortic valve planimetry and to assess ventricular volumes and mass. Gadolinium enhancement was assessed after injection of 0.1 mmol/kg of gadolinium contrast agent. Semi-automated image analysis was performed by two specialist reviewers blinded to patient treatment. Results: The mean age of the population studied was 79 years (IQR 74-85); mean follow-up was 805 days (IQR 368-1025). The mean BNP level was 698 ng/l (range 14-6048); univariate linear regression showed significant relationships between BNP and left ventricular (LV) ejection fraction (p<0.0001), end diastolic volume (p=0.001), end systolic volume (p<0.0001), and indexed mass (p=0.012). Median BNP levels were lower in patients who survived than in those who died (287ng/l vs. 560ng/l; p=0.099); ROC curve analysis found a BNP level of >170ng/l to be the optimal cutoff for the prediction of all-cause mortality. Survival curve analysis showed a significantly increased risk of all-cause mortality in patients with BNP>170ng/l and MRI LV ejection fraction <50% (Hazard ratio 5.72, p=0.015; Figure). Conclusions: In patients with severe aortic stenosis undergoing TAVI, BNP levels are closely correlated with LV function, indexed LV mass, and both end-systolic and end-diastolic volumes, as measured by MRI. Patients with BNP>170ng/l and MRI LV ejection fraction<50% are at significantly higher risk of death following TAVI.

Poor scar formation after ablation is associated with atrial fibrillation recurrence.

Patients routinely undergo ablation for atrial fibrillation (AF) but the recurrence rate remains high. We explored in this study whether poor scar formation as seen on late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) correlates with AF recurrence following ablation. We retrospectively identified 94 consecutive patients who underwent their initial ablation for AF at our institution and had pre-procedural magnetic resonance angiography (MRA) merged with left atrial (LA) anatomy in an electroanatomic mapping (EAM) system, ablated areas marked intraprocedurally in EAM, 3-month post-ablation LGE-MRI for assessment of scar, and minimum of 3-months of clinical follow-up. Ablated area was quantified retrospectively in EAM and scarred area was quantified in the 3-month post-ablation LGE-MRI. With the mean follow-up of 336 days, 26 out of 94 patients had AF recurrence. Age, hypertension, and heart failure were not associated with AF recurrence, but LA size and difference between EAM ablated area and LGE-MRI scar area was associated with higher AF recurrence. For each percent higher difference between EAM ablated area and LGE-MRI scar area, there was a 7-9% higher AF recurrence (p values 0.001-0.003) depending on the multivariate analysis. In AF ablation, poor scar formation as seen on LGE-MRI was associated with AF recurrence. Improved mapping and ablation techniques are necessary to achieve the desired LA scar and reduce AF recurrence.

Uterine artery embolization for symptomatic fibroids in postmenopausal women

The aim of the current study was to evaluate the efficacy of uterine artery embolization (UAE) for symptomatic fibroids in postmenopausal women. Among 900 cases who underwent UAE between 2007 and 2013, a total of 9 postmenopausal women with symptomatic fibroids (n=6) and fibroid with adenomyosis (n=3) were included in this retrospective study. Ages ranged from 49 to 55years (median of 52). The embolic agent was nonspherical polyvinyl alcohol particles. We evaluated 18 uterine arteries in nine patients and compared the size of the uterine artery relative to inferior mesenteric artery (IMA) in preprocedural magnetic resonance (MR) angiography. Magnetic resonance imaging (MRI) was performed before and 3months after UAE. Predominant fibroid and uterine volumes were calculated from MR images. Urinary frequency was the most common symptom, observed in seven patients (77.8%). Of two patients (22.2%) with vaginal bleeding from submucosal myomas, one patient had been on hormone replacement therapy (HRT). One patient underwent UAE due to growing leiomyoma after HRT. All of the 18 uterine arteries were bigger than the corresponding IMAs in MR angiography. Contrast-enhanced MRI revealed complete necrosis of the predominant fibroid in all patients. Eight (88.9%) of the nine participants demonstrated resolution of symptoms. The mean predominant fibroid and uterine volume reduction rates were 39.7% and 36.9%, respectively. In postmenopausal women, UAE was effective to treat symptomatic fibroids, and it could be considered as an alternative treatment to hysterectomy.

