Differentiation of Jugular Foramen Paragangliomas versus Schwannomas Using Golden-Angle Radial Sparse Parallel Dynamic Contrast-Enhanced MRI.

BACKGROUND AND PURPOSE: Accurate differentiation of paragangliomas and schwannomas in the jugular foramen has important clinical implications because treatment strategies may vary but differentiation is not always straightforward with conventional imaging. Our aim was to evaluate the accuracy of both qualitative and quantitative metrics derived from dynamic contrast-enhanced MR imaging using golden-angle radial sparse parallel MR imaging to differentiate paragangliomas and schwannomas in the jugular foramen. MATERIALS AND METHODS: A retrospective study of imaging data was performed on patients (n = 30) undergoing MR imaging for jugular foramen masses with the golden-angle radial sparse parallel MR imaging technique. Imaging data were postprocessed to obtain time-intensity curves and quantitative parameters. Data were normalized to the dural venous sinus for relevant parameters and analyzed for statistical significance using a Student t test. A univariate logistic model was created with a binary output, paraganglioma or schwannoma, using a wash-in rate as a variable. Additionally, lesions were clustered on the basis of the wash-in rate and washout rate using a 3-nearest neighbors method. RESULTS: There were 22 paragangliomas and 8 schwannomas. All paragangliomas demonstrated a type 3 time-intensity curve, and all schwannomas demonstrated a type 1 time-intensity curve. There was a statistically significant difference between paragangliomas and schwannomas when comparing their values for area under the curve, peak enhancement, wash-in rate, and washout rate. A univariate logistic model with a binary output (paraganglioma or schwannoma) using wash-in rate as a variable was able to correctly predict all observed lesions (P < .001). All 30 lesions were classified correctly by using a 3-nearest neighbors method. CONCLUSIONS: Paragangliomas at the jugular foramen can be reliably differentiated from schwannomas using golden-angle radial sparse parallel MR imaging-dynamic contrast-enhanced imaging when imaging characteristics cannot suffice.

Brain Imaging Use and Findings in COVID-19: A Single Academic Center Experience in the Epicenter of Disease in the United States.

Coronavirus disease 2019 (COVID-19) is a serious public health crisis and can have neurologic manifestations. This is a retrospective observational case series performed March 1-31, 2020, at New York University Langone Medical Center campuses. Clinical and imaging data were extracted, reviewed, and analyzed. Two hundred forty-two patients with COVID-19 underwent CT or MRI of the brain within 2 weeks after the positive result of viral testing (mean age, 68.7 ± 16.5 years; 150 men/92 women [62.0%/38.0%]). The 3 most common indications for imaging were altered mental status (42.1%), syncope/fall (32.6%), and focal neurologic deficit (12.4%). The most common imaging findings were nonspecific white matter microangiopathy (134/55.4%), chronic infarct (47/19.4%), acute or subacute ischemic infarct (13/5.4%), and acute hemorrhage (11/4.5%). No patients imaged for altered mental status demonstrated acute ischemic infarct or acute hemorrhage. White matter microangiopathy was associated with higher 2-week mortality (P < .001). Our data suggest that in the absence of a focal neurologic deficit, brain imaging in patients with early COVID-19 with altered mental status may not be revealing.

Dynamic Contrast-Enhanced MRI to Differentiate Parotid Neoplasms Using Golden-Angle Radial Sparse Parallel Imaging.

