AIM: To evaluate a novel deep-learning denoising method for ultra-low dose CT (ULDCT) in the assessment of coronary artery calcium score (CACS). MATERIALS AND METHODS: Sixty adult patients who underwent two unenhanced chest CT examinations, a normal dose CT (NDCT) and an ULDCT, were enrolled prospectively between September 2017 to December 201. A special training set was created to learn the characteristics of the real noise affecting the ULDCT implementing a fully convolutional neural network with batch normalisation. Subsequently, the 60 ULDCTs of the evaluation set were denoised. Two blinded radiologists assessed the NDCT, ULDCT, and denoised-ULDCT (DULDCT), assigning a CACS and categorised each scan as having a score above or below 100 and presence of calcifications (score 0 versus 0.001). Interobserver agreement was almost perfect between readers (intraclass correlation coefficient 0.001). In differentiating between the presence and absence of coronary artery calcifications, DULDCT showed greater accuracy (98-10 0%) and positive likelihood ratio (14.29- 99) compared to ULDCT (92% and 2.78, respectively). CONCLUSION: DULCT significantly reduced the image noise and better identified patients with no coronary artery calcifications than native ULDCT. ?? 2022 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

We present a brief description of our recent work that was submitted for journal publication introducing a novel system for generation of virtual PET images using CT scans [1]. We combine a fully convolutional network (FCN) with a conditional generative adversarial network (GAN) to synthesize PET images from given input CT images. Clinically, such solutions may reduce the need for the more expensive and radioactive PET/CT scan. Quantitative evaluation was conducted using an existing lesion detection software, combining the synthesized PET as a false positive reduction layer for the detection of malignant lesions in the liver. Current results look promising showing a reduction in the average false positive per case while keeping the same true positive rate. The suggested solution is comprehensive and can be expanded to additional body organs, and different modalities.

AIM: To present the computed tomography (CT) imaging features of floating aortic thrombus with emphasis on clinical and radiographic predictors for systemic shower emboli. MATERIALS AND METHODS: A retrospective computerised search for patients with protruding thoracic aortic thrombus on CT was conducted. Clinical and demographic characteristics were retrieved from medical files. Patients were divided into two groups: symptomatic and asymptomatic, based on the presence or absence of documented systemic emboli at the time of diagnosis or during follow-up. CT imaging features were analysed: location and extent of systemic emboli, presence or absence of thrombus insertion calcification, percentage of thrombus circumference that is attached to the aortic wall and thrombus volume. Clinical and demographic variables and CT imaging features were analysed as potentially associated with symptomatic emboli. RESULTS: The symptomatic group included 6/15 (40%) patients and the asymptomatic group included 9/15 (60%) patients. Patients in the symptomatic group were significantly younger (symptomatic: 53.3 +/- 11.7 years, asymptomatic: 76.9 +/- 8.4 years, p = 0.003). All the symptomatic patients were women (100%), while 2/9 (22.2%) of the asymptomatic patients were women, (p = 0.007). A non-calcified insertion site was more frequent in the symptomatic group (symptomatic 4/6 [66.7%] versus asymptomatic group 1/9 [11.1%], p = 0.011). The percentage of thrombus circumference attached to the aortic wall was significantly smaller in symptomatic patients (symptomatic: 31.8 +/- 8.4%, asymptomatic: 43.7 +/- 5%, p = 0.003). CONCLUSION: The imaging features of symptomatic floating thrombus include a narrow base of attachment and lack of insertion calcification. Free-floating thrombus should be actively sought and diagnosed or excluded when performing CT andiography for emboli. (C) 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

