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Purpose Conventional cardiac T2 mapping suffers from the partial-voluming effect in the endocardium and epicardium due to the co-presence of intra-cavity blood and epicardial fat. The aim of the study is to develop a novel single-breath-hold Fat-Saturated Dark-Blood (FSDB) cardiac T2-mapping technique to mitigate the partial-voluming and improve T2 accuracy. Methods The proposed FSDB T2-mapping technique combines T2-prepared bSSFP, a novel use of double inversion-recovery with heart-rate-adaptive TI, and spectrally-selective fat saturation to mitigate partial-voluming from both the blood and fat. FSDB T2 mapping was compared to conventional T2 mapping via simulations, phantom imaging, healthy-subject imaging (n = 8), and patient imaging (n = 7). In the healthy subjects, a high-resolution coplanar anatomical imaging was performed to provide a gold standard for segmentation of endocardium and epicardium. T2 maps were registered to the gold standard image to evaluate any inter-layer T2 difference, which is a surrogate for partial-voluming. Results Simulations and phantom imaging showed that FSDB T2 mapping was accurate in a range of heartrates, off-resonance, and T2 values, and blood/fat reasonably nulled in a range of heartrates. In healthy subjects, FSDB T2 mapping showed similar T2 values over different myocardial layers in all 3 short-axis slices (e.g. basal epicardial/mid-wall/endocardial T2 = 42 ± 2 ms/41 ± 1 ms/42 ± 1 ms), whereas conventional T2 mapping showed considerably increased T2 in the endocardium and epicardium (e.g. basal epicardial/mid-wall/endocardial T2 = 48 ± 3 ms/43 ± 1 ms/49 ± 3 ms). The homogeneous T2 in the FSDB T2 mapping increased the apparent LV-wall thickness by 25–41% compared with the conventional method. Conclusions The proposed technique improves accuracy of myocardial T2 mapping against partial-voluming associated with both fat and blood, facilitating a multi-layer T2 evaluation of the myocardium. This technique may improve utility of cardiac T2 mapping in diseases affecting the endocardium and epicardium, and in patients with a small heart.

Background Intramyocardial hemorrhage (IMH) within myocardial infarction (MI) is associated with major adverse cardiovascular events. Bright-blood T2*-based cardiovascular magnetic resonance (CMR) has emerged as the reference standard for non-invasive IMH detection. Despite this, the dark-blood T2*-based CMR is becoming interchangeably used with bright-blood T2*-weighted CMR in both clinical and preclinical settings for IMH detection. To date however, the relative merits of dark-blood T2*-weighted with respect to bright-blood T2*-weighted CMR for IMH characterization has not been studied. We investigated the diagnostic capacity of dark-blood T2*-weighted CMR against bright-blood T2*-weighted CMR for IMH characterization in clinical and preclinical settings. Materials and methods Hemorrhagic MI patients (n = 20) and canines (n = 11) were imaged in the acute and chronic phases at 1.5 and 3 T with dark- and bright-blood T2*-weighted CMR. Imaging characteristics (Relative signal-to-noise (SNR), Relative contrast-to-noise (CNR), IMH Extent) and diagnostic performance (sensitivity, specificity, accuracy, area-under-the-curve, and inter-observer variability) of dark-blood T2*-weighted CMR for IMH characterization were assessed relative to bright-blood T2*-weighted CMR. Results At both clinical and preclinical settings, compared to bright-blood T2*-weighted CMR, dark-blood T2*-weighted images had significantly lower SNR, CNR and reduced IMH extent (all p p Conclusion While IMH can be visible on dark-blood T2*-weighted CMR, the overall conspicuity of IMH is significantly reduced compared to that observed in bright-blood T2*-weighted images, across infarct age in clinical and preclinical settings at 1.5 and 3 T. Hence, bright-blood T2*-weighted CMR would be preferable for clinical use since dark-blood T2*-weighted CMR carries the potential to misclassify hemorrhagic MIs as non-hemorrhagic MIs.

Purpose: In perfusion cardiovascular magnetic resonance (CMR), ischemic burden predicts adverse prognosis and is often used to guide revascularization. Ischemic scar tissue can cause stress perfusion defects that do not represent myocardial ischemia. Dark-blood late gadolinium enhancement (LGE) methods detect more scar than conventional bright-blood LGE, however, the impact on the myocardial ischemic burden estimation is unknown and evaluated in this study. Methods: Forty patients with CMR stress perfusion defects and ischemic scar on both dark-blood and bright-blood LGE were included. For dark-blood LGE, phase sensitive inversion recovery imaging with left ventricular blood pool nulling was used. Ischemic scar burden was quantified for both methods using >5 standard deviations above remote myocardium. Perfusion defects were manually contoured, and the myocardial ischemic burden was calculated by subtracting the ischemic scar burden from the perfusion defect burden. Results: Ischemic scar burden by dark-blood LGE was higher than bright-blood LGE (13.3 +/- 7.4% vs. 10.3 +/- 7.1%, p < 0.001). Dark-blood LGE derived myocardial ischemic burden was lower compared with bright-blood LGE (15.6% (IQR: 10.3 to 22.0) vs. 19.3 (10.9 to 25.5), median difference -2.0%, p < 0.001) with a mean bias of -2.8% (95% confidence intervals: -4.0 to -1.6%) and a large effect size (r = 0.62). Conclusion: Stress perfusion defects are associated with higher ischemic scar burden using dark-blood LGE compared with bright-blood LGE, which leads to a lower estimation of the myocardial ischemic burden. The prognostic value of using a dark-blood LGE derived ischemic burden to guide revascularization is unknown and warrants further investigation.

Background To assess the feasibility of biventricular SAPPHIRE T1 mapping in vivo across field strengths using diastolic, systolic and dark-blood (DB) approaches. Methods 10 healthy volunteers underwent same-day non-contrast cardiovascular magnetic resonance at 1.5 Tesla (T) and 3 T. Left and right ventricular (LV, RV) T1 mapping was performed in the basal, mid and apical short axis using 4-variants of SAPPHIRE: diastolic, systolic, 0th and 2nd order motion-sensitized DB and conventional modified Look-Locker inversion recovery (MOLLI). Results LV global myocardial T1 times (1.5 T then 3 T results) were significantly longer by diastolic SAPPHIRE (1283 ± 11|1600 ± 17 ms) than any of the other SAPPHIRE variants: systolic (1239 ± 9|1595 ± 13 ms), 0th order DB (1241 ± 10|1596 ± 12) and 2nd order DB (1251 ± 11|1560 ± 20 ms, all p 1 signal contamination (longer T1) at the blood-myocardial interface not seen with the other 3 SAPPHIRE variants (all p 1 times across the mid septum when compared to diastolic SAPPHIRE (interquartile ranges respectively: 25 ms, 71 ms, 73 ms vs 143 ms, all p 1 mapping was achievable using systolic, 0th and 2nd order DB SAPPHIRE but not with MOLLI or diastolic SAPPHIRE. All 4 SAPPHIRE variants showed excellent re-read reproducibility (intraclass correlation coefficients 0.953 to 0.996). Conclusion These small-scale preliminary healthy volunteer data suggest that DB SAPPHIRE has the potential to reduce partial volume effects at the blood-myocardial interface, and that systolic SAPPHIRE could be a feasible solution for right ventricular T1 mapping. Further work is needed to understand the robustness of these sequences and their potential clinical utility.