BACKGROUND AND PURPOSE: Conventional imaging frequently shows overlapping features between benign and malignant parotid neoplasms. We investigated dynamic contrast-enhanced MR imaging using golden-angle radial sparse parallel imaging in differentiating parotid neoplasms. MATERIALS AND METHODS: For this retrospective study, 41 consecutive parotid neoplasms were imaged with dynamic contrast-enhanced MR imaging with golden-angle radial sparse parallel imaging using 1-mm in-plane resolution. The temporal resolution was 3.4 seconds for 78.2 seconds and 8.8 seconds for the remaining acquisition. Three readers retrospectively and independently created and classified time-intensity curves as follows: 1) continuous wash-in; 2) rapid wash-in, subsequent plateau; and 3) rapid wash-in with washout. Additionally, time-intensity curve-derived semiquantitative metrics normalized to the ipsilateral common carotid artery were recorded. Diagnostic performance for the prediction of neoplasm type and malignancy was assessed. Subset multivariate analysis (n = 32) combined semiquantitative time-intensity curve metrics with ADC values. RESULTS: Independent time-intensity curve classification of the 41 neoplasms produced moderate-to-substantial interreader agreement (κ = 0.50-0.79). The time-intensity curve classification threshold of ≥2 predicted malignancy with a positive predictive value of 56.0%-66.7%, and a negative predictive value of 92.0%-100%. The time-intensity curve classification threshold of <2 predicted pleomorphic adenoma with a positive predictive value of 87.0%-95.0% and a negative predictive value of 76.0%-95.0%. For all readers, type 2 and 3 curves were associated with malignant neoplasms (P < .001), and type 1 curves, with pleomorphic adenomas (P < .001). Semiquantitative analysis for malignancy prediction yielded an area under the receiver operating characteristic curve of 0.85 (95% CI, 0.73-0.99). Combining time-to-maximum and ADC predicts pleomorphic adenoma better than either metric alone (P < .001). CONCLUSIONS: Golden-angle radial sparse parallel MR imaging allows high spatial and temporal resolution permeability characterization of parotid neoplasms, with a high negative predictive value for malignancy prediction. Combining time-to-maximum and ADC improves pleomorphic adenoma prediction compared with either metric alone.

Hyperintense Dentate Nuclei on T1-Weighted MRI: Relation to Repeat Gadolinium Administration.

BACKGROUND AND PURPOSE: A hyperintense appearance of the dentate nucleus on T1-weighted MR images has been related to various clinical conditions, but the etiology remains indeterminate. We aimed to investigate the possible associations between a hyperintense appearance of the dentate nucleus on T1-weighted MR images in patients exposed to radiation and factors including, but not limited to, the cumulative number of contrast-enhanced MR images, amount of gadolinium administration, dosage of ionizing radiation, and patient demographics. MATERIALS AND METHODS: The medical records of 706 consecutive patients who were treated with brain irradiation at The Johns Hopkins Medical Institutions between 1995 and 2010 were blindly reviewed by 2 readers. RESULTS: One hundred eighty-four subjects were included for dentate nuclei analysis. Among the 184 subjects who cumulatively underwent 2677 MR imaging studies following intravenous gadolinium administration, 103 patients had hyperintense dentate nuclei on precontrast T1-weighted MR images. The average number of gadolinium-enhanced MR imaging studies performed in the group with normal dentate nuclei was significantly lower than that of the group with hyperintense dentate nuclei. The average follow-up time was 62.5 months. No significant difference was observed between hyperintense and normal dentate nuclei groups in terms of exposed radiation dose, serum creatinine and calcium/phosphate levels, patient demographics, history of chemotherapy, and strength of the scanner. No dentate nuclei abnormalities were found on the corresponding CT scans of patients with hyperintense dentate nuclei (n = 44). No dentate nuclei abnormalities were found in 53 healthy volunteers. CONCLUSIONS: Repeat performance of gadolinium-enhanced studies likely contributes to a long-standing hyperintense appearance of dentate nuclei on precontrast T1-weighted-MR images.

Asymmetric mineralization of the arytenoid cartilages in patients without laryngeal cancer.