AIM: To assess the frequency of undetected colon cancer on conventional abdominal CT and to evaluate the imaging features that are characteristic of those cancers.MATERIALS AND METHODS: The present study included consecutive patients diagnosed with colorectal cancer at colonoscopy (2006-2015) who also underwent abdominal computed tomography (CT) performed for various reasons within a year prior to the colonoscopy. The frequency of undetected lesions was evaluated for the original CT interpretations ("original readers"). Two radiologists ("study readers"), blinded to the tumour location, independently performed interpretations oriented for colon cancer detection. The study readers analysed the imaging features of detected tumours (tumour shape, length, maximal wall thickness, free fluid, fat stranding, vascular engorgement, stenosis, and lymphadenopathy). Imaging features of the cancers undetected by the original readers were evaluated.RESULTS: The study included 127 patients. The original readers' frequency of undetected cancer was 25/127 (19.7%). Each study reader could not identify the cancer in 8/127 (6.3%) patients. Imaging features associated with undetected cancers by the original readers included the absence of fat stranding (p=0.007, p=0.003), absence of vascular engorgement (p<0.0001, p<0.0001) and absence of lymphadenopathy (p=0.005, p=0.004). Undetected tumours were shorter than those detected (original reader: 33.2 +/- 11.9 versus 51.4 +/- 18.2 mm; study reader: 32.5 +/- 9.6 versus 61.3 +/- 23.4 mm; p<0.001).CONCLUSION: Colon cancer is undetected in 20% of abdominal CT examinations in patients subsequently proven to have colon cancer at colonoscopy. The absence of fat stranding, vascular engorgement, or lymphadenopathy, and an average tumour length of 3.3 cm are contributing factors for failure of detection. Radiologists' training should emphasis these findings as it may improve cancer detection, and clinicians should be aware of the limitations of abdominal CT. (C) 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

To re-evaluate existing normal biometric reference data of fetal posterior fossa in MRI, suggest new biometric parameters, and demonstrate the possible clinical applications of this data. A retrospective review of 215 normal fetal MR examinations and eight examinations of fetuses with a diagnosed pathological PF. The six previously reported parameters measured were: A-P diameter of the vermis, vermian height, vermian perimeter, vermian cross sectional area (CSA), trans-cerebellar diameter, and pontine A-P diameter. The ten new parameters measured were: the vermian anterior lobe CSA (VALS), vermian posterior lobe CSA (VPLS), pontine height (PH), pontine CSA (PS), brain stem CSA (BSS), cistrana-magna CSA (CMS), cerebellar perimeter (CP), cerebellar CSA (CS) and cerebellar hemispheres CSA (CHSA, CHSB). Three ratios were calculated: between vermian anterior and posterior lobes (VLR), between VS and CMS (VCMR), and between CHSA and CHSB (CHR). Inter-observer agreement was calculated. 151 To 211 MRI examinations were selected adequate for measuring each structure, resulting in a normal biometry curve according to gestational age (GA) for each parameter. Analysis of the ratio parameters showed that VLR stays constant with GA, CHR stays constant and equals 1, and VCMR varies with GA. Measurements of the eight pathological PF were presented in comparison to the normal curves. Inter-observer agreement was excellent, with all parameters above ICC of 0.65. The biometry curves of the normal fetal PF, derived from existing biometric data and new biometric data presented in this study,are a simple, repeatable and objective tool with a potential clinical significance when evaluating the fetal PF pathology and possible outcome. By applying the extensive biometric data presented, we re-evaluated pathological fetal PF, and showed that the suspected pathologies may be confirmed, better classified, or completely altered.

Abstract Purpose: 1) To evaluate and classify the indications for fetal brain MRI in a tertiary referral center. 2) To assess the contribution of fetal brain MRI to fetal neurosonography. Materials and Methods: A retrospective study in a tertiary medical center during a two-year period (2011 – 2012) included pregnant women who underwent fetal brain MRI. MRI was implemented at 32 weeks of gestation unless a severe abnormality possibly requiring earlier medical intervention was suspected. Results: 633 patients were included, 40 (6.3 %) underwent repeated examinations with a total of 733 fetal MRI scans. Patients were classified to three main indication cohorts: Suspected primary brain anomaly (52.9 %), non-CNS disorders (32.5 %) and obstetrical complications (14.6 %). These cohorts were further divided into 16 separate groups with lateral ventricle abnormalities being the most common (23.7 %), followed by exposure to TORCH (17.5 %) and cerebral cortex abnormalities (13 %). 149 (19.3 %) fetal MRI scans demonstrated additional findings. Repeated examinations were commonly implemented in complicated monochorionic-biamniotic (MCBA) twin pregnancies (34.6 %) and in cases of supra-tentorial cysts (19 %). The average gestational age for MRI scan in the MCBA group was 26 ± 5 weeks in comparison to ≥ 31st weeks in all other groups (p < 0.001). Conclusion: The current study describes a detailed picture of fetal brain MRI indications. Most patients were referred because of CNS anomalies. The impressive diversity of 16 separate entities emphasizes the expanding use of fetal brain MRI. Complicated MCBA pregnancies, which may have dramatic events, constitute a unique challenge due to early and repetitive MRI examinations and may serve as a role model for the contribution of fetal MRI during antenatal evaluation. The contribution of MRI to prenatal evaluation in various indications is discussed.