Feasibility of a Modified Cone-Beam CT Rotation Trajectory to Improve Liver Periphery Visualization during Transarterial Chemoembolization.

To compare liver coverage and tumor detectability by using preprocedural magnetic resonance (MR) images as a reference, as well as radiation exposure of cone-beam computed tomography (CT) with different rotational trajectories. Fifteen patients (nine men and six women; mean age ± standard deviation, 65 years ± 5) with primary or secondary liver cancer were retrospectively included in this institutional review board-approved study. A modified cone-beam CT protocol was used in which the C-arm rotates from +55° to -185° (open arc cone-beam CT) instead of -120° to +120° (closed arc cone-beam CT). Each patient underwent two sessions of transarterial chemoembolization between February 2013 and March 2014 with closed arc and open arc cone-beam CT (during the first and second transarterial chemoembolization sessions, respectively, as part of the institutional transarterial chemoembolization protocol). For each cone-beam CT examination, liver volume and tumor detectability were assessed by using MR images as the reference. Radiation exposure was compared by means of a phantom study. For statistical analysis, paired t tests and a Wilcoxon signed rank test were performed. Mean liver volume imaged was 1695 cm(3) ± 542 and 1857 cm(3) ± 571 at closed arc and open arc cone-beam CT, respectively. The coverage of open arc cone-beam CT was significantly higher compared with closed arc cone-beam CT (97% vs 86% of the MR imaging liver volume, P = .002). In eight patients (53%), tumors were partially or completely outside the closed arc cone-beam CT field of view. All tumors were within the open arc cone-beam CT field of view. The open arc cone-beam CT radiation exposure by means of weighted CT index was slightly lower compared with that of closed arc cone-beam CT (-5.1%). Open arc cone-beam CT allowed for a significantly improved intraprocedural depiction of peripheral hepatic tumors while achieving a slight radiation exposure reduction.

Graphics Processing Unit–Accelerated Nonrigid Registration of MR Images to CT Images During CT-Guided Percutaneous Liver Tumor Ablations

Accuracy and speed are essential for the intraprocedural nonrigid magnetic resonance (MR) to computed tomography (CT) image registration in the assessment of tumor margins during CT-guided liver tumor ablations. Although both accuracy and speed can be improved by limiting the registration to a region of interest (ROI), manual contouring of the ROI prolongs the registration process substantially. To achieve accurate and fast registration without the use of an ROI, we combined a nonrigid registration technique on the basis of volume subdivision with hardware acceleration using a graphics processing unit (GPU). We compared the registration accuracy and processing time of GPU-accelerated volume subdivision-based nonrigid registration technique to the conventional nonrigid B-spline registration technique. Fourteen image data sets of preprocedural MR and intraprocedural CT images for percutaneous CT-guided liver tumor ablations were obtained. Each set of images was registered using the GPU-accelerated volume subdivision technique and the B-spline technique. Manual contouring of ROI was used only for the B-spline technique. Registration accuracies (Dice similarity coefficient [DSC] and 95% Hausdorff distance [HD]) and total processing time including contouring of ROIs and computation were compared using a paired Student t test. Accuracies of the GPU-accelerated registrations and B-spline registrations, respectively, were 88.3 ± 3.7% versus 89.3 ± 4.9% (P = .41) for DSC and 13.1 ± 5.2 versus 11.4 ± 6.3 mm (P = .15) for HD. Total processing time of the GPU-accelerated registration and B-spline registration techniques was 88 ± 14 versus 557 ± 116 seconds (P < .000000002), respectively; there was no significant difference in computation time despite the difference in the complexity of the algorithms (P = .71). The GPU-accelerated volume subdivision technique was as accurate as the B-spline technique and required significantly less processing time. The GPU-accelerated volume subdivision technique may enable the implementation of nonrigid registration into routine clinical practice.

