Prophylactic embolization of the cystic artery prior to radioembolization of liver malignancies--an evaluation of necessity.

PURPOSE: Prior to radioembolization (RE) of hepatic tumors, many centers prophylactically occlude the cystic artery (CA) during evaluation angiography (EVA) to prevent radiation-induced cholecystitis. There is no conclusive evidence for the protective effect of CA embolization and it bears the risk of inducing ischemic cholecystitis. The aim of this study is to evaluate the justification for CA embolization by comparing clinical and morphologic imaging parameters between patients undergoing coil occlusion of the cystic artery (COCA) and those with uncoiled CA (UCCA). MATERIALS AND METHODS: Retrospective comparison of 37 patients with UCCA versus 68 patients with COCA in terms of clinical findings (CRP, leukocyte count, body temperature, upper abdominal pain) and morphologic imaging parameters associated with cholecystitis (gallbladder (GB) wall thickness, free fluid in GB bed, bremsstrahlung SPECT) after EVA, after RE, and at 6-week follow-up. RESULTS: At none of the 3 time points (EVA, RE, 6-week follow-up) was there any significant difference in CRP, leukocyte count, body temperature, or upper abdominal pain between the UCCA and COCA group. There was also no significant difference between the two groups with regard to GB wall thickness, fluid in the GB bed, and bremsstrahlung in SPECT. One patient of the UCCA group and two patients of the COCA developed cholecystitis requiring treatment. CONCLUSION: Comparison of clinical and imaging findings between patients with and without CA embolization prior to RE identified no predictors of radiogenic or ischemic cholecystitis after RE. Our study provides no evidence for a benefit of prophylactic CA embolization before RE.

Percutaneous abscess drainage using near real-time MR guidance in an open 1.0-T MR scanner: proof of concept.

OBJECTIVES: The aims of our study were (1) to assess the feasibility, effectiveness, and safety of exclusively magnetic resonance (MR)-guided freehand percutaneous abscesses drainage using a 1.0-T open MR scanner and (2) to evaluate the optimal method to visualize drainage catheters in situ. MATERIAL AND METHODS: In vitro studies in a dedicated MR gelatin phantom were performed to assess visualization of 8 different sizes of drainage catheters after instillation of sole 0.9% sodium chloride (NaCl) and diluted (1.0%) or concentrated (12.0%) gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) using a T1-weighted (T1w) 2-dimensional fast field echo (FFE) and a T2-weighted single-shot (ssh) turbo spin-echo (TSE) fast dynamic sequence. The catheter artifacts were evaluated with regard to the contrast-to-noise ratio (CNR), the artifact width using the full width at half-maximum (FWHM) method, and the artifact intensity, being the product of the CNR and the FWHM. We used the general linear model procedure as the global test and the Tukey studentized range test for post hoc analysis. In vivo MR-guided freehand drainage was prospectively performed in patients with increased systemic inflammation markers and abdominal, retroperitoneal, and pelvic abscess collections. This study had been approved by the institutional review board. All patients provided written informed consent. Technical success was the primary efficacy variable. The secondary efficacy variables were visibility of the puncture needle and drainage catheter artifact, using a qualitative 5-point rating scale, intervention and procedure time, and rate of postinterventional complications. RESULTS: The FWHM, the CNR, and the artifact intensity of the drainage catheters filled with 0.9% NaCl or diluted or concentrated Gd-DTPA increased according to the drainage catheter size in an almost linear fashion in both image weighting (all P ≤ 0.006; all R(2) ≥ 0.73). The T1w FFE sequence yielded the highest FWHM, CNR, and artifact intensity of all groups, using 12.0% Gd-DTPA instillation (all P < 0.001), and the least FWHM and artifact intensity, using 1.0% Gd-DTPA instillation (all P < 0.022; all P < 0.009). The T2w ssh TSE yielded higher FWHM, using 12.0% Gd-DTPA instillation, whereas the CNR was higher for 0.9% NaCl instillation (all P < 0.001). Magnetic-resonance-guided abscess drainage was performed in 22 patients with 24 abdominal, retroperitoneal, or pelvic abscess collections. The technical success rate of in vivo MR-guided freehand drainage was 100%. Visibility of the puncture needle was excellent (≥4.4 [0.5] points). Visibility of the drainage catheters was rated with 3.9 (0.9) and 4.5 (0.8) points using T2w ssh TSE with 0.9% NaCl and 12.0% Gd-DTPA instillation as well as 4.8 (0.5) and 4.2 (0.8) points using T1w FFE with 1.0% and 12.0% Gd-DTPA instillation, respectively. The procedure and intervention time was 52.4 (16.4) minutes (range, 28-78 minutes) and 27.4 (7.2) minutes (range, 17-40 minutes). Two minor and no major complications were recorded. CONCLUSIONS: Magnetic-resonance-guided freehand percutaneous abscesses drainage using fast dynamic sequences in an open 1-T MR scanner is feasible, effective, and safe. Visualization of drainage catheters can be facilitated by instillation of 0.9% NaCl or diluted or concentrated contrast media.

