Computed tomography imaging findings in hospitalized patients with coronavirus disease 2019 (COVID-19): a descriptive study of 81 cases.

PURPOSE: Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has proven to be a diagnostic challenge. Early studies have shown that computed tomography (CT) imaging may be useful in diagnosis of these patients. We aim to report CT findings in a series of hospitalized patients. MATERIAL AND METHODS: A total of 81 patients were included in this study. All of the patients were hospitalized and had SARS-CoV-2 infection proven by molecular assay. All patients had a CT scan on the first day of admission. Imaging results were reviewed by two separate radiologists, and imaging findings were documented. RESULTS: Seventy-eight patients had abnormal CT imaging, while 3 had normal CT imaging. The sensitivity of CT in diagnosing coronavirus disease 2019 (COVID-19) was estimated to be 96%. The most common imaging finding was ground glass opacities, followed by septal thickening. Most lesions were located at the periphery and posterior of the lungs. Most lesions were multifocal, and involved the right lower lobe more frequently. Chest X-rays were normal in 38 patients, and the sensitivity of chest X-ray in diagnosing SARS-Cov-2 was 54%. CONCLUSIONS: CT scans could be used in diagnosis of patients with a high sensitivity (93%). No common imaging findings may also be seen alongside ground glass opacities, based on the degree of disease progression.

Melatonin: An atypical hormone with major functions in the regulation of angiogenesis.

Melatonin (N-acetyl-5-methoxytryptamine), a pleotropic molecule with a wide distribution, has received considerable attention in recent years, mostly because of its various major effects on tissues or cells since it has both receptor-dependent and receptor-independent actions over a wide range of concentrations. These biological and physiological functions of melatonin include regulation of circadian rhythms by modulating the expression of core oscillator genes, scavenging the reactive oxygen species and reactive nitrogen species, modulating the immune system and inflammatory response, and exerting cytoprotective and antiapoptotic effects. Given the multiple critical roles of melatonin, dysregulation of its production or any disruption in signaling through its receptors may have contributed in the development of a wide range of disorders including type 2 diabetes, aging, immune-mediated diseases, hypertension, and cancer. Herein, we focus on the modulatory effects of melatonin on angiogenesis and its implications as a therapeutic strategy in cancer and related diseases.

Accuracy of diffusion-weighted imaging in discriminating atypical vertebral haemangiomas from malignant masses in patients with vertebral lesions: a cross-sectional study.

PURPOSE: Vertebral haemangiomas are incidental findings in imaging modalities. Atypical haemangiomas are haeman-giomas rich in vascular tissue, and they are found to be hypointense in T1 sequences and hyperintense in T2 sequences, mimicking the findings of metastatic lesions. In the present study we aim to evaluate the ability of diffusion- weighted imaging to differentiate these two groups of vertebral lesions. MATERIAL AND METHODS: In the present cross-sectional study, a total of 23 lesions were included, including 10 haemangiomas and 13 malignant lesions. Diffusion-weighted imaging was used to compare atypical haemangiomas and metastatic lesions. The apparent diffusion co-efficient was determined for each lesion, and then the mean of each group was calculated. The means were then compared. Receiver operating characteristic analysis was used to determine a cut-off ADC value to differentiate these lesions. RESULTS: The difference between the mean age of the two groups was not significant. The mean ADC value for atypical haemangiomas was 1884 ± 74 × 10-6 mm2/s and 1008 ± 81 × 10-6 mm2/s for the malignant lesions. The difference between the two groups was statistically significant (p < 10-3). ROC curve analysis determined an ADC value of 958 × 10-6 mm2/s to be able to differentiate between atypical haemangiomas and malignant lesions. CONCLUSIONS: Diffusion-weighted MRI could be used to differentiate between atypical haemangiomas and malignant metastatic lesions.

Visibility of Different Intraorbital Foreign Bodies Using Plain Radiography, Computed Tomography, Magnetic Resonance Imaging, and Cone-Beam Computed Tomography: An In Vitro Study.

PURPOSE: The study sought to compare the usefulness of 4 imaging modalities in visualizing various intraorbital foreign bodies (IOFBs) in different sizes. METHODS: Six different materials including metal, wood, plastic, stone, glass. and graphite were cut in cylindrical shapes in 4 sizes (dimensions: 0.5, 1, 2, and 3 mm) and placed intraorbitally in the extraocular space of fresh sheep's head. Four skilled radiologists rated the visibility of the objects individually using plain radiography, spiral computed tomography (CT), magnetic resonance imaging (MRI), and cone-beam computed tomography (CBCT) in accordance with a previously described grading system. RESULTS: Excluding wood, all embedded foreign bodies were best visualized in CT and CBCT images with almost equal accuracies. Wood could only be detected using MRI, and then only when fragments were more than 2 mm in size. There were 3 false-positive MRI reports, suggesting air bubbles as wood IOFBs. CONCLUSIONS: Because of lower cost and using less radiation in comparison with conventional CT, CBCT can be used as the initial imaging technique in cases with suspected IOFBs. Optimal imaging technique for wood IOFBs is yet to be defined.