Preprocedural magnetic resonance imaging for image-guided catheter ablation of scar-related ventricular tachycardia.

To present and validate a highly automated MRI analysis workflow for image-guided catheter ablation of scar-related ventricular tachycardia (VT) ablation procedures. A cohort of 15 post-infarction patients underwent MRI prior to VT ablation. The MRI study included a black-blood turbo spin echo sequence for visualizing the aortic root and ostium of the left main (LM) coronary artery, and a 3D late gadolinium enhanced sequence for visualizing the LV anatomy and myocardial scar substrate. Semi-automated segmentation of the LV, aortic root and ostium of LM was performed, followed by fully automated segmentation of myocardial scar. All segmented structures were aligned using an automated image registration algorithm to remove inter-scan displacement. MRI was integrated at the beginning of the procedure after mapping a single LM point. The integration performance was compared to that of the traditional iterative closest point (ICP) method. The proposed method required a single LM mapping point only, compared to 255 ± 43 points with the ICP method. The single-point method achieved a mean point-to-surface distance of 4.9 ± 1.5 mm on the LV surface and 5.1 ± 1.7 mm on the aorta surface (ICP: 3.7 ± 0.8 and 9.2 ± 7.2 mm, P < 0.05). The Cohen's kappa coefficient between the MRI-defined and EAM-defined scar was 0.36 ± 0.16 for the presented method, significantly higher than that of ICP method (0.23 ± 0.21, P = 0.03), indicating more accurate scar substrate localization during integration. This study demonstrated the feasibility of preprocedural MRI integration into the VT ablation procedure, with highly automated image analysis workflow and minimal mapping effort.

Uterine artery embolisation for uterine leiomyomas

Background. Many forms of minimally invasive treatment have gained substantial popularity, both with the medical fraternity and the public. With the correct clinical indications and in skilled hands, uterine artery embolisation (UAE) has been accepted internationally as part of the standard of care that should be offered to patients with symptomatic uterine leiomyomas (fibroids). Objectives. To introduce UAE as an effective and safe treatment option in patients with symptomatic fibroids in the Western Cape Provincial Service, South Africa. Methods. Setting: Groote Schuur and Tygerberg hospitals, Western Cape. Design: Prospective observational multi-centre study. Methods: 36 women (mean age 38 years, range 30 - 47 years) with symptomatic fibroids were treated with UAE between November 2009 and February 2012. Pre-procedure magnetic resonance imaging (MRI) followed by a 6-month clinical follow-up plus MRI or an ultrasound scan were performed. Results. The presenting symptoms were menorrhagia, dysmenorrhoea, pressure symptoms and intermenstrual bleeding. Three women were treated for primary infertility. Uterine artery sub-selection and embolisation was successful in all patients. Complications included low-grade pyrexia (3/36, 8.3%) and readmission (1/36, 2.8%). The average reduction in uterine volume at 6 months was 50%. At followup (mean 15 months, range 7 - 32), 91.7% (33/36) had complete symptomatic resolution and 83.3% (30/36) were ‘completely satisfied’. Participants treated for primary infertility and concurrent adenomyosis did not receive any benefit from UAE. Conclusion. Uterine artery embolisation is associated with a high clinical success rate. This study suggests that UAE should be offered as an attractive alternative to surgery in our practice.

Three-dimensional rotational angiography fused with multimodal imaging modalities for targeted endomyocardial injections in the ischaemic heart