Magnetic resonance-guided freehand radiofrequency ablation of malignant liver lesions: a new simplified and time-efficient approach using an interactive open magnetic resonance scan platform and hepatocyte-specific contrast agent.

OBJECTIVES: The aims of this study were to develop magnetic resonance (MR)-guided freehand radiofrequency ablation (RFA) using a near-real-time interactive MR platform in an open 1.0-T MR scanner and to determine the feasibility and safety of this new approach in the clinical setting. METHODS: The study was performed using an open 1.0-T MR system and a low-pass filter to prevent interaction between the RFA generator and the scanner. Artifact size of the radiofrequency needle was measured in 2 perpendicular views (transversal [tra] and coronal [cor]) in vitro and in the tra orientation in vivo for diagnostic (T1 high resolution isotropic volume excitation [THRIVE]/T2 turbo spin-echo [TSE]) and near-real-time (T1 fast-field-echo [FFE]) imaging. A liver-specific contrast medium (gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid) was administered 20 minutes before the intervention to enhance lesion visibility. Visibility was rated and compared for both interventional and diagnostic imaging sequences using a 10-point grading scale. Intervention time and complications were recorded. RESULTS: The mean diameter of needle artifact size for interventional T1 FFE was 17.4 ± 0.7 mm (tra) and 17.1 ± 1.1 mm (cor) in vitro and 15.2 ± 1.5 mm (tra) in vivo. Artifact size for diagnostic imaging was 12.5 ± 1.8 mm (tra) and 11.2 ± 1.4 mm (cor) in vitro and 10.5 ± 1.7 mm in vivo using THRIVE and 8.1 ± 2.4 mm (tra) and 10.8 ± 1.8 mm (cor) in vitro and 9.7 ± 2.0 mm (tra) in vivo using T2 TSE. A total of 57 patients with liver malignancies (mean tumor size, 17 ± 7 mm) underwent freehand MR-guided RFA. In all patients, the ablative procedure was technically successful. Lesion visibility of the diagnostic T2 TSE sequence (4 ± 2) was significantly decreased compared with both the diagnostic (THRIVE, 7 ± 2) and interventional (T1 FFE, 8 ± 1) T1-weighted sequences. Mean time to position the applicator was 7.5 ± 2 minutes. Procedure times ranged from 30 to 60 minutes. The mean in-room time was 57 ± 22 minutes. No major complications were recorded. CONCLUSIONS: Magnetic resonance-guided freehand RFA using a near-real-time interactive MR platform in an open 1.0-T MR scanner is feasible, safe, and applicable in clinical routine. The administration of a hepatocyte-specific contrast agent enhances lesion visualization and therefore improves targeting. Without the need for additional sophisticated devices, this new approach simplifies and shortens the RFA procedure compared with previously published methods.

MR-guided freehand biopsy of breast lesions in a 1.0-T open MR imager with a near-real-time interactive platform: preliminary experience.

