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Purpose: Detecting bladder cancer (BC) in routine CT images is important but is sometimes difficult when cancer is small. We evaluated the ability of 40-keV advanced monoenergetic images to depict BC. Materials and methods: Fifty-two patients with a median age of 74 years (range 45–92) who were diagnosed as BC with transurethral resection or cystectomy, were included. They were examined with contrast-enhanced dual-energy CT (DE-CT) and advanced virtual monoenergetic images (40 keV) were reconstructed. For evaluating depictability of BC on 40-keV or virtual-120-kVp images, the difference in CT number between the cancer and bladder wall (BC–BW value) were calculated. We also subjectively assessed depictability of BC in virtual-120-kVp and 40-keV images using a 4-grade Likert scale (3: clear, 0: not visualized). Results: In 42 of 52 patients, BC–BW values could be calculated because BC was detected on CT images. The mean BC–BW value at 40 keV was significantly higher than that of virtual 120 kVp [80.5 ± 54 (SD) vs. 11.4 ± 12.5 HU, P < 0.01]. Average scores of subjective evaluations in the virtual-120-kVp and 40-keV images were 1.7 ± 1.2 and 2.1 ± 1.2, respectively (P < 0.001). Conclusion: The advanced monoenergetic reconstruction technique reconstructed using DE-CT image is useful to depict BC. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the usefulness of the advanced monoenergetic imaging (AMI) reconstruction technique for dual-energy computed tomography to evaluate endoleaks after endovascular stent-graft placement. Materials and methods: Ninety-five dual-phase (early and delayed phases) enhanced CT examinations were performed for 60 patients who underwent endovascular stent-graft placement. AM images were reconstructed at 40 keV and compared with the standard 120-kVp images (SI). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the aorta and endoleak were measured. Two radiologists subjectively assessed endoleak delineation and contrast enhancement conditions using a 5-point Likert scale (1: poor—5: excellent). Results: Mean SNRs of the aorta were higher by AMI (early; 34.7 ± 10.2 [SD], delay; 11.4 ± 3.2) than by SI (early; 23.1 ± 6.3, delay; 8.6 ± 2.2) (P < 0.001). SNRs of the endoleak were higher by AMI (early; 26.3 ± 7.5, delay; 10.5 ± 3.1) than by SI (early; 18.2 ± 4.7, delay; 8.3 ± 2.1) (P < 0.001). CNRs by AMI (early; 32.9 ± 9.8, delay; 8.9 ± 2.8) were higher than those by SI (early; 19.5 ± 6.0, delay; 4.7 ± 1.6) in both phases (P < 0.001). Endoleak delineation and contrast enhancement conditions by AMI (4.4 ± 1.0 and 4.5 ± 0.6) were higher than those by SI (3.4 ± 1.0 and 3.3 ± 0.8) in the delayed phase (P < 0.001). There was no difference in the early phase. Conclusion: AMI may be useful for evaluating endoleaks after endovascular stent-graft placement. [ABSTRACT FROM AUTHOR]

This short report clarifies the heterogeneity of structural magnetic resonance imaging (MRI) findings in seven demented patients due to pathologically accumulated TAR DNA-binding protein-43 (TDP-43) protein using visual analyses including visual rating scales (i.e., global cortical atrophy and medial temporal atrophy scales). In addition to the well-known frontotemporal lobar atrophy, structural MRI has revealed multifaceted imaging findings including asymmetric atrophy of the frontoparietal lobe and cerebral peduncle, midbrain atrophy, and localized or diffuse white matter T2 hyperintensity. Understanding of these multifaceted neuroimaging findings is important for the precise antemortem diagnosis of TDP-43 proteinopathy. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to clarify the characteristic structural magnetic resonance imaging (MRI) findings in demented patients with pathologically confirmed argyrophilic grain disease (AGD). Methods: Nine pathologically confirmed AGD patients with cerebral three-dimensional T1-weighted MRI were evaluated in this study. In addition to visual rating scales of atrophic and asymmetric changes in the limbic and temporal lobes, voxel-based morphometry (VBM) was performed to assess group difference between pathologically confirmed AGD and Alzheimer's disease (AD) patients. Results: On visual analyses of AGD patients, the medial temporal, anterior temporal, and posterior temporal atrophy scores were 3.3 ± 0.7, 1.7 ± 0.5, and 1.0 ± 0.7, respectively. Asymmetric scores of the hippocampus and parahippocampal gyrus, amygdala and ambient gyrus, anterior temporal, and posterior temporal lobes were rated as 1.1 ± 0.7, 1.6 ± 0.5, 1.3 ± 0.8, and 0.4 ± 0.7, respectively. In spite of no statistical differences in atrophic scores, AGD patients showed the higher score and proportion of anterior temporal asymmetric score than AD (p = 0.03 and 0.02). Compared with controls, VBM analysis revealed left dominant asymmetric atrophy predominantly in the limbic and anterior temporal lobe in AGD patients. By contrast, there was no significant gray matter reduction between AGD and AD patients. Conclusions: Asymmetric atrophy relatively localized to the anterior temporal and limbic lobes including the amygdala and ambient gyrus is a characteristic MRI finding of AGD. For the precise antemortem diagnosis, especially to differentiation from AD, it is important to pay attention to this asymmetric change. [ABSTRACT FROM AUTHOR]