Diagnosis and management of multiple ventricular septal defects still remain a challenging task. Although many new diagnostic modalities have been used for the perioperative diagnosis of ventricular septal defects, the discovery of residual or additional shunts in the postoperative period is not uncommon. We report a case where we observed an undiagnosed additional ventricular septal defect shunting deoxygenated dark blood into the aortic root vent during deairing of the heart, which was confirmed on transesophageal echocardiography and addressed with reinstitution of cardiopulmonary bypass.

For almost 20 years, late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has been the reference standard for the non-invasive assessment of myocardial viability. Since the blood pool often appears equally bright as the enhanced scar regions, detection of subendocardial scar patterns can be challenging. Various novel LGE methods have been proposed that null or suppress the blood signal by employing additional magnetization preparation mechanisms. This review aims to provide a comprehensive overview of these dark-blood LGE methods, discussing the magnetization preparation schemes and findings in phantom, preclinical, and clinical studies. Finally, conclusions on the current evidence and limitations are drawn and new avenues for future research are discussed. Dark-blood LGE methods are a promising new tool for non-invasive assessment of myocardial viability. For a mainstream adoption of dark-blood LGE, however, clinical availability and ease of use are crucial.

ObjectivesFree-breathing 3-dimensional (3D) late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) techniques with high isotropic resolution and dark-blood contrast may optimize the delineation of myocardial scar patterns. The extended acquisition times required for such scans, however, are paralleled by a declining contrast agent concentration. Consequently, the optimal inversion time (TI) is continuously increasing. We hypothesize that a steadily increasing (dynamic) TI can compensate for this effect and can lead to improved blood nulling to optimize the dark-blood contrast. Materials and MethodsFifty consecutive patients with previous cardiac arrhythmias, scheduled for high-resolution 3D LGE MRI, were prospectively enrolled between October 2017 and February 2020. Free-breathing 3D dark-blood LGE MRI with high isotropic resolution (1.6 x 1.6 x 1.6 mm) was performed using a conventional fixed TI (n = 25) or a dynamic TI (n = 25). The average increase in blood nulling TI per minute was obtained from Look-Locker scans before and after the 3D acquisition in the first fixed TI group. This average increment in TI was used as input to calculate the dynamic increment of the initial blood nulling TI value as set in the second dynamic TI group. Regions of interest were drawn in the left ventricular blood pool to assess mean signal intensity as a measure for blood pool suppression. Overall image quality, observer confidence, and scar demarcation were scored on a 3-point scale. ResultsThree-dimensional dark-blood LGE data sets were successfully acquired in 46/50 patients (92%). The calculated average TI increase of 2.3 +/- 0.5 ms/min obtained in the first fixed TI group was incorporated in the second dynamic TI group and led to a significant decrease of 72% in the mean blood pool signal intensity compared with the fixed TI group (P < 0.001). Overall image quality (P = 0.02), observer confidence (P = 0.02), and scar demarcation (P = 0.01) significantly improved using a dynamic TI. ConclusionsA steadily increasing dynamic TI improves blood pool suppression for optimized dark-blood contrast and increases observer confidence in free-breathing 3D dark-blood LGE MRI with high isotropic resolution.

Recently developed dark-blood techniques such as Flow-Independent Dark-blood DeLayed Enhancement (FIDDLE) allow simultaneous visualization of tissue contrast-enhancement and blood-pool suppression. Critical to FIDDLE is the magnetization preparation, which accentuates differences between myocardium and blood-pool. Here, we compared magnetization transfer (MT)-preparation and T2-preparation for use with FIDDLE. Variants of FIDDLE were developed with MT- or T2-preparation modules and tested in 35 patients (11 at 1.5 T, 24 at 3 T). Images were acquired with each FIDDLE variant in an interleaved fashion 10 minutes after gadolinium administration with otherwise identical acquisition parameters. Images were visually and quantitatively assessed for artifacts and differences in right ventricle to left ventricle (RV-to-LV) blood-pool suppression. Bright artifacts, reflecting incomplete blood-pool suppression, were frequently observed in the left atrium with T2-preparation FIDDLE at 1.5 and 3 T (82% and up to 100% of patients, respectively). MT-preparation FIDDLE resulted in fewer patients with artifacts (0% at 1.5 T, 22% at 3 T; P < .01). Left atrial blood-pool signal was significantly more homogeneous with MT-preparation than with T2-preparation at 1.5 and 3 T (P < .001 for all comparisons). Visibly different RV-to-LV blood-pool suppression was observed with T2-preparation in 36% of patients at 1.5 T and up to 94% at 3 T. In these patients, RV blood-pool signal was elevated, reducing the conspicuity of the myocardial-RV blood-pool border. Conversely, there were no visible differences in RV-to-LV blood-pool suppression with MT-preparation. Quantitative assessment of differences in blood-pool suppression and blood-pool artifacts was consistent with visual analyses. We conclude that for dark blood-blood delayed-enhancement imaging of the heart, MT-preparation results in fewer bright blood-pool artifacts and more uniform blood-pool suppression than T2-preparation.

Background To compare the Self-referenced and Referenced measurement methods in assessing basilar artery (BA) atherosclerotic plaque employing dark blood high-resolution MRI at 3 Tesla. Methods Forty patients with > 20% stenosis as identified by conventional MRA were recruited and evaluated on a 3 Tesla MRI system. The outer wall, inner wall and lumen areas of maximal lumen narrowing site and the outer wall and lumen areas of sites that were proximal and distal to the maximal lumen narrowing site were manually traced. Plaque area (PA), stenosis rate (SR) and percent plaque burden (PPB) were calculated using the Self-referenced and Referenced measurement methods, respectively. To assess intra-observer reproducibility, BA plaque was measured twice with a 2-week interval in between measurements. Results Thirty-seven patients were included in the final analysis. There were no significant differences in PA, SR and PPB measurements between the two methods. The intra-class coefficients and coefficient of variations (CV) ranged from 0.976 to 0.990 and from 3.73 to 5.61% for the Self-referenced method and ranged from 0.928 to 0.971 and from 4.64 to 9.95% for the Referenced method, respectively. Both methods are effective in the evaluation of BA plaque. However, the CVs of the Self-referenced method is lower than the Referenced measurement method. Moreover, Bland-Altman plots showed that the Self-referenced method has a narrower interval than the Referenced measurement method. Conclusions The Self-referenced method is better and more convenient for evaluating BA plaque, and it may serve as a promising method for evaluation of basilar atherosclerotic plaque.