Biological therapies for ischaemic heart disease require efficient, safe, and affordable intramyocardial delivery. Integration of multiple imaging modalities within the fluoroscopy framework can provide valuable information to guide these procedures. We compared an anatomo-electric method (LARCA) with a non-fluoroscopic electromechanical mapping system (NOGA(®)). LARCA integrates selective three-dimensional-rotational angiograms with biplane fluoroscopy. To identify the infarct region, we studied LARCA-fusion with pre-procedural magnetic resonance imaging (MRI), dedicated CT, or (18)F-FDG-PET/CT. We induced myocardial infarction in 20 pigs by 90-min LAD occlusion. Six weeks later, we compared peri-infarct delivery accuracy of coloured fluospheres using sequential NOGA(®)- and LARCA-MRI-guided vs. LARCA-CT- and LARCA-(18)F-FDG-PET/CT-guided intramyocardial injections. MRI after 6 weeks revealed significant left ventricular (LV) functional impairment and remodelling (LVEF 31 ± 3%, LVEDV 178 ± 15 mL, infarct size 17 ± 2% LV mass). During NOGA(®)-procedures, three of five animals required DC-shock for major ventricular arrhythmias vs. one of ten during LARCA-procedures. Online procedure time was shorter for LARCA than NOGA(®) (77 ± 6 vs. 130 ± 3 min, P < 0.0001). Absolute distance of injection spots to the infarct border was similar for LARCA-MRI (4.8 ± 0.5 mm) and NOGA(®) (5.4 ± 0.5 mm). LARCA-CT-integration allowed closer approximation of the targeted border zone than LARCA-PET (4.0 ± 0.5 mm vs. 6.2 ± 0.6 mm, P < 0.05). Three-dimensional -rotational angiography fused with multimodal imaging offers a new, cost-effective, and safe strategy to guide intramyocardial injections. Endoventricular procedure times and arrhythmias compare favourably to NOGA(®), without compromising injection accuracy. LARCA-based fusion imaging is a promising enabling technology for cardiac biological therapies.

4:15 PM; Abstract No. 280 - 3D fusion of preprocedural MRI with intraprocedural C-arm CT for confirmation of bone biopsy location in pediatric interventional radiology

Preprocedural magnetic resonance images (MRI) are used to identify the target lesion for a bone biopsy procedure, but are not typically used in the interventional suite to guide the biopsy needle. Additionally, MRI has the advantage of being able to visualize lesions, such as bone marrow abnormalities with an intact cortex that cannot be readily seen with computed tomography (CT) or C-arm CT, the modalities commonly used for biopsies. Therefore we present a pilot study to evaluate the application of syngo iGuide needle guidance and syngo InSpace 3D/3D Fusion (Siemens Healthcare AG, Forchheim, Germany) using preprocedural MRI and intraprocedural C-arm CT for bone biopsies in the pediatric population.

Comparison of Left Atrial Area Marked Ablated in Electroanatomical Maps with Scar in MRI

Three-dimensional electroanatomic mapping (EAM) is routinely used to mark ablated areas during radiofrequency ablation. We hypothesized that, in atrial fibrillation (AF) ablation, EAM overestimates scar formation in the left atrium (LA) when compared to the scar seen on late-gadolinium enhancement magnetic resonance imaging (LGE-MRI). Of the 235 patients who underwent initial ablation for AF at our institution between August 2011 and December 2012, we retrospectively identified 70 patients who had preprocedural magnetic resonance angiography merged with LA anatomy in EAM software and had a 3-month postablation LGE-MRI for assessment of scar. Ablated area was marked intraprocedurally using EAM software and quantified retrospectively. Scarred area was quantified in 3-month postablation LGE-MRI. The mean ablated area in EAM was 30.5 ± 7.5% of the LA endocardial surface and the mean scarred area in LGE-MRI was 13.9 ± 5.9% (P < 0.001). This significant difference in the ablated area marked in the EAM and scar area in the LGE-MRI was present for each of the 3 independent operators. Complete pulmonary vein (PV) encirclement representing electrical isolation was observed in 87.8% of the PVs in EAM as compared to only 37.4% in LGE-MRI (P < 0.001). In AF ablation, EAM significantly overestimates the resultant scar as assessed with a follow-up LGE-MRI.

Cardiac Remodeling After Atrial Fibrillation Ablation.

