Pediatric tinnitus: The role of neuroimaging.

Tinnitus is defined as the perception of sound without an external source and can be categorized as either pulsatile or nonpulsatile (ie, continuous). A variety of etiologies have been reported to cause pediatric tinnitus, many with long-lasting implications due to hearing and concentration impairments. Therefore, imaging can be an essential part of the accurate and timely diagnosis of treatable etiologies. We describe neuroimaging findings in different etiologies of pediatric tinnitus. Etiologies of pulsatile tinnitus are frequently vascular in nature and include vascular loops, congenital vascular anomalies or variants, high riding jugular bulbs with or without a jugular bulb diverticulum, idiopathic intracranial hypertension, aneurysms, internal auditory canal hemangiomas, and petrous apex cephaloceles. Etiologies of continuous tinnitus frequently affect the middle/inner ear structures and include vestibular schwannomas, cholesteatomas, trauma, Chiari malformations, and labyrinthitis ossificans. CT and MR are often complementary modalities: CT is better suited to evaluate the integrity of the temporal osseous structures and MR is better suited to evaluate the vestibulocochlear nerve and to assess for the presence of any masses or malformations. Prompt diagnosis of the etiology of tinnitus in pediatric patients is important to avoid any potential long-term developmental impairments. In the approach to pediatric tinnitus, categorizing the symptoms as either pulsatile versus nonpulsatile and then being aware of the possible causes and imaging findings of either can assist both the clinician and the radiologist in making an expeditious diagnosis.

To Sustain or not to Sustain: Varying Educational Sessions on Advanced Imaging of Low Back Pain and R-SCAN.

PURPOSE: The aim is to present our long-term institutional experience on the use of the American College of Radiology's (ACR's) Radiology Support, Communication, and Alignment Network (R-SCAN) via educational presentations and guideline dissemination in sustaining lumbar spine magnetic resonance imaging (MRI) appropriateness for low back pain. METHODS: Initial educational presentations on appropriate use criteria for lumbar spine MRI were given to referring providers at three county clinics in April and May of 2016. A second educational refresher was given to the same 3 clinics in November 2017: Clinic A received guideline dissemination, Clinic B served as a control group, and Clinic C received a refresher presentation. Wilcoxon rank-sum test was used to compare the monthly MRI referral rate and ACR Appropriateness Criteria rating. RESULTS: There was no significant difference in monthly referral rates and ACR Appropriateness Criteria after the second education. Monthly referral rates were significantly lower than the baseline rates before the first education for Clinic A (P <0.001), C (P = 0.004), and the combined total (P = 0.002). ACR Appropriateness Criteria ratings were significantly higher than the baseline ratings before the first education for Clinic C (P = 0.002) and the combined total (P = 0.024). DISCUSSION: After the second education, inappropriateness, and referral rates remained significantly lower when compared to rates before but not after the first education. Radiology Support, Communication, and Alignment Network is an invaluable online tool for both radiology practices and referring clinicians to become familiar in preparing to comply with the Protecting Access to Medicare Act and satisfying the Improvement Activities category of the Merit Based Incentive Payment Systems.

Diffusion-weighted MR imaging histogram analysis in HIV positive and negative patients with primary central nervous system lymphoma as a predictor of outcome and tumor proliferation.