Background Conventional bright blood late gadolinium enhancement (bright blood LGE) imaging is a routine cardiovascular magnetic resonance (CMR) technique offering excellent contrast between areas of LGE and normal myocardium. However, contrast between LGE and blood is frequently poor. Dark blood LGE (DB LGE) employs an inversion recovery T2 preparation to suppress the blood pool, thereby increasing the contrast between the endocardium and blood. The objective of this study is to compare the diagnostic utility of a novel DB phase sensitive inversion recovery (PSIR) LGE CMR sequence to standard bright blood PSIR LGE. Methods One hundred seventy-two patients referred for clinical CMR were scanned. A full left ventricle short axis stack was performed using both techniques, varying which was performed first in a 1:1 ratio. Two experienced observers analyzed all bright blood LGE and DB LGE stacks, which were randomized and anonymized. A scoring system was devised to quantify the presence and extent of gadolinium enhancement and the confidence with which the diagnosis could be made. Results A total of 2752 LV segments were analyzed. There was very good inter-observer correlation for quantifying LGE. DB LGE analysis found 41.5% more segments that exhibited hyperenhancement in comparison to bright blood LGE (248/2752 segments (9.0%) positive for LGE with bright blood; 351/2752 segments (12.8%) positive for LGE with DB; p

BACKGROUND: For two decades, bright-blood late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has been considered the reference standard for the non-invasive assessment of myocardial viability. While bright-blood LGE can clearly distinguish areas of myocardial infarction from viable myocardium, it often suffers from poor scar-to-blood contrast, making subendocardial scar difficult to detect. Recently, we proposed a novel dark-blood LGE approach that increases scar-to-blood contrast and thereby improves subendocardial scar conspicuity. In the present study we sought to assess the clinical value of this novel approach in a large patient cohort with various non-congenital ischemic and non-ischemic cardiomyopathies on both 1.5 T and 3 T CMR scanners of different vendors.METHODS: Three hundred consecutive patients referred for clinical CMR were randomly assigned to a 1.5 T or 3 T scanner. An entire short-axis stack and multiple long-axis views were acquired using conventional phase sensitive inversion recovery (PSIR) LGE with TI set to null myocardium (bright-blood) and proposed PSIR LGE with TI set to null blood (dark-blood), in a randomized order. The bright-blood LGE and dark-blood LGE images were separated, anonymized, and interpreted in a random order at different time points by one of five independent observers. Each case was analyzed for the type of scar, per-segment transmurality, papillary muscle enhancement, overall image quality, observer confidence, and presence of right ventricular scar and intraventricular thrombus.RESULTS: Dark-blood LGE detected significantly more cases with ischemic scar compared to conventional bright-blood LGE (97 vs 89, p = 0.008), on both 1.5 T and 3 T, and led to a significantly increased total scar burden (3.3 ± 2.4 vs 3.0 ± 2.3 standard AHA segments, p = 0.015). Overall image quality significantly improved using dark-blood LGE compared to bright-blood LGE (81.3% vs 74.0% of all segments were of highest diagnostic quality, p = 0.006). Furthermore, dark-blood LGE led to significantly higher observer confidence (confident in 84.2% vs 78.4%, p = 0.033).CONCLUSIONS: The improved detection of ischemic scar makes the proposed dark-blood LGE method a valuable diagnostic tool in the non-invasive assessment of myocardial scar. The applicability in routine clinical practice is further strengthened, as the present approach, in contrast to other recently proposed dark- and black-blood LGE techniques, is readily available without the need for scanner adjustments, extensive optimizations, or additional training.

BACKGROUND: Late gadolinium enhancement (LGE) imaging was validated for diagnosis and quantification of myocardial infarction (MI). Despite good contrast between scar and normal myocardium, contrast between blood pool and myocardial scar can be limited. Dark blood LGE sequences attempt to overcome this issue. PURPOSE: To evaluate T1 rho (T1 ρ)-prepared dark blood sequence and compare to blood nulled (BN) phase sensitive inversion recovery (PSIR) and standard myocardium nulled (MN) PSIR for detection and quantification of scar. STUDY TYPE: Prospective. POPULATION: Thirty patients with prior MI. FIELD STRENGTH/SEQUENCE: Patients underwent identical 1.5 T MRI protocols. Following routine LGE imaging, a slice with scar, remote myocardium, and blood pool was selected. PSIR LGE was repeated with inversion time set to MN, to BN, and T1 ρ FIDDLE (flow-independent dark-blood delayed enhancement) in random order. ASSESSMENT: Three observers. Qualitative assessment of confidence scores in scar detection and degree of transmurality. Quantitative assessment of myocardial scar mass (grams), and contrast-to-noise ratio (CNR) measurements between scar, blood pool, and myocardium. STATISTICAL TESTS: Repeated-measures analysis of variance (ANOVA) with Bonferroni correction, coefficient of variation, and the Cohen κ statistic. RESULTS: CNRscar-blood was significantly increased for both BN (27.1 ± 10.4) and T1 ρ (30.2 ± 15.1) compared with MN (15.3 ± 8.4 P < 0.001 for both sequences). There was no significant difference in CNRscar-myo between BN (55.9 ± 17.3) and MN (51.1 ± 17.8 P = 0.512); both had significantly higher CNRscar-myo compared with the T1 ρ (42.6 ± 16.9 P = 0.007 and P = 0.014, respectively). No significant difference in scar size between LGE methods: MN (2.28 ± 1.58 g) BN (2.16 ± 1.57 g) and T1 ρ (2.29 ± 2.5 g). Confidence scores were significantly higher for BN (3.87 ± 0.346) compared with MN (3.1 ± 0.76 P < 0.001) and T1 ρ (3.20 ± 0.71 P < 0.001). DATA CONCLUSION: PSIR with inversion time (TI) set for blood nulling and the T1 ρ LGE sequence demonstrated significantly higher scar to blood CNR compared with routine MN. PSIR with TI set for blood nulling demonstrated significantly higher reader confidence scores compared with routine MN and T1 ρ LGE, suggesting routine adoption of a BN PSIR approach might be appropriate for LGE imaging. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

Background Delayed presentation of orbital trauma as an acute subperiosteal hematoma. Case report A 12-year-boy developed sudden painful abaxial proptosis of the left eyeball 15 days after blunt trauma over the forehead. On contrast-enhanced computed tomography, a heterogeneous, hypodense, non-enhancing mass with biconvex contour was seen adjacent to the orbital roof. Direct needle drainage was performed and about 10 mL dark blood was aspirated. Proptosis reduced immediately and resolved completely at 2 weeks follow-up. Why Should an Emergency Physician Be Aware of This? Sudden proptosis with no immediate history of trauma can be alarming for the emergency physician. Familiarity with this clinical entity and early drainage can decrease morbidity.

Purpose We aimed to evaluate the interscan, intraobserver, and interobserver reproducibility of basilar atherosclerotic plaque employing dark blood high-resolution magnetic resonance imaging (HR-MRI) at 3 Tesla. Methods Sixteen patients (14 males and 2 females) with > 30% basilar stenosis as identified by conventional magnetic resonance angiography were prospectively recruited for scan and rescan examinations on a 3 Tesla MRI system using T2-weighted turbo spin-echo protocol. Two observers independently measured the areas of vessels and lumens. Wall area was derived by subtracting the lumen area from the vessel area. Areas of vessels, lumens and walls were compared for the evaluation of interscan variability of basilar plaque. To assess the intraobserver variability, one observer reevaluated all the images of the first scan after a 4-week interval. Results Fourteen patients were included in the final analysis. No clinically significant difference was observed for interscan, intraobserver, and interobserver measurements. The intraclass correlations for vessel, lumen, and wall areas were excellent and ranged from 0.973 to 0.981 for the interscan measurements, 0.997 to 0.998 for the intraobserver measurements and 0.979 to 0.985 for the interobserver measurements. The coefficients of variation for quantitative basilar morphology measurements were 4.31%-10.35% for the interscan measurements, 1.41%-4.62% for the intraobserver measurements and 3.79%-8.46% for the interobserver measurements. Compared with the interscan and interobserver measurements, narrow intervals of the scatterplots were observed for the intraobserver measurements by Bland-Altman plots. Conclusion Basilar atherosclerotic plaque imaging demonstrates excellent reproducibility at 3 Tesla. The study proves that dark blood HR-MRI may serve as a reliable tool for clinical studies focused on the progression and treatment response of basilar atherosclerosis.

