Faculty Bibliography

OBJECTIVES: Contrast-enhanced fat-suppressed T1-weighted-2D-TSE and MPRAGE sequence with water excitation are routinely obtained to evaluate orbit pathology. However, these sequences can be marred by artifacts. The Radial-VIBE sequence is a motion-robust fat-suppressed T1W sequence which has demonstrated value in pediatric and body imaging. The purpose of our study is to evaluate its role in assessing the orbit, and to compare it with routinely acquired sequences. METHODS: A HIPAA-compliant and IRB-approved retrospective study was performed in 46 patients (age range: 1-81 years) who underwent orbit studies on a 1.5-T MRI using contrast-enhanced Radial-VIBE, MPRAGE and 2D-TSE sequences. Two radiologists blinded to the sequence analyzed evaluated multiple parameters of image quality including motion artifact, degree of fat-suppression, clarity of choroidal enhancement, intraorbital vessels, extraocular muscles, optic nerves, brain parenchyma and evaluation of pathology. Each parameter was assessed on a 5-point scale, with a higher score indicating the more optimal exam. Mix-model analysis of variance and interobserver variability were assessed. RESULTS: Radial-VIBE demonstrated superior quality (p<0.001) for all orbit parameters when compared to MPRAGE and 2D-TSE. Interobserver agreement demonstrated average fair-to -good agreement for: degree of motion artifact (0.745), fat suppression (0.678), clarity of choroidal enhancement (0.688), vessels (0.655), extraocular muscles (0.675), optic nerves (0.518), brain parenchyma (0.710), and evaluation of pathology (0.590). CONCLUSION: Radial-VIBE sequence demonstrates superior image quality when evaluating the orbits as compared to conventional MPRAGE and 2D-TSE sequences. Advances in knowledge: Radial-VIBE employs unique non-Cartesian k-space sampling in a radial or spoke-wheel fashion which provides superior image quality improving diagnostic capability in evaluation of the orbits.

Parry Romberg syndrome is a rare progressive hemiatrophy of the face that typically occurs in children and young adults and has a peculiar progression that ceases without apparent cause after a highly variable period. Only a subset of patients with Parry Romberg syndrome will develop secondary neurologic or ophthalmologic symptoms, and prognosis is highly variable. Inconsistency in the pattern of atrophy and the development of associated symptoms in patients with Parry Romberg syndrome has made it challenging to diagnose, prognosticate, and treat. The precise etiology of this disease remains unknown, but some authors have implicated sympathetic cervical ganglion dysfunction, abnormal embryogenesis, autoimmune and inflammatory mechanisms, or vasculopathy as potential causes. We present 7 cases of Parry Romberg syndrome and their associated clinical and imaging findings with specific attention to the radiographic characteristics of this disease.

Age-related loss of muscle bulk and strength (sarcopenia) is often cited as a potential mechanism underlying age-related changes in swallowing. Our goal was to explore this phenomenon in the pharynx, specifically, by measuring pharyngeal wall thickness and pharyngeal lumen area in a sample of young versus older women. MRI scans of the neck were retrospectively reviewed from 60 women equally stratified into three age groups (20s, 60s, 70+). Four de-identified slices were extracted per scan for randomized, blinded analysis: one mid-sagittal and three axial slices were selected at the anterior inferior border of C2 and C3, and at the pit of the vallecula. Pixel-based measures of pharyngeal wall thickness and pharyngeal lumen area were completed using ImageJ and then converted to metric units. Measures of pharyngeal wall thickness and pharyngeal lumen area were compared between age groups with one-way ANOVAs using Sidak adjustments for post-hoc pairwise comparisons. A significant main effect for age was observed across all variables whereby pharyngeal wall thickness decreased and pharyngeal lumen area increased with advancing age. Pairwise comparisons revealed significant differences between 20s versus 70+ for all variables and 20s versus 60s for all variables except those measured at C2. Effect sizes ranged from 0.54 to 1.34. Consistent with existing sacropenia literature, the pharyngeal muscles appear to atrophy with age and consequently, the size of the pharyngeal lumen increases.

