Joel P Felmlee

Mayo Clinic - Rochester, Rochester, Minnesota, United States

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Publications (182)479.41 Total impact

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    ABSTRACT: MRI in patients with LV leads may cause tissue or lead heating, dislodgement, venous damage, or lead dysfunction.Objective Determine the safety of MRI in patients with LV pacing leads.Methods Prospective data were collected in patients with CS LV leads undergoing clinically indicated MRI at 3 institutions. Patients were not pacemaker dependent. Scans were performed under pacing nurse, technician, radiologist, and physicist supervision using continuous vital sign, pulse oximetry, and ECG monitoring and a 1.5 T scanner with SAR < 1.5 Watts/kg. Devices were interrogated pre- and post-MRI, programmed to asynchronous or inhibition mode with tachyarrhythmia therapies off (if present) and reprogrammed to their original settings post-MRI.ResultsMRI scans (n=42) were performed in 40 patients with non-MRI conditional LV leads between 2005-2013 (mean age 67 ± 9 years, n=16 or 40% women, median lead implant duration 740 days with IQ range 125-1173 days). MRIs were performed on the: head/neck/spine (n=35, 83%), lower extremities (n=4, 10%), chest (n=2, 5%), and abdomen (n=1, 2%). There were no overall differences in pre- and post-MRI interrogation LV lead sensing (12.4 ± 6.2 vs. 12.9 ± 6.7 mV, p=0.38), impedance (724 ± 294 vs. 718 ± 312 Ohms, p=0.67), or threshold (1.4 ± 1.1 vs. 1.4 ± 1.0 V, p=0.91). There were no individual LV lead changes requiring intervention.ConclusionMRI scanning was performed safely in non-pacemaker dependent patients with CS LV leads who were carefully monitored during imaging without clinically significant adverse effect on LV lead function.
    Heart Rhythm. 11/2014;
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    ABSTRACT: Magnetic resonance imaging (MRI) has been safely performed in some patients with cardiac implantable electronic devices (CIEDs) under careful protocols. Pacemaker dependent patients are often excluded, in part due to concern of "power-on reset" (PoR), which can result in a change from asynchronous to inhibited pacing with consequent inhibition of pacing due to noise from the MRI. We reviewed risk factors for PoR during MRI. Prospective data were collected starting in 2008 in patients with CIEDs undergoing clinically indicated MRI. Eligible patients were not pacemaker dependent. Devices were interrogated pre- and post-MRI, programmed to asynchronous pacing or inhibition mode with tachyarrhythmia therapies off, and reprogrammed to their original settings post-MRI. MRI scans (n=256) were performed in 198 patients with non-MRI conditional CIEDs between 2008-2013 (median age 66, IQ 57-77; 59% men). PoR occurred during 9 MRI scans (3.5%) in 8 patients. PoR was more frequent with Medtronic devices than other generator brands (n=9/139 vs. 0/117, 6% vs. 0%, p=0.005). Devices with PoR were all released before 2002 and were implanted from 1999 to 2004. Effects of PoR included a decrease in heart rate during MRI (n=4) and transient anomalous battery life indication (n=1). All devices functioned normally following MRI. PoR occurs infrequently but can cause deleterious changes to pacing mode and heart rate. MRI scans should not be performed in pacemaker dependent patients with older, at risk generators. Continuous monitoring during MRI is essential as unrecognized PoR may inhibit pacing or accelerate power depletion due to high pacing output. Copyright © 2014. Published by Elsevier Inc.