Radiofrequency catheter ablation procedures are considered a reasonable option for patients with symptomatic, drug refractory atrial fibrillation (AF). Ablation procedures have been reported to effectively restore sinus rhythm and provide long-term relief of symptoms. Both electrical and structural remodeling occurs with AF. A reversal of the electrical remodeling develops within 1 week after restoration to sinus rhythm following the catheter ablation. The recovery rate is faster in the right atrium than the left atrium. Reverse structural remodeling takes longer and is still present 2 to 4 months after restoration of sinus rhythm. The left atrial transport function also improves after successful catheter ablation of AF. Left atrial strain surveys from echocardiography are able to identify patients who respond to catheter ablation with significant reverse remodeling after ablation. Pre-procedural delayed enhancement magnetic resonance imaging is also able to determine the degree of atrial fibrosis and is another tool to predict the reverse remodeling after ablation. The remodeling process is complex if recurrence develops after ablation. Recent evidence shows that a combined reverse electrical and structural remodeling occurs after ablation of chronic AF when recurrence is paroxysmal AF. Progressive electrical remodeling without any structural remodeling develops in those with recurrence involving chronic AF. Whether progressive atrial remodeling is the cause or consequence during the recurrence of AF remains obscure and requires further study.

ERCP without radiation during pregnancy in the minimal invasive world

The current guidelines recommend endoscopic retrograde cholangiopancreatography (ERCP) procedures in pregnant women with minimal radiation exposure. Regarding the safety of ERCP during pregnancy, data are limited in the literature. In this study, we report our experience with five ERCP procedures performed in five pregnant women without radiation at a single tertiary health center. Between May 2007 and February 2012, five pregnant patients underwent ERCP without radiation, analyzed retrospectively. Clinical disease was confirmed with either pre-procedure ultrasonography and magnetic resonance cholangiopancreatography in all patients. In all cases, selective deep cannulation was performed and confirmed by the aspiration and/or direct visualization of the bile. The data regarding laboratory, ultrasonography, magnetic resonance imaging, endoscopic findings, and clinical course of the patients were analyzed. Fetal complications were noted at delivery and 30 days postdelivery follow-up. The mean patient age was 26 years (22-33) and the mean duration of pregnancy was 20 weeks (12-32). In all cases, no secondary ERCP procedures were needed. Also, no maternal and fetal adverse events and complications were determined after the procedures or on follow-up. All stages of the procedure including cannulation, sphincterotomy, and stone extraction were performed without the use of fluoroscopy. As far we know, there is no report in the literature regarding the failure of endoscopic retraction of stones without fluoroscopy during pregnancy. Our series notes that ERCP is safe and prevents recurrent biliary pancreatitis during pregnancy. Unfortunately, due to the small limited number of patient data, our study notes the requirement of further large randomized and controlled series.

Abstract No. 349 - Management of back pain in myeloma patients using kyphoplasty: a practical approach to the reduction of pain, improvement of functional status, and palliative success

Purpose To determine the utility of MR STIR imaging findings relative to fluoroscopic exam in the efficacy of treating vertebral compression fractures due to multiple myeloma. Materials and Methods Ten consecutive MM patients from a single center with vertebral compression fractures refractory to conservative treatment were treated with kyphoplasty. After a thorough review of pre-procedure magnetic resonance imaging (MRI), fluoroscopic examination of the spine was performed. Demographic, clinical, and procedural data on patients were retrospectively analyzed. Primary measure of outcome was pain relief and functional status, as assessed by the pre and post-procedure Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Paired-Samples T test was used for comparison of pre and post measures of outcome. Results Ten patients with refractory back pain representing 36 levels of vertebral compression by MRI were evaluated for potential kyphoplasty. After fluoroscopic assisted palpation of the spine eliciting a moderate to severe pain-response, the ten patients represented 18 treated vertebral levels. A review of the MRI findings of the treated levels showed the absence of traditional MR signal finding of marrow edema; and had little utility in guiding therapy at the time of exam. All patients experienced significant improvement in pain score as measured by VAS. The mean pre and post-procedure VAS were 6.8 and 1.3 (p=0.001), respectively. All patients experienced significant improvement in there functional ability as measured by their ODI questionnaire. Mean pre and post-procedure ODI were 51.4 and 29.8, (p=0.001), respectively. Conclusion Solely relying on MRI alone to determine who may benefit from vertebral augmentation is not sufficient, and often may preclude a patient’s potential to gain significant benefit if treatment is withheld due to the absence of traditional MR STIR imaging findings of bone marrow edema. Symptomatic levels may be missed due to the presence of multilevel, heterogeneous MR signal abnormalities in multiple myeloma, but by using a clinical-based approach and utilizing the fluoroscopic exam, excellent results may be achieved, which is critical to palliative success.