PURPOSE: To identify the most appropriate magnetic resonance (MR) sequence for breast biopsy with regard to lesion visibility and artifact size and to assess feasibility and safety of this approach in a clinical setting. MATERIALS AND METHODS: MR-guided interventions were performed in an open 1.0-T MR imager between November 2009 and January 2011. The prospective clinical study was approved by the institutional review board. Written informed consent was obtained. Four different fast dynamic sequences (balanced steady-state free precession, T1-weighted turbo gradient-echo, T1-weighted turbo spin-echo [SE], and T2-weighted single-shot SE sequences) were evaluated for artifact size of biopsy needle and in vivo for lesion visibility. In vivo breast biopsies were performed with the freehand technique and without immobilization or a positioning device by using an interactive MR mode that allowed continuous imaging in two orthogonal planes for guidance. RESULTS: On the basis of good lesion detection in combination with small artifact size, T1-weighted SE imaging was used for biopsy. A total of 75 biopsies were performed successfully in 69 patients (mean age, 53 years; age range, 35-78 years) (mean lesion size, 7.1 mm; range, 4-15 mm). The interactive MR platform enabled immediate localization and correction of intended needle trajectory. Average time for freehand biopsy was 12 minutes (range, 8-23 minutes). No major complications were recorded. CONCLUSION: MR-guided freehand biopsy of breast lesions with the near-real-time interactive MR platform in an open 1.0-T MR imager is safe and feasible in a clinical setting. The method simplifies work flow and intervention performance.

ZASPopathy with childhood-onset distal myopathy.

We report on a German family presenting with a predominantly distal myopathy primarily affecting anterior compartments of lower legs in childhood. Proximal lower limb and hip girdle weakness developed later in early adulthood in the female index patient and likewise in her mother. Consecutive muscle biopsy findings were first attributed to a mild congenital myopathy and later on interpreted as neurogenic changes without clear signs of a myopathy. Molecular genetic analysis was performed because of the clinical impression of a distal myopathy combined with dominant inheritance. The heterozygous mutation c.349G>A (p.D117N) in the ZASP gene could be found. This mutation had been previously associated with an adult-onset, isolated, dilated left ventricular non-compaction cardiomyopathy (OMIM*605906.0007), which was not present in our patients. Our data show that this mutation can be associated with an isolated skeletal muscle phenotype. Second, mutation analysis of the ZASP gene is suggested for distal myopathies of any age, even in cases of uncharacteristic muscle biopsy findings on routine analysis.

Dual-source radiofrequency transmission with patient-adaptive local radiofrequency shimming for 3.0-T cardiac MR imaging: initial experience.

PURPOSE: To evaluate the effect of dual-source parallel radiofrequency (RF) transmission with patient-adaptive local RF shimming on image quality, image contrast, and diagnostic confidence at routine clinical cardiac magnetic resonance (MR) imaging with use of a 3.0-T dual-channel transmit whole-body MR system. MATERIALS AND METHODS: Written informed consent was obtained from all patients, and the study protocol was approved by the local institutional review board. Cardiac MR imaging was performed in 28 patients by using a 3.0-T MR unit equipped with a dual-source RF transmission system. The effect of conventional versus dual-source RF transmission on steady-state free precession (SSFP) cine sequences and turbo spin-echo (TSE) black-blood (BB) sequences was evaluated. The homogeneity of the B1 field and contrast-to-noise ratios (CNRs) were measured and tested for statistical significance with the paired t test. Images were analyzed qualitatively for homogeneity, the presence of off-resonance artifacts, and diagnostic confidence independently by two readers. Statistical significance was assessed with the Wilcoxon signed rank test. Inter- and intraobserver agreement was assessed with κ statistics. RESULTS: Quantitative image analysis revealed that B1 homogeneity and CNR were significantly improved for images acquired with dual-source RF transmission compared with conventional RF transmission (P = .005). The quality of SSFP and TSE BB images of the left and the right ventricles showed a significant improvement with respect to image homogeneity and diagnostic confidence as evaluated by the readers (P = .0001, κ > 0.74). As a side effect, off-resonance artifacts were significantly reduced on SSFP images (P = .0001, κ > 0.76). CONCLUSION: Dual-source parallel RF transmission significantly improves image homogeneity, image contrast, and diagnostic confidence compared with conventional RF transmission of cardiac SSFP and TSE BB sequences.

Transarterial endovascular treatment in the management of life-threatening intra- and postoperative haemorrhages after otorhinolaryngological surgery.

