Strain and Shear Wave Elastography in Diagnosis of Retrobulbar Neuritis

PubMed: 31022061BACKGROUND: In the early stages of retrobulbar neuritis (RN), the optic disc appears normal on ophthalmoscopy. Therefore, the diagnosis of RN is usually made clinically. However, imaging tools are needed for precise diagnosis of RN, and usually MRI is used. In this study, we investigated the diagnostic performance of strain elastography (SE) and shear wave elastography (SWE) in patients with RN. Elastography is a new sonographic technique and a noninvasive ultrasound method for evaluating the elastic properties of tissues based on static compression: the elastographic techniques of SE compress the tissues axially, and SWE uses waves that are generated by transducers and interact with the tissue. METHODS: The study included 40 eyes of 20 patients with sudden visual loss, who were diagnosed with RN. The eyes of the patients were divided into 2 groups: the eye with a diagnosis of RN was the group of RN eyes, and the healthy second eye was the group of control eyes. Ophthalmologic examination, orbital and brain MRI, SE, and SWE were performed. SE color mapping was divided into 3 types: blue-hardest tissue (Type 1), blue/green-hard tissue (Type 2), and green-intermediate tissue (Type 3). All patients were treated with high-dose corticosteroids. The measurements of SE and SWE were made immediately after diagnosis and 1 month after treatment. RESULTS: The mean age of 11 male and 9 female patients was 38.3 ± 12.2 years. At the time of diagnosis, the mean shear wave values for the control eyes were 18.47 ± 7.26 kPa (kilopascals), and the mean shear wave values for the RN eyes were 37.21 ± 8.24 kPa. There was a statistically significant difference between the control and RN eyes at the time of diagnosis (P < 0.001). The mean shear wave value was 19.92 ± 4.77 kPa in the RN eyes after treatment. There was a statistically significant difference in values at the time of diagnosis and after treatment (P < 0.001). Strain types found in the RN eyes before treatment were Type 1 in 60% of eyes, Type 2 in 25%, and Type 3 in 15%; at the end of the treatment, Type 2 was observed in 25% of eyes and Type 3 in 75%, while Type 1 was not observed. CONCLUSIONS: SE and SWE may be important alternative diagnostic tools in the diagnosis of RN

Diffusion-weighted imaging measurements of central smell regions in COVID-19 patients: insular gyrus, corpus amygdala, and thalamus

OBJECTIVE: The aim of this study was to investigate central smell centers with cranial magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) in COVID-19. PATIENTS AND METHODS: This retrospective study evaluated cranial MRI images of 54 adults. The experimental group (Group 1), consisting of 27 patients with positive COVID-19 real-time polymerase chain reaction (RT-PCR) assays, was compared to the control group (Group 2), comprising 27  healthy controls without COVID-19. The apparent diffusion coefficient (ADC) values were measured in the corpus amygdala, thalamus, and insular gyrus in both groups. RESULTS: Thalamus ADC values of the COVID-19 group were significantly lower compared to the control group bilaterally. However, no differences were found in the insular gyrus and corpus amygdala ADC values between the two groups. Positive correlations were observed between the insular gyrus and corpus amygdala ADC values and the thalamus ADC values. Insular gyrus ADC values (right) were higher in females. Left insular gyrus and corpus amygdala ADC values were higher in COVID-19 patients with smell loss. Right insular gyrus and left corpus amygdala ADC values were lower in COVID-19 patients with lymphopenia. CONCLUSIONS: Diffusion restriction in olfactory areas can be considered an obvious indicator that the COVID-19 virus affects and damages the immune system at the neuronal level. Given the urgency and lethality of the current pandemic, acute onset odor loss should be considered a high suspicion-adhesive index for patients with SARS-CoV-2 infection. Therefore, the sense of smell should be considered and evaluated simultaneously with other neurological symptoms. DWI should be widely used as an early imaging method for central nervous system (CNS) infections, especially in relation to COVID-19

The presence of Clival foramen through Multidetector computed tomography of the skull base

PubMed: 26468827Objectives: Technological advancements in the diagnostic radiology recently permitted reviewing the normal anatomy through multidetector computed tomography (MDCT) imagination. The aim of this paper is retrospectively investigation of the clival foramen and canal through MDCT. Materials and Methods: One hundred eighty-six MDCT scans were reviewed. First, images were taken at axial plane, and then coronal and sagittal reconstructions of raw data were performed. Later investigations were carried out on these three-dimensional images (3-D imaging). The images were evaluated as clival foramen ''present'' or ''absent.'' Results: In our 186 patients, evaluation of MDCT showed that clival foramenwas absent in 66.7% (n=124) of patients. Only 33.3% (n=62) of patients had a clival foramen. In 3-D images, clival canal and clival foramen were shown more clearly compared with the MDCT. Conclusions: Knowledge of the clival canal might be useful in patients of questionable clival fracture or during neurosurgical operations in this region. During life the canal contained a vein connecting the basilar plexus with the venous plexus of the vertebral canal, and inferior petrosal sinuses. Before the surgical interventions in the clival region, the presence of the clival canal and foramen should also be known due to its vascular contents. By multidetector computed tomography and 3-D images, clival canal and foramen may be viewed preoperatively. Copyright © 2015 by Mutaz B. Habal, MD