The effect of uterine fibroid embolization on lower urinary tract symptoms

The objective was to determine the effect of uterine fibroid embolization (UFE) on lower urinary tract symptoms (LUTS) and quality of life (QoL). This prospective study included women with symptomatic fibroids and LUTS who underwent UFE between March 2008 and May 2010. Subjects underwent pre-procedural pelvic magnetic resonance imaging (MRI) and completed the Urogenital Distress Inventory (UDI-6), Incontinence Impact Questionnaire (IIQ-7), Prolapse and Incontinence Sexual Questionnaire (PISQ-12), Uterine Fibroid Symptom Quality of Life questionnaire (UFS-QoL), and a standardized 48-h bladder diary at baseline and 3 months after the procedure. Patient Global Impression of Improvement (PGI-I) assessed post-procedural patient satisfaction. The primary outcome was subjective improvement in LUTS at 3 months, as measured by a decrease in UDI-6 score. Univariate analysis, paired t test and a stepwise regression analysis were appropriately conducted. Fifty-seven patients underwent UFE and completed bladder diaries and questionnaires. At 3 months after UFE, patients reported a significant decrease in UDI-6, IIQ-7, and UFS-QoL, indicating an improvement in urinary symptoms and QoL. Bladder diaries showed a significant reduction in daytime and night-time voids. No difference was found in incontinence episodes. Uterine volume, dominant fibroid size, fibroid location, and MRI-confirmed bladder compression did not affect the difference in UDI-6 scores. In a stepwise regression model, BMI had a significant impact on the change in UDI-6 score, with a decrease of 1.18 points for each 1 unit increase in BMI. Uterine fibroid embolization significantly improves LUTS and urinary-related QoL. Obesity seems to attenuate this effect.

Ultraschall im elektrophysiologischen Herzkatheterlabor

During recent years the need for intraprocedural imaging has increased. Fluoroscopy and angiography are frequently supplemented by pre-procedural magnetic resonance or computed tomography imaging as well as electroanatomic mapping techniques. However, poor real-time imaging quality of soft tissue, radiation exposure, and contrast media consumption are disadvantageous. Ultrasound techniques are characterized by high-quality imaging of soft tissue that can be obtained in real time. All relevant anatomical structures and their relationships to catheters can be evaluated at any time during the procedure. Moreover, functional analysis, e.g., flow measurements and monitoring for complications, is possible. Transesophageal and especially intracardiac echocardiography (ICE) contribute enormously to effectiveness and safety of complex procedures. ICE has been shown to be useful in transseptal procedures like atrial fibrillation ablation but also in ablation procedures for ventricular tachycardias.

Management of Back Pain in Myeloma Patients Using Vertebral Augmentation: A Practical Approach to Elimination of Pain and Improvement of Functional Status