Management of life-threatening postsurgical bleeding is complex. If conservative or surgical therapy is demanding, an endovascular treatment can be considered. The goal of this study was to evaluate the outcome of endovascular approaches in the diagnosis and therapy of otherwise intractable postoperative haemorrhages with a study design of outcomes research. Charts of all patients with postsurgical bleedings receiving endovascular treatment were reviewed for clinical outcome, complications, and demographic data. 15 patients were identified. They had rhinosurgery (12/15), tonsillectomy (2/15) or transoral tumour debulking (1/15) prior to the endovascular procedure. In more than 70%, the source of bleeding was directly located angiographically and subsequently superselectively embolized. The remaining patients suffered from post-rhinosurgical epistaxis and underwent a bilateral embolization of the sphenopalatine artery. All bleedings were successfully controlled and no procedure-related complication was noted. In conclusion, endovascular treatment of life-threatening postsurgical haemorrhages should be considered if the source of bleeding is unknown or if surgery is difficult and may result in devastating postoperative complications.

Cardiomyopathies (hypertrophy and failure): what can offer cardiac magnetic resonance imaging?

In routine, cardiomyopathy, confirmed or not, is a frequent reason for cardiac MRI evaluation. Step by step, by using a wide panel of sequences, cardiac MRI is able to characterize cardiomyopathies by their morphologic and functional phenotype as well as by tissue characterization. Cardiac-MRI is also considered as the most appropriate technique for the follow-up of this disease. The purpose of this article is to browse an overview of the main MRI features of cardiomyopathy, focusing the purpose on hypertrophic forms and myocardial diseases leading to cardiac failure.

Safety, feasibility, and diagnostic value of cardiac magnetic resonance imaging in patients with cardiac pacemakers and implantable cardioverters/defibrillators at 1.5 T.

BACKGROUND: Recent studies suggest that magnetic resonance (MR) imaging of the brain and spine may safely be performed in patients with pacemakers (PMs) and implantable cardioverter/defibrillators (ICDs), when taking adequate precautions. The aim of this study was to investigate safety, feasibility, and diagnostic value (DV) of MR imaging in cardiac applications (cardiac MR [CMR]) in patients with PMs and ICDs for the first time. METHODS: Thirty-two PM/ICD patients with a clinical need for CMR were examined. The specific absorption rate was limited to 1.5 W/kg. Devices were reprogrammed pre-CMR to minimize interference with the electromagnetic fields. Devices were interrogated pre-CMR and post-CMR and after 3 months. Troponin I levels were measured pre-CMR and post-CMR; image quality (IQ) and DV of CMR were assessed. RESULTS: All devices could be reprogrammed normally post-CMR. No significant changes of pacing capture threshold, lead impedance, and troponin I were observed. Image quality in patients with right-sided devices (RSD) was better compared with that in patients with left-sided devices (LSD) (P < .05), and less myocardial segments were affected by device-related artefacts (P < .05). Diagnostic value was rated as sufficiently high, allowing for diagnosis, or better in 12 (100%) of 12 patients with RSD, and only in 7 (35%) of 20 patients with LSD. CONCLUSIONS: Cardiac MR may be performed safely when limiting specific absorption rate, appropriately monitoring patients, and following device reprogramming. Cardiac MR delivers good IQ and DV in patients with RSD. Cardiac MR in patients with RSD may therefore be performed with an acceptable risk/benefit ratio, whereas the risk/benefit ratio is rather unfavorable in patients with LSD.

Endovascular treatment of epistaxis: indications, management, and outcome.

