SUMMARY Purpose: To apply the CAD-RADS classification in the assessment of chronic coronary artery disease on multislice computed tomography. Material and methods: Cross-sectional description of 179 patients undergoing coronary computed tomography angiography, diagnosed according to CAD-RADS classification by two physicians independently, the intra-class correlation was used to test the inter-reviewer agreement (IRA), and comparing with results invasive coronary angiography. Results: There was an excellent IRA between the two for CADRADS (κ=0.904), by each CAD-RADS classification (κ=0.827-1.00), by coronary artery stenosis (κ=0.878-0.931). There is an excellent IRA for modifiers G (κ=1), and S (κ=1), moderate IRA for V (κ=0.574). The best cutoff value for predicting significant CAD was ≥ CAD-RADS 3. The diagnostic value of CAD-RADS classification according to the common segment: sensitivity 77.54%, specificity 87.23%, positive predictive value 89.92%, negative predictive value 72.56%. Conclusion: There is an excellent inter-reviewer agreement when applying the CAD-RADS classification to clinical practice, with high sensitivity, specificity, and accuracy when compared with invasive coronary angiography. Keywords: coronary artery, CAD-RADS, CT angiography, graft, stent

SUMMARY Objective: To determine the proportion of bone metastasis and whole-body scintigraphy with 99mTc-MDP in neuroblastoma (NB) in children. Subjects and Methods: A retrospective descriptive combined prospective study was conducted on 86 patients under 15 years old, diagnosed with NB according to the standards of Pediatric Oncologists Conference in 1988 and had whole-body scintigraphy with 99mTc-MDP at Vietnam National Children's Hospitalfrom January 2018 to March 2020. Results: The proportion of detection metastasis was 33.7%. There are 55.2% patients with bone metastases without clinical manifestations (without bone pain). 100% cases of bone metastases on whole-body scintigraphy have images of increased radioactivity. Most of the patients were about 2 - 4 years old 58.6%, lower limb position 62.1%, multifocal lesions 72.4%, of which 58.6% patients had over 5 lesions. Conclusions: Whole-body scintigraphy with 99mTc-MDP is a valuable technique for detecting bone metastases on NB in the early stage when absence of clinical manifestations of bone metastases. Keywords: Neuroblastoma, whole-body scintigraphy, 99mTc-MDP.

SUMMARY Objective: To describe the anatomical variations in posterior half of the circle of Willis and to determine the rate of the anatomical variability of these arteries. Materials and Methods: We conducted a cross-sectional study in 480 people who were performed CT angiography of the cerebral arteries at the University Medical Center Hospital between January 2019 and December 2020. The blood vessels to be investigated included: posterior communicating arteries, posterior cerebral arteries, basal artery, anterior inferior cerebellar arteries, posterior inferior cerebellar arteries, and the superior cerebellar artery. A radiologist who had more than 5 years of experience of CT brain evaluates these anatomical variations: hypoplasia, aplasia, fetal type, fenestration, duplication, triplication and double origin. Results: The study was composed of 480 people (259 males, 221 females). The mean age of people was 55.7 ± 16.7 years (range, 2 - 102 years). 50 - 69 age group accounts for the majority with 237 people (49.4%). The anatomical variations of posterior communicating artery: unilateral hypoplasia 38.5%, bilateral hypoplasia 19.4%, unilateral aplasia 22.9%, bilateral aplasia 4.0%, fenestration 0.4%. The anatomical variations of posterior cerebral artery: unilateral hypoplasia 10.2%, bilateral hypoplasia 3.5%, unilateral aplasia 8.8%, bilateral aplasia 1.3%, unilateral fetal 17.9%, bilateral fetal 5%. The anatomical variations of basal artery: hypoplasia 5.6%, aplasia 0%, fenestration 0.6%. The anatomical variations of anterior inferior cerebellar artery: unilateral aplasia 30%, bilateral aplasia 10.4%, unilateral duplication 1.3%, bilateral duplication 5.8%, triplication 0.2%. The anatomical variations of posterior inferior cerebellar artery: unilateral aplasia 29%, bilateral aplasia 5.8%, unilateral duplication 0.4%, bilateral duplication 0%, fenestration 0.2%, double origin 0.2%. The anatomical variations of the superior cerebellar artery: aplasia 0%, unilateral duplication 11.3%, bilateral duplication 2.9%, triplication 1.7%, double origin 0.4%. Conclusion : The anatomical variations in posterior half of the circle of Willis are common. The most common abnormalities are the fetal type of posterior cerebral artery, hypoplasia or aplasia of the posterior communicating artery, hypoplasia or aplasia anterior and posterior inferior cerebellar artery, and the duplication of the superior cerebellar artery. Keywords: posterior circulatory system, computed tomography, anatomical variations.

Renal tumors in the Phakomatosis disease, what to note: two case report SUMMARY Phakomatosis are a group of neurocutaneous disorders characterised by involvement of structures that arise from the embryonic ectoderm , consist of central nervous system, skin ,eyes and others: kidney, heart, lung… In this article we focus on the incidence of renal tumors in Tuberous sclerosis, one of the common diseases in Phakomatosis. Tuberous sclerosis is a rare neurocutaneous disorder (phakomatosis) characterized by the development of multiple benign tumours in various organs, including the kidneys. Tuberous sclerosis complex has several renal manifestations including angiomyolipomas (AML) and renal epithelial neoplasms. Angiomyolipomas is found in 40% of patients with tuberous sclerosis, and its most common complication is ruptures due to aneurysms. We present two cases was diagnosed with bilateral angiomyolipomas in tuberculosis and emphasizes the importance of the diagnosis and choice of appropriate treatment for each patient. Key words : Phakomatosis, renal tumor