    Heart rhythm: the official journal of the Heart Rhythm Society 11/2014; · 4.56 Impact Factor
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    ABSTRACT: IntroductionAbandoned cardiovascular implantable electronic device (CIED) leads remain a contraindication to magnetic resonance imaging (MRI) studies, largely due to in vitro data showing endocardial heating secondary to the radiofrequency field. We tested the hypothesis that abandoned CIED leads do not pose an increased risk of clinical harm for patients undergoing MRI.Methods This single-center retrospective study examined the outcomes of patients who had device generators removed before MRI, rendering the device leads abandoned. Information was gathered through chart review. Data collected included lead model, pacing threshold before MRI, anatomic region examined, threshold data after generator reimplantation, and clinical patient outcome.ResultsPatients (n = 19, 11 men and eight women) ranged in age from 19 to 85 at the time of MRI. There was a mean of 1.63 abandoned leads at the time of imaging; none of the leads were MRI conditional. Of the three implantable cardioverter defibrillator (ICD) leads, two of three were dual coil. Most (31/35) of the scans performed were of the central nervous system, including head and spinal imaging. There were no adverse events associated with MRI in any of these patients with abandoned leads within 7 days of the scan. No lead malfunctions or clinically significant change in pacing thresholds were noted with generator reimplantation.Conclusion The use of MRI in patients with abandoned cardiac device leads appears feasible when performed under careful monitoring, with no adverse events, although the experience is small. MRI did not affect the function of leads that were subsequently reconnected to a cardiac device.
    Pacing and Clinical Electrophysiology 05/2014; · 1.75 Impact Factor
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    ABSTRACT: Radiofrequency (RF) shields have been recently developed for the purpose of shielding portions of the patient's body during magnetic resonance imaging (MRI) examinations. We present an experimental evaluation of a commercially available RF shield in the MRI environment. All tests were performed on 1.5 T and 3.0 T clinical MRI scanners. The tests were repeated with and without the RF shield present in the bore, for comparison. Effects of the shield, placed within the scanner bore, on the RF fields generated by the scanner were measured directly using tuned pick-up coils. Attenuation, by as much as 35 dB, of RF field power was found inside the RF shield. These results were supported by temperature measurements of metallic leads placed inside the shield, in which no measurable RF heating was found. In addition, there was a small, simultaneous detectable increase (∼1 dB) of RF power just outside the edges of the shield. For these particular scanners, the autocalibrated RF power levels were reduced for scan locations prescribed just outside the edges of the shield, which corresponded with estimations based on the pick-up coil measurements. Additionally, no significant heating during MRI scanning was observed on the shield surface. The impact of the RF shield on the RF fields inside the magnet bore is likely to be dependent on the particular model of the RF shield or the MRI scanner. These results suggest that the RF shield could be a valuable tool for clinical MRI practices.
    Medical devices (Auckland, N.Z.). 01/2014; 7:363-70.
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    ABSTRACT: Background Functional magnetic resonance imaging (fMRI) is a powerful method for identifying in vivo network activation evoked by deep brain stimulation (DBS). Objective Identify the global neural circuitry effect of subthalamic nucleus (STN) DBS in nonhuman primates (NHP). Method An in-house developed MR image-guided stereotactic targeting system delivered a mini-DBS stimulating electrode, and blood oxygenation level-dependent (BOLD) activation during STN DBS in healthy NHP was measured by combining fMRI with a normalized functional activation map and general linear modeling. Results STN DBS significantly increased BOLD activation in the sensorimotor cortex, supplementary motor area, caudate nucleus, pedunculopontine nucleus, cingulate, insular cortex, and cerebellum (FDR < 0.001). Conclusion Our results demonstrate that STN DBS evokes neural network grouping within the motor network and the basal ganglia. Taken together, these data highlight the importance and specificity of neural circuitry activation patterns and functional connectivity.
