Brain MRI in Autism Spectrum Disorder: Narrative Review and Recent Advances.

Autism spectrum disorder (ASD) is neuropsychiatric continuum of disorders characterized by persistent deficits in social communication and restricted repetitive patterns of behavior which impede optimal functioning. Early detection and intervention in ASD children can mitigate the deficits in social interaction and result in a better outcome. Various non-invasive imaging methods and molecular techniques have been developed for the early identification of ASD characteristics. There is no general consensus on specific neuroimaging features of autism; however, quantitative magnetic resonance techniques have provided valuable structural and functional information in understanding the neuropathophysiology of ASD and how the autistic brain changes during childhood, adolescence, and adulthood. In this review of decades of ASD neuroimaging research, we identify the structural, functional, and molecular imaging clues that most accurately point to the diagnosis of ASD vs. typically developing children. These studies highlight the 1) exaggerated synaptic pruning, 2) anomalous gyrification, 3) interhemispheric under- and overconnectivity, and 4) excitatory glutamate and inhibitory GABA imbalance theories of ASD. The application of these various theories to the analysis of a patient with ASD is mitigated often by superimposed comorbid neuropsychological disorders, evolving brain maturation processes, and pharmacologic and behavioral interventions that may affect the structure and function of the brain. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 3.

Coronavirus disease 2019 (COVID-19): A systematic review of 133 Children that presented with Kawasaki-like multisystem inflammatory syndrome.

Kawasaki-like disease (KLD) and multisystem inflammatory syndrome in children (MIS-C) are considered as challenges for pediatric patients under the age of 18 infected with coronavirus disease 2019 (COVID-19). A systematic search was performed on July 2, 2020, and updated on December 1, 2020, to identify studies on KLD/MIS-C associated with COVID-19. The databases of Scopus, PubMed, Web of Science, Embase, and Scholar were searched. The hospitalized children with a presentation of Kawasaki disease (KD), KLD, MIS-C, or inflammatory shock syndromes were included. A total number of 133 children in 45 studies were reviewed. A total of 74 (55.6%) cases had been admitted to pediatric intensive care units (PICUs). Also, 49 (36.8%) patients had required respiratory support, of whom 31 (23.3%) cases had required mechanical ventilation/intubation, 18 (13.5%) cases had required other oxygen therapies. In total, 79 (59.4%) cases had been discharged from hospitals, 3 (2.2%) had been readmitted, 9 (6.7%) had been hospitalized at the time of the study, and 9 (6.7%) patients had expired due to the severe heart failure, shock, brain infarction. Similar outcomes had not been reported in other patients. Approximately two-thirds of the children with KLD associated with COVID-19 had been admitted to PICUs, around one-fourth of them had required mechanical ventilation/intubation, and even some of them had been required readmissions. Therefore, physicians are strongly recommended to monitor children that present with the characteristics of KD during the pandemic as they can be the dominant manifestations in children with COVID-19.

Clinical, laboratory, and chest CT features of severe versus non-severe pediatric patients with COVID-19 infection among different age groups.

BACKGROUND: This study was performed with the intention of comparing the clinical, laboratory, and chest computed tomography (CT) findings between severe and non-severe patients as well as between different age groups composed of pediatric patients with confirmed COVID-19. METHOD: This study was carried out on a total of 53 confirmed COVID-19 pediatric patients who were hospitalized in Namazi and Ali Asghar Hospitals, Shiraz, Iran. The patients were divided into two severe (n = 27) and non-severe (n = 28) groups as well as into other three groups in terms of their age: aged less than two years, aged 3-12 years and 13-17 years. It should be noted that CT scans, laboratory, and clinical features were taken from all patients at the admission time. Abnormal chest CT in COVID-19 pneumonia was found to show one of the following findings: ground-glass opacities (GGO), bilateral involvement, peripheral and diffuse distribution. RESULT: Fever (79.2%) and dry cough (75.5%) were the most common clinical symptoms. Severe COVID-19 patients showed lymphocytosis, while the non-severe ones did not (P = 0.03). C-reactive protein (CRP) was shown to be significantly lower in patients aged less than two years than those aged 3-12 and 13-17 years (P = 0.01). It was shown also that O2 saturation experienced a significant increase as did patients' age (P = 0.01). Severe patients had significantly higher CT abnormalities than non-severe patients (48.0% compared to 17.9%, respectively) (P = 0.02). CONCLUSION: Lymphocytosis and abnormal CT findings are among the factors most associated with COVID-19 severity. It was, moreover, showed that the severity of COVID-19, O2 saturation, and respiratory distress were improved as the age of confirmed COVID-19 pediatric patients increased.

MR imaging of thoracic annular fissures.

