Faculty Bibliography

PURPOSE: To determine if pretreatment apparent diffusion coefficient (ADC) of leiomyomas could predict volumetric response (VR) following uterine artery embolization (UAE). MATERIALS AND METHODS: We retrospectively studied 11 women who underwent pelvic MRI before and >120 days following UAE. MRI included conventional and diffusion weighted imaging sequences. Percentage change in leiomyoma volume was determined by multiplanar T2-weighted imaging. A Pearson correlation coefficient was calculated between leiomyoma VR following UAE and the following pre-embolization parameters: initial volume, relative enhancement, relative T2 signal intensity (SI) and ADC. Receiver operating characteristic (ROC) curve analysis was used to determine the sensitivity and specificity of ADC for predicting volumetric response. RESULTS: Twenty-eight leiomyomas were included with a mean interval from UAE to follow-up MRI of 207 days. The preprocedural volume of the leiomyomas ranged from 18 to 182 cm(3) (median 47 cm(3)). and ADC ranged from 0.37 to 1.71 mm(2)/s (mean 0.80 mm(2)/s). All leiomyomas were 100% necrotic following UAE. Leiomyoma VR following UAE was 48% +/- 3.5%. with significant correlation between VR and ADC (r = 0.41; P = 0.017) but no correlation with initial leiomyoma volume, relative T2 SI, or relative enhancement. Using a threshold of 0.875 x 10(-3) mm(2)/s, ADC could predict > 50% VR with sensitivity and specificity of 70% and 83%, respectively. CONCLUSION: Pre-UAE ADC of leiomyomas correlated significantly with percent VR following UAE. In contrast, no correlation was seen between VR post-UAE and conventional imaging findings. This suggests that VR following UAE depends on leiomyoma histology reflected in DWI rather than features revealed by conventional MRI

Non-human primates are often used as preclinical model systems for (mostly diffuse or multi-focal) neurological disorders and their experimental treatment. Due to cost considerations, such studies frequently utilize non-destructive imaging modalities, MRI and proton MR spectroscopy ((1) H MRS). Cost may explain why the inter- and intra-animal reproducibility of the (1) H MRS observed brain metabolites, are not reported. To this end, we performed test-retest three-dimensional brain (1) H MRS in five healthy rhesus macaques at 3 T. Spectra were acquired from 224 isotropic (0.5 cm)(3) = 125 muL voxels, over 28 cm(3) ( approximately 35%) of the brain, then individually phased, frequency aligned and summed into a spectrum representative of the entire volume of interest. This dramatically increases the metabolites' signal-to-noise ratios, while maintaining the (narrow) voxel linewidth. The results show that the average N-acetylaspartate, creatine, choline, and myo-inositol concentrations in the macaque brain are: 7.7 +/- 0.5, 7.0 +/- 0.5, 1.2 +/- 0.1 and 4.0 +/- 0.6 mM/g wet weight (mean +/- standard deviation). Their inter-animal coefficients of variation (CV) are 4%, 4%, 6%, and 15%; and the longitudinal (intra-animal) CVs are lower still: 4%, 5%, 5%, and 4%, much better than the 22%, 33%, 36%, and 45% intra-voxel CVs, demonstrating the advantage of the approach and its utility for preclinical studies of diffuse neurological diseases in rhesus macaques. Magn Reson Med, 2011. (c) 2011 Wiley-Liss, Inc