Abstract Abstract 4713 Background: Management of pain and height restoration in multiple myeloma (MM) patients with vertebral compression fractures remains an important area of symptom management among a group of patients that is living longer through advances in therapeutic approaches. Prior studies demonstrated that pain reduction after vertebral augmentation was associated with reduction in patient-reported symptom relief, but clearly more emphasis is needed in this quarter (Julka A, 2012; Mendoza TR, 2012).We report the multidisciplinary approach adapted at our center to management of back pain in MM patients through early and aggressive intervention. Materials and Methods: Our study evaluated ten consecutive MM patients from a single center with vertebral compression fractures refractory to conservative treatment and treated with vertebral augmentation. Per our protocol, after a thorough review of pre-procedure magnetic resonance imaging (MRI), fluoroscopic examination of the spine was performed. Symptomatic levels were topographically localized by marking the skin. Demographic, clinical, and procedural data on patients were retrospectively analyzed. The primary measure of outcome is pain relief and functional status, as assessed by the pre and post-procedure Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Paired-Samples T test is used for comparison of pre and post measures of outcome. Results: Ten patients with refractory back pain and 36 levels of vertebral compression by MRI were evaluated for potential cement augmentation. Of these levels, 50% (18 levels) were selected for treatment based on fluoroscopic assisted palpation of the spine eliciting a moderate to severe pain-response. A review of the MRI findings of the treated levels showed the absence of traditional MR signal finding of marrow edema; and had little utility in guiding therapy at the time of exam. 15 levels were treated with kyphoplasty alone and 3 levels by a combination of pediculoplasty and kyphoplasty with no adverse outcomes. All patients experienced significant improvement in pain score as measured by VAS. The mean pre and post-procedure VAS were 6.8 and 1.3 (p=0.000), respectively. All patients experienced significant improvement in there functional ability as measured by their ODI questionnaire. Mean pre and post-procedure ODI were 51.4 and 29.8, (p=0.001), respectively. Conclusion: Solely relying on MRI alone to determine who may benefit from vertebral augmentation and pain relief is not sufficient, and often may preclude patient's potential to gain significant benefit. Careful selection of symptomatic levels may be difficult due to the presence of multilevel MR signal abnormalities, but by utilizing a clinical-based approach and primarily relying on palpation of the spine under direct fluoroscopy, excellent results may be achieved, which is critical to palliative success. Disclosures: No relevant conflicts of interest to declare.

Re: Phantom Study of a Novel Stereotactic Prostate Biopsy System Integrating Preinterventional Magnetic Resonance Imaging and Live Ultrasonography Fusion(From: Kuru TH, Roethke M, Popeneclu V, et al. J Endourol 2012;26:807–813.)

Dear Editor: Prostate biopsies may soon be “unblinded” as new techniques are translated to clinic that add MRI to transrectal ultrasonographic guidance. The team from Heidelberg is to be commended for performing an elegant phantom study defining the accuracy of their novel MRI-ultrasound fusion-guided biopsy system using stereotaxy. The targeting error of under a millimeter is certainly impressive and should translate into clinical benefit. The National Institutes of Health urology and radiology teams have developed and implemented a similar approach over the past decade using electromagnetic tracking to register the preprocedural MRI to the real-time ultrasonography in an outpatient office-based setting to track the location of more than 11,000 biopsies in more than 600 patients, with an initial significant improvement in cancer detection rates in specific populations.1–3 There are several different methods for MRI + ultrasound fusion-guided prostate biopsies, including electromagnetic tracking, optical tracking, stereotactic mechanical arms, and retrospective image based registration. The emergence of multiple fusion technologies that can be deployed in an office setting could augment the “blind” or “random” transrectal ultrasonography guided prostate biopsy for patients with anterior lesions, central zone lesions (Fig. 1), previously negative biopsy in the face of a rising prostate-specific antigen level, or patients undergoing active surveillance for low Gleason score prostate cancers.1 FIG. 1. Transrectal ultrasound and corresponding preprocedural magnetic resonance imaging with anterior gland prostate cancer target (red-blue dot) in area not normally sampled by standard blind (random or sextant) biopsy. The team from Heidelberg has shown tremendous accuracy with their system, which should translate into fertile ground for clinical impact as the MRI “ManoGram” matures and evolves for use in specific settings.

