Conventional MRI findings in hereditary degenerative ataxias: a pictorial review.

PURPOSE: Cerebellar ataxias are a large and heterogeneous group of disorders. The evaluation of brain parenchyma via MRI plays a central role in the diagnostic assessment of these conditions, being mandatory to exclude the presence of other underlying causes in determining the clinical phenotype. Once these possible causes are ruled out, the diagnosis is usually researched in the wide range of hereditary or sporadic ataxias. METHODS: We here propose a review of the main clinical and conventional imaging findings of the most common hereditary degenerative ataxias, to help neuroradiologists in the evaluation of these patients. RESULTS: Hereditary degenerative ataxias are all usually characterized from a neuroimaging standpoint by the presence, in almost all cases, of cerebellar atrophy. Nevertheless, a proper assessment of imaging data, extending beyond the mere evaluation of cerebellar atrophy, evaluating also the pattern of volume loss as well as concomitant MRI signs, is crucial to achieve a proper diagnosis. CONCLUSION: The integration of typical neuroradiological characteristics, along with patient's clinical history and laboratory data, could allow the neuroradiologist to identify some conditions and exclude others, addressing the neurologist to the more appropriate genetic testing.

The "crab sign": an imaging feature of spinocerebellar ataxia type 48.

PURPOSE: A new form of autosomal dominant hereditary spinocerebellar ataxia (SCA) has been recently described (SCA48), and here we investigate its conventional MRI findings to identify the presence of a possible imaging feature of this condition. METHODS: In this retrospective observational study, we evaluated conventional MRI scans from 10 SCA48 patients (M/F = 5/5; 44.7 ± 7.8 years). For all subjects, atrophy of both supratentorial and infratentorial compartments were recorded, as well as the presence of possible T2-weighted imaging (T2WI) signal alterations. RESULTS: In SCA48 patients, no meaningful supratentorial changes were found, both in terms of volume loss or MRI signal changes. Atrophy of the cerebellum was present in all cases, involving both the vermis and the hemispheres, but particularly affecting the postero-lateral portions of the cerebellar hemispheres. In all patients, with the exception of only one subject (90.0% of the cases), a T2WI hyperintensity of both dentate nuclei was found. The association of such signal alteration with the pattern of cerebellar atrophy resembled the appearance of a crab ("crab sign"). CONCLUSION: Our findings suggest that SCA48 patients are characterized by cerebellar atrophy, mainly involving the postero-lateral hemisphere areas, along with a T2WI hyperintensity of dentate nuclei. We propose that the association of such signal change, along with the atrophy of the lateral portion of the cerebellar hemispheres, resembled the appearance of a crab, and therefore, we propose the "crab sign" as a neuroradiological sign present in SCA48 patients.

Acute Ischemic Hemorrhagic Stroke in Two COVID-19 Patients.

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). First identified in December 2019, in Wuhan, China, it has since become a global pandemic. Complications of COVID-19 are not limited to the pulmonary system, but also include neurologic manifestations such as stroke. We report two cases of coincidental presentation of COVID-19 and cerebrovascular accident. Further studies are needed for a comprehensive understanding of the neurological pathology of COVID-19 and its effects on the nervous system, but stroke teams should be wary of the fact that COVID-19 patients may present with cerebrovascular accidents.

Chest CT Findings after 4 Months from the Onset of COVID-19 Pneumonia: A Case Series.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although the reference standard for SARS-CoV-2 diagnosis is real-time reverse transcription polymerase chain reaction (RT-PCR), computed tomography (CT) is recommended for both initial evaluation and follow-up. There is a growing body of published evidence about CT evolution during the course of COVID-19 pneumonia. Here, we report six confirmed cases of COVID-19 patients who underwent unenhanced chest CT on admission and after 4 months from the onset of symptoms. Chest-CT at first admission showed the typical CT features of COVID-19. Interestingly, the follow-up CT revealed the persistence of lung abnormalities in five cases even if all the patients were completely asymptomatic. Further studies are needed for a comprehensive understanding of the disease progression and the resulting late imaging modifications.

Involvement of the Mediastinal Subpleural Pulmonary Parenchyma on Chest CT in COVID-19 patients: A Case Series.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). First identified in December 2019 in Wuhan, China, it has since become a global pandemic. Although the reference standard for SARS-CoV-2 diagnosis is real-time reverse transcription polymerase chain reaction (RT-PCR), computed tomography (CT) is recommended for both initial evaluation and follow-up. The CT findings in COVID-19 are varied, but typical ground-glass opacities are usually reported to occupy a peripheral costal subpleural distribution. Here we report eight confirmed COVID-19 cases who underwent clinical evaluation, laboratory testing, and unenhanced chest CT. In all patients, chest CT showed the presence of ground-glass opacities in the mediastinal subpleural parenchyma. While these cases also showed the typical CT features of COVID-19, involvement of the mediastinal subpleural parenchyma should not lower the index of suspicion for COVID-19.

Ultrasonographic and multimodal imaging of pediatric genital female diseases.

Ultrasonography is the first-line imaging modality in the evaluation of the female pelvis in childhood and adolescence, because it is easy to perform, non-invasive and it does not require sedation. The transabdominal approach is preferred in children and adolescents, after filling the bladder to move away the bowel loops from the pelvis. The probe frequency must be adapted to age, thickness of tissues and depth of the structures under examination. High-frequency (4-12 MHz) linear or convex probes are used in newborns; high-frequency linear probes (4-12 MHz) in toddler, convex 5-7.5 MHz probes in girls and convex 3.5-5 MHz probes in teenagers. In this article, the main pathological conditions of the genital female tract in pediatric age are examined, such as congenital anomalies, disorders of sex development, ovarian cysts, ovarian tumors, adnexal torsion, primary amenorrhea, precocious puberty and pelvic inflammatory disease.