To evaluate the agreement between ultrasound (US) and fetal brain magnetic resonance imaging (feMRI) head biometry. A retrospective analysis was performed on 60 sequential feMRI scans obtained between 2011-2013 following US suspicion of microcephaly w/wo severe intrauterine growth retardation (head circumference ≤ -2 standard deviations [SD] and estimated fetal weight [EFW] ≤2 SD). Inclusion criteria were single fetus and fewer than 21 days between performance of US and feMRI. The mean gestational age (GA) of fetuses at US and feMRI acquisition was 33 ± 3.3 and 34 ± 3 weeks, respectively. The mean interval between US and feMRI scanning was 7.3 ± 6 days. Biparietal diameter (BPD) and occipitofrontal diameter (OFD) results were converted to percentiles and SD by Hadlock and Chervenak normograms for US and compared to Garel normograms for feMRI. US measurements of OFD were recorded in 36/60 of the scans. Data on GA, EFW and interval between scans were also recorded. Forty-two of the 60 fetuses with US-suspected microcephaly (70%) were IUGR. BPD values were ≤ -2 SD in only 5 (8.3%) according to feMRI (P < 0.001). OFD measurements on feMRI were ≤ -2 SD in 2 fetuses (5.5%) (P < 0.001). Abnormal anatomical findings were observed In 5 cases. There is discrepancy between US and feMRI findings in the assessment of fetal head biometry. US measurements are performed only on the skull, while feMRI enables direct measurement of the brain. Abnormal anatomical findings are more predictive for true microcephaly in both US and feMRI. Thus, diagnosis of microcephaly by US alone is not sufficient and should be validated by feMRI before a final diagnosis is established and consultations with the parents are held.

Objectives: Accurate diagnosis of constrictive pericarditis (CP) is a well-recognized clinical challenge. Since magnetic resonance imaging (MRI) provides high resolution assessment of ventricular volumes, we sought to investigate left ventricular (LV) and right ventricular (RV) time-volume curve using four-dimensional MRI (4D MRI) in patients with CP. Methods: Fourteen patients with CP who had undergone surgery for pericardiectomy and 10 normal subjects were included. Three dimensional MRI covering the whole myocardium in the short axis projection was performed. LV and RV volumes were evaluated over the whole cardiac cycle to generate a four-dimensional MRI dataset for assessment of ventricular time volume curve yielding systolic function and filling parameters: end-diastolic and end-systolic volume, ejection fraction, filling time, early and late filling volume, E/A ratio, peak filling rate (PFR), and time to peak filling rate (TPFR). Results: In patients compared with normal subjects, LV and RV end-diastolic and end-systolic volumes were decreased (all P < 0.05), but biventricular ejection fraction was similar. The filling time of both ventricles was significantly shorter (both P < 0.001). In early diastole, LV and RV filling volumes were increased (P = 0.004, P < 0.001; respectively), in late diastole; however, LV and RV filling volumes were reduced (both P < 0.001). Biventricular E/A ratio and PFR were higher (all P < 0.001) and TPFR of the right ventricle was lower (P = 0.02) in patients compared with normal subjects. Conclusion: In patients with CP quantitative 4D MRI analysis provides reduction in end-diastolic and end-systolic volumes and demonstrated a typical hemodynamic response. In early diastole both ventricles have an increased filling, in late diastole, however; the constricted physiology allowed only a slight ventricular filling.