OBJECTIVE: Annular fissures are common findings on MR studies of the lumbar spine but have not been specifically examined in the thoracic spine. We sought to review the prevalence and stability of MRI imaging features of thoracic annular fissures and the association of thoracic AFs with intervertebral degenerative disk changes. MATERIALS AND METHODS: We surveyed 10 years of MRI studies in which patients had one or more repeated examinations of the thoracic spine. For every annular fissure, we recorded its imaging features on all pulse sequences and the evolution of those imaging findings across all time periods. RESULTS: We reviewed 210 patients and discovered that 66 (31.4%) had at least one thoracic annular fissure. The presence of annular fissures was positively correlated with older age and male gender. The initial annular fissure was always hyperintense on T2WI and annular fissures remained hyperintense on T2WI over time in all cases but showed less hyperintensity in 23.9% (n = 39/163) and more hyperintensity in 4.9% (n = 8/163). The rate of concomitant disk bulges was 85.8% (n = 140/163). Of the 71 annular fissures in which gadolinium-enhanced studies were performed, 20 (28.1%) showed enhancement and 14/20 (70%) annular fissures showed persistent enhancement over time (mean follow-up = 39.6 ± 44.1 months). CONCLUSION: Thoracic annular fissures rarely resolve, remain hyperintense on T2WI, and, if they enhance, that enhancement generally persists.

Longitudinal assessment of annular fissures of the cervical spine: overlooked and static.

Background: Cervical annular fissures (AFs) have not been studied specifically as to their prevalence, imaging features, and persistence over time. We sought to determine the prevalence and natural history of cervical AFs. We hypothesized that these are static lesions that are not prevalent in the population. Methods: This was a cross-sectional retrospective study of cervical MRI examinations performed between 2011-2021. We retrospectively reviewed the studies of 115 consecutive patients (63 female, 52 male) who had 2 or more MRI studies of the cervical spine to identify (1) imaging features of cervical AFs on various pulse sequences, (2) the concurrence of disc bulges/herniations, (3) changes in those imaging findings over time (mean follow-up 39.3 months) and (4) rate at which cervical AFs were mentioned in radiology reports. 620 initial and follow-up studies were reviewed. Results: 50/115 (43.5%) patients had cervical AFs; 21 patients had a single AF and 29 patients had multi-level AFs (total 109 AFs). The most common levels affected were C4-C5 (28%, n = 31) and C5-C6 (27%, n = 30). All cervical AFs were hyperintense on T2WI and, over time, 95% (n = 104/109) of the AFs remained hyperintense; 22% (n = 25) showed less hyperintensity, 10% (n = 11) more hyperintensity, and 60% (n = 66) the same hyperintensity. 5 AFs (4%) resolved completely. Only 2 (8%) of 25 cervical AFs enhanced with gadolinium. The rate of concomitant disc bulges and herniations was 71% (n = 78) and 22% (n = 24) respectively. The presence of cervical AFs did not increase the risk of progression to bulges or herniations. None of the cervical AFs were mentioned in the radiology reports. Conclusions: Cervical AFs occurred in 43.5% of patients but were rarely reported. They usually remained bright on T2W but their brightness could vary over time. Cervical AFs were often associated with disc bulges/herniations and enhanced less frequently (8%) than lumbar disk AFs.

Lymphadenopathy Following COVID-19 Vaccination: Imaging Findings Review.

RATIONALE AND OBJECTIVES: Despite all the benefits and effectiveness of the coronavirus disease 2019 (COVID-19) vaccines mentioned in recent clinical trials, some post-vaccination side effects such as lymphadenopathy (LAP) were observed. The present study reviewed all studies with imaging findings presentation of LAP after COVID-19 vaccination. MATERIALS AND METHODS: We conducted a literature search in online databases, including Scopus, Medline (PubMed), Web of Science, Embase (Elsevier), Cochrane library, and Google Scholar. RESULTS: A total of 19 studies (68 cases), including 60 (88.2%) females and eight (11.8%) males with a presentation of LAP after COVID-19 vaccination, were reviewed. LAP was identified after first or second dosages of three types of COVID-19 vaccines, including Pfizer-BioNTech (n = 30, 44.1%), Moderna (n = 17, 25%), and Oxford-AstraZeneca (n = 1, 1.5%). In 20 (29.4%) cases, vaccine type was not reported or only reported as mRNA COVID-19 vaccine. The median days of LAP presentation after the first and second dosages of COVID-19 vaccination, were 12 and 5 days, respectively. Most of the LAP imaging findings related to COVID-19 vaccination (n = 66, 97%) were seen from first day to 4 weeks after vaccination. However, LAP remained after 5 and 6 weeks of the first and second dosages of COVID-19 vaccination with decreased lymph nodes' size and residual cortical thickening in two cases. CONCLUSION: This review study of cases with LAP-associated COVID-19 vaccination guides radiologists and physicians to rely on patient's clinical context and updated resources to prevent potential disease upstaging and change in therapy.