This study introduced and validated a novel flow-independent delayed enhancement technique that shows hyperenhanced myocardium while simultaneously suppressing blood-pool signal.The diagnosis and assessment of myocardial infarction (MI) is crucial in determining clinical management and prognosis. Although delayed enhancement cardiac magnetic resonance (DE-CMR) is an in vivo reference standard for imaging MI, an important limitation is poor delineation between hyperenhanced myocardium and bright LV cavity blood-pool, which may cause many infarcts to become invisible.A canine model with pathology as the reference standard was used for validation (n = 22). Patients with MI and normal controls were studied to ascertain clinical performance (n = 31).In canines, the flow-independent dark-blood delayed enhancement (FIDDLE) technique was superior to conventional DE-CMR for the detection of MI, with higher sensitivity (96% vs. 85%, respectively; p = 0.002) and accuracy (95% vs. 87%, respectively; p = 0.01) and with similar specificity (92% vs, 92%, respectively; p = 1.0). In infarcts that were identified by both techniques, the entire length of the endocardial border between infarcted myocardium and adjacent blood-pool was visualized in 33% for DE-CMR compared with 100% for FIDDLE. There was better agreement for FIDDLE-measured infarct size than for DE-CMR infarct size (95% limits-of-agreement, 2.1% vs. 5.5%, respectively; p 0.0001). In patients, findings were similar. FIDDLE demonstrated higher accuracy for diagnosis of MI than DE-CMR (100% [95% confidence interval [CI]: 89% to 100%] vs. 84% [95% CI: 66% to 95%], respectively; p = 0.03).The study introduced and validated a novel CMR technique that improves the discrimination of the border between infarcted myocardium and adjacent blood-pool. This dark-blood technique provides diagnostic performance that is superior to that of the current in vivo reference standard for the imaging diagnosis of MI.

We thank Dr Di Marco et al1 for their letter. We agree that contrast-enhanced multidetector computed tomography is excellent for noninvasively defining myocardial structure for electroanatomical map integration to determine, for example, the impact of epicardial fat.2 Myocardial tissue characterization by imaging, computed tomography (CT) and magnetic resonance imaging (MRI), provides insights into underlying activated disease pathways for focal fat and focal fibrosis in arrhythmogenic right ventricular cardiomyopathy (ARVC). How do they compare and how can they synergize? Contraindications to MRI include presence of implanted devices and it has lower resolution than CT, but new approaches are emerging. Third-generation late gadolinium enhancement techniques with motion correction are superior while dark blood techniques3 visualize …

Background: This study evaluates a novel dark-blood late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) method, without using additional magnetization preparation, and compares it to conventional bright-blood LGE, for the detection of ischaemic myocardial scar. LGE is able to clearly depict myocardial infarction and macroscopic scarring from viable myocardium. However, due to the bright signal of adjacent left ventricular blood, the apparent volume of scar tissue can be significantly reduced, or even completely obscured. In addition, blood pool signal can mimic scar tissue and lead to false positive observations. Simply nulling the blood magnetization by choosing shorter inversion times, leads to a negative viable myocardium signal that appears equally as bright as scar due to the magnitude image reconstruction. However, by combining blood magnetization nulling with the extended grayscale range of phase-sensitive inversion-recovery (PSIR), a darker blood signal can be achieved whilst a dark myocardium and bright scar signal is preserved.Methods: LGE was performed in nine male patients (63 +/- 11y) using a PSIR pulse sequence, with both conventional viable myocardium nulling and left ventricular blood nulling, in a randomized order. Regions of interest were drawn in the left ventricular blood, viable myocardium, and scar tissue, to assess contrast-to-noise ratios. Maximum scar transmurality, scar size, circumferential scar angle, and a confidence score for scar detection and maximum transmurality were also assessed. Bloch simulations were performed to simulate the magnetization levels of the left ventricular blood, viable myocardium, and scar tissue.Results: Average scar-to-blood contrast was significantly (p Conclusions: Nulling left ventricular blood magnetization for PSIR LGE leads to improved scar-to-blood contrast and increased expert confidence in scar detection and scar transmurality. As no additional magnetization preparation is used, clinical application on current MR systems is readily available without the need for extensive optimizations, software modifications, and/or additional training.

Purpose In multiple sclerosis (MS) the sensitivity for detection of contrast enhancing lesions (CEL) in T1-weighted scans is essential for diagnostics and therapy decisions. The purpose of our study was to evaluate the sensitivity of T1w MPRAGE scans in comparison to T1w dark blood technique (T1-DB) for CEL in MS. Materials and methods 3T MR imaging was performed in 37 MS patients, including T2-weighted imaging, T1w MPRAGE before and after gadolinium injection (unenhanced-T1 and T1-CE) and T1-DB imaging. After gadolinium application, the T1-DB scan was performed prior to T1-CE. From unenhanced-T1 and T1-CE scans, subtraction images (T1-SUB) were calculated. The number of CEL was determined separately on T1-CE and T1-DB by two raters independently. Lesions only detected on T1-DB scans then were verified on T1-SUB. Only lesions detected by both raters were included in further analysis. Results In 16 patients, at least one CEL was detected by both rater, either on T1-CE or T1-DB. All lesions that were detected on T1-CE were also detected on T1-DB images. The total number of contrast enhancing lesions detected on T1-DB images (n = 54) by both raters was significantly higher than the corresponding number of lesions identified on T1-CE (n = 27) (p = 0.01); all of these lesions could be verified on SUB images. In 21 patients, no CEL was detected in any of the sequences. Conclusions The application of T1-DB technique increases the sensitivity for CEL in MS, especially for those lesions that show only subtle increase in intensity after Gadolinium application but remain hypo- or iso-intense to surrounding tissue.

