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1.  Postradiation imaging changes in the CNS: how can we differentiate between treatment effect and disease progression? 
Future oncology (London, England)  2014;10(7):1277-1297.
A familiar challenge for neuroradiologists and neuro-oncologists is differentiating between radiation treatment effect and disease progression in the CNS. Both entities are characterized by an increase in contrast enhancement on MRI and present with similar clinical signs and symptoms that may occur either in close temporal proximity to the treatment or later in the disease course. When radiation-related imaging changes or clinical deterioration are mistaken for disease progression, patients may be subject to unnecessary surgery and/or a change from otherwise effective therapy. Similarly, when disease progression is mistaken for treatment effect, a potentially ineffective therapy may be continued in the face of progressive disease. Here we describe the three types of radiation injury to the brain based on the time to development of signs and symptoms – acute, subacute and late – and then review specific imaging changes after intensity-modulated radiation therapy, stereotactic radiosurgery and brachytherapy. We provide an overview of these phenomena in the treatment of a wide range of malignant and benign CNS illnesses. Finally, we review the published data regarding imaging techniques under investigation to address this well-known problem.
PMCID: PMC4325371  PMID: 24947265
pseudoprogression; radiation treatment effect; radionecrosis; radiosurgery
2.  Axial Black Blood Turbo Spin Echo Imaging of the Right Ventricle 
Black blood turbo spin echo (TSE) imaging of the right ventricle (RV) free wall is highly sensitive to cardiac motion, frequently resulting in non-diagnostic images. Temporal and spatial parameters of a black blood TSE pulse sequence were evaluated for visualization of the RV free wall. 74 patient studies were retrospectively evaluated for the effects of acquisition timing on image quality. Axial black blood TSE images were acquired on 10 healthy volunteers to assess the role of spatial misregistration on right ventricle visualization; increasing the double inversion recovery (DIR) slice thickness beyond 300% had no effect on image quality (p=0.2). 35 patient studies were prospectively evaluated with inversion times (TIs) corresponding to the mid-diastolic rest period and end-systole based on visual analysis of a four chamber cine. When TIs were chosen to be within the patients’ RV rest period, mean image quality score was significantly improved (2.3 vs. 1.86, p<0.001) and the number of clinically diagnostic images increased from 32% to 46%. Black blood TSE imaging of the RV free wall is highly sensitive to cardiac motion. Image quality can be improved by choosing TIs concordant with the rest period of the patient’s RV that may occur at mid-diastole or end-systole.
PMCID: PMC4301616  PMID: 19165884
cardiac MRI; black blood; turbo spin echo; right ventricle
3.  Left Ventricular Structure and Function by Cardiac Magnetic Resonance Imaging in Rheumatoid Arthritis 
Arthritis and rheumatism  2010;62(4):940-951.
Heart failure is a major contributor to cardiovascular morbidity and mortality in rheumatoid arthritis. However, little is known about myocardial structure and function in this population.
Using cardiac magnetic resonance imaging, measures of myocardial structure and function were assessed in men and women with rheumatoid arthritis enrolled in ESCAPE RA, a cohort study of subclinical cardiovascular disease in rheumatoid arthritis, and compared with controls without rheumatoid arthritis enrolled in the Baltimore cohort of the Multi-Ethnic Study of Atherosclerosis.
Myocardial measures were compared between 75 rheumatoid arthritis patients and 225 matched controls. After adjustment, mean left-ventricular mass was 26 grams lower for the RA group compared to controls (p<0.001), an 18% difference. After similar adjustment, mean left-ventricular ejection fraction, cardiac output, and stroke volume were modestly lower in the rheumatoid arthritis group vs. controls. Mean left-ventricular end-systolic and end-diastolic volumes did not differ by rheumatoid arthritis status. Within the rheumatoid arthritis group, higher levels of anti-CCP antibodies and current use of biologics, but not other disease activity or severity measures, were associated with significantly lower adjusted mean left-ventricular mass, end-diastolic volume, and stroke volume, but not ejection fraction. The combined associations of anti-CCP antibody level and biologic use on myocardial measures were additive, without evidence of interaction.