The utility of ultrasonographic bone age determination in detecting growth disturbances; a comparative study with the conventional radiographic technique.

OBJECTIVE: To test whether the conventional radiographic technique in determining bone age abnormalities can be replaced by ultrasonography. MATERIALS AND METHODS: A total of 54 Caucasian subjects up to 7 years of age with clinically suspected growth problems underwent left hand and wrist radiographic and ultrasonographic bone age estimations with the use of the Greulich-Pyle atlas. The ultrasonographic scans targeted the ossification centers in the radius and ulna distal epiphysis, carpal bones, epiphyses of the first and third metacarpals, and epiphysis of the middle phalanx, as described in previous reports. The degree of agreement between the two sets of data, as well as the accuracy of the ultrasonographic method in detecting radiographically suggested bone age abnormities, was examined. RESULTS: The mean chronological age, radiographic bone age, and ultrasonographic bone age (all in months) were 41.96 ± 22.25, 26.68 ± 14.08, and 26.71 ± 13.50 in 28 boys and 43.62 ± 24.63, 30.12 ± 17.69, and 31.27 ± 18.06 in 26 girls, respectively. According to the Bland-Altman plot there was high agreement between the results of the two methods with only three outliers. The deviations in bone age from the chronological age taken by the two techniques had the same sign in all patients. Supposing radiography to be the method of reference, the sensitivity, specificity, positive predictive value, and negative predictive value of sonography in detecting growth abnormalities were all 100% in males and 90.9, 100, 100, and 93.8%, respectively, in females. CONCLUSION: The conventional radiographic technique for determining bone age abnormalities could be replaced by ultrasonography.

The Effect of Everolimus on Subependymal Giant Cell Astrocytoma (SEGA) in Children with Tuberous Sclerosis Complex.

OBJECTIVE: Subependymal Giant Cell Astrocytomas (SEGAs) are slow-growing glioneuronal tumors typically found around the ventricles of the brain, particularly near the foramen of Monro in 15%-20% of patients with tuberous sclerosis complex (TSC). Surgical resection is the standard treatment for these symptomatic tumors. The mTOR inhibitor everolimus can be regarded as an alternative treatment for SEGAs due to the complications of surgery. The present study primarily aimed to specify the effect of everolimus on SEGA volume change before and after treatment. The secondary objective was to determine the effect of this drug on renal angiomyolipoma (AML), skin lesions, and seizures in TSC patients. MATERIALS & METHODS: This pre- and post-treatment clinical trial was performed on 14 children (eight females and six males with a mean age of 10 years) previously diagnosed with TSC based on the diagnostic criteria. The subjects received oral everolimus at a dose of 3 mg/m2 for at least six months. RESULTS: Half of the patients had more than 30% of volume loss in SEGA, and in 28.5% of them, a ≥ 50% reduction in SEGA volume was observed (P=0.01). Moreover, 92.9% of the patients had a ≥ 50% decrease in the frequency of seizures (P=0.000). The response rate in AML and skin lesions was 14.2% and 50%, respectively. CONCLUSION: Everolimus significantly reduced the seizure frequency and SEGA volume in the subjects; hence, it can be used as a potential alternative treatment for symptomatic SEGA in TSC patients.

Accuracy of ultrasonography in detecting gastrointestinal tract obstructions in children; a prospective study in a tertiary referral hospital.

AIMS: To examine the diagnostic accuracy of plain radiography, abdominal ultrasonography (US), and their combination in pediatric patients with suspected gastrointestinal (GI) tract obstruction. MATERIAL AND METHODS: A cohort of 48 patients (age, 0-14 years, 27 boys) with clinical manifestations of GI tract obstruction underwent plain radiography and abdominal US examination. The final diagnoses were based on intraoperative findings, rectal biopsies (in Hirschsprung's disease), or adequate follow-ups. RESULTS: The GI tract obstruction was diagnosed in 40 patients. The sensitivity, specificity, positive predictive value and negative predictive value of plain radiography in diagnosing GI tract obstruction were 87.5%, 75.0%, 94.6%, and 54.6%, respectively. The corresponding values were 95%, 100%, 100%, and 80%, respectively when US was used alone; and 97.5%, 100%, 100% and 88.9%, respectively when radiography and US were used together. Except for two patients (one with Hirschsprung's disease and the other with massive peritonitis), US detected the underlying causes of obstruction correctly in all patients. CONCLUSIONS: US is a highly sensitive and specific modality in diagnosing pediatric GI tract obstructions, as well as their causes. The combination of plain radiography and US further increase the diagnostic sensitivity and negative predictive value.