Purpose: Children with congenital heart diseases (CHDs) may need to be followed up with contrast-enhanced CT following the Fontan operation because complications such as the occlusion of conduits may occur. The purpose of the present study was to develop an adequate contrast-enhanced CT protocol for children with CHD following the Fontan operation.Materials and Methods: Between July 2012 and July 2017, 29 CT examinations for 26 patients aged 2-11 years (median 5 years) with CHD following the Fontan operation were performed using dual-source CT. A non-ionized contrast medium was injected through the dorsum manus vein. Scanning began 60 or 70 s after the start of the injection. The delayed phase was randomly selected to be 60 s in 14 cases and 70 s in 15 cases. We evaluated the enhancement of conduits following the Fontan operation at delayed phases.Results: The CT numbers of conduits at 60 and 70 s were 185 ± 46 and 185 ± 31 HU, respectively (P = 0.97).Conclusion: In contrast-enhanced CT for children after the Fontan operation, both of the delayed phases (60 and 70 s) appeared to be adequate for evaluating intraconduit patency. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy and safety of transcatheter arterial embolization (TAE) for renal angiomyolipoma (AML) using a micro-balloon catheter and a mixture of ethanol and lipiodol.Materials and Methods: Twelve consecutive patients with 15 AMLs, 9 females and 3 males, with a median age of 44 years (range, 11-81), underwent this procedure between 2011 and 2016. In all procedures, a micro-balloon catheter was advanced to the feeding artery of the AML and TAE was performed with a mixture of ethanol and lipiodol under balloon inflation. We reviewed medical records and images, and evaluated the technical success rate, clinical success rate, and complications. Technical success was defined as completion of TAE using the micro-balloon catheter and the mixture of ethanol and lipiodol. Clinical success was defined as reduction of tumor size on CT, which was performed before and after TAE.Results: In 14 of 15 AMLs, the micro-balloon catheter could be advanced to the feeding artery, and TAE was performed successfully. Thus, the technical success rate was 93%. Among these 14 AMLs of 11 patients, 13 AMLs of 10 patients could be followed and tumor shrinkage was confirmed in all. Thus, the clinical success rate was 100%. Four patients had mild symptoms after TAE; the minor complication rate was 33% (4/12), and the major complication rate was 0%.Conclusion: TAE for renal AML using the micro-balloon catheter and mixture of ethanol and lipiodol appears to be effective and safe. [ABSTRACT FROM AUTHOR]

Purpose: Recently, it has been recognized that pathologically proven progressive supranuclear palsy (PSP) cases are classified into various clinical subtypes with non-uniform symptoms and imaging findings. This article reviews essential imaging findings, general information, and advanced magnetic resonance imaging (MRI) techniques for PSP and presents these MRI findings of pathologically proven typical and atypical PSP cases for educational purposes. Methods: With the review of literatures, notably including atypical pathologically proven PSP cases, MRI and clinical information of 15 pathologically proven typical and atypical PSP cases were retrospectively evaluated. Results: In addition to typical symptoms, PSP patients can exhibit atypical symptoms including levodopa-responsive parkinsonism, pure akinesia, non-fluent aphasia, corticobasal syndrome, and predominant cerebellar ataxia. As well as clinical symptoms, the degree of midbrain atrophy, a well-known imaging hallmark, is not consistent in atypical PSP cases. This fact has important implications for the limitation of midbrain atrophy as a diagnostic imaging biomarker of PSP pathology. Additional evaluation of other imaging findings including various regional atrophies of the globus pallidus, frontal lobe, cerebral peduncle, and superior cerebellar peduncle is essential for the diagnosis of atypical PSP cases. Conclusion: It is necessary for radiologists to recognize the wide clinical and radiological spectra of typical and atypical PSP cases. [ABSTRACT FROM AUTHOR]