Background Bright blood late gadolinium enhancement (LGE) imaging typically achieves excellent contrast between infarcted and normal myocardium. However, the contrast between the myocardial infarction (MI) and the blood pool is frequently suboptimal. A large fraction of infarctions caused by coronary artery disease are sub-endocardial and thus adjacent to the blood pool. It is not infrequent that sub-endocardial MIs are difficult to detect or clearly delineate. Methods In this present work, an inversion recovery (IR) T2 preparation was combined with single shot steady state free precession imaging and respiratory motion corrected averaging to achieve dark blood LGE images with good signal to noise ratio while maintaining the desired spatial and temporal resolution. In this manner, imaging was conducted free-breathing, which has benefits for image quality, patient comfort, and clinical workflow in both adults and children. Furthermore, by using a phase sensitive inversion recovery reconstruction the blood signal may be made darker than the myocardium (i.e., negative signal values) thereby providing contrast between the blood and both the MI and remote myocardium. In the proposed approach, a single T1-map scout was used to measure the myocardial and blood T1 using a MOdified Look-Locker Inversion recovery (MOLLI) protocol and all protocol parameters were automatically calculated from these values within the sequence thereby simplifying the user interface. Results The contrast to noise ratio (CNR) between MI and remote myocardium was measured in n = 30 subjects with subendocardial MI using both bright blood and dark blood protocols. The CNR for the dark blood protocol had a 13 % loss compared to the bright blood protocol. The CNR between the MI and blood pool was positive for all dark blood cases, and was negative in 63 % of the bright blood cases. The conspicuity of subendocardial fibrosis and MI was greatly improved by dark blood (DB) PSIR as well as the delineation of the subendocardial border. Conclusions Free-breathing, dark blood PSIR LGE imaging was demonstrated to improve the visualization of subendocardial MI and fibrosis in cases with low contrast with adjacent blood pool. The proposed method also improves visualization of thin walled fibrous structures such as atrial walls and valves, as well as papillary muscles.

Background— T2-Weighted MRI reveals myocardial edema and enables estimation of the ischemic area at risk and myocardial salvage in patients with acute myocardial infarction (MI). We compared the diagnostic accuracy of a new bright-blood T2-weighted with a standard black blood T2-weighted MRI in patients with acute MI. Methods and Results— A breath-hold, bright-blood T2-weighted, Acquisition for Cardiac Unified T2 Edema pulse sequence with normalization for coil sensitivity and a breath-hold T2 dark-blood short tau inversion recovery sequence were used to depict the area at risk in 54 consecutive acute MI patients. Infarct size was measured on gadolinium late contrast enhancement images. Compared with dark-blood T2-weighted MRI, consensus agreements between independent observers for identification of myocardial edema were higher with bright-blood T2-weighted MRI when evaluated per patient ( P P P P Conclusions— Bright-blood T2-weighted MRI has higher diagnostic accuracy than dark-blood T2-weighted MRI. Additionally, dark-blood T2-weighted MRI may underestimate area at risk and myocardial salvage.

Delayed enhancement MRI using fast segmented k-space inversion recovery (IR) gradient-echo imaging is a well established "bright-blood" technique for identifying myocardial infarction and is used as the reference standard sequence in this study. The purpose of this study was to validate a recently developed dark blood-pool delayed enhancement technique in a porcine animal model, evaluate its performance in human patients, and quantify its performance compared with the reference standard in both.In an animal study, the reference standard and dark blood-pool delayed enhancement were assessed in three pigs with induced myocardial infarction. In a human study, 26 patients, 31-81 years old (19 men and seven women), with a known history of myocardial infarction were imaged using the reference standard and dark blood-pool delayed enhancement. Contrast-to-noise ratio (CNR), signal intensity ratio, signal-to-noise ratio (SNR), and qualitative scores of hyperenhancement were recorded. Measurements were compared using paired samples t test and Wilcoxon's signed rank test.In the animal study, the mean CNR of infarct to blood pool was 11 times higher for dark blood-pool delayed enhancement than for the reference standard. The mean SNR was 4.4 times higher for the reference standard. In the human study, the mean CNR and signal intensity ratio of hyperenhancing myocardium to the blood pool were 1.9 (p = 0.04) and 5.5 (p0.01) times higher, respectively, for dark blood-pool delayed enhancement compared with reference standard. The mean CNR and signal intensity ratio of hyperenhancing myocardium to normal myocardium and SNR were 2.8 (p0.01), 1.3 (p = 0.07), and 2.8 (p0.01) higher, respectively, for the reference standard. Qualitative analysis identified seven extra segments with grade 1 scars using dark blood-pool delayed enhancement (p0.01).Dark blood-pool delayed enhancement is complementary to the reference standard. It can detect more subendocardial foci of hyperenhancement, thus potentially identifying more infarcts and changing patient management.

PURPOSE To describe a new method for performing dark blood (DB) magnetization preparation in TrueFISP (bSSFP) and apply the technique to high-resolution carotid artery imaging. MATERIALS AND METHODS The developed method (HEFEWEIZEN) provides directional flow suppression, while preserving bSSFP contrast, by periodically applying spatial saturation in short repetition time (TR) TrueFISP. Steady-state free precession (SSFP) conditions are maintained throughout the acquisition for the imaging slice magnetization. HEFEWEIZEN was implemented on a 1.5 T scanner with standard receiver coils. Studies were performed in phantoms, eight asymptomatic volunteers, and two patients with low- and high-grade carotid artery stenosis. RESULTS Average flow suppression was 88% +/- 4% (arterial) and 85% +/- 3% (venous) in a multislice study. Stationary signal, contrast, and fine details were maintained with only slight signal suppression (11% +/- 11%). Comparison to diffusion-prepared SSFP in the common carotid artery demonstrated significant improvement in wall-lumen contrast-to-noise ratio efficiency (P = 0.024). DB contrast was achieved with only 13% increased acquisition time (14.3 sec). Further acceleration was possible by confining the DB preparation to the central 60% of k-space. CONCLUSION A fast, short TR, DB TrueFISP pulse sequence was developed and tested in the carotid arteries of asymptomatic volunteers and patients.

The purpose of this article is to review the MR principles of blood signal and normal flow-related phenomena seen in the aorta and inferior vena cava (IVC) on T2-weighted images of the abdomen and to discuss the physiologic and physical basis of signal alterations with breath-hold imaging. We define time-of-flight (TOF) loss and list the factors that affect it; explain the physiologic effects of breath-hold imaging on both aortic and IVC waveforms and velocity; state which abdominal T2 imaging techniques are most susceptible to variable TOF effects and explain why based on physiologic effects and MR principles; and describe three trouble-shooting techniques to confirm that unexpected signal does not reflect pathology.T2 images customarily result in TOF loss and dark blood signal. Abdominal MRI relies extensively on breath-hold imaging techniques that may alter markedly the flow velocity in normal vessels. This marked flow change results in signal heterogeneity and variable TOF loss especially with faster sequences filling k-space in shorter time frames. Breath-hold imaging decreases k-space fill time, and of the breath-hold T2 techniques, single-shot fast spin-echo decreases k-space fill time the most. Atypical blood signal during breath-hold imaging may mimic pathology, but abnormal findings can be verified by review of other sequences and planes of imaging.