Diabetic patients with coronary artery disease (CAD) are more likely to develop heart failure (HF) than nondiabetic patients, but the mechanism responsible is unclear. Evidence suggests that infarct size and accompanying remodeling may not explain this difference. We used cardiac magnetic resonance (CMR) imaging to compare degree of left ventricular (LV) myocardial scar and remodeling in diabetic and nondiabetic patients with CAD. We evaluated 85 patients (39 diabetic, 46 nondiabetic) who underwent coronary angiography showing obstructive CAD and CMR imaging within 6 months of each other. Myocardial scar was measured by late gadolinium enhancement on CMR imaging and was graded according to spatial and transmural extents on a semiquantitative scale. More diabetic than nondiabetic patients had HF (69% vs 43%, p <0.03); however, groups did not differ in total scar burden (0.94 +/- 0.60 vs 1.17 +/- 0.74, p = NS), spatial extent of scar, or extent of transmural scar. Diabetes remained an independent predictor of HF after adjustment for CAD and other variables. LV ejection fraction (36 +/- 12% vs 37 +/- 14%, p = NS) and end-diastolic volume (215 +/- 56 vs 217 +/- 76 ml, p = NS) were similar for diabetic and nondiabetic patients, respectively. In conclusion, although diabetic patients with CAD had a higher prevalence of HF than nondiabetic patients, there was no difference in myocardial scar, LV volume, or LV ejection fraction. These findings support the theory that mechanisms other than extent of myocardial injury and negative remodeling play a significant role in the development of HF in diabetic patients with CAD

OBJECTIVE: : Jugular bulb (JB) abnormalities such as JB diverticulum and high-riding JBs of the temporal bone can erode into the inner ear and present with hearing loss, vestibular disturbance, and pulsatile tinnitus. Their cause and potential to progress remain to be studied. This comprehensive radiologic study investigates the postnatal development of the venous system from transverse sinus to internal jugular vein (IJV). SETTING: : Academic medical center. PATIENTS, INTERVENTION, MAIN OUTCOME MEASURE:: Measurements of the transverse and sigmoid sinus, the JB, IJV, and carotid artery were made from computed tomographic scans of the neck with intravenous contrast in infants (n = 5), children (n = 13), adults (n = 35), and the elderly (n = 15). RESULTS: : Jugular bulbs were not detected in patients younger than 2 years, enlarged in adulthood, and remained stable in the elderly. The venous system was larger in men than in women. From transverse sinus to IJV, the greatest variation in size was just proximal and distal to the JB with greater symmetry observed as blood returned to the heart. Right-sided venous dominance was most common occurring in 70% to 80% of cases. CONCLUSION: : The JB is a dynamic structure that forms after 2 years, and its size stabilizes in adulthood. The determinants in its exact position and size are multifactorial and may be related to blood flow. Improved understanding of this structure's development may help to better understand the cause of the high-riding JB and JB diverticulum, both of which may cause clinical symptoms

OBJECTIVE: The objective of our study was to evaluate the diagnostic utility of conventional radiography for diagnosing bisphosphonate-related atypical subtrochanteric femoral fractures. MATERIALS AND METHODS: Retrospective interpretation of 38 radiographs of complete subtrochanteric and diaphyseal femoral fractures in two patient groups-one group being treated with bisphosphonates (19 fractures in 17 patients) and a second group not being treated with bisphosphonates (19 fractures in 19 patients)-was performed by three radiologists. The readers assessed four imaging criteria: focal lateral cortical thickening, transverse fracture, medial femoral spike, and fracture comminution. The odds ratios and the sensitivity, specificity, and accuracy of each imaging criterion as a predictor of bisphosphonate-related fractures were calculated. Similarly, the interobserver agreement and the sensitivity, specificity, and accuracy of diagnosing bisphosphonate-related fractures (i.e., atypical femoral fractures) were determined for the three readers. RESULTS: Among the candidate predictors of bisphosphonate-related fractures, focal lateral cortical thickening and transverse fracture had the highest odds ratios (76.4 and 10.1, respectively). Medial spike and comminution had odd ratios of 3.8 and 0.63, respectively. Focal lateral cortical thickening and transverse fracture were also the most accurate factors for detecting bisphosphonate-related fractures for all readers. The sensitivity, specificity, and overall accuracy for diagnosing bisphosphonate-related fractures were 94.7%, 100%, and 97.4% for reader 1; 94.7%, 68.4%, and 81.6% for reader 2; and 89.5%, 89.5%, and 89.5% for reader 3, respectively. The interobserver agreement was substantial (kappa > 0.61). CONCLUSION: Radiographs are reliable for distinguishing between complete femoral fractures related to bisphosphonate use and those not related to bisphosphonate use. Focal lateral cortical thickening and transverse fracture are the most dependable signs, showing high odds ratios and the highest accuracy for diagnosing these fractures

