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Objective: This prospective multicenter study aimed to evaluate the diagnostic performance of 80-kVp thin-section pancreatic CT in determining pancreatic ductal adenocarcinoma (PDAC) resectability according to the recent National Comprehensive Cancer Network (NCCN) guidelines. Methods: We prospectively enrolled surgical resection candidates for PDAC from six tertiary referral hospitals (study identifier: NCT03895177). All participants underwent pancreatic CT using 80 kVp tube voltage with 1-mm reconstruction interval. The local resectability was prospectively evaluated using NCCN guidelines at each center and classified into three categories: resectable, borderline resectable, and unresectable. Results: A total of 138 patients were enrolled; among them, 60 patients underwent neoadjuvant therapy. R0 resection was achieved in 103 patients (74.6%). The R0 resection rates were 88.7% (47/53), 52.4% (11/21), and 0.0% (0/4) for resectable, borderline resectable, and unresectable disease, respectively, in 78 patients who underwent upfront surgery. Meanwhile, the rates were 90.9% (20/22), 76.7% (23/30), and 25.0% (2/8) for resectable, borderline resectable, and unresectable PDAC, respectively, in patients who received neoadjuvant therapy. The area under curve of high-resolution CT in predicting R0 resection was 0.784, with sensitivity, specificity, and accuracy of 87.4% (90/103), 48.6% (17/35), and 77.5% (107/138), respectively. Tumor response was significantly associated with the R0 resection after neoadjuvant therapy (odds ratio [OR] = 38.99, p = 0.016). Conclusion: An 80-kVp thin-section pancreatic CT has excellent diagnostic performance in assessing PDAC resectability, enabling R0 resection rates of 88.7% and 90.9% for patients with resectable PDAC who underwent upfront surgery and patients with resectable PDAC after neoadjuvant therapy, respectively. Key Points: • The margin-negative (R0) resection rates were 88.7% (47/53), 52.4% (11/21), and 0.0% (0/4) for resectable, borderline resectable, and unresectable pancreatic ductal adenocarcinoma (PDAC), respectively, on 80-kVp thin-section pancreatic CT in the 78 patients who underwent upfront surgery. • Among the 60 patients who underwent neoadjuvant therapy, the R0 rates were 90.9% (20/22), 76.7% (23/30), and 25.0% (2/8) for resectable, borderline resectable, and unresectable PDAC, respectively. • Tumor response, along with the resectability status on pancreatic CT, was significantly associated with the R0 resection rate after neoadjuvant therapy. [ABSTRACT FROM AUTHOR]

Increasing utilization of computed tomography (CT) has raised concerns regarding CT radiation dose and technology has been developed to achieve an appropriate balance between image quality, radiation dose, and the amount of contrast material. This study was planned to evaluate the image quality and radiation dose in pancreatic dynamic computed tomography (PDCT) with 90-kVp tube voltage and reduction of the standard amount of contrast agent, compared with 100-kVp PDCT of the research hospital's convention. Total of 51 patients with both CT protocols were included. The average Hounsfield units (HU) values of the abdominal organs and image noise were measured for objective image quality analysis. Two radiologists evaluated five categories of image qualities such as subjective image noise, visibility of small structure, beam hardening or streak artifact, lesion conspicuity and overall diagnostic performance for subjective image quality analysis. The total amount of contrast agent, radiation dose, and image noise decreased in the low-kVp group, by 24.4%, 31.7%, and 20.6%, respectively (p < 0.001). The intraobserver and interobserver agreements were moderate to substantial (k = 0.4−0.8). The contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and figure of merit of the almost organs except psoas muscle in the low-kVp group were significantly higher (p < 0.001). Except for lesion conspicuity, both reviewers judged that subjective image quality of the 90-kVp group was better (p < 0.001). With 90-kVp tube voltage, 25% reduced contrast agent volume with advanced iteration algorithm and high tube current modulation achieved radiