Prediction of Therapeutic Response of Hepatocellular Carcinoma to Transcatheter Arterial Chemoembolization Based on Pretherapeutic Dynamic CT and Textural Findings.

OBJECTIVE: The objective of our study was to assess the value of CT texture analysis for prediction of therapeutic response of hepatocellular carcinoma (HCC) to transcatheter arterial chemoembolization (TACE) with pretherapeutic dynamic CT. MATERIALS AND METHODS: We retrospectively analyzed 132 HCCs in 96 patients treated with TACE who underwent dynamic CT before initial TACE. Imaging findings and arterial enhancement ratios were analyzed. All HCCs were manually segmented, and their texture features were quantitatively extracted using in-house software. CT texture was quantified with 2D and 3D analysis. HCCs were classified as with and without complete response (CR) according to modified Response Evaluation Criteria in Solid Tumors. Predictive factors for CR were assessed with multivariate analysis. Radiologic responses were correlated with time to progression (TTP). RESULTS: Of the 132 HCCs, CR was achieved in 75 (56.8%). Tumor size, subjective arterial tumor attenuation, and arterial enhancement ratios were significantly associated with CR. On 2D and 3D analysis, tumors with CR showed significantly lower homogeneity and higher mean attenuation, gray-level co-occurrence matrix (GLCM) moments, and CT number percentiles (p < 0.05). On multivariate analysis, higher subjective tumor attenuation (adjusted odds ratio [OR] = 23.35), arterial enhancement ratio (OR = 14.07), GLCM moments (OR = 6.57), smaller tumor size (OR = 17.26), and lower homogeneity (OR = 0.69) were significant predictors of CR compared with incomplete response (p < 0.05). Median survival value for TTP was significantly longer in tumors with CR (p < 0.001). CONCLUSION: Pretherapeutic dynamic CT texture analysis can be valuable to predict CR of HCC to TACE. Higher arterial enhancement and GLCM moments, lower homogeneity, and smaller tumor size are significant predictors of CR after TACE.

Diaphragmatic Hernia After Living-Donor Right Hepatectomy: An Important Late Donor Complication.

OBJECTIVE: This study was performed to evaluate the incidence and clinical outcome of diaphragmatic hernia after living-donor right hepatectomy. METHODS: Three hundred thirty-six patients (202 men, 134 women; mean age, 37.6 years) who underwent abdominal computed tomography (CT) after right donor hepatectomy were enrolled in this study. The CT images and the electronic medical records were reviewed. We evaluated the associations between diaphragmatic hernia and patient characteristics. RESULTS: Diaphragmatic hernia developed in 9 (2.7%) of 336 patients at a median time interval of 173 days (range, 98-488 days) after hepatectomy. In all 6 patients with available follow-up CT images, diaphragmatic hernia increased in size. Three patients presented with abdominal pain and underwent diaphragmatic repair. Diaphragmatic hernia was associated with older age but not with body mass index or sex. CONCLUSIONS: Clinicians and radiologists should not overlook the possibility of diaphragmatic hernia after living-donor right hepatectomy, especially in old liver donors.

Performance of Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging for Predicting Patient Eligibility for Liver Transplantation Based on the Milan Criteria.

PURPOSE: This study aimed to evaluate the accuracy of gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) in predicting eligibility for liver transplantation in patients with hepatocellular carcinoma (HCC) based on Milan criteria (MC). MATERIALS AND METHODS: We reviewed Gd-EOB-MRI of 44 patients who underwent liver transplantation for HCC with cirrhosis for the presence/size of HCCs, vascular invasion, and transplant eligibility based on MC. Hepatocellular carcinoma was diagnosed based on conventional radiological hallmarks (arterial enhancement and washout) or the modified criteria. RESULTS: Among 44 patients, 16 was beyond MC. Sensitivity, specificity, and accuracy of conventional radiological hallmark and the modified criteria for predicting eligibility by MC were 31.3%, 96.3%, and 72.7%, and 68.8%, 96.3%, and 86.4%, respectively. CONCLUSIONS: Gd-EOB-MRI showed high specificity but poor sensitivity for assessing transplant eligibility based on MC when adopting the conventional radiological hallmarks of HCC. Our modified criteria showed significantly better sensitivity and accuracy than the conventional radiological hallmarks.

Factors Related to Radiation Exposure during Lumbar Spine Intervention.

Fluoroscopy guidance is useful to confirm anatomical landmark and needle location for spine intervention; however, it can lead to radiation exposure in patients, physicians, and medical staff. Physicians who used fluoroscopy should be cognizant of radiation exposure and intend to minimize radiation dose. We retrospectively reviewed three lumbar spine intervention procedures (nerve root block, medial branch block, and facet joint block) at our institution between June and December, 2014. We performed 268 procedures on 220 patients and found significant difference in radiation dose between two groups classified by performing physicians. The physician who controlled the fluoroscopy unit directly used significantly shorter fluoroscopy (6 seconds) that resulted in a smaller radiation dose (dose area product [DAP] 0.59 Gy∙cm(2)) than the physician supervising the radiographer controlling the fluoroscopy unit (72 seconds, DAP 5.31 Gy∙cm(2), P < 0.001). The analysis indicates that the difference in fluoroscopy time depends on whether a physician or a radiographer controls the fluoroscopy unit.

Correlation of dynamic contrast-enhanced MRI perfusion parameters with angiogenesis and biologic aggressiveness of rectal cancer: Preliminary results.

PURPOSE: To investigate whether quantitative parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) are correlated with angiogenesis and biologic aggressiveness of rectal cancer. MATERIALS AND METHODS: A total of 46 patients with rectal cancer underwent DCE-MRI. Using a two-compartmental model, quantitative parameters (K(trans) , kep , ve , and iAUC) were calculated from the whole-transverse region of interest (ROI) and high K(trans) area ROI of entire tumors. Histological specimens were analyzed for tumor size; T/N stage; lymphatic, vascular, perineural invasion; expression of epidermal growth factor receptor (EGFR); and KRAS gene mutations. Tumor angiogenesis was evaluated based on the microvessel density (MVD) and the expression level of the vascular endothelial growth factor. Correlations of the DCE-MRI parameters with histological markers and angiogenesis were determined using Student's t-test and analysis of variance (ANOVA). RESULTS: The mean kep from high K(trans) area ROIs showed a significantly positive correlation with MVD (P = 0.030, r = 0.514, R(2) = 0.264). The mean kep from the whole-transverse ROIs showed a significant inverse correlation with T stage (T1 vs. T2-4, P = 0.021). EGFR-positive cancer displayed higher mean K(trans) (P = 0.045) and kep (P = 0.038) than EGFR-negative cancer in whole-transverse ROIs. CONCLUSION: These preliminary results suggest that the determination of kep of high K(trans) area permits the noninvasive estimation of tumor angiogenesis in rectal cancer and that DCE-MRI parameters can be used as imaging biomarkers to predict the biologic aggressiveness of the tumor and patient prognosis.

CT and MR imaging findings of hepatic epithelioid hemangioendotheliomas: emphasis on single nodular type.

PURPOSE: To evaluate imaging findings of hepatic epithelioid hemangioendothelioma (HEH), with emphasis on solitary form at the initial presentation. MATERIALS AND METHODS: Ten cases of pathologically confirmed HEH were retrospectively reviewed; seven patients had CT and MR images and three had only CT images. Two radiologists assessed the followings in consensus: lesion number, size, location, presence of capsular retraction and calcification, attenuation, signal intensity, and enhancement pattern. RESULTS: Initially, HEHs manifested as a single mass (n = 5) or multiple masses (n = 5). One case demonstrated a solitary nodule at first, which subsequently transformed to multifocal nodules on serial follow-up. The maximal diameter of the lesions ranged from 1.8 to 10 cm (mean 4.2 cm). All cases showed predominant subcapsular location. Capsular retraction was seen in multinodular types, but not in solitary types. Two patients had intra-lesional calcifications. HEHs showed minimal enhancement (7/7 patients) on the hepatic arterial phase CT and rim-like enhancement (5/10 patients), minimal enhancement (2/10 patients), multilayered target enhancement (2/10 patients), and peripheral nodular enhancement (1/10 patients) on the portal venous phase CT. On MR images (n = 7), HEHs showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images. Dynamic contrast-enhanced MR images revealed progressive centripetal fill-in enhancement (7/7 patients). On Gd-EOB-DTPA-enhanced hepatobiliary phase images, HEH manifested as homogeneous hypointensity (3/5 patients) and target-shaped hypointensity (2/5 patients). CONCLUSION: HEH can manifest as single nodular, multinodular, or diffuse type. Common imaging features of HEH are multiple subcapsular nodules with coalescence, capsular retraction, peripheral, and delayed enhancement. However, HEH can manifest as a solitary subcapsular mass with minimal or rim-like enhancement at early phase and progressive centripetal fill-in enhancement during dynamic phase imaging, representing early stage of HEH. A single nodular type can progress to multifocal nodular type during follow-up.

Reflux venous flow in dural sinus and internal jugular vein on 3D time-of-flight MR angiography.

INTRODUCTION: Reflux venous signal on the brain and neck time-of-flight magnetic resonance angiography (TOF MRA) is thought to be related to a compressed left brachiocephalic vein. This study is aimed to assess the prevalence of venous reflux flow in internal jugular vein (IJV), sigmoid sinus/transverse sinus (SS/TS), and inferior petrosal sinus (IPS) on the brain and neck TOF MRA and its pattern. METHODS: From the radiology database, 3,475 patients (1,526 men, 1,949 women, age range 19-94, median age 62 years) with brain and neck standard 3D TOF MRA at 3 T and 1.5 T were identified. Rotational maximal intensity projection images of 3D TOF MRA were assessed for the presence of reflux flow in IJV, IPS, and SS/TS. RESULTS: Fifty-five patients (1.6%) had reflux flow, all in the left side. It was more prevalent in females (n = 43/1,949, 2.2%) than in males (n = 12/1,526, 0.8%) (p = 0.001). The mean age of patients with reflux flow (66 years old) was older than those (60 years old) without reflux flow (p = 0.001). Three patients had arteriovenous shunt in the left arm for hemodialysis. Of the remaining 52 patients, reflux was seen on IJV in 35 patients (67.3%). There were more patients with reflux flow seen on SS/TS (n = 34) than on IPS (n = 25). CONCLUSION: Venous reflux flow on TOF MRA is infrequently observed, and reflux pattern is variable. Because it is exclusively located in the left side, the reflux signal on TOF MRA could be an alarm for an undesirable candidate for a contrast injection on the left side for contrast-enhanced imaging study.

Comparing the Clinical Manifestations of Bell's Palsy between Pre-COVID-19 Pandemic and COVID-19 Pandemic Periods.

BACKGROUND: COVID-19 has been shown to affect the onset and severity of various diseases. We examined whether the clinical characteristics of Bell's palsy differed between before and during the COVID-19 pandemic. METHODS: From January 2005 to December 2021, 1839 patients were diagnosed and treated for Bell's palsy at Kyung Hee University Hospital. These patients were divided into a pre-COVID period group and COVID-19 period group, and the clinical characteristics of the two groups were compared. RESULTS: There were 1719 patients in the pre-COVID period group and 120 patients in the COVID-19 period group. There were no between-group differences in sex (p = 0.103) or in the presence of underlying hypertension (p = 0.632) or diabetes (p = 0.807). Regarding symptoms, there were no significant between-group differences in otalgia, dizziness, tinnitus, hyperacusis, or hearing loss (p = 0.304, p = 0.59, p = 0.351, p = 0.605, and p = 0.949). There were also no significant between-group differences in electroneurography results (p = 0.398), electromyography results (p = 0.331), House-Brackmann Grade at visit (p = 0.634), or recovery rate after treatment (p = 0.525). CONCLUSIONS: Contrary to our expectation that Bell's palsy cases during the COVID-19 pandemic would show different clinical features than those occurring before COVID-19, the present study found no differences in clinical features or prognosis.

Effect of beam-flow angle on velocity measurements in modern Doppler ultrasound systems.

OBJECTIVE: The purpose of this article is to examine the effect of different beam-flow angles on the accuracy of Doppler ultrasound velocity measurements in modern ultrasound systems. MATERIALS AND METHODS: A flow phantom was used to create a steady flow of water in a 4.3-mm-diameter tube. Using three different modern university-grade ultrasound systems, flow was measured at 30°, 40°, 50°, 60°, 70°, 80°, and 88° beam-flow angles twice by two radiologists in consensus using a convex and linear probe. Measured flow ratio, defined as measured velocity divided by estimated actual velocity, was calculated. Intraprobe, interprobe, and intermachine mean variation of measured flow ratio were calculated. RESULTS: Measured flow ratio increased as beam-flow angles increased. Measured flow ratios for the angles 30°, 40°, 50°, 60°, 70°, 80°, and 88° were 0.90, 0.97, 1.10, 1.22, 1.62, 2.34, and 10.29, respectively. Intraprobe, interprobe, and intermachine variation did not show marked differences. For angles grouped as 30-40°, 50-60°, 70°, and 80-88°, intraprobe variation was 12%, 15%, 15%, and 26%; interprobe variation was 20%, 16%, 13%, and 26%; and intermachine variation was 16%, 16%, 17%, and 54%, respectively. As beam-flow angle increased, an increase in spectral broadening was also noted. CONCLUSION: There is no simple cutoff beam-flow value, such as the well-quoted less than 60°, at which velocity measurements can be considered accurate. For follow-up imaging, beam-flow angle differences should be considered, and the same beam-flow angles should be used when possible. Follow-up imaging by different sonography machines is feasible.

Ruptured endometrial cysts as a rare cause of acute pelvic pain: can we differentiate them from ruptured corpus luteal cysts on CT scan?

PURPOSE: To evaluate the usefulness of CT in the differentiation of ruptured endometrial cysts and corpus luteal cysts. METHODS: Sixteen patients (mean age, 26 years) with a surgically proven ruptured endometrial cyst and 19 patients (mean age, 28 years) with a surgically proven corpus luteal cyst were included in this study. All patients had undergone portal phase contrast-enhanced computed tomographic (CT) scans. We retrospectively analyzed the CT findings on the ovarian cysts for the size and shape of the ovarian cyst, the thickness of the cyst wall, the attenuation of the cyst content, the presence of a discontinuity of the cyst wall, and on the peritoneum for the amount and attenuation of the ascites and the presence of hazy infiltration in the peritoneal fat. We compared the CT imaging characteristics in patients with ruptured endometrial cysts and corpus luteal cysts, using the Mann-Whitney U test. RESULTS: Ruptured endometrial cysts tend to show larger, multilocular cysts with a thicker wall compared to ruptured corpus luteal cysts (P < 0.05). A distorted shape of the cyst was more commonly seen in ruptured endometrial cyst, but direct CT findings that can suggest a rupture of an ovarian cyst, such as a discontinuity of the cyst wall and hemoperitoneum, were more commonly seen in ruptured corpus luteal cysts than in endometrial cysts (P < 0.05). CONCLUSIONS: Computed tomography is useful in the differentiation of ruptured endometrial cysts and corpus luteal cysts in a patient with acute pelvic pain.

Injuries of adjacent organs by the expanded polytetrafluoroethylene grafts in the venoplasty of middle hepatic veins in living-donor liver transplantation: computed tomographic findings and possible risk factors.