Purpose: To assess the usefulness of transcatheter arterial embolization (TAE) for the hepatic arterial injury related to percutaneous transhepatic portal intervention (PTPI).Materials and Methods: Fifty-four patients, 32 males and 22 females with a median age of 68 years (range 43-82 years), underwent PTPI. The procedures consisted of 33 percutaneous transhepatic portal vein embolizations, 19 percutaneous transhepatic variceal embolizations, and 2 percutaneous transhepatic portal venous stent placements. Two patients with gastric varices underwent percutaneous transhepatic variceal embolization twice because of recurrence. Therefore, the total number of procedures was 56. Among them, hepatic arterial injury occurred in 6 PTPIs in 5 patients, and TAE was performed. We assessed technical success, complications related to TAE, and clinical outcome. Technical success was defined as the disappearance of findings due to hepatic arterial injury on digital subtraction angiography.Results: As hepatic arterial injuries, 4 extravasations and 2 arterioportal shunts developed. All TAEs were performed successfully. The technical success rate was 100 %. Complication of TAE occurred in 5 of 6 TAEs; 3 were focal liver infarction, not requiring further treatment, and 2 were biloma that required percutaneous drainage. Five TAEs in 4 patients were performed immediately after the PTPI, and these 4 patients were alive. However, one TAE was performed 10 h later, and the patient died due to multiple organ failure 2 months later although TAE was successful.Conclusion: TAE is a useful treatment for hepatic arterial injury related to PTPI. However, it should be performed at an early stage. [ABSTRACT FROM AUTHOR]

Purpose: We evaluated the ability of dual source CT (DSCT) with ECG-triggered high-pitch spiral acquisition (Flash Spiral Cardio mode) to depict the morphological features of ventricles in pediatric patients with congenital heart defects (CHD).Materials and Methods: Between July 2013 and April 2015, 78 pediatric patients with CHD (median age 4 months) were examined using DSCT with the Flash Spiral Cardio mode. The types of ventricular abnormalities were ventricular septal defect (VSD) in 42 (the malaligned type in 11, perimembranous type in 23, supracristal type in 2, atrioventricular type in 2, and muscular type in 4), single ventricle (SV) in 11, and congenital corrected transposition of the great arteries (ccTGA) in 4. We evaluated the accuracy of the diagnosis of the VSD type. In cases of SV and ccTGA, we assessed the detectability of the anatomical features of both ventricles for a diagnosis of ventricular situs.Results: DSCT confirmed the diagnoses for all VSDs. The type of defect was precisely diagnosed for all patients. The anatomical features of both ventricles were also depicted and ventricular situs of SV and ccTGA was correctly diagnosed.Conclusion: The results suggest that DSCT has the ability to clearly depict the configuration of ventricles. [ABSTRACT FROM AUTHOR]

Objective: Although a correct diagnosis is important for appropriate management, accurately differentiating between multiple system atrophy with predominant parkinsonism (MSA-P) and Parkinson's disease (PD) is often difficult because of similarities in the early-stage symptoms. The aim of this study was to evaluate the diagnostic value of cerebral perfusion single photon emission computed tomography (SPECT) and voxel-based analysis for diagnosing MSA-P patients. Methods: Thirty-eight subjects (9 with early-stage MSA-P, 11 with PD, and 18 controls) were included in this study. Z-scores suggestive of hypoperfusion were calculated between patients and controls using statistical parametric mapping (SPM) 8 and easy Z-score imaging system (eZIS) programs. A voxel-based stereotactic extraction estimation (vbSEE) program was performed to determine the target volumes of interest (VOIs) in the putamen, pons, and cerebellum, and quantify Z-scores as 'extent' (the rate of voxels with a Z-score >2.0 in these VOIs) and 'severity' (average Z-scores in these VOIs). These parameters were used as the determinant in receiver operating characteristic (ROC) analyses. Results: The extent and severity of the cerebellar VOIs were higher in MSA-P patients than in PD patients. In ROC analyses, the extent and severity of the cerebellar VOI exhibited the highest areas under the curves of 0.86 and 0.84, and accuracies of 90 and 90 %, respectively. Conclusions: The diagnostic value of significant cerebellar hypoperfusion was the highest for differentiating MSA-P from PD. This voxel-based analysis of cerebral perfusion SPECT using the SPM8, eZIS, and vbSEE programs is useful for clinically diagnosing MSA-P. [ABSTRACT FROM AUTHOR]