OBJECTIVE: Epistaxis is a common clinical problem, and the majority of bleedings can be managed conservatively. However, due to extensive and sometimes life-threatening bleeding, further treatment, such as superselective embolization, may be required. We report our experience with endovascular treatment of life-threatening epistaxis. METHODS: All patients presenting with excessive epistaxis, which received endovascular treatment at a German tertiary care facility between January 2001 and December 2009, were retrospectively identified. Demographic data, etiology, origin and clinical relevance of bleeding, interventional approach, therapy-associated complications, and outcome were assessed. RESULTS: A total of 48 patients required 53 embolizations. Depending on the etiology of bleeding, patients were assigned to three groups: 1) idiopathic epistaxis (31/48), 2) traumatic or iatrogenic epistaxis (12/48), and 3) hereditary hemorrhagic telangiectasia (HHT) (5/48). Eleven of 48 patients required blood transfusions, and 9 of these 11 patients (82%) were termed clinically unstable. The sphenopalatine artery was embolized unilaterally in 10 of 53 (18.9%) and bilaterally in 41 of 53 (77.4%) procedures. During the same procedure, additional vessels were embolized in three patients (3/53; 5.7%). In 2 of 53(3.8%) cases, the internal carotid artery (ICA) was occluded. Long-term success rates of embolization were 29 of 31 (93.5%) for group 1 and 11 of 12 (91.7%) for group 2 patients. Embolization of patients with HHT offered at least a temporary relief in three of five (60%) cases. Two major complications (necrosis of nasal tip and transient hemiparesis) occurred after embolization. CONCLUSIONS: Endovascular treatment proves to be effective for prolonged and life-threatening epistaxis. It is easily repeatable if the first procedure is not successful and offers a good risk-benefit profile.

Prevalence of asymptomatic upper extremity venous obstruction in 302 patients undergoing first implantation of cardioverter defibrillator.

BACKGROUND: Little is known about the prevalence of upper extremity vein obstruction or anomalies in patients before first implantation of implantable cardioverter defibrillator (ICD). It remains unclear in which patients contrast venography is warranted before implantation procedure. METHODS: Results of clinical data and contrast venography of 302 consecutive patients scheduled for first ICD implantation were analyzed. RESULTS: Prevalence of upper vein obstruction was 6.6% (20/302 patients) in a typical patient population undergoing first ICD implantation. Age, left ventricular ejection fraction, underlying heart disease, prior open-heart surgery, or cardiopulmonary resuscitation were not predictors of obstruction. Patients with previous cardiac pacemaker implantation had a higher rate of obstruction, though this was not statistically significant (20% vs 15.7%, P = 0.54). Persistent left vena cava was found in 0.7%. CONCLUSION: There is no clinical parameter sufficient enough to predict upper extremity venous obstruction. Contrast venography may be considered in patients with previous pacemaker placement but should not be a routine diagnostic tool in unselected patients prior to first ICD-implantation procedure.

Low-field magnetic resonance imaging: increased safety for pacemaker patients?

AIMS: The number of low-field (<0.5 T) magnetic resonance (MR) scanners installed worldwide is increasing due to a favourable cost and safety profile and improved patient comfort using an open-scanner design. Therefore, the aim of our study was to evaluate a strategy for the safe performance of magnetic resonance imaging (MRI) at a field strength of 0.2 T, in pacemaker (PM) patients without limitations on scan region, PM dependency, or the presence of abandoned leads. METHODS AND RESULTS: One hundred and fourteen PM patients, including PM-dependent patients and patients with abandoned leads, examined at a 0.2 T MR scanner due to an urgent clinical need for an MRI examination, were evaluated. All PMs were reprogrammed before MRI: if heart rate was <60 bpm, the asynchronous mode (with a rate of 80 bpm) was programmed to avoid MR-induced inhibition; if heart rate was >60 bpm, sense-only mode (ODO/OVO/OAO) was used to avoid MR-induced competitive pacing and potential proarrhythmia. Patients were monitored with electrocardiogram (ECG) and pulse oximetry. All PMs were interrogated before and after MRI, including measurement of lead impedance, pacing capture threshold (PCT), and battery voltage. All MRI scans were completed safely. No induction of arrhythmias or inhibition of PM output occurred. There were no statistically significant changes in lead impedance, PCT, or battery voltage (P>0.05). CONCLUSION: Low-field MRI of PM patients, including high-risk PM patients and MRI scan regions, can be performed with an acceptable risk-benefit ratio under controlled conditions.

Incidence and predictors of silent cerebral embolism during pulmonary vein catheter ablation for atrial fibrillation.