Ischemic gastrointestinal complications of COVID-19: a systematic review on imaging presentation.

BACKGROUND: Limited data is available addressing gastrointestinal (GI) ischemia in coronavirus disease 2019 (COVID-19). We reviewed the clinical and radiologic features of GI ischemia and its related complications in thirty-one COVID-19 patients reported in literature. METHODS: A systematic literature review was performed using a search strategy on all studies published from January 1, 2020, to June 13, 2020, and updated on September 6, 2020, on databases from PubMed, Scopus, Embase, Web of Science, and Google Scholar. Every study with at least one presentation of COVID-19-related GI ischemia complication and one GI imaging finding was included. RESULTS: In total, twenty-two studies and thirty-one patients with the mean age of 59 ± 12.7 (age range: 28-80) years old were included, of which 23 (74.2%) patients were male, 7 (22.5%) female, and one unknown gender. The significant GI imaging findings include mesenteric arterial or venous thromboembolism, followed by small bowel ischemia. Nine patients (29%) presented with arterial compromise due to superior mesenteric thromboembolism, resulting in bowel ischemia. Also, 6 patients (19.3%) demonstrated occlusive thrombosis of the portal system and superior mesenteric vein. More than two-thirds of patients (20, 64.5%) required laparotomy and bowel resection. Eventually, five (16.1%) patients were discharged, of whom four cases (12.9%) readmitted. Five (16.1%) patients remained ICU hospitalized at the report time and 12 (38.7%) patients died. CONCLUSION: Macrovascular arterial/venous thrombosis is identified in almost half of COVID-19 patients with bowel ischemia. Overall mortality in COVID-19 patients with GI ischemia and radiologically evident mesenteric thrombotic occlusion was 38.7% and 40%, retrospectively.

Coronavirus Disease 2019 (COVID-19) in Molecular Imaging: A Systematic Review of Incidental Detection of SARS-CoV-2 Pneumonia on PET Studies.

There have been several reports of the incidental detection of severe acute respiratory syndrome coronavirus 2 pneumonia on positron emission tomography/computed tomography (PET/CT) studies, which represent the potential role of molecular imaging in the detection and management of coronavirus disease 2019. Here, we systematically review the value of PET/CT in this setting. We conducted a systematic search on June 23, 2020, for PET studies with findings suggestive of coronavirus disease 2019. Web of Science, PubMed, Scopus, EMBASE, and Google Scholar databases were used. Patients with at least one PET/CT imaging evaluation were included in the study. Fifty-two patients in 30 publications with a mean age of 60 ± 12.74 (age range; 27-87) were included in this study, of which 28 (53.8%) were male, and 19 (36.5%) were female. In 5 (9.7%) patients, gender was not reported. PET/CT was performed with 18F-fluorodeoxyglucose for 48 (92.3%), 18F-choline for 3 (5.8%), and 68Ga-PSMA for 1 (1.9%) patients. The mean SUV max of pulmonary lesions with 18F-fluorodeoxyglucose uptake was 4.9 ± 2.3. Moreover, 39 (75%) cases had an underlying malignancy, including 18 different type of primary cancers and 6 (11.5%) patients with metastatic disease. The most common pulmonary findings in PET/CT were bilateral hypermetabolic ground-glass opacities in 39 (75%), consolidation in 18 (34.6%), and interlobular thickening in 4 (7.6%). In addition, mediastinal 14 (27%) and hilar 10 (19.2%) lymph node involvement with increased metabolic activity was frequently identified. Early diagnosis of severe acute respiratory syndrome coronavirus 2 pneumonia is not only crucial for both appropriate patient management but also helps to ensure appropriate postexposure precautions are implemented for the department and hospital staff and those who have been in contact with the patient.

Extramedullary haematopoiesis presenting as a periportal mass.

Extramedullary haematopoiesis (EMH) is defined as haematopoiesis occurring in organs outside the bone marrow. The liver is one of the rare sites of EMH, and to the best of our knowledge, a few cases of adult EMH of the liver have been reported in the last 20 years. Here, we reported the case of a 68-year-old man with a known history of myelofibrosis presented with vague abdominal pain. An abdominal CT scan showed a hypoattenuating periportal mass encasing the portal vein. The final diagnosis of EMH was made through the histopathological examination. This is a rare presentation of EMH, which may be easily mistaken for other pathologies such as metastases. Familiarity with this type of presentation aids in correctly diagnosing it in an appropriate clinical setting.