Background: Myocarditis with an acute coronary syndrome (ACS)-like presentation poses an important clinical challenge in the differential diagnosis of acute myocardial infarction (AMI). Comparing ACS-like myocarditis with AMI patients can shed a light on the similarities and the important differences between the two clinical syndromes. Objective: To compare the clinical, laboratory and echocardiographic characteristics of patients with ACS-like myocarditis and acute myocardial infarction. Methods: We conducted a retrospective analysis comparing consecutive patients, hospitalized at the Sheba Heart Center, with cardiac magnetic resonance (CMR)-proven ACS-like acute myocarditis and non-ST elevation MI (NSTEMI) between February 2002 and May 2012. The AMI group included patients with NSTEMI, without prior structural heart disease (SHD). Elderly NSTEMI patients (age>65) were excluded to achieve a minimal degree of matching between the cohort populations. Results: One hundred and one consecutive patients with CMR confirmed myocarditis were included along with 124 patients with first NSTEMI, average age of 33.9±12.5 vs. 52.4±7.6 respectively (p<0.001). Cardiac risk factors were significantly more prevalent in the AMI group (p<0.01). The average ejection fraction was 54.0% and 54.6% (NS) respectively, with similar prevalence of localized regional wall motion abnormality (WMA) and average WM score index of 1.2 in both study groups. The cardiac biomarkers were markedly higher in the myocarditis group including troponin I (14.5 vs. 5.9, p<0.001) and peak CPK (648.5 vs. 447.5, p=0.008). In-hospital clinical outcome parameters like hemodynamic instability and pulmonary congestion were similar while we found a trend towards more tachyarrhythmia in patients with myocarditis (8 vs. 4, p=0.07). Conclusions: Localized regional WMA is as prevalent in ACS-like myocarditis as in AMI patients, emphasizing the diagnostic dilemma between the two entities. Interestingly, we show significantly higher cardiac biomarkers elevation for the same extent of myocardial dysfunction in patients with acute myocarditis compared to myocardial infarction.

Objectives: Microvascular obstruction (MVO) demonstrated on cardiac MRI (CMR) following primary percutaneous coronary interventions (PPCI) is an independent predictor of adverse outcome in patients with ST segment elevation MI (STEMI). The purpose of this study was to determine demographic, clinical and angiographic correlates of MVO (on CMR) post PPCI for STEMI. Methods: The study comprised 60 consecutive patients who underwent PPCI for first STEMI within 12 hours of symptoms onset. CMR scans were performed 4 ± 1 days post PPCI. CMR was evaluated for left ventricular (LVEF), right ventricular ejection fractions (RVEF), presence and amount (gr) of delayed enhancement (DE) and MVO. The patients were stratified into 3 thirds based on the MVO/LV mass. Peak troponin levels were determined in all patients. Results: Patients in the upper third (mean MVO/LV mass =5.4 ± 2; N = 20) compared with the patients in the other two thirds (0.7 ± 0.8; N = 40) had larger extent of DE (27 ±10 gr VS. 17 ±12 gr; p < 0.01 ), lower LVEF ( 50% ±10 VS. 57% ±10%; p = 0.03 ), higher peak troponin value (131 ±96 VS. 40 ±33; p < 0.01 ) and numerically higher incidence of LV thrombus (16% VS. 2.6%; p = 0.09). Patients in the upper third were less likely to have an open infarct related artery (IRA) on the first angiography (16% VS. 53%; p = 0.04). Patients in the two study groups were similar with respect to their age, gender distribution, risk factors for CAD including diabetes and hypertension as well as angiographic extent of CAD and IRA distribution. There were also no significant differences in the clinical features including ischemic time, door to balloon time, initial infarct extent as manifested by the summation of ST – segment elevation. Conclusions: In STEMI patients undergoing PPCI, MVO (on CMR) extent was associated with indices of larger infarction, presence of LV thrombus and was less likely in patients with open IRA on initial angiogram.