Purpose: To test the hypothesis that anterior cingulate cortex (ACC) subregions in patients with schizophrenia are metabolically different from those in healthy control subjects. Materials and Methods: This institutional review board-approved study was HIPAA compliant, and all participants provided written informed consent. Twenty-two patients with schizophrenia (13 male, nine female; 39.4 years +/- 10.6 [standard deviation]) and 11 age- and sex-matched control subjects (seven male, four female; 35.5 years +/- 10.7) underwent magnetic resonance (MR) imaging and three-dimensional 3-T voxel proton MR spectroscopy to measure absolute rostral and caudal ACC N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) concentrations. Exact Mann-Whitney test was used to compare patient data with control data, paired-sample Wilcoxon signed rank test was used to compare subregions within groups, and receiver operating characteristic curve analysis was used to assess sensitivity and specificity in diagnosis of schizophrenia. Results: There were no significant metabolic differences between patients and control subjects or between ACC subregions in control subjects. In patients, rostral ACC NAA and Cr concentrations were significantly lower than those in caudal ACC (6.2 mM +/- 1.3 vs 7.1 mM +/- 1.3, P < .01; 5.7 mmol/L +/- 1.4 vs 6.3 mmol/L +/- 1.6, P < .01; respectively); however, this did not hold true for Cho concentrations (1.7 mmol/L +/- 0.5 vs 1.8 mmol/L +/- 0.5). For individual differences between caudal and rostral measurements, only NAA in patients was different from that in control subjects (0.9 mmol/L +/- 1.3 vs -0.1 mmol/L +/- 0.5, P < .01), enabling prediction of schizophrenia with 68% sensitivity and 91% specificity, for a difference of more than 0.4. Conclusion: Significant differences between caudal and rostral NAA concentration are found in ACC of patients with schizophrenia but not in ACC of healthy control subjects, indicating that neuronal density or integrity differences between ACC subregions may be characteristic of the disease. (c) RSNA, 2011

BACKGROUND AND PURPOSE: Experimental studies have suggested a role for iron accumulation in the pathology of TBI. Magnetic field correlation MR imaging is sensitive to the presence of non-heme iron. The aims of this study are to 1) assess the presence, if any, and the extent of iron deposition in the deep gray matter and regional white matter of patients with mTBI by using MFC MR imaging; and 2) investigate the association of regional brain iron deposition with cognitive and behavioral performance of patients with mTBI. MATERIALS AND METHODS: We prospectively enrolled 28 patients with mTBI. Eighteen healthy subjects served as controls. The subjects were administered the Stroop color word test, the Verbal Fluency Task, and the Post-Concussion Symptoms Scale. The MR imaging protocol (on a 3T imager) consisted of conventional brain imaging and MFC sequences. After the calculation of parametric maps, MFC was measured by using a region of interest approach. MFC values across groups were compared by using analysis of covariance, and the relationship of MFC values and neuropsychological tests were evaluated by using Spearman correlations. RESULTS: Compared with controls, patients with mTBI demonstrated significant higher MFC values in the globus pallidus (P = .002) and in the thalamus (P = .036). In patients with mTBI, Stroop test scores were associated with the MFC value in frontal white matter (r = -0.38, P = .043). CONCLUSIONS: MFC values were significantly elevated in the thalamus and globus pallidus of patients with mTBI, suggesting increased accumulation of iron. This supports the hypothesis that deep gray matter is a site of injury in mTBI and suggests a possible role for iron accumulation in the pathophysiological events after mTBI