Purpose: Age-related loss of muscle bulk and strength has been documented in the tongue and geniohyoid. Our goal was to explore this phenomenon in the pharynx, specifically by measuring pharyngeal wall thickness (PWT) and pharyngeal lumen area (PLA) in a sample of young vs older women. Method(s): MRI scans of the neck were retrospectively reviewed from 60 women equally stratified by 3 age groups (20s, 60s, 70+). Exclusion criteria included dysphagia, c-spine surgery, neurological illness, head and neck malignancy and obstructive sleep apnea. Three de-identified axial slices were extracted per scan for randomized, blinded analysis: at the levels of the anterior inferior border of C2 and C3, and at the pit of the vallecula (Vpit). Pixel-based measures of PWT and PLA were completed using ImageJ and converted to metric units using the calibration markers on the original images. Measures of PWT and PLA (at three levels) were compared between age groups with one-way ANOVAs using Sidak adjustments for post-hoc pairwise comparisons. Result(s): A significant main effect of age was observed for all variables whereby PWT decreases and PLA increases with advancing age (Table 1). Pairwise comparisons revealed significant differences between 20s vs 70+ for all variables and 20s vs 60s for all variables except PWT and PLA at C2. Effect sizes ranged from 0.56-1.34. Conclusions (Including Clinical Relevance): Consistent with the existing sacropenia literature, the pharyngeal muscles appear to atrophy with age and consequently, PLA increases as well. Future work should explore the relationship between pharyngeal muscle size/ atrophy and functional swallowing outcomes. (Table Presented)

OBJECTIVE: The preferential delayed enhancement of the perilymphatic space enables detection of the non-enhancing endolymphatic hydrops present in patients with Meniere's disease. The aim of this study was to evaluate the diagnostic utility of delayed postcontrast 3D FLAIR images and a color map of fused postcontrast FLAIR and constructive interference steady state (CISS) images in the identification of endolymphatic hydrops in patients with clinically diagnosed Meniere's disease. STUDY DESIGN: Case control, blinded study. SETTING: Tertiary referral center. PATIENTS: Ten patients with Meniere's disease and five volunteer controls. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURE: Two neuroradiologists blinded to the clinical history independently evaluated for the presence of endolymphatic hydrops on the images of both inner ears for test and control subjects. Both the standard gray-scale FLAIR images and the fused color map images were independently reviewed. RESULTS: The gray-scale 3D FLAIR images demonstrated 68.2% sensitivity and 97.4% specificity, and the fused color map images demonstrated 85.0% sensitivity and 88.9% specificity in the identification of endolymphatic hydrops in Meniere's disease. There was significant correlation between the gray-scale 3D FLAIR images and fused color map images with the categorization of involvement (p = 0.002). Inter-evaluator reliability was excellent (kappa = 0.83 for gray-scale images, kappa = 0.81 for fused color map). CONCLUSION: Delayed 3D FLAIR and fused 3D FLAIR-CISS color map images of the inner ears after intravenous contrast administration are potentially useful diagnostic tools in the evaluation of patients with suspected Meniere's disease.