AIM: To evaluate a revised protocol for whole-body computed tomography (CT) for multi-trauma patients in an emergency department and compare it to conventional protocols.MATERIALS AND METHODS: Forty-two of 82 multi-trauma patients underwent unenhanced CT examinations of the head, cervical spine, and upper abdomen, followed by an arterial-phase contrast-enhanced CT examination of the thorax and a porto-venous scan of the abdomen and pelvis (conventional protocol). The other 40 patients underwent unenhanced CT examinations of the head, cervical spine, and upper abdomen, followed by a one-step acquisition of the thorax, abdomen, and pelvis using a 64-section multidetector CT (MDCT) system following a triphasic injection (revised protocol). Contrast enhancement was measured in the ascending, descending, and abdominal aorta, common iliac arteries, inferior vena cava (IVC), liver, spleen, and kidneys. Image count, radiation dose, total acquisition time, mediastinal artefacts, and image quality of each area were reviewed.RESULTS: Mean enhancement values in the ascending and descending aorta were significantly greater with the conventional protocol. Enhancement of the abdominal aorta, iliac arteries, IVC, liver, spleen, and kidneys was significantly greater with the revised protocol. Mediastinal streak artefacts were present in all conventional protocol images and absent in all revised protocol images. Image quality using the revised protocol was significantly better (p < 0.002). The mean effective radiation dose was significantly lower (p = 0.005), and image number reduced (p < 0.001).CONCLUSION: The revised triphasic injection single-pass whole-body imaging protocol was superior to the conventional protocol using 64-MDCT. It enabled better vascular and abdominal parenchymal imaging with reduction in radiation dose and image overload. (c) 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

<正>该研究旨在根据是否存在冠状动脉钙化(coronary artery calcium,CAC)将高血压合并糖尿病患者心血管危险分为低或高。方法:研究包括高血压患者423例,所有患者都进行基础CT检查,应用非增强双

Objectives: Familial Mediterranean fever (FMF) is characterized by recurrent episodes of fever, peritonitis, arthritis, and pleuritis, caused by neutrophil-induced sterile serositis. Another clinical manifestation in patients with FMF is exertional leg and ankle pain that appears after minor exercise, for which the underlying mechanism is obscure. The purpose of the current study was to feature distal leg changes in FMF patients complaining of exertional leg pain, using magnetic resonance imaging (MRI). Methods: Eleven patients with FMF who suffer from exertional leg pain (eight males, three females; mean age 33 years) and six unaffected controls (three males, three females; mean age 39 years) underwent MRI (3 T) of the ankle, including conventional T1 and T2 with fat saturation sequences, before and after graded exercise on a treadmill. Clinical and genetic data and sacroiliac radiographs were obtained. Results: Ten patients (91%) with FMF but none of the control group had signs compatible with enthesitis of the Achilles tendon, long plantar ligament, or the plantar fascia (including enthesophytes, erosions, and bone marrow oedema). Nine patients (80%) had radiographic signs of sacroiliitis on the pelvic radiograph. Conclusions: Exertional leg pain in FMF patients, shown to be associated with signs of enthesopathy on imaging, may be included within the spectrum of spondyloarthropathy.

AIM:To evaluate the effect of physical activity on the structural, morphological, and metabolic characteristics of the gastrocnemius muscle in familial Mediterranean fever (FMF) patients, utilizing quantitative (31)P magnetic resonance spectroscopy (MRS), in order to elucidate the mechanism of their exertional leg pain. MATERIALS AND METHODS:Eleven FMF patients suffering from exertional leg pain (eight male, three female; mean age 33 years) and six healthy individuals (three male, three female; mean age 39 years) constituted the control group. All of the participants underwent magnetic resonance imaging (MRI) and non-selective (31)P MRS (3 T) of the leg muscles before and after graded exercise on a treadmill. Phosphocreatine (PCr):inorganic phosphate (Pi), PCr:adenosine triphosphate (ATP) ratios and the intracellular pH of the leg muscles were measured using (31)P MRS. RESULTS:For both groups, normal muscle mass with no signal alterations was observed on the MRI images after exercise. The normal range of pre- and post- exercise MRS muscle parameters was observed in both groups. However, the intracellular pH post-exercise, was significantly higher (less acidic) in the FMF group compared to the control group [pH (FMF) = 7.03 ± 0.02; pH (control) 7.00 ± 0.02; p < 0.0006]. CONCLUSIONS:The finding of a less prominent, post-exercise acidification of the gastrocnemius muscle in this FMF patient group suggests a forme fruste of glycogenosis. This preliminary observation should be further investigated in a future, larger-scale study.