The purpose of this study was to compare the performance of 3D diffusion-prepared balanced steady-state free precession (SSFP) imaging with that of 3D contrast-enhanced MR angiography in evaluation of the thoracic aorta.Twenty-one patients with indications for contrast-enhanced MR angiography and diffusion-prepared SSFP of the thoracic aorta were involved in this retrospective chart review study conducted with 1.5-T MRI. Two observers scored the quality of the contrast-enhanced MR angiographic and diffusion-prepared SSFP images on the basis of depicting the thoracic aorta. Image quality scores and diametric measurements of the aorta from both image sets were compared.Diametric measurements of the thoracic aorta showed a strong linear association (r = 0.971, p0.0001; regression line indifferent from line of equality, p0.05). The aortic root was better visualized with contrast-enhanced MR angiography (image quality score, 3.6 +/- 0.9 vs 3.0 +/- 0.8 of 5; p0.05); however, the aortic wall was better visualized with diffusion-prepared SSFP (image quality score, 4.4 +/- 0.6 vs 1.9 +/- 0.3 of 5; p0.0001).Three-dimensional diffusion-prepared SSFP yields better image quality than 3D contrast-enhanced MR angiography in evaluation of the thoracic aortic wall and appears to be a useful adjunct to 3D contrast-enhanced MR angiography for assessing aortic abnormalities before administration of a contrast agent.

The objective of this study was to develop and demonstrate a technique to eliminate venous enhancement in contrast-enhanced magnetic resonance lymphangiography through shortening T2 ⁎ in the blood pool, thus allowing for a lymphatic-only map. Administration of the blood-pool iron agent ferumoxtyol in addition to intracutaneous gadolinium during contrast-enhanced magnetic resonance lymphangiography allows for suppression of vascular structures to achieve venous-free lymphatic mapping.

This study demonstrates, in patients with 22q11.2 deletion, the wide variety of complex aortic arch anomalies that can be accurately defined by cardiac magnetic resonance imaging (MRI) compared with echocardiography. From May 1999 to August 2003, 17 of 68 patients (25%) with 22q11.2 deletion referred for cardiac evaluation required cardiac MRI, after echocardiography, to clarify aortic arch anatomy. Images of cardiac anatomy were obtained using steady-state free precession, half-Fourier acquired single turbo spin-echo dark blood sequences and gadolinium for 3-dimensional reconstruction. All MRI findings were abnormal, and in 16 of 17 cases, echocardiography was unable to define aortic arch anomalies correctly compared with MRI.

Purpose Three-dimensional (3D) dark-blood MRI has shown great potential in coronary artery plaque evaluation. However, substantial variability in quantification could result from superficial calcification because of its low signal. To address this issue, a 3D coronary dark-blood interleaved with gray-blood (cDIG) technique was developed. Methods cDIG is based on a balanced steady-state free precession readout combined with a local re-inversion-based double-inversion-recovery (LocReInv-DIR) preparation. The LocReInv-DIR is applied every two RR intervals. Dark-blood and gray-blood contrasts are collected in the first and second RR interval, respectively. To improve the respiratory gating efficiency, two independent navigators were developed to separately gate the respiratory motion for the two interleaved acquisitions. In vivo experiments in eight healthy subjects and one patient were conducted to validate the technique. Results cDIG provided dual-contrasts without compromise in scan time. The dark-blood images with cDIG demonstrated excellent wall and lumen signal performances and morphological measurements. Advantageously, cDIG yielded a second contrast that was shown to help identify the superficial calcification in the coronary plaque of a patient. Conclusion A novel technique was developed for obtaining 3D coronary vessel wall and gray lumen images. The additional contrast may aid in identifying calcified nodules and thus potentially improve the evaluation of coronary plaque burden. Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.

In this paper, we evaluate a recently proposed dual-phase dark-blood MR sequence for estimating the left ventricular ejection fraction, compare Simpson's method of estimation of ejection fraction with a model based on the biplane method, assess the reproducibility of both methods, and finally, test a semiautomated method for contouring the endocardial border.An MR pulse sequence was implemented to acquire cardiac images in both diastolic and systolic phases within a single breath-hold. A special magnetization preparation scheme rendered blood dark while a segmented acquisition allowed breath-hold scan times. Five healthy volunteers and five patients with cardiac disease were imaged. Ejection fractions were estimated using (1) long-axis and four-chamber biplane views with an ellipsoid model and (2) a series of short-axis views in combination with Simpson's model. These values of ejection fractions were then compared with values obtained from echocardiography.Estimates of ejection fractions obtained using biplane ellipsoid volume and Simpson's rule methods varied by 14% in healthy volunteers. However, for patients with severe cardiomyopathy, differences between the values of ejection fraction obtained with the two methods varied by as much as 150%. Ejection fraction estimates obtained from MR images with the biplane ellipsoid method and from echocardiography varied by approximately 14% for all subjects. Ejection fraction estimates obtained with the semiautomated algorithm agreed well with estimates obtained with manual contours made by experienced radiologists. Intraobserver variability was low for both the short-axis (3%) and biplane (4%) methods. However, interobserver variability of the biplane method (12%) exceeded that of the short-axis method (4%). Interexamination variability (9%) was the largest factor in determining the reproducibility of the ejection fraction estimates.Breath-hold dark-blood MR imaging technique with simultaneous acquisition of a series of short-axis views during systolic and diastolic phases permits rapid and accurate estimates of ejection fractions in healthy subjects and in patients. Model based biplane MR imaging methods are less reliable in patients with global cardiomyopathy. The estimation of ejection fractions can be automated using the proposed contouring algorithm and the dark-blood short-axis views.

To compare the effectiveness of dark blood (DB) versus bright blood (BB) sequences. To assess the intra and inter-observer variability and inter-study reproducibility between BB versus DB. To evaluate image quality level in the two sequences.In a setting of 138 patients we performed CMR using cardiac gated Gradient-multiecho single breath-hold BB and DB sequences in the middle ventricular septum. Each acquisition was repeated during the same exam. Truncation method was used to account for background noise. Image quality (IQ) was assessed using a 5 point grading scale and image analysis was conducted by 2 experienced observers.Compared with the conventional BB acquisition, the coefficient of correlation and significance of the DB technique was superior for intra-observer reproducibility (p0.001), inter-observer reproducibility (p0.001) and inter-study reproducibility (p0.001). The variability is also lower for DB sequences for T2* values14 ms. Assessment of artifacts showed a superior score for DB versus BB scans (4 versus 3, p0.001).Improvement in terms of inter observer and inter study variability using DB sequences was obtained. The greatest disparity between them was seen in inter-study reproducibility and higher IQ in DB was seen. Study demonstrates better performance of DB imaging compared to BB in presence of comparable effectiveness.

Purpose: To compare different state-of-the-art T2-weighted (T2w) imaging sequences combined with late gadolinium enhancement (LGE) for myocardial salvage area (MSA) assessment by cardiac magnetic resonance (CMR). T2w imaging has been used to assess the myocardial area at risk (AAR) in acute myocardial infarction (AMI) patients, but its clinical application is challenging due to technical and physical limitations. Materials and Methods: Thirty patients with reperfused AMI underwent complete CMR imaging 2–5 days after hospital admission. Myocardial AAR and MSA were quantified on four different T2w sequences: (a) free-breathing T2-prepared single-shot balanced steady-state free precession (T2p_ssbSSFP); (b) breathhold T2-weighted acquisition for cardiac unified T2 edema (ACUTE); (c) breathhold T2w dark-blood inversion recovery turbo-spin echo (IR-TSE) (short-term inversion recovery: STIR); and (d) free-breathing high-resolution T2 dark-blood navigated BLADE. The diagnostic performance of each technique was also assessed. Results: Quantitative analysis showed significant differences in myocardial AAR extent as quantified by the four T2w sequences (P < 0.05). There were also significant differences in sensitivity, specificity and overall diagnostic performance. Conclusion: Detection and quantification of AAR, and thus of MSA, by T2wCMR in reperfused AMI patients varied significantly between different T2w sequences in the same clinical setting. J. Magn. Reson. Imaging 2012;328-339. © 2011 Wiley Periodicals, Inc.