Congenital abdominal wall defects include several entities such as gastroschisis, omphalocele, and cloacal exstrophy. It is important for perinatal management and parental counseling to understand the magnetic resonance (MR) imaging features essential for correctly diagnosing the clinical condition and predicting the prognosis of fetal patients. The purpose of this pictorial review is to demonstrate the MR imaging features of fetal cases with an abdominal wall defect and the pitfalls of image findings. [ABSTRACT FROM AUTHOR]

Purpose: Improved time resolution using dual-source computed tomography (DSCT) enabled adaptation of electrocardiography (ECG)-gated cardiac CT for children with a high heart rate. In this study, we evaluated the ability of ECG-gated DSCT (ECG-DSCT) to depict the morphological ventricular features in patients with congenital heart disease (CHD).Materials and Methods: Between August 2006 and March 2010, a total of 66 patients with CHD (aged 1 day to 9 years, median 11 months) were analyzed using ECG-DSCT. The type of anomaly was ventricular septal defect (VSD) in 32 (malaligned type in 20, perimembranous type in 7, supracristal type in 3, muscular type in 2), single ventricle (SV) in 11, and corrected transposition of the great arteries (cTGA) in 3. All patients underwent ECG-DSCT and ultrasonography (US). We evaluated the accuracy of diagnosing the type of VSD. For the cases with SV and cTGA, we evaluated the ability to depict anatomical ventricular features.Results: In all 32 cases of VSD, DSCT could confirm the VSD defects, and the findings were identical to those obtained by US. Anatomical configurations of the SV and cTGA were correctly diagnosed, similar to that on US.Conclusion: Our study suggests that ECG-DSCT can clearly depict the configuration of ventricles. [ABSTRACT FROM AUTHOR]

The optimal conditions for abdominal contrast-enhanced (CE) CT, especially with respect to depiction of the hepatic veins (HVs), have not been well studied in small children. We compared the depiction of the HVs in small children using scan delay times of 50 s and 60 s and a power injector. The degree of contrast enhancement of the HVs according to body weight was also evaluated. A total of 50 CT studies in 31 children ages 2 days to 3 years 4 months (median 12 months) with a body weight less than 15 kg were prospectively evaluated. Nonionic contrast medium (300 mgI/ml) at a dose of 2 ml/kg and an injection rate calculated as (body weight in kilograms × 0.1) ml/s was injected through a 24-gauge intravenous catheter. Scan delay time was randomly chosen at 50 s or 60 s (25 times each). Subjective assessment of HV depiction was performed and the difference in CT number between the HV and hepatic parenchyma (HV−HP value) was calculated. In all cases, subjective assessment of HV depiction was good and the HV−HP value was greater than 20 HU. The mean±SD HV−HP value was 47.7±13.2 HU. There were no differences in the mean HV−HP values between scan delay times of 50 s and 60 s ( P=0.58). For small children, this protocol for pediatric abdominal CECT resulted in good depiction of the HVs with no difference between scan delay times of 50 s and 60 s. [ABSTRACT FROM AUTHOR]

The pulmonary artery (PA) is involved in most congenital heart diseases; and in these patients it is necessary to evaluate precisely the PA configuration and development. The accuracy of 16 multidetector row computed tomography (16-MDCT) in evaluating the central PA was evaluated. 16-MDCT and angiocardiography (ACG) were performed in 26 patients with various congenital heart diseases aged 7 days to 9 years (median 1.2 years). We reconstructed coronal oblique images along the long axis of the right and left PAs and measured the PA diameter and Nakata’s PA index, which were compared with those obtained by ACG. Correlations between PA diameters [ R 2 = 0.80, standard error of the estimate (SEE) = 1.3, n = 52] and PA indices ( R 2 = 0.81, SEE = 42, n = 26) obtained from coronal oblique images and ACG were excellent. Bland-Altman plots showed a mean ± SD difference of −0.3 ± 1.3 mm for the PA diameter and ±15.1 ± 41.5 for the PA index. 16-MDCT might be useful for evaluating the central PA in patients with congenital heart disease. [ABSTRACT FROM AUTHOR]