Aim: Despite clear evidence of immune system involvement in the pathogenesis of myocarditis, the treatment of myocarditis remains nonspecific and supportive. We sought to test the hypothesis that injection of a collagen-based implant into the inflamed myocardium would stabilize the left ventricular (LV) wall and prevent adverse remodeling and dysfunction. Methods and Results: Autoimmune myocarditis was induced in 42 male Lewis rats. Development of myocarditis was evaluated and confirmed by serial echocardiography and cardiac magnetic resonance scans, LV wall thickening, global and regional LV wall motion abnormalities, and in some cases pericardial effusion. Sick animals were randomized to either injectable collagen implantation or saline injection into the anterior inflamed myocardium 14 days after immunization. Significantly, injectable collagen implantation improved 31-day survival compared with controls (85.7% vs 50%; P = .03). Furthermore, although injectable collagen significantly attenuated LV systolic and diastolic dilatation and preserved LV geometry and function, control animals developed significant LV dilatation and dysfunction. These favorable effects on LV remodeling were confirmed by postmortem morphometry. Significantly, the injectable collagen implant attenuated cardiomyocyte hypertrophy and infiltration of macrophages and lymphocytes into the myocardium. Conclusions: The present study shows, for the first time, that injectable collagen biomaterial improves survival and attenuates cardiac inflammation, cardiomyocyte hypertrophy, LV remodeling, and dysfunction in the early period after myocarditis in rats. Our findings suggest a new biomaterial-based strategy to ameliorate the devastating effects of myocarditis.

Prenatal diagnosis is nowadays a multidisciplinary task in which participate obstetricians, radiologists, geneticists, neonatologists, pediatrics and pathologies. In many countries fetal imaging is divided into two major fields: ultrasonography which is performed by obstetricians with special skills, and magnetic resonance imaging which performed by radiologists sometimes pediatric- radiologists. The aim of this study was to describe our experience and results with the new concept of MR-Ultrasonography collaboration team. Five hundred twenty-nine fetal MR scans were performed in one tertiary medical center, during a year period (2011). We used GE 1.5-T system. The conventional T1, T2, Gradient Echo, DWI sequences were performed. In selected cases we added spectroscopy. Four hundred and forty nine were brain and face examinations and the rest were body and placenta. In all MR examinations and interpretation, both radiologist and obstetrician participate. The scans performed according to the following indication: exposure to CMV, Monochorionic Twins, severe discordance, abnormal lateral ventriceles, micro/macrocephaly, previous CNS malformations, abnormal Corpus callosum or Cavum septm pellucidum, abnormal sulcation, posterior fossa anomalies, cystic lesions, neural tube defects, brain tumors, club feet, severe IUGR, Congenital Heart Defect, abnormal karyotype, maternal obesity, hypovolemic shock or exposure to teratogen during pregnancy, fetal thrombocytopenia, craniosynostosis, cleft palate, cystic lesions of the face, gastrointestinal tract/gallbladder/ adrenal/renal/liver malformations, esophageal/lung/chest and placental anomalies. Seventy-three examinations were found with significant pathology. Magnetic resonance modality is an important tool in the field of fetal imaging with significant added value to ultrasonography. The MR-Ultrasonography Collaboration Team improves the variety and conditions to performed fetal MR, thus, opens new horizon in this developing filled.