AIMS: Left atrial catheter ablation of the pulmonary veins (PV) has evolved as an important therapeutic option for the treatment of atrial fibrillation (AF). We aimed to investigate the incidence and predictors of silent cerebral embolism associated with PV catheter ablation, detected by diffusion-weighted magnetic resonance imaging (DW-MRI). METHODS AND RESULTS: We performed a prospective analysis of 53 consecutive patients with persistent or paroxysmal AF that underwent PV ablation and post-procedural cerebral MRI 1 day after lasso catheter-guided ostial PV ablation. Patients were analysed for possible demographical, medical, echocardiographical, and procedural predictors of embolic events. A mean of 3.5 +/- 0.5 PVs were ablated per patient. In six patients, DW-MRI depicted new clinically silent microembolism after PV ablation (11%). The number of ineffective medical antiarrhythmic agents prior to ablation procedure was significantly higher in the embolism group (3.3 +/- 0.5 vs. 2.2 +/- 1.4, P = 0.014). Coronary heart disease (CAD) was more frequent in patients with cerebral embolisms (33 vs. 2%, P = 0.031); left ventricular volume (130 +/- 12 vs. 103 +/- 26 mL, P = 0.002), and septal wall thickness (13.0 +/- 1.4 vs. 7.9 +/- 4.8 mm, P = 0.025) were significantly increased. CONCLUSION: This study shows a high incidence of silent micro-embolic events after PV ablation. CAD, left ventricular dilatation, and hypertrophy were potential predictors of this complication.

Massive hypercoagulable state despite full-dose anticoagulant treatment in a patient with occult malignancy: considerations concerning chemotherapy without definitive diagnosis.

A 55-year-old female patient presented with recurrent deep venous thrombosis and pulmonary embolism while on oral anticoagulant treatment using the vitamin K antagonist phenprocoumon. Hypercoagulable state was regarded to be paraneoplastic, but no underlying malignancy could be identified despite extensive screening for cancer, including gastroscopy and colonoscopy, a bone marrow biopsy, thoracoabdominal CT scans with subsequent biopsies of possibly malignant findings, octreotide scintigraphy, skeletal scintigraphy and gynaecological screening. In the course of her hospital stay she developed progressive right cardiac insufficiency due to the formation of new thromboses despite aggressive anticoagulant treatment and died of right-sided heart failure. The autopsy showed a poorly differentiated adenocarcinoma in the middle lobe of the right lung. In addition, pulmonary lymphangiosis carcinomatosa, pleural and pericardial carcinosis, and lymph node metastases and osteoblastic vertebral body metastases were shown.

Evaluation of cumulative effects of MR imaging on pacemaker systems at 1.5 Tesla.

BACKGROUND: The purpose of this study was to evaluate possible cumulative effects of repeated magnetic resonance imaging (MRI) examinations on pacemaker systems in patients with cardiac pacemakers. METHODS AND RESULTS: The records of pacemaker patients who underwent repetitive MRI examinations in our institution were reviewed to identify patients who underwent two or more MRI examinations at 1.5T of any anatomical region. Using these criteria, a total of 47 patients who underwent a total 171 MRI examinations were identified and included in this study. Institutional Review Board approval for all pacemaker investigations was obtained. Written informed consent was obtained from all patients. Pacemakers were interrogated immediately before and after MR imaging, and after 3 months, including measurement of pacing capture threshold (PCT), lead impedance (LI), and battery voltage (BV). PCT, LI, and BV were analyzed for changes dependant on the number of MRI exams performed. Mean changes over time and changes between first and last pacemaker interrogation of PCT, LI, and BV were calculated. A statistically significant (P < 0.05), but clinically irrelevant trend for decrease in PCT and BV was found. No significant or clinically relevant changes in LI were observed. CONCLUSION: In this first study, no clinically relevant, cumulative changes in PCT, LI, or BV could be detected in PM patients who underwent two or more MRI examinations. However, a careful benefit/risk evaluation, among other MRI- and pacemaker-related safety precautions, remains mandatory, as clinically relevant alterations to the PM system cannot be excluded by all means.

Magnetic resonance imaging at 1.5-T in patients with implantable cardioverter-defibrillators.