Valoración mediante resonancia magnética cerebral de embolias clínicamente silentes en pacientes con fibrilación auricular sometidos a cardioversión eléctrica

To study electrical cardioversion in patients with atrial fibrillation as a potential cause of acute ischemic brain lesions.We performed prospective analysis of 62 consecutive patients (62 [10] years, 16 female). All of them were anticoagulated for at least 3 weeks with an international normalized ratio of 2.69 (0.66). In all cases a magnetic resonance imaging of the brain was performed before and 24h after the cardioversion, including diffusion-weighted sequences. A neurological exploration was also performed before and after the procedure, using the modified Ictus on the National Institute of Health Stroke Scale and the modified Rankin scale. Written informed consent was obtained in all cases.Of the 62 patients, 51 (85%) reverted to sinus rhythm. The neurological examination showed no changes after cardioversion. The pre-procedure magnetic resonance imaging showed microvascular disease in 35 (56%), including 2 patients with known cerebrovascular disease, and did not depict new clinically silent ischemic areas after cardioversion.After electrical cardioversion no acute ischemic lesions in the brain nor alteration in the neurological scales were found. Nevertheless, in 35 patients (56%) with persistent atrial fibrillation, the magnetic resonance imaging showed clinically silent ischemic lesions.

Assessment of Silent Microembolism by Magnetic Resonance Imaging After Cardioversion in Atrial Fibrillation

Abstract Introduction and objectives To study electrical cardioversion in patients with atrial fibrillation as a potential cause of acute ischemic brain lesions. Methods We performed prospective analysis of 62 consecutive patients (62 [10] years, 16 female). All of them were anticoagulated for at least 3 weeks with an international normalized tatio of 2.69 (0.66). In all cases a magnetic resonance imaging of the brain was performed before and 24 h after the cardioversion, including diffusion-weighted sequences. A neurological exploration was also performed before and after the procedure, using the modified Ictus on the National Institute of Health Stroke Scale and the modified Rankin scale. Written informed consent was obtained in all cases. Results Of the 62 patients, 51 (85%) reverted to sinus rhythm. The neurological examination showed no changes after cardioversion. The pre-procedure magnetic resonance imaging showed microvascular disease in 35 (56%), including 2 patients with known cerebrovascular disease, and did not depict new clinically silent ischemic areas after cardioversion. Conclusions After electrical cardioversion no acute ischemic lesions in the brain nor alteration in the neurological scales were found. Nevertheless, in 35 patients (56%) with persistent atrial fibrillation, the magnetic resonance imaging showed clinically silent ischemic lesions.

Different Image Integration Modalities to Guide AF Ablation: Impact on Procedural and Fluoroscopy Times

Different image integration modalities are available for atrial fibrillation (AF) ablation, but their impact on procedural and fluoroscopy times has not been evaluated yet. Sixty patients (mean age 52.2 ± 12.0 years, 48.3% men, 75% paroxysmal AF) undergoing pulmonary vein (PV) encircling with PV disconnection for symptomatic drug-refractory AF were randomized to ablation with CARTO electroanatomical mapping (Biosense Webster, Diamond Bar, CA, USA) integrated with: (1) preprocedural magnetic resonance imaging (MRI; Group 1); (2) intracardiac echocardiography (ICE; Group 2); (3) preprocedural MRI and ICE (Group 3). PV disconnection was achieved in all patients. Total procedural time (Group 1: 124.7 ± 47.0; Group 2: 112.5 ± 30.4; Group 3: 108.6 ± 34.7 minutes) and total ablation time were similar between groups (P = ns). MRI integration alone required a higher fluoroscopy time (23.8 ± 6.9 in Group 1 vs 11.0 ± 2.3 and 13.9 ± 4.2 minutes in Groups 2 and 3, respectively; P < 0.005) and a longer time spent in the left atrium (109.0 ± 43.5 in Group 1 vs 78.2 ± 29.7 and 74.8 ± 34.3 minutes in Groups 2 and 3, respectively; P = 0.03) in comparison to ICE integration. Addition of MRI to ICE integration showed a tendency for a higher fluoroscopy time in comparison to ICE integration alone (P = 0.06). At a mean follow-up of 9.1 ± 2.2 months, there were no significant differences in AF recurrences among the groups (P = ns). ICE image integration significantly reduces the fluoroscopy time and the time spent in the left atrium in comparison to MRI integration alone. Addition of MRI to ICE integration does not reduce total procedural time and seems to lead to higher fluoroscopy time in comparison to ICE integration alone.