OBJECTIVE: The objective of the study was to analyze computed tomography (CT) appearance and clinical features of adjacent-organ injuries related to expanded polytetrafluoroethylene (ePTFE) grafts after living-donor liver transplantation (LDLT). METHODS: We evaluated follow-up CT images of 204 patients who underwent venoplasty with ePTFE during LDLT and encountered 4 patients (1.96%) with adjacent-organ injuries related to ePTFE. Clinical imaging records were reviewed in terms of imaging findings and possible risk factors. RESULTS: In 3 patients, ePTFE graft perforated gastric antrum or duodenal bulb; in another patient, the common bile duct was injured. The mean interval between transplantation and identification of injury was 30 months. In patients with adjacent-organ injuries, biliary or perihepatic interventional treatments, adhesion of bowel and early occlusion of ePTFE grafts were commonly observed. CONCLUSIONS: Adjacent-organ injuries by ePTFE graft after LDLT were rare but present. Interventional procedures, adhesion of the bowel wall and early occlusion of the grafts were possible risk factors.

Protection of the renal collecting system during radiofrequency ablation with antegrade cold dextrose infusion.

PURPOSE: To evaluate the feasibility and efficacy of antegrade renal cooling during radiofrequency (RF) ablation to protect the renal collecting system in pigs. MATERIALS AND METHODS: With the approval of the institutional animal care and use committee, RF ablation was planned bilaterally after nephrostomy in 20 kidneys from 10 domestic pigs. A coaxial assembly consisting of a 7-F pigtail catheter and a 12-F arterial sheath was placed at the renal pelvis. Cooled 5% dextrose in water solution was perfused in only one of the kidneys in each pig. A 17-gauge internally cooled tip RF electrode with a 3-cm tip was placed near the renal pelvis with ultrasonographic guidance. On postprocedural days 1 and 7, computed tomography (CT) was performed to evaluate the RF ablation effect, the presence of a fluid collection, and the leakage of contrast material. Ex vivo retrograde pyelography was performed to assess the integrity of the urinary tract after kidney harvest. Histologic findings related to the urothelial damage were scored semiquantitatively. RESULTS: The mean maximal diameter of the RF ablation area measured at CT and in specimens was not significantly different between cooled and noncooled kidneys. A fluid collection around the RF ablation area was seen in eight of the 10 noncooled kidneys on day 7 CT scans compared with two of the 10 cooled kidneys; the difference was statistically significant (P = .035). Ex vivo retrograde pyelography depicted leakage of contrast material in only the noncooled group. The mean histologic damage score was lower in the cooled group than in the noncooled group. CONCLUSION: RF ablation after placement of an antegrade cooling system in pig kidneys was feasible. Antegrade cold dextrose infusion of the urinary tract during RF ablation is effective in protecting the renal collecting system without compromising the RF ablation effect.

Giant aneurysm of the common hepatic artery: US and CT imaging findings.

Giant hepatic artery aneurysm is a very rare vascular lesion, but can be detected incidentally during abdominal imaging. We report the sonographic and computed tomography (CT) features of a giant hepatic artery aneurysm in a 52-year-old woman presenting with vague abdominal discomfort. This report illustrates that a giant hepatic artery aneurysm can manifest as an incidental large mass in the porta hepatis, and we discuss the role of sonography and CT in the diagnosis of the lesion and review the natural history and clinical presentation of hepatic artery aneurysm.

MR Imaging findings of hydrosalpinx: a comprehensive review.