These findings suggest that the progression to heart failure in RA may occur through reduced myocardial mass rather than hypertrophy. Both modifiable and non-modifiable factors may contribute to lower levels of left-ventricular mass and volume.
PMCID: PMC3008503  PMID: 20131277
myocardial dysfunction; heart failure; inflammation; cardiac imaging
4.  Coronary Vessel Wall Evaluation by Magnetic Resonance Imaging in the Multi-Ethnic Study of Atherosclerosis: Determinants of Image Quality 
Coronary artery wall magnetic resonance imaging (MRI) has been developed to assess coronary lumen diameter and wall thickness. The purpose of this study was to evaluate the physiological parameters that affect the measures of coronary wall thickness using black-blood MRI pulse sequences.
Eighty-seven participants (38 men and 49 women) of the Multi-Ethnic Study of Atherosclerosis were enrolled in the coronary artery wall MRI study. Cine 4-chamber imaging was used to determine the coronary artery rest period. Free-breathing whole-heart magnetic resonance angiography with motion adaptor navigator was performed to localize the coronary arteries in 64 participants. Cross-sectional free-breathing black-blood images were acquired using electrocardiogram-gated, turbo spin echo sequence. Imaging parameters were as follows: repetition time = 2 R-R intervals, time to echo = 33 milliseconds, echo train length = 13, bandwidth = 305 Hz/pixel, matrix = 416 × 416, field of view = 420 × 420 mm, and slice thickness = 4 to 5 mm.
Imaging was completed in 215 (92%) of 234 coronary segments; 9 participants had incomplete scans. Mean age was 62.6 ± 8.4 years (range, 45–81 years). Mean body mass index was 29.2 ± 5.9 kg/m2. A higher proportion of images with quality of “good” was seen in the right coronary artery (40.5%) compared to the left main and left anterior descending coronary arteries (31.9% and 26.4%, respectively). There was a very good agreement between observers in the image quality scores (κ = 0.79, P < 0.001). Lower heart rate, male sex, and longer coronary rest period were associated with higher image quality score (P < 0.05). Signal-to-noise ratio was higher in participants with Agatston calcium score of more than 10 in the right coronary and left main arteries (48.5 vs 69.7, P = 0.001; and 53.4 vs 61.6, P = 0.032, respectively).
Improved depiction of the coronary artery wall with MRI is related to coronary rest period and atherosclerotic plaque burden as measured by calcium score and inversely related to heart rate. Because longer coronary artery rest periods are associated with improved image quality both for angiography with MRI and coronary artery wall imaging, heart rate–lowering methods in association with these techniques appear to be a logical application.
PMCID: PMC3037090  PMID: 19188777
coronary; magnetic resonance imaging; image quality; MRI; cardiac
5.  MRI detects increased coronary wall thickness in asymptomatic individuals: The Multi-Ethnic Study of Atherosclerosis (MESA) 
To evaluate the use of coronary wall MRI as a measure of atherosclerotic disease burden in an asymptomatic population free of clinical cardiovascular disease.
Coronary wall magnetic resonance imaging (MRI) is a noninvasive method for evaluation of arterial wall remodeling associated with atherosclerosis.
Materials and Methods
Asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis (MESA) study were studied using black blood MRI. MRI assessed coronary wall thickness was compared to computed tomography calcium score, carotid intimal-medial thickness and risk factors for coronary artery disease.