Can Chest Computed Tomography Be Replaced by Lung Ultrasonography With or Without Plain Chest Radiography in Pediatric Pneumonia?

PURPOSE: The purpose of this study was to answer the following question: can chest computed tomography (CT) requested by pediatricians be replaced by lung ultrasonography (US) with or without chest radiography in pediatric pneumonia? MATERIALS AND METHODS: A total of 98 children with suspected pneumonia who were referred by pediatricians for CT examinations were prospectively studied. Levels of agreement between CT findings and plain radiography, lung US, and chest radiography plus lung US results were investigated. RESULTS: CT defined pneumonia in 84 patients, among which 26 cases were complicated. κ values between radiography and CT findings were 0.82 in complicated cases, 0.67 in uncomplicated cases, and 0.72 overall. The corresponding values between US and CT findings were 1, 0.52, and 0.62, respectively, and between radiography plus US and CT findings were 1, 0.86, and 0.88, respectively. CONCLUSIONS: CT can be replaced by US when complex effusions are present in children with pneumonia. In case of an ambiguous diagnosis of pediatric pneumonia with or without complex effusions, a combination of chest radiography and US is a reliable surrogate for chest CT.

Normal Values of Spleen Length and Volume: An Ultrasonographic Study in Children.

We aimed to determine normal ultrasonographic limits of spleen length and volume in healthy Caucasian neonates and children. A total of 458 healthy cases (age, 1 d to 15 y; sex, 241 males and 217 females) with normal body measurements were included. Spleen length and volume were obtained ultrasonographically. The two genders were comparable for the mean spleen length and volume. Lower and upper normal limits were tabulated according to age and sex groups. Significant correlations (Pearson r > 0.80; p < 0.001) were present between spleen length/volume and age, height and weight. Two equations were created to estimate spleen length and volume by age. Normal spleen lengths and volumes and their lower and upper limits were obtained ultrasonographically in a large sample of Caucasian pediatric patients.

Comparison of non-electrophoresis grade with electrophoresis grade BIS in NIPAM polymer gel preparation.

INTRODUCTION: The main objective of this study was to investigate the possibility of replacing electrophoresis cross-linker with non-electrophoresis N, N'-methylenebisacrylamide (BIS) in N-isopropyl acrylamide (NIPAM) polymer gel and its possible effect on dose response. METHODS: NIPAM polymer gel was prepared from non-electrophoresis grade BIS and the relaxation rate (R2) was measured by MR imaging after exposing the gel to gamma radiation from Co-60 source. To compare the response of this gel with the one that contains electrophoresis grade BIS, two sets of NIPAM gel were prepared using electrophoresis and non-electrophoresis BIS and irradiated to different gamma doses. RESULTS: It was found that the dose-response of NIPAM gel made from the non-electrophoresis grade BIS is coincident with that of electrophoresis grade BIS. CONCLUSION: Taken all, it can be concluded that the non-electrophoresis grade BIS not only is a suitable alternative for the electrophoresis grade BIS but also reduces the cost of gel due to its lower price.

Imaging findings of Gorlin-Goltz syndrome.

A 15-year-old girl was referred to a dentist complaining of parageusia, bad taste in the mouth, which started 9 months ago. Panoramic X-ray and non-enhanced computed tomography scan revealed multiple bilateral unilocular cysts in the mandible and maxilla, along with calcification of anterior part of the falx cerebri. She was eventually diagnosed with Gorlin-Goltz syndrome based on imaging and histopathologic finding of keratocystic odontogenic tumor.

Dosimetric properties of N-isopropylacrylamide polymer gel using nonelectrophoresis grade BIS in preparation.

INTRODUCTION: Unlike availability of the different grades of N, N'-methylenebisacrylamide (BIS), electrophoresis is recommended in literature as a crosslinking agent in gel preparation. As the cost of non-electrophoresis grade BIS is much less than that of electrophoresis, the dosimetric characteristics of the of the polymer gel using non-electrophoresis BIS is evaluated in terms of photon energy and dose rate. MATERIALS AND METHODS: To compare the response of this gel with the one that contains electrophoresis grade BIS, two sets of N-isopropylacrylamide (NIPAM) gel were prepared using electrophoresis and non-electrophoresis BIS and irradiated to different gamma doses. RESULTS: It was shown that the dose-response of NIPAM gel made from non-electrophoresis grade BIS is coincident to that of electrophoresis grade BIS. The study of dose response of NIPAM with non-electrophoresis grade BIS as a function of beam energy revealed no dependence on radiation energies of 1.25 MV from 60 Co and 6 MV and 18MV from linear accelerator. It was found that dose rate has no influence on dose response of NIPAM gel with non-electrophoresis BIS. CONCLUSION: Substitution non-electrophoresis grade BIS not only reduces the cost of gel preparation without any adverse effect on its dose response, but also its lower background increases the dynamic range of dose linearity.