    Brain Stimulation 01/2014; · 4.54 Impact Factor
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    ABSTRACT: Introduction of urethral warmers to aid cryosurgery in the prostate has significantly reduced the incidence of urethral sloughing; however, the incidence rate still remains as high as 15%. Furthermore, urethral warmers have been associated with an increase of cancer recurrence rates. Here, we report results from our phantom-based investigation to determine the impact of an urethral warmer on temperature distributions around cryoneedles during cryosurgery. Cryoablation treatments were simulated in a tissue mimicking phantom containing an urethral warming catheter. Four different configurations of cryoneedles relative to urethral warming catheter were investigated. For each configuration, the freeze-thaw cycles were repeated with and without the urethral warming system activated. Temperature histories were recorded at various pre-arranged positions relative to the cryoneedles and urethral warming catheter. In all configurations, the urethral warming system was effective at maintaining sub-lethal temperatures at the simulated surface of the urethra. The warmer action, however, was additionally demonstrated to potentially negatively impact treatment lethality in the target zone by elevating minimal temperatures to sub-lethal levels. In all needle configurations, rates of freezing and thawing were not significantly affected by the use of the urethral warmer. The results indicate that the urethral warming system can protect urethral tissue during cryoablation therapy with cryoneedles placed as close as 5 mm to the surface of the urethra. Using an urethral warming system and placing multiple cryoneedles within 1 cm of each other delivers lethal cooling at least 5 mm from the urethral surface while sparing urethral tissue.
    Cryobiology 01/2014; · 2.14 Impact Factor
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    Journal of the American College of Radiology: JACR 01/2014; 11(1):94-6.
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    ABSTRACT: To establish the feasibility of magnetic resonance imaging (MRI)-guided cryoablation in patients with previous radical prostatectomy and MRI visualized biopsy-proven local recurrence of prostate adenocarcinoma. Eighteen postprostatectomy patients (mean 67, 57-78 years) were treated with MRI-guided cryoablation for recurrent prostate carcinoma. Patients were found to have a hyperenhancing nodule using multiparametric MRI with endorectal coil followed by a positive transrectal ultrasound-guided biopsy. Of 18 postsurgical patients, 6 had additional salvage external beam radiation with subsequent recurrence. Under general anesthesia and MRI guidance (wide-bore 1.5T MRI), 2-5 cryotherapy probes were placed in or around the recurrence by transperineal approach and cryoablation performed. The patients were stratified into 2 groups: the initial 9 consecutive patients had cryoprobes placed 1 cm apart with 2 freeze-thaw cycles (group 1), and the subsequent 9 patients had cryoprobes placed 0.5 cm apart with 3 freeze-thaw cycles (group 2). In group I, the average preprocedure prostate-specific antigen (PSA) was 1.21 ± 1.12 ng/mL, and 1-3 months postprocedure PSA was 0.14 ± 0.11 ng/mL (P <.01). Sixty-seven percent of patients had PSA ≤0.2 ng/mL at 1-3 months follow-up, but only 25% at 4-6 months. No change in impotence or incontinence occurred. In group II, average preprocedure PSA was 2.24 ± 2.71 ng/mL, and 1-3 month postprocedure PSA was 0.08 ± 0.10 ng/mL (P <.05). Eighty-nine percent of patients had PSA ≤0.2 ng/mL at 1-3 months follow-up and at 4-6 months. Complications in group 2 included worsening incontinence in 3 patients. MRI-guided salvage cryoablation of postradical prostatectomy prostate cancer recurrence is safe and feasible. Both techniques produce early PSA decrease with more lasting PSA results in the more aggressive group II methodology.
    Urology 08/2013; · 2.42 Impact Factor
  • Journal of the American College of Radiology: JACR 07/2013;
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    ABSTRACT: Recent studies have shown that magnetic resonance imaging (MRI) of patients with pacemakers can be safely performed under careful monitoring, but they excluded patients with recently implanted devices. Patients with recent implants may be at a greater risk for complications during MRI imaging due to lack of lead and wound maturity. We implemented a clinical protocol for MRI imaging of patients with implanted cardiac devices, and prospectively collected data. For this study, we retrospectively analyzed two groups of patients: those with recently implanted (≤42 days) and nonrecently implanted (>42 days) leads at the time of MRI scanning. All devices were interrogated before and after scanning, and were reprogrammed during the scan as per protocol. Of the 219 scans (in 171 patients), eight included patients with recently implanted (range: 7-36 days) and 211 with only nonrecently implanted pacemaker leads. During the scan, there were no complications in the early or late group. In one patient imaged 79 days postimplant, frequent premature ventricular complexes were noted during the scan, requiring no action. No patient reported pain during or immediately after the procedure. No clinically significant changes in function were seen at subsequent follow up (average 104 days post-MRI). Compared to patients with nonrecently implanted leads, there was no difference in any parameter between the two groups. With a strong clinical indication and with careful monitoring, MRI imaging is feasible in patients with recently implanted pacemakers, although experience is limited.