Eighty eight arterial segments were evaluated in 38 MESA participants (mean age, 61.3 ± 8.7 years). The maximum coronary wall thickness was greater for participants with 2 or more cardiovascular risk factors than for those with 1 or no risk factors (2.59 ± 0.33 mm versus 2.36 ± 0.30 mm, respectively, p=0.05.) For participants with zero calcium score, the mean and maximum coronary wall thickness for subjects with 2 or more risk factors for coronary artery disease were greater than the wall thickness for subjects with 1 or no risk factors (mean thickness: 1.95 ± 0.17 mm versus 1.7 ± 0.19 mm; maximum thickness: 2.67 ± 0.24 mm versus 2.32 ± 0.27 mm, respectively, p <0.05). Subjects with increased carotid intimal-medial thickness also had increased coronary artery wall thickness (p< 0.05).
Coronary artery wall MRI detects increased coronary wall thickness in asymptomatic individuals with subclinical markers of atherosclerotic disease and in individuals with zero calcium score.
PMCID: PMC2577717  PMID: 18837001
coronary artery disease; atherosclerosis; MRI; plaque
6.  Relation of Aortic Wall Thickness and Distensibility to Cardiovascular Risk Factors (From the Multi-Ethnic Study of Atherosclerosis [MESA]) 
The American journal of cardiology  2008;102(4):491-496.
To determine the relationship between aortic wall thickness (WT) and distensibility with traditional cardiovascular risk factors in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort; 1053 participants of the MESA study with cardiac MRI were consecutively selected for measurement of aortic wall thickness and distensibility. Double inversion recovery fast spin echo images of the thoracic aorta were obtained to measure average and maximum WT. Aortic distensibility (AD) was measured at the same level using a gradient echo cine sequence. Both average and maximum WT were positively correlated with increasing age, and AD was inversely related to age (p<0.01). Compared to normotensive participants, those with hypertension had significantly greater mean average WT (2.45 mm vs. 2.23 mm, p<0.01), maximum WT (3.61 mm vs. 3.41 mm, p<0.01) and lower AD (0.15 vs. 0.2 mm Hg−1, p<0.01), respectively. In multiple regression analysis, older age and hypertension were significantly associated with higher mean average WT, while older age, male gender, and higher blood pressure were associated with higher mean maximum WT. AD was inversely related to older age, hypertension, current smoker status, African-American ethnicity and lower HDL-cholesterol (HDL-c) levels. In conclusion, in the MESA cohort, older age and higher blood pressure were associated with higher aortic wall thickness and lower aortic distensibilility. Decreased aortic distensibility was further associated with current smoking, African American ethnicity and higher HDL-c levels.
PMCID: PMC2586608  PMID: 18678312
7.  Cardiac Cine MRI: Quantification of the Relationship Between Fast Gradient Echo and Steady-State Free Precession for Determination of Myocardial Mass and Volumes 
To determine the correlation function between the steady-state free precession (SSFP) and fast gradient echo (FGRE) cine MRI pulse sequences for measuring the myocardial mass and volumes.
Materials and Methods
Cardiac cine MRI examinations were acquired in 50 individuals (female: 35, male: 15, mean age 64.1 ± 9.1 years, range 48–83) using SSFP and FGRE cardiac pulse sequences.
The mean (standard deviation [SD]) left ventricular end diastolic volume measured by SSFP was significantly larger (4.5%) than by FGRE (p < 0.001); this was also the case for end systolic volume (15.0%, p < 0.001). The relationship between SSFP and FGRE measures were linear and highly correlated (p < 0.001) for both left ventricular end diastolic and end systolic volumes (r2 = 0.90 vs. 0.91, respectively). We determined linear regression models to estimate the SSFP values based on the FGRE measures. Slope (intercept) for ejection fraction, stroke volume, and cardiac output were 0.99 (−2.79), 0.77 (17.5), and 0.76 (1.29), respectively.
Linear relationships exist for key LV function parameters when comparing SSFP and FGRE cine MRI. These results indicate that existing databases and normal values for FGRE LV function may be converted to corresponding LV function values for SSFP MRI.
PMCID: PMC2671062  PMID: 18581356
magnetic resonance imaging; normal cardiac function; steady state free precession; fast gradient echo

Results 1-7 (7)