INTRODUCTION: Ki-67 expression, a marker of tumor proliferation, is considered a prognostic factor in primary CNS lymphoma (PCNSL). Apparent diffusion coefficient (ADC) parameters have also been proposed as imaging biomarkers for tumor progression and proliferative activity in various malignancies. The aim of this study is to investigate the correlation between ADC parameters, Ki-67 expression, overall survival (OS) and progression free survival (PFS) in PCNSL. MATERIALS AND METHODS: Patients diagnosed with PCNSL at MD Anderson Cancer Center between Mar 2000 and Jul 2016 and at Ben Taub Hospital between Jan 2012 and Dec 2016 were retrospectively studied. Co-registered ADC maps and post-contrast images underwent whole tumor segmentation. Normalized ADC parameters (nADC) were calculated as the ratio to normal white matter. Percentiles of nADC were calculated and were correlated with Ki-67 using Pearson's correlation coefficient and clinical outcomes (OS and PFS) using Cox proportional hazards models. RESULTS: Selection criteria yielded 90 patients, 23 patients living with HIV (PLWH) and 67 immunocompetent patients. Above median values for nADCmean, nADC15, nADC75 and nADC95 were associated with improved OS in all patients (p < 0.05). Above median values for nADCmin, nADCmean, nADC1, nADC5 and kurtosis were associated with improved PFS in all patients (p < 0.05). In patients with available Ki-67 expression data (n = 22), nADCmean, nADC15 and nADC75 inversely correlated with Ki-67 expression (p < 0.05). For PLWH, there was no correlation between ADC parameters and Ki-67 expression or clinical outcomes. CONCLUSIONS: ADC histogram analysis can predict tumor proliferation and survival in immunocompetent patients with PCNSL, but with limited utility in PLWH.

Papillary thyroid carcinoma metastasis to a branchial cleft cyst: a case report and review of imaging.

Branchial cleft cysts are the most common lesions in the lateral neck with ectopic thyroid tissue found only rarely within these cysts. Over the years, multiple cases of papillary thyroid carcinoma arising from these ectopic thyroid tissues have been described in the literature with these cases sharing a normal thyroid gland on surgical and histological evaluation. Recently, however, there are three cases of papillary thyroid carcinoma in a branchial cleft cyst reported to be the result of metastasis from a thyroid primary. We present a 49-year-old female with a rare case of papillary thyroid carcinoma metastasis to a branchial cleft cyst with imaging characteristics that may prospectively suggest metastatic involvement.

Whole Tumor Histogram Analysis Using DW MRI in Primary Central Nervous System Lymphoma Correlates with Tumor Biomarkers and Outcome.

The ability to non-invasively predict outcomes and monitor treatment response in primary central nervous system lymphoma (PCNSL) is important as treatment regimens are constantly being trialed. The aim of this study was to assess the validity of using apparent diffusion coefficient (ADC) histogram values to predict Ki-67 expression, a tumor proliferation marker, and patient outcomes in PCNSL in both immunocompetent patients and patients living with HIV (PLWH). Qualitative PCNSL magnetic resonance imaging (MRI) characteristics from 93 patients (23 PLWH and 70 immunocompetent) were analyzed, and whole tumor segmentation was performed on the ADC maps. Quantitative histogram analyses of the segmentations were calculated. These measures were compared to PCNSL Ki-67 expression. Progression-free survival (PFS) and overall survival (OS) were analyzed via comparison to the International Primary Central Nervous System Lymphoma Collaboration Group Response Criteria. Associations between ADC measures and clinical outcomes were assessed using univariate and multivariate Cox proportional hazards models. Normalized ADC (nADC)Min, nADCMean, nADC1, nADC5, and nADC15 values were significantly associated with a poorer OS. nADCMax, nADCMean, nADC5, nADC15, nADC75, nADC95, nADC99 inversely correlated with Ki-67 expression. OS was also significantly associated with lesion hemorrhage. PFS was not significantly associated with ADC values but with lesion hemorrhage. ADC histogram values and related parameters can predict the degree of tumor proliferation and patient outcomes for primary central nervous system lymphoma patients and in both immunocompetent patients and patients living with HIV.

Primary central nervous system lymphoma in patients with and without HIV infection: a multicenter study and comparison with U.S national data.