    Pacing and Clinical Electrophysiology 07/2013; · 1.75 Impact Factor
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    ABSTRACT: Deep Brain Stimulation (DBS) of the nucleus accumbens (NAc) has previously been investigated clinically for the treatment of several psychiatric conditions, including obsessive-compulsive disorder and treatment resistant depression. However, the mechanism underlying the therapeutic benefit of DBS, including the brain areas that are activated, remains largely unknown. Here, we utilized 3.0 T functional Magnetic Resonance Imaging (fMRI) changes in Blood Oxygenation Level-Dependent (BOLD) signal to test the hypothesis that NAc/internal capsule DBS results in global neural network activation in a large animal (porcine) model Animals (n = 10) were implanted in the NAc/internal capsule with DBS electrodes and received stimulation (1, 3, and 5 V, 130 Hz, and pulse widths of 100 and 500 µsec). BOLD signal changes were evaluated using a gradient echo-echo planar imaging (GRE-EPI) sequence in 3.0 T MRI. We used a normalized functional activation map for group analysis and applied general linear modeling across subjects (FDR<0.001). The anatomical location of the implanted DBS lead was confirmed with a CT scan We observed stimulation-evoked activation in the ipsilateral prefrontal cortex, insula, cingulate and bilateral parahippocampal region along with decrease in BOLD signal in the ipsilateral dorsal region of the thalamus. Furthermore, as the stimulation voltage increased from 3 V to 5 V, the region of BOLD signal modulation increased in insula, thalamus, and parahippocampal cortex and decreased in the cingulate and prefrontal cortex. We also demonstrated that right and left NAc/internal capsule stimulation modulates identical areas ipsilateral to the side of the stimulation Our results suggest that NAc/internal capsule DBS results in modulation of psychiatrically important brain areas notably the prefrontal cortex, cingulate, and insular cortex, which may underlie the therapeutic effect of NAc DBS in psychiatric disorders. Finally, our fMRI setup in the large animal may be a useful platform for translational studies investigating the global neuromodulatory effects of DBS.
    PLoS ONE 01/2013; 8(2):e56640. · 3.53 Impact Factor
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    ABSTRACT: To develop a reliable magnetic resonance elastography (MRE)-based method for measuring regional brain stiffness. First, simulation studies were used to demonstrate how stiffness measurements can be biased by changes in brain morphometry, such as those due to atrophy. Adaptive postprocessing methods were created that significantly reduce the spatial extent of edge artifacts and eliminate atrophy-related bias. Second, a pipeline for regional brain stiffness measurement was developed and evaluated for test-retest reliability in 10 healthy control subjects. This technique indicates high test-retest repeatability with a typical coefficient of variation of less than 1% for global brain stiffness and less than 2% for the lobes of the brain and the cerebellum. Furthermore, this study reveals that the brain possesses a characteristic topography of mechanical properties, and also that lobar stiffness measurements tend to correlate with one another within an individual. The methods presented in this work are resistant to noise- and edge-related biases that are common in the field of brain MRE, demonstrate high test-retest reliability, and provide independent regional stiffness measurements. This pipeline will allow future investigations to measure changes to the brain's mechanical properties and how they relate to the characteristic topographies that are typical of many neurologic diseases.