Hydrosalpinx is a common adnexal lesion that may occur either in isolation or as a component of a complex pathologic process (eg, pelvic inflammatory disease, endometriosis, fallopian tube tumor, or tubal pregnancy) that leads to distal tubal occlusion. On magnetic resonance (MR) images, hydrosalpinx appears as a fluid-filled C- or S-shaped tubular structure that arises from the upper lateral margin of the uterus. Although hydrosalpinx is most often seen on ultrasonographic images, it also may be delineated on multiplanar MR images. MR imaging also may be useful for determining the cause of a hydrosalpinx or its associated adnexal process by characterizing the nature of the contents of the dilated tube. Tubal fluid with high signal intensity on T1-weighted images is suggestive of hematosalpinx associated with endometriosis and tubal pregnancy. A thickened wall of a dilated fallopian tube that displays variable or heterogeneous signal intensity may be indicative of pyosalpinx as a component of a tubo-ovarian abscess. The presence of an enhancing solid mass within a dilated tube is suggestive of fallopian tube carcinoma, whereas enhancement of the dilated tubal wall surrounding a saclike cystic mass may be indicative of a tubal pregnancy. Understanding the pathogenesis and clinical manifestations of conditions associated with hydrosalpinx may aid in the timely diagnosis of complex adnexal masses at MR imaging, enabling avoidance of unnecessary procedures.

Transitional cell tumor of the ovary: computed tomographic and magnetic resonance imaging features with pathological correlation.

OBJECTIVE: To describe computed tomographic (CT) and magnetic resonance (MR) imaging findings of transitional cell tumors, including newly established transitional cell carcinoma, according to tumor type with pathological correlation. METHODS: We retrospectively reviewed the CT and MR images of 22 patients with transitional cell tumors of ovary (14 benign Brenner, 2 borderline Brenner, 2 malignant Brenner, and 4 transitional cell carcinomas) for the following factors: size, location, configuration, signal intensity, staging, and accompanying ovarian tumors. RESULTS: Sixteen tumors were detected on CT or MRI (8 benign, 2 borderline, and 6 malignant tumors), and the mean size of measurable tumors was 8.8 cm. Benign Brenner tumors were homogeneous solid (n = 6) or unilocular cystic (n = 2). Two borderline Brenner tumors were multilocular cystic. Malignant tumors, including malignant Brenner tumors and transitional cell carcinomas, were heterogeneous solid (n = 3) or multilocular cystic (n = 3). The signal intensity of solid components on T2-weighted images was isointense compared with that of muscle in benign and borderline Brenner tumors and hyperintense in malignant tumors. CONCLUSIONS: The CT and MR appearance of transitional cell tumors varied according to tumor type. Benign Brenner tumors were homogeneous solid or unilocular cystic pattern, and malignant tumors were heterogeneous solid or multilocular cystic.

Recurrent ovarian granulosa cell tumors: clinical and imaging features.

BACKGROUND: Granulosa cell tumor of the ovary differs from epithelial ovarian tumors in histologic appearance, clinical course and imaging findings. The purpose of this study was to evaluate clinical and imaging features of recurrent ovarian granulosa cell tumors. METHODS: We performed retrospective evaluation of the medical, surgicopathologic records and CT or MR images of 11 patients with pathologically proven recurrent ovarian granulosa cell tumor. RESULTS: The first recurrence of granulosa cell tumor was diagnosed at between 4 months and 18 years after the initial surgical resection of tumor (mean; 9.7 years). Six patients relapsed after 10 years after initial diagnosis. The recurrent tumors were located in the pelvic cavity alone in three patients, extrapelvic peritoneal cavity alone in two, both pelvic and extrapelvic peritoneal cavity in three, and paraaortic retroperitoneal space in three. The imaging appearances of recurrent masses were variable ranging from solid masses to completely cystic masses. CONCLUSION: Recurrent granulosa cell tumor is characterized by late tumor recurrence manifested as a relatively small number of discrete peritoneal or retroperitoneal masses with variable imaging appearances from solid to cystic masses.

CT-quantified muscle and fat change in patients after surgery or endoscopic resection for early gastric cancer and its impact on long-term outcomes.