Purpose: To evaluate the use of a T2-weighted SPACE sequence (T2w-SPACE) to assess carotid stenosis via sev- eral methods and compare its performance with contrast- enhanced magnetic resonance angiography (ceMRA). Materials and Methods: Fifteen patients with carotid ath- erosclerosis underwent dark blood (DB)-MRI using a 3D turbo spin echo with variable ？ip angles sequence (T2w- SPACE) and ceMRA. Images were coregistered and eval- uated by two observers. Comparisons were made for lumi- nal diameter, luminal area, degree of luminal stenosis (NAS- CET: North American Symptomatic Endarterectomy Trial; ECST: European Carotid Surgery Trial, and area stenosis), and vessel wall area. Degree of NASCET stenosis was clini- cally classi？ed as mild (69%). Results: Excellent agreement was seen between ceMRA and T2w-SPACE and between observers for assessment of lumen diameter, lumen area, vessel wall area, and degree of NAS- CET stenosis (r > 0.80, P < 0.001). ECST stenosis was con- sistently higher than NASCET stenosis (48 6 14% vs. 24 6 22%, P < 0.001). Area stenosis (72 6 2%) was signi？cantly higher (P < 0.001) than both ESCT and NASCET stenosis. Conclusion: DB-MRI of carotid arteries using T2w-SPACE is clinically feasible. It provides accurate measurements of lumen size and degree of stenosis in comparison with ceMRA and offers a more reproducible measure of ECST stenosis than ceMRA.

A 6-month pregnant 35-year-old woman with hematemesis and dark blood in her stool was evaluated for location of an active gastrointestinal bleeding site. The findings from 2 esophagogastroduodenoscopies and a colonoscopy were negative. The patient was referred for a Tc-99m red blood cell scintigraphy, for location of an active bleeding site. As the patient was 6 months pregnant, the necessity of the case was discussed with the patient's referring physician and after determining that this study was necessary, the risk of radiation exposure to the fetus was discussed with the radiation safety officer and the patient. The procedure was performed after the patient signed informed consent regarding the considerations of radiation safety to the fetus. The Tc-99m red blood cell bleeding scan clearly shows activity in the fetus in addition to a large arteriovenous malformation in the patient. The visualized fetus prompted this report to discuss radiation risks concerns and a brief review of indications and guidelines for performing nuclear medicine procedures in pregnant patients.

The aim of this study was to assess the potential diagnostic value of three-dimensional T2-weighted imaging using the dark blood method for detecting pulmonary embolism (PE).Ten consecutive patients with already diagnosed acute PE (five men, five women; mean age 58.6 years, range 35-79 years) were prospectively enrolled in this study. All patients underwent lung magnetic resonance imaging (MRI) with a 1.5-T scanner. MRI was performed on the same day as CT angiography (CTA), which was undertaken to monitor treatment. Two radiologists performed a consensus evaluation of MRI followed by CTA on a per-vessel basis: the main pulmonary artery (PA), lobar PA, segmental PA, and subsegmental PA. Each modality was evaluated independently on separate days (at least 8 weeks apart). The accuracy of MRI for detecting PE was determined by comparing it with CTA results, which were used as a reference standard. Cohen's kappa analysis was used for statistical analyses.Among the 10 patients, pulmonary emboli were seen in 6 of 20 main arteries, 22 of 60 lobar arteries, 35 of 180 segmental arteries, and 8 of 410 subsegmental arteries on CTA. The sensitivities/specificities of MRI were 100%/100% for the main PA, 90.9%/97.3% for the lobar PA, and 74.2%/97.9% for the segmental PA, respectively. Altogether, 304 (83%) of 410 subsegmental arteries were not visualized on MRI and only 1 of the 8 emboli in the subsegmental branches was depicted. The kappa values for the main, lobar, and segmental arteries were 1.0, 0.89, and 0.77, respectively.Three-dimensional T2-weighted imaging using the dark blood method appears to be principally useful for diagnosing main, lobar, and segmental PEs.

Background Investigate a novel three-dimensional (3D) turbo spin echo (TSE) magnetic resonance imaging (MRI) sequence to assess stented segments in adults with congenital heart disease (CHD) after transcatheter intervention. Methods Adults with CHD referred for computed tomography (CT) after transcatheter intervention underwent MR exam with a 3D respiratory gated TSE sequence. Data obtained at the time of the study included type of CHD, radiation dose, length of time between exams, and luminal diameters of stented segments from each exam. Continuous variables were analyzed using Student'st and Bland–Altman plots performed to analyze measurements obtained from both examinations. Results Eleven patients underwent both examinations. Type of defects included coarctation of the aorta (n=6) and tetralogy of Fallot. Average radiation dose was 19.6mSv and average time between CT and MRI was 99±160days. Luminal diameters of stented vessels correlated closely between TSE MRI and CT (r 2 =.85) with a bias toward overestimation with MRI (mean 22.4±4.3mm and 20.9±3.7mm, p Conclusion This novel 3D respiratory gated TSE MR technique provides a feasible method to reduce metallic artifact and improve visualization of stented segments and surrounding anatomic structures without exposure to radiation.

Purpose To evaluate the feasibility of a multi-station three dimensional (3D) T1-weighted turbo spin echo (TSE) dark-blood Sampling Perfection with Application optimized Contrasts using different flip angle Evolution sequence (T1w-SPACE), to assess aorta, iliac, and superficial femoral (SFA) arteries (inflow vessels) by comparing it with a multi-station contrast enhanced MR angiography (CE-MRA) with identical resolution. Materials and Methods A total of 6 volunteers and 14 peripheral arterial disease (PAD) patients were included in the study. Abdominal and thigh T1w-SPACE and lower leg time-resolved MRA (TR-MRA) with low dose contrast were followed by 3-station CE-MRA. Quantitative measurements of lumen area at 17 locations from T1w-SPACE and CE-MRA were obtained. Additionally, vessel wall areas at the same locations were obtained from the T1w-SPACE images. Results Quantitative comparison of lumen areas with T1w-SPACE and CE-MRA revealed strong correlation between the two techniques and strong inter-observer agreement for each of the two imaging methods (r > 0.9; P < 0.001). Localized vessel wall area measurements obtained in PAD patients were significantly greater compared with those obtained in normal volunteers (mean difference 43.75 ± 12.46 mm2; P < 0.001). Stenosis severity obtained from T1w-SPACE localized measurements showed significant arterial area stenosis in PAD patients. Conclusion T1w-SPACE imaging of inflow vessels is feasible, and in addition to CE-MRA has the ability to assess atherosclerotic plaque and vascular remodeling. J. Magn. Reson. Imaging 2009;30:785–793. © 2009 Wiley-Liss, Inc.