OBJECTIVES: Our aim was to establish and evaluate a strategy for safe performance of magnetic resonance imaging (MRI) at 1.5-T in patients with implantable cardioverter-defibrillators (ICDs). BACKGROUND: Expanding indications for ICD placement and MRI becoming the imaging modality of choice for many indications has created a growing demand for MRI in ICD patients, which is still considered an absolute contraindication. METHODS: Non-pacemaker-dependent ICD patients with a clinical need for MRI were included in the study. To minimize radiofrequency-related lead heating, the specific absorption rate was limited to 2 W/kg. ICDs were reprogrammed pre-MRI to avoid competitive pacing and potential pro-arrhythmia: 1) the lower rate limit was programmed as low as reasonably achievable; and 2) arrhythmia detection was programmed on, but therapy delivery was programmed off. Patients were monitored using electrocardiography and pulse oximetry. All ICDs were interrogated before and after the MRI examination and after 3 months, including measurement of pacing capture threshold, lead impedance, battery voltage, and serum troponin I. RESULTS: Eighteen ICD patients underwent a total of 18 MRI examinations at 1.5-T; all examinations were completed safely. All ICDs could be interrogated and reprogrammed normally post-MRI. No significant changes of pacing capture threshold, lead impedance, and serum troponin I were observed. Battery voltage decreased significantly from pre- to post-MRI. In 2 MRI examinations, oversensing of radiofrequency noise as ventricular fibrillation occurred. However, no attempt at therapy delivery was made. CONCLUSIONS: MRI of non-pacemaker-dependent ICD patients can be performed with an acceptable risk/benefit ratio under controlled conditions by taking both MRI- and pacemaker-related precautions. (Implantable Cardioverter Defibrillators and Magnetic Resonance Imaging of the Heart at 1.5-Tesla; NCT00356239).

Combined myocardial stress perfusion imaging and myocardial stress tagging for detection of coronary artery disease at 3 Tesla.

BACKGROUND: Adenosine stress perfusion is very sensitive for detection of coronary artery disease (CAD), and yields good specificity. Standard adenosine cine imaging lacks high sensitivity, but is very specific. Myocardial tagging improves detection of wall motion abnormalities (WMAs). Perfusion and tagging cardiovascular magnetic resonance (CMR) both benefit from high field imaging (improved contrast to noise ratio and tag persistence). We investigated the diagnostic impact of a combined stress perfusion-tagging protocol for detection of CAD at 3 Tesla. METHODS: Stress perfusion and tagging images were acquired in 3 identical short axis locations (slice thickness 8 mm, FOV 320-380 mm, matrix 256(2)). A positive finding at coronary angiography was defined as stenosis or flow limiting restenosis > 50% in native and graft vessels. A true positive CMR - finding was defined as > or = 1 perfusion deficit or new WMA during adenosine-stress in angiographically corresponding regions. RESULTS: We included 60 patients (males: 41, females: 19; 21 suspected, 39 known CAD). Myocardial tagging extended stress imaging by 1.5-3 min and was well tolerated by all patients. Sensitivity and specificity for detection of significant CAD by adenosine stress perfusion were 0.93 and 0.84, respectively. The sensitivity of adenosine stress tagging was less (0.64), while the specificity was very high (1.0). The combination of both stress perfusion and stress tagging did not increase sensitivity. CONCLUSION: The combined adenosine stress perfusion-tagging protocol delivers high sensitivity and specificity for detection of significant CAD. While the sensitivity of adenosine stress tagging is poor compared to perfusion imaging, its specificity is very high. This technique should thus prove useful in cases of inconclusive perfusion studies to help avoid false positive results.

Clinical, genetic, and cardiac magnetic resonance imaging findings in primary desminopathies.

We report the clinical, genetic and cardiac magnetic resonance imaging (MRI) findings in 11 German patients with heterozygous E245D, D339Y, R350P and L377P desmin mutations and without cardiac symptoms. Clinical evaluation revealed a marked variability of skeletal muscle, respiratory and cardiac involvement even between patients with identical mutations, ranging from asymptomatic to severely affected. While echocardiography did not show any pathological findings in all 11 patients, cine MRI revealed focal left ventricular hypertrophy in 2 patients and MR delayed enhancement imaging displayed intramyocardial fibrosis in the left ventricle in 4 patients indicating early myocardial involvement. Our data argue against distinct genotype-phenotype correlations and suggest that comprehensive cardiac MRI is superior to conventional echocardiography for the detection of early and clinically asymptomatic stages of cardiomyopathy in desminopathy patients. Therefore, cardiac MRI may serve as a screening tool to identify patients at risk, which might benefit from early pharmacological and/or interventional (e.g. implantable cardioverter-defibrillator devices) therapy.