OBJECTIVE. Traditional fat-suppressed T1-weighted spin-echo or turbo spin-echo (TSE) sequences (T1-weighted images) may be degraded by motion and pulsation artifacts in head-and-neck studies. Our purpose is to evaluate the role of a fat-suppressed T1-weighted 3D radial gradient-recalled echo sequence (radial-volumetric interpolated breath-hold examination [VIBE]) in the head and neck as compared with standard contrast-enhanced fat-suppressed T1-weighted images. MATERIALS AND METHODS. We retrospectively evaluated 21 patients (age range, 9-67 years) who underwent head-and-neck MRI at 1.5 T. Both contrast-enhanced radial-VIBE and conventional fat-suppressed TSE contrast-enhanced T1-weighted imaging were performed. Two radiologists evaluated multiple parameters of image quality, graded on a 5-point scale. Mixed-model analysis of variance and interobserver variability assessment were performed. RESULTS. The following parameters were scored as significantly better for the contrast-enhanced radial-VIBE sequence than for conventional contrast-enhanced T1-weighted imaging: overall image quality (p < 0.0001), degree of fat suppression (p = 0.006), mucosal enhancement (p = 0.004), muscle edge clarity (p = 0.049), vessel clarity (p < 0.0001), respiratory motion artifact (p = 0.002), pulsation artifact (p < 0.0001), and lesion edge sharpness (p = 0.004). Interobserver agreement in qualitative evaluation of the two sequences showed fair-to-good agreement for the following variables: overall image quality (intraclass correlation coefficient [ICC], 0.779), degree of fat suppression (ICC, 0.716), mucosal enhancement (ICC, 0.693), muscle edge clarity (ICC, 0.675), respiratory motion artifact (ICC, 0.516), lesion enhancement (ICC, 0.410), and lesion edge sharpness (ICC, 0.538). Excellent agreement was shown for vessel clarity (ICC, 0.846) and pulsation artifact (ICC, 0.808). CONCLUSION. The radial-VIBE sequence is a viable motion-robust improvement on the conventional fat-suppressed T1-weighted sequence.

Background Activation of the mammalian target of rapamycin (mTOR) signaling pathway is thought to be a key driver of tumor growth in Merlin (NF2)-deficient tumors. Everolimus is an oral inhibitor of mTOR complex 1 (mTORC1) with antitumor activity in a variety of cancers. Methods We conducted a single-institution, prospective, 2-stage, open-label phase II study to estimate the response rate to everolimus in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannoma (VS). Ten eligible patients were enrolled, including 2 pediatric patients. Everolimus was administered at a daily dose of 10 mg (adults) or 5 mg/m(2)/day (children <18 y) orally in continuous 28-day courses, for up to 12 courses. Response was assessed every 3 months with MRI, using 3-dimensional volumetric tumor analysis, and audiograms. Nine patients were evaluable for the primary response, defined as >/=15% decrease in VS volume. Hearing response was evaluable as a secondary endpoint in 8 patients. Results None of the 9 patients with evaluable disease experienced a clinical or MRI response. No objective imaging or hearing responses were observed in stage 1 of the trial, and the study was closed according to predefined stopping rules. Conclusion Everolimus is ineffective for the treatment of progressive VS in NF2 patients. We are currently conducting a pharmacokinetic/pharmacodynamic ("phase 0") study of everolimus in presurgical VS patients to elucidate the biological basis for apparent treatment resistance to mTORC1 inhibition in these tumors.

BACKGROUND AND PURPOSE: Trigeminal nerve injury or dysfunction is associated with denervation atrophy of muscles innervated by the mandibular branch of the trigeminal nerve. The purpose of our study was to evaluate the association between chronic CN V denervation and parotid gland atrophy. MATERIALS AND METHODS: Twenty-six patients with chronic masticator muscle atrophy were retrospectively identified and evaluated for the presence of ipsilateral parotid gland atrophy. Twenty-six age-matched control subjects with no clinical or imaging evidence of chronic masticator space atrophy were also identified. Segmentation of the parotid gland was performed to calculate a parotid asymmetry index. The Fisher exact test and t test were respectively used to determine the correlation between parotid gland atrophy and ipsilateral masticator muscle atrophy and to evaluate any difference in the size of the involved parotid gland when compared with that in the control subjects. RESULTS: Ipsilateral parotid gland atrophy was seen in 9/26 (42.8%) patients with fatty replacement of the masticator group of muscles, suggesting a correlation between parotid gland atrophy and CN V denervation (P < .001). The parotid asymmetry index was significantly different in patients with CN V denervation (0.59 +/- 0.25) compared with control subjects (0.92 +/- 0.03) (P < .001). CONCLUSIONS: Ipsilateral parotid gland atrophy can accompany chronic CN V denervation change, and its clinical significance remains to be determined.