The purpose of this study was to evaluate the impact of the body composition changes on patients' long-term outcomes after endoscopic resection or surgery for mucosal gastric cancer.This case-control study included 96 patients who underwent endoscopic resection or surgery after propensity score matching. Areas of fat and muscle measured on CT were compared between the 2 groups. The effects of the variables on disease-free and overall survival were assessed using Cox-regression analysis and Kaplan-Meier survival analysis.The median overall survival of the surgical and endoscopic resection groups was 91.1 and 93.9 months (P = .080). Fat area was decreased significantly more after surgery (P < .001). The number of patients with sarcopenia was increased in the surgery group. Kaplan-Meier plot showed that overall survival was significantly correlated with post-treatment sarcopenia (P = .049).CT-based body composition analysis was helpful to evaluate the change in fat and muscle areas after treatment of early gastric cancer. The losses of fat and muscle after treatment were negatively associated with the patient overall survival.

Educational Effects of Radiation Reduction During Fluoroscopic Examination of the Adult Gastrointestinal Tract.

RATIONALE AND OBJECTIVES: This study aimed to evaluate the effects of educating radiology residents and radiographers about radiation exposure on reduction of dose area product (DAP) and fluoroscopy time in diagnostic fluoroscopy of the gastrointestinal (GI) tract in adult patients. MATERIALS AND METHODS: In April 2015, we offered 1 hour of education to radiology residents and radiographers on how to reduce radiation doses during fluoroscopic examinations. Fluoroscopic examinations of the GI tracts of adult patients performed from June 2014 to February 2016 were evaluated. A total of 2326 fluoroscopic examinations (779 and 1547 examinations before and after education, respectively) were performed, including 10 kinds of examinations. Fluoroscopy time and DAP were collected. A radiologist evaluated the number of spot images, captured images, cine video, captured video, and the use of collimation or magnification. We used the Mann-Whitney U test to assess the difference in fluoroscopy-related factors before and after education. RESULTS: Median DAP decreased significantly after education, from 21.1 to 18.2 Gy∙cm2 (P < .001) in all examinations. After education DAP decreased significantly in defecography (P < .001) and fluoroscopy time decreased significantly in upper gastrointestinal series with water-soluble contrast (P < .001). Spot and cine images that increased the radiation dose were used less frequently after education than before in some kinds of examinations, especially in defecography (P < .001). More images were collimated after education in barium swallow than before (P < .001). CONCLUSIONS: Educating radiologist residents and radiographers could reduce DAP in fluoroscopy examinations of the GI tract in adult patients.

Validation of intimate correlation between visceral fat and hepatic steatosis: Quantitative measurement techniques using CT for area of fat and MR for hepatic steatosis.

BACKGROUND & AIM: The relationship between obesity and hepatic steatosis is well known, and there are many methods to measure obesity and severity of hepatic steatosis. Because of advances in radiologic techniques, the areas of certain body components can be measured on computed tomography (CT) while the severity of hepatic steatosis can be measured by magnetic resonance spectroscopy (MRS) with high accuracy. The aim of this study is to investigate the relationship between degree of fatty infiltration of the liver measured by MRS and body composition measured from CT images. MATERIALS AND METHODS: We evaluated 95 potential liver donors who underwent abdomen CT and liver MRI (including MRS) between February 2014 and September 2015 in a tertiary university hospital. Body composition analysis was performed on CT images using commercial software. The areas of subcutaneous fat, visceral fat and abdominal circumference were measured automatically and the area of muscle was measured semi-automatically. The degree of hepatic steatosis was measured by MRS. RESULTS: The degree of hepatic steatosis showed a significant correlation with total fat area, visceral fat area, subcutaneous fat area, muscle area, abdominal circumference, BMI, and ratio of visceral fat to total fat. The strongest correlation was between hepatic steatosis and the area of visceral fat in all subjects (r=0.569). Multivariate regression analysis showed that male gender and visceral fat area were significantly associated with hepatic steatosis (P = 0.031, <0.001, respectively). CONCLUSIONS: The area of visceral fat has the most intimate correlation to the severity of hepatic steatosis among all significantly correlated parameters associated with body habitus. Accurate and quantitative body composition measurement and degree of hepatic steatosis can be noninvasively performed using advanced radiological techniques.