The evaluation of myocardium characterization is an important role in cardiac MRI. The dark-blood (DB) sequence is used for non-enhanced T2-weighted myocardial images. The purpose of this study was to evaluate and optimize the DB T2WI sequence in myocardium images. We changed the parameters TE, echo train length (ETL), inversion time (TI), and fat suppression method, respectively. Data acquisition with end-diastolic phase was effective for avoiding the blur that was caused by cardiac motion. Consequently, the optimal setting of ETL and TI was important for myocardial images. STIR was suitable for fat suppression in unstable susceptibility. Setting the parameters synchronized with the cardiac cycle provided optimal myocardial images in DB T2WI.

Objective To describe the successful laparoscopic management of an omental pregnancy. Design Case report. Setting University of Schleswig-Holstein, Campus Luebeck, Department of Gynecology and Obstetrics. Patient(s) A 25-year-old patient with an omental pregnancy. Intervention(s) Laparoscopic partial omentectomy. Main Outcome Measure(s) Successful laparoscopic management of an omental pregnancy. Result(s) A 25-year-old woman reported having abdominal pain. Her urine pregnancy test was positive. She had been using an intrauterine copper device for a period of 2.5 years. Gynecologic examination revealed normal results, in the uterus and fallopian tubes especially, where no signs of pregnancy were found through clinical and sonographic examination. Because the patient had had increasing pain, a laparoscopy was performed. There was approximately 500 mL of dark blood found in the cul de sac. The uterus and fallopian tubes appeared normal and without any signs of pregnancy. However, there was a cavity detected in the omentum majus. A partial omentectomy then was performed laparoscopically. An omental pregnancy was confirmed by β-hCG–positive trophoblast cells in the omentum majus. Conclusion(s) Omental pregnancy can be rather difficult to identify. If there is no evidence of tubal pregnancy, laparoscopy may help to confirm the diagnosis of omental pregnancy and simultaneously offer minimal invasive therapy.

Purpose To compare two multislice turbo spin-echo (TSE) carotid artery wall imaging techniques at 1.5 T and 3.0 T, and to investigate the feasibility of higher spatial resolution carotid artery wall imaging at 3.0 T. Materials and Methods Multislice proton density-weighted (PDW), T2-weighted (T2W), and T1-weighted (T1W) inflow/outflow saturation band (IOSB) and rapid extended coverage double inversion-recovery (REX-DIR) TSE carotid artery wall imaging was performed on six healthy volunteers at 1.5 T and 3.0 T using time-, coverage-, and spatial resolution–matched (0.47 × 0.47 × 3 mm3) imaging protocols. To investigate whether improved signal-to-noise ratio (SNR) at 3.0 T could allow for improved spatial resolution, higher spatial resolution imaging (0.31 × 0.31 × 3 mm3) was performed at 3.0 T. Carotid artery wall SNR, carotid lumen SNR, and wall-lumen contrast-to-noise ratio (CNR) were measured. Results Signal gain at 3.0 T relative to 1.5 T was observed for carotid artery wall SNR (223%) and wall-lumen CNR (255%) in all acquisitions (P < 0.025). IOSB and REX-DIR images were found to have different levels of SNR and CNR (P < 0.05) with IOSB values observed to be larger. Normalized to a common imaging time, the higher spatial resolution imaging at 3.0 T and the lower spatial resolution imaging at 1.5 T provided similar levels of wall-lumen CNR (P = NS). Conclusion Multislice carotid wall imaging at 3.0 T with IOSB and REX-DIR benefits from improved SNR and CNR relative to 1.5 T, and allows for higher spatial resolution carotid artery wall imaging. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.

UNLABELLED: Magnetic resonance imaging (MRI) is uniquely suited to study the pathophysiology of arteriosclerosis. So far, magnetic resonance (MR) measurements of vessel dimensions have mainly been done by manual tracing of vessel wall contours. However, such data postprocessing is very time-consuming and has limited accuracy due to difficulties in precise tracing of the thin vessel wall. PURPOSE: To assess the accuracy and reproducibility of quantitative vascular MR imaging applying a data analysis method based on (1) vessel wall unwrapping, followed by (2) a gradient detection algorithm for MR data postprocessing. Vascular MR imaging studies were done both in vessel phantoms and in healthy volunteers (n=29) on a clinical 1.5 T MR scanner. A dark blood double-inversion turbo spin echo sequence with fat suppression was applied, with proton-density-weighted and breath-hold acquisition for aortic imaging and T2-weighted acquisition for carotid imaging. Intraobserver and interobserver variability were systematically evaluated by two independent observers. A repeat study within 10 days of the first MRI was performed in 10 of these subjects for assessment of interstudy reproducibility. RESULTS: The semiautomated edge detection software revealed a clear view of the inner and outer vessel wall boundaries both in the phantoms and in the volunteers studied. There was close agreement between MR-derived measurements and phantom dimensions (mean difference of 1.1+/-16.9 mm2, 8.0+/-19.9 mm2, 9.0+/-12.1 mm2 for vessel wall cross-sectional area, inner vessel area, and total vessel area, respectively). Quantification of vessel dimensions was feasible in all 29 healthy volunteers studied. Semiautomated quantification of cross-sectional vessel wall area (mean+/-SD, 253.6+/-208.4 mm2) revealed close correlation for repeated measurements by one or two observers (r=0.99 each). Both intraobserver and interobserver variability of vessel wall area MR measurements were low (mean difference 7.5+/-16.7 mm2 and 14.4+/-24.6 mm2 , respectively). In the repeat study of 10 volunteers, MRI with semiautomated postprocessing quantitation revealed a high correlation and agreement of vessel dimensions between the two scans (r=0.994, mean difference 2.6+/-25.1 mm2). CONCLUSION: Semiautomated analysis methods can provide approaches that benefit from the human understanding of the image and the computer's ability to measure precisely and rapidly. Thus, by combining the latest MRI methods and semiautomated image analysis methods, we are now able to reproducibly determine the geometric parameters of blood vessels.

We describe a time of flight subtraction method for cine MR angiography that provides nearly perfect suppression of background signal intensity with excellent flow contrast. The method consists of a preparation phase, during which the longitudinal magnetization of the target tissue is inverted on alternate acquisitions and the background tissue is presaturated, followed by a readout phase using a cine segmented turboFLASH sequence with a shared echo modification to improve temporal resolution. With appropriate alternation of the phases of the radiofrequency excitation pulses, there is cancellation of the background signal intensity but flow signal is optimized. By using a thick section (up to 25 mm), substantial portions of the vascular territory are encompassed in a single plane. This permits rapid, dynamic assessment of flow patterns in areas such as the circle of Willis, carotid bifurcation, or renal arteries. Applications of the method for bright and dark blood cine MR angiography are demonstrated.

A healthy 29-year-old woman presented at 20 weeks’ gestation with a 3-week history of a paracentral scotoma in her right eye. Visual acuity was 20/20 in both eyes. Fundus examination of the right eye showed a mass of numerous, grape-like, aneurysms filled with dark blood along the optic disc. White fibroglial tissue covered the surface. A triangular haemorrhage was observed in the macular area, under the internal limiting membrane, and stopping just at the …