    PLoS ONE 01/2013; 8(12):e81668. · 3.53 Impact Factor
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    ABSTRACT: PURPOSE/AIM MR imaging can be used in evaluating various pathology involving the penis and urethra. Given long course and mobile nature, imaging of these organs is often challenging. The purpose of this study includes 1. To discuss technical challenges and advances to improve image quality. 2. To discuss indications of MR imaging. 3. To demonstrate MR imaging findings of various pathology of the penis and urethra. CONTENT ORGANIZATION 1. Technical Challenges and Improvements When the penis is twisted or bent, image interpretation is challenging. Proper positioning and immobilization of the penis is essential. Use of 3T magnet and surface coil can improve image quality. MR urethrography can be performed by administrating saline or gel into the urethra. 2. Indications MR imaging can be used for evaluating urethral abnormalities including congenital anomalies, traumatic rupture, amyloidosis, and neoplasms, as well as penile abnormalities including fracture, thrombus, Peyronie's disease, vascular malformation, and neoplasms. 3. Imaging Findings MR imaging findings of the various penile and urethral abnormalities will be presented. SUMMARY MR imaging is an excellent modality for evaluating the penile and male urethral pathology. Proper positioning and immobilization and application of surface coil are essential for good quality imaging.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
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    ABSTRACT: Object The object of this study was to determine the potential of magnetic resonance elastography (MRE) to preoperatively assess the stiffness of meningiomas. Methods Thirteen patients with meningiomas underwent 3D brain MRE examination to measure stiffness in the tumor as well as in surrounding brain tissue. Blinded to the MRE results, neurosurgeons made a qualitative assessment of tumor stiffness at the time of resection. The ability of MRE to predict the surgical assessment of stiffness was tested using a Spearman rank correlation. Results One case was excluded due to a small tumor size. In the remaining 12 cases, both tumor stiffness alone (p = 0.023) and the ratio of tumor stiffness to surrounding brain tissue stiffness (p = 0.0032) significantly correlated with the surgeons' qualitative assessment of tumor stiffness. Results of the MRE examination provided a stronger correlation with the surgical assessment of stiffness compared with traditional T1- and T2-weighted imaging (p = 0.089), particularly when considering meningiomas of intermediate stiffness. Conclusions In this cohort, preoperative MRE predicted tumor consistency at the time of surgery. Tumor stiffness as measured using MRE outperformed conventional MRI because tumor appearance on T1- and T2-weighted images could only accurately predict the softest and hardest meningiomas.
    Journal of Neurosurgery 10/2012; · 3.15 Impact Factor
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    ABSTRACT: The combination of deep brain stimulation (DBS) and functional MRI (fMRI) is a powerful means of tracing brain circuitry and testing the modulatory effects of electrical stimulation on a neuronal network in vivo. The goal of this study was to trace DBS-induced global neuronal network activation in a large animal model by monitoring the blood oxygenation level-dependent (BOLD) response on fMRI. We conducted DBS in normal anesthetized pigs, targeting the subthalamic nucleus (STN) (n=7) and the entopeduncular nucleus (EN), the non-primate analog of the primate globus pallidus interna (n=4). Using a normalized functional activation map for group analysis and the application of general linear modeling across subjects, we found that both STN and EN/GPi DBS significantly increased BOLD activation in the ipsilateral sensorimotor network (FDR<0.001). In addition, we found differential, target-specific, non-motor network effects. In each group the activated brain areas showed a distinctive correlation pattern forming a group of network connections. Results suggest that the scope of DBS extends beyond an ablation-like effect and that it may have modulatory effects not only on circuits that facilitate motor function but also on those involved in higher cognitive and emotional processing. Taken together, our results show that the swine model for DBS fMRI, which conforms to human implanted DBS electrode configurations and human neuroanatomy, may be a useful platform for translational studies investigating the global neuromodulatory effects of DBS.