BACKGROUND AND PURPOSE/OBJECTIVE:Pseudomeningocele is a well-known MR imaging finding in Erb palsy. Our aim was to evaluate the prevalence and imaging features of PST, a lesser known but, in our experience, more common finding in Erb palsy. MATERIALS AND METHODS/METHODS:This retrospective study consisted of 37 subjects with Erb palsy from birth trauma. MR imaging examinations of the brachial plexus were evaluated independently by 2 neuroradiologists for the presence and signal-intensity characteristics/configuration of PST. Other findings included pseudomeningocele and posterior humeral head subluxation. The Blyth-Still-Casella procedure was used to construct an exact 95% CI for the percentage of patients seen to be positive for a specific imaging or anatomic feature by at least 1 observer and for the percentage positive according to both readers. RESULTS:The percentage of subjects found to have PST by both readers was 95% (35/37) (95% CI, 86.2%-99.9%). The PST was typically isointense to muscle on T1- and hyperintense on T2-weighted images. The most common morphology of the PST was a round or oval mass, though other morphologies were observed. Pseudomeningocele and posterior humeral head subluxation were reported in 40% (15/37) and 81% (30/37) of subjects, respectively. CONCLUSIONS:PST was the most common MR imaging finding in our series of subjects with Erb palsy and was observed more frequently than currently used imaging features. Although the morphology of PST is somewhat variable, several distinct patterns were observed, possibly reflecting different histologic compositions.

BACKGROUND/PURPOSE: The prognostic value of defining subcategories of gliomas is still controversial. This study aims to determine the utility of relative cerebral blood volume (rCBV) in predicting clinical response in patients with low-grade glioma at multiple institutions. MATERIALS AND METHODS: Sixty-nine patients were studied with dynamic susceptibility contrast-enhanced perfusion MRI at two institutions. The pathologic diagnoses of the low-grade gliomas were 34 astrocytomas, 20 oligodendroglioma, 9 oligoastrocytomas, 1 ganglioglioma and 5 with indeterminate histology. Wilcoxon tests were used to compare patients in different response categories with respect to baseline rCBV. Kaplan-Meier curve and log-rank tests were used to predict the association of rCBV with time to progression. RESULTS: At both institutions, patients with an adverse event (progressive disease or death) had a significantly higher baseline rCBV than those without (complete response or stable disease) (p value=0.0138). The odds ratio for detecting an adverse event when using rCBV was 1.87 (95% confidence interval: 1.14-3.08). rCBV was significantly negatively associated with time to progression (p=0.005). The median time to progression among subjects with rCBV>1.75 was 365 days, while there was 95% confidence that the median time to progression was at least 889 days among subjects with rCBV<1.75. CONCLUSION: Our study suggests not only that rCBV measurements correlate well with time to progression or death, but also that the findings can be replicated across institutions, which supports the application of rCBV as an adjunct to pathology in predicting glioma biology

Objective:This study aimed to investigate the utility of three-dimensional reconstructions of paranasal sinus computed tomography data in depicting the anatomy of the frontal sinus drainage pathway.Methods:Twenty-nine patients underwent imaging of the sinuses for various clinical indications. Variations in frontal sinus recess anatomy were determined from 0.75-mm thick coronal, axial and sagittal computed tomography images. Three-dimensional, reformatted images were generated from manually segmented volumes of interest. Observations were made on the variation and usefulness of these reconstructions.Results:Three-dimensional, reformatted images of segmented volumes aided delineation of the spatial relationships of the frontal sinus, frontal sinus drainage pathway, infundibular and meatal direction of drainage, agger nasi cells, ethmoid bulla cells, supraorbital cells, and suprabullar cells.Conclusion:Three-dimensional, reformatted images of frontonasal anatomy enable improved understanding of the frontal sinus drainage pathway anatomy and of the spatial relationships between ethmoid air cells in this region. Such images may provide a useful adjunct to surgical planning and education