PURPOSE: Primary central nervous system lymphoma (PCNSL) in patients living with HIV (PLWH) is a distinct entity; however, the management is adopted from patients without HIV. The study aims to examine the differences in presentation, treatment, and outcomes of PCNSL patients with or without HIV. METHODS: We retrospectively compared the characteristics of 144 patients with PCNSL with and without HIV, and analyzed factors associated with overall and progression-free survival. Results were compared to the Central Brain Tumor Registry of the United States (CBTRUS) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) system. RESULTS: Among all patients with PCNSL, 19% had HIV. PLWH were younger (38 vs. 63 years; p < 0.01) and more likely to be African American (59% vs. 7%; p < 0.01) and male (74% vs. 49%; p = 0.02) than patients without HIV. PLWH were more likely to have multiple lesions (67% vs. 43%; p = 0.02), hemorrhage (59 vs. 37%; p = 0.03), and peripheral rim enhancement (57% vs. 7%; p < 0.01) on imaging; to receive palliative care (15% vs. 2%) or whole brain radiation (63% vs. 3%); and less likely to receive chemotherapy (22% vs. 95%) (p < 0.01). Twenty-four patients, none PLWH, underwent stem cell transplant. Not receiving transplant was an independent factor in mortality and disease progression. Our cohort of patients, compared to the national database, were younger (60 vs. 65 years), 58% were white vs. 75%, and had longer median overall survival 43 vs. 25 months. CONCLUSION: Epidemiology, imaging, and treatment options for patients with PCNSL with and without HIV differ, but HIV was not an independent factor of mortality or disease progression. More efforts are needed to improve access to research and treatment options for PLWH with PCNSL.

Cryptococcal meningitis in a multiple sclerosis patient treated with Fingolimod: a case report and review of imaging findings.

Fingolimod is an oral medication approved by the Food and Drug Administration in 2009 for the treatment of relapsing remitting multiple sclerosis (RRMS). Initial clinical trials did not show a significantly increased rate of serious infections with fingolimod therapy. However, a mildly increased risk of less serious infections, such as varicella zoster virus and herpes simplex virus, was reported. Recently, however, several instances of serious opportunistic infections have been reported. In the years following approval of fingolimod for use in multiple sclerosis (MS), seven cases of cryptococcal meningitis in patients undergoing treatment have been described in the literature. We present a 40-year old woman with RRMS on fingolimod therapy presenting with a rare case of cryptococcal meningitis exhibiting alterations of consciousness, which was initially diagnosed as an MS relapse.

Analysis of erectile responses to bradykinin in the anesthetized rat.

The kallikrein-kinin system is expressed in the corpus cavernosa, and bradykinin (BK) relaxes isolated corpora cavernosal strips. However, erectile responses to BK in the rat have not been investigated in vivo. In the present study, responses to intracorporal (ic) injections of BK were investigated in the anesthetized rat. BK, in doses of 1-100 µg/kg ic, produced dose-related increases in intracavernosal pressure (ICP) and dose-related deceases in mean arterial pressure (MAP). When decreases in MAP were prevented by intravenous injections of angiotensin II (Ang II), increases in ICP, in response to BK, were enhanced. Increases in ICP, ICP/MAP ratio, and area under the curve and decreases in MAP in response to BK were inhibited by the kinin B2 receptor antagonist HOE-140 and enhanced by the angiotensin-converting enzyme (ACE) inhibitor captopril and by Ang-(1-7). Increases in ICP, in response to BK, were not attenuated by the nitric oxide (NO) synthase inhibitor (N(ω)-nitro-L-arginine methyl ester) or the soluble guanylate cyclase inhibitor (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) but were attenuated by the cyclooxygenase inhibitor, sodium meclofenamate. Decreases in MAP were not attenuated by either inhibitor. These data suggest that erectile responses are mediated by kinin B2 receptors and modulated by decreases in MAP. These data indicate that ACE is important in the inactivation of BK and that erectile and hypotensive responses are independent of NO in the penis or the systemic vascular bed. Erectile responses to cavernosal nerve stimulation are not altered by BK or HOE-140, suggesting that BK and B2 receptors do not modulate nerve-mediated erectile responses under physiologic conditions. These data suggest that erectile responses to BK are mediated, in part, by the release of cyclooxygenase products.

Direct carbon-carbon bond formation via soft enolization: aldol addition of α-halogenated thioesters.

α-Halo thioesters undergo soft enolization and syn-selective direct aldol addition to aldehydes in the presence of MgBr(2)·OEt(2) and i-Pr(2)NEt to produce α-halo-ß-hydroxy thioesters.