BACKGROUND AND PURPOSE: Sclerosis of the arytenoid cartilage may be seen as an incidental finding in patients who do not have laryngeal cancer but may also be an early sign of neoplastic infiltration. Our purpose was to determine the frequency of asymmetric mineralization, in particular sclerosis, of the arytenoid cartilages on CT scans in adults who have no history of laryngeal cancer. MATERIALS AND METHODS: Cervical CT scans of 972 consecutive patients seen in our emergency department were retrospectively evaluated. Three hundred twenty-two patients were excluded who were younger than 18 years of age or whose arytenoids could not be reliably seen due to artifacts. Six hundred fifty patients (424 men, 226 women) were assessed, and their arytenoid cartilages were graded as nonmineralized, calcified, sclerotic, or ossified on each side separately. The mean age of patients was 44.3 ± 17.8 years (range, 18-97 years). RESULTS: The frequencies of asymmetric arytenoid cartilage sclerosis, calcification, and ossification were 4.9% (32/650), 4.4% (29/650), and 3.4% (23/650), respectively, with an overall asymmetric mineralization frequency of 12.9% (84/650). Asymmetric sclerosis was more common in women (16/226, 7.1%) than in men (16/424, 3.8%), but the difference was just at statistical significance (P = .05). The rate of unilateral arytenoid sclerosis was 4.6% in all subjects, 6.6% in women, and 3.5% in men. Unilateral sclerosis is much more frequently associated with the left arytenoid than the right. CONCLUSIONS: Asymmetric mineralization of the arytenoid cartilages was seen in 12.9% of our study population. This should be taken into account when evaluating CT scans of patients with laryngeal cancer for arytenoid cartilage invasion to avoid false-positive reads.

Adult lumbar scoliosis: underreported on lumbar MR scans.

BACKGROUND AND PURPOSE: Adult lumbar scoliosis is an increasingly recognized entity that may contribute to back pain. We investigated the epidemiology of lumbar scoliosis and the rate at which it is unreported on lumbar MR images. MATERIALS AND METHODS: The coronal and sagittal sequences of lumbar spine MR imaging scans of 1299 adult patients, seeking care for low back pain, were reviewed to assess for and measure the degree of scoliosis and spondylolisthesis. Findings were compared with previously transcribed reports by subspecialty trained neuroradiologists. Inter- and intraobserver reliability was calculated. RESULTS: The prevalence of adult lumbar scoliosis on MR imaging was 19.9%, with higher rates in ages >60 years (38.9%, P < .001) and in females (22.6%, P = .002). Of scoliotic cases, 66.9% went unreported, particularly when the scoliotic angle was <20 degrees (73.9%, P < .001); 10.5% of moderate to severe cases were not reported. Spondylolisthesis was present in 15.3% (199/1299) of cases, demonstrating increased rates in scoliotic patients (32.4%, P < .001), and it was reported in 99.5% of cases. CONCLUSIONS: Adult lumbar scoliosis is a prevalent condition with particularly higher rates among older individuals and females but is underreported on spine MR images. This can possibly result in delayed 1) identification of a potential cause of low back pain, 2) referral to specialized professionals for targeted evaluation and management, and 3) provision of health care. The coronal "scout images" should be reviewed as part of the complete lumbar spine evaluation if dedicated coronal sequences are not already part of the spine protocol.

Middle ear adenoma: a challenging diagnosis.

Middle ear adenomas are rare benign tumors, which can easily be mistaken for other conditions radiologically. They derive from the middle ear mucosa. We report the case of a 48-year-old man with a history of decreased left-sided hearing and intermittent pulsatile tinnitus. High-resolution CT of the temporal bones revealed a well-defined left middle ear soft-tissue attenuation abutting the head of the malleus. Surgical excision revealed a middle ear adenoma.

Stability of saliva for measuring HIV in the tropics.

If HIV is to be detected among pregnant women in remote regions of the tropics, HIV antibodies need to remain stable until specimens arrive at the laboratory. Our objective was to assess the stability of HIV antibodies in saliva held for up to 1 month at ambient temperature in Yangon, Myanmar. We gathered 10 saliva specimens from each of 102 HIV-infected persons with the Omni-Sal collection device (Saliva Diagnostic Systems, Inc.), and for each subject, divided the saliva into 15 portions. During 33 days, the 102 saliva specimens, kept at ambient temperature, were tested every 2-3 days for HIV antibodies (total 1530 assays) with the GACELISA (Murex Diagnostics Ltd), a highly sensitive test designed for use with saliva. We observed no reduction in test performance over 33 days, indicating that the antimicrobial and antiproteolytic transport medium in the Omni-Sal device can preserve HIV antibodies without refrigeration for up to a month before saliva specimens reach the laboratory.