    NeuroImage 08/2012; 63(3):1408-20. · 6.25 Impact Factor
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    ABSTRACT: OBJECTIVE: To validate the diagnostic performance of an in-scanner exercise-based magnetic resonance imaging (MRI) examination used to screen for chronic exertional compartment syndrome (CECS). Final clinical impression and intracompartmental needle manometry (INM) served as the reference standards. MATERIALS AND METHODS: Consecutive patients, referred by a sports medicine physician or orthopedic surgeon, underwent the MRI examination for lower extremity pain over the past 4 years and 9 months. Utilizing a diagnostic T2-weighted intensity ratio threshold of 1.54, established by a prior cohort of patients, sensitivity, specificity, predictive value, and diagnostic odds ratio were calculated for the anterior compartments. The means of the T2-weighted intensity ratios were compared using the Wilcoxon rank sum test. RESULTS: A total of 79 patients were identified, and 76 met the inclusion criteria and were evaluated. Of these, 23 met clinical diagnostic criteria. Sensitivity and specificity were 96% (95% CI: 79-99%) and 87% (95% CI: 75-94%) using the established threshold of 1.54. T2-weighted intensity ratio provided excellent discrimination with a concordance statistic of 0.96 (95% CI: 0.91-1.00). In the subset of 36 patients with INM results, 23 patients met criteria for CECS, although only 19 patients met both INM and clinical criteria. The sensitivity and specificity of the MRI examination relative to INM results were 87% (95%: 70-96%) and 62% (95% CI: 36-82%) respectively. CONCLUSION: In-scanner exercise-based MRI demonstrated reliability and reproducibility as a non-invasive screening test for CECS, thus reducing the need for invasive INM.
    Skeletal Radiology 07/2012; · 1.74 Impact Factor
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    ABSTRACT: Visual cortical surface area varies two- to threefold between human individuals, is highly heritable, and has been correlated with visual acuity and visual perception. However, it is still largely unknown what specific genetic and environmental factors contribute to normal variation in the area of visual cortex. To identify SNPs associated with the proportional surface area of visual cortex, we performed a genome-wide association study followed by replication in two independent cohorts. We identified one SNP (rs6116869) that replicated in both cohorts and had genome-wide significant association (P(combined) = 3.2 × 10(-8)). Furthermore, a metaanalysis of imputed SNPs in this genomic region identified a more significantly associated SNP (rs238295; P = 6.5 × 10(-9)) that was in strong linkage disequilibrium with rs6116869. These SNPs are located within 4 kb of the 5' UTR of GPCPD1, glycerophosphocholine phosphodiesterase GDE1 homolog (Saccharomyces cerevisiae), which in humans, is more highly expressed in occipital cortex compared with the remainder of cortex than 99.9% of genes genome-wide. Based on these findings, we conclude that this common genetic variation contributes to the proportional area of human visual cortex. We suggest that identifying genes that contribute to normal cortical architecture provides a first step to understanding genetic mechanisms that underlie visual perception.
    Proceedings of the National Academy of Sciences 03/2012; 109(10):3985-90. · 9.81 Impact Factor
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    ABSTRACT: Visual cortical surface area varies two- to threefold between human individuals, is highly heritable, and has been correlated with visual acuity and visual perception. However, it is still largely unknown what specific genetic and environmental factors contribute to normal variation in the area of visual cortex. To identify SNPs associated with the proportional surface area of visual cortex, we performed a genome-wide association study followed by replication in two independent cohorts. We identified one SNP (rs6116869) that replicated in both cohorts and had genome-wide significant association (P(combined) = 3.2 × 10(-8)). Furthermore, a metaanalysis of imputed SNPs in this genomic region identified a more significantly associated SNP (rs238295; P = 6.5 × 10(-9)) that was in strong linkage disequilibrium with rs6116869. These SNPs are located within 4 kb of the 5' UTR of GPCPD1, glycerophosphocholine phosphodiesterase GDE1 homolog (Saccharomyces cerevisiae), which in humans, is more highly expressed in occipital cortex compared with the remainder of cortex than 99.9% of genes genome-wide. Based on these findings, we conclude that this common genetic variation contributes to the proportional area of human visual cortex. We suggest that identifying genes that contribute to normal cortical architecture provides a first step to understanding genetic mechanisms that underlie visual perception.
    Proceedings of the National Academy of Sciences of the United States of America. 03/2012; 109(10):3985-90.
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    ABSTRACT: The increasing prevalence of Alzheimer's disease (AD) has provided motivation for developing novel methods for assessing the disease and the effects of potential treatments. Magnetic resonance elastography (MRE) is an MRI-based method for quantitatively imaging the shear tissue stiffness in vivo. The objective of this research was to determine whether this new imaging biomarker has potential for characterizing neurodegenerative disease. Methods were developed and tested for applying MRE to evaluate the mouse brain, using a conventional large bore 3.0T MRI system. The technique was then applied to study APP-PS1 mice, a well-characterized model of AD. Five APP-PS1 mice and 8 age-matched wild-type mice were imaged immediately following sacrifice. Brain shear stiffness measurements in APP-PS1 mice averaged 22.5% lower than those for wild-type mice (P = .0031). The results indicate that mouse brain MRE is feasible at 3.0T, and brain shear stiffness has merit for further investigation as a potential new biomarker for Alzheimer's disease.
    Magnetic Resonance Imaging 02/2012; 30(4):535-9. · 2.06 Impact Factor
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    ABSTRACT: PURPOSE To introduce axial balanced steady state free precession (bSSFP) MR imaging with provocative maneuvers as an adjunct test for popliteal artery entrapment syndrome (PAES). METHOD AND MATERIALS All scans were performed on a 1.5 T scanner. An axial 2D bSSFP, non-fat saturated imaging technique was performed through both knees simultaneously with the following parameters: TR 3.2-8.2 ms, minimum TE (1.3-1.8 ms), flip angle 45º, field of view to include both knees (30-40 cm), 5 mm slice thickness with 0 skip, 224 pixel × 256 pixel matrix, and number of excitations 1. An 8 channel torso phased array coil was used in association with a Plexiglas footplate. bSSFP was performed in the neutral position and then in resisted plantar and dorsiflexion (Figure). All scans were performed and analyzed by a single fellowship trained musculoskeletal radiologist. A retrospective chart review was performed to identify patients who underwent additional diagnostic evaluation with provocative ultrasound (US) and/or conventional angiography. RESULTS One hundred and twenty legs were evaluated in 60 patients. A total of 22 extremities (11 patients) underwent conventional diagnostic angiography and/or subsequent surgical intervention. The positive predictive value (PPV) of provocative bSSFP was 100% with 14 true positives and no false positives. The negative predictive value (NPV) of bSSFP was 50% with 4 true negatives and 4 false negatives. Arterial US exams with provocative measures were evaluated independently with a PPV of 64% (7 true positives and 4 false positives.) There were no true negatives and 7 false negatives for arterial US. Eighteen extremities underwent both provocative bSSFP and arterial US prior to conventional provocative diagnostic angiography. The PPV of provocative bSSFP and US were 100% and 64%, respectively. The NPV of bSSFP was 67% in this subset of patients. There were 7 false negatives and no true negatives with US. CONCLUSION The bSSFP PPV in our study group was 100% compared with 64% for provocative arterial US. The bSSFP NPV was only 50%, but this was superior to provocative arterial US in our study group. CLINICAL RELEVANCE/APPLICATION bSSFP may simplify the evaluation of patients with chronic exertional leg pain by identifying patients who may benefit from conventional diagnostic angiography to exclude PAES.
    Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011

Publication Stats

4k Citations
479.41 Total Impact Points

Institutions

  • 1990–2014
    • Mayo Clinic - Rochester
      • • Department of Radiology
      • • Department of Otorhinolaryngology
      Rochester, Minnesota, United States
  • 1988–2012
    • Mayo Foundation for Medical Education and Research
      • • Department of Radiology
      • • Department of Obstetrics and Gynecology
      • • Mayo Graduate School
      • • Department of Diagnostic Radiology
      Scottsdale, AZ, United States
  • 2004
    • University of Pennsylvania
      • School of Veterinary Medicine
      Philadelphia, PA, United States
  • 2002–2004
    • University of Pittsburgh
      • Department of Radiology
      Pittsburgh, PA, United States
  • 2001
    • Center for Magnetic Resonance Research Minnesota, USA
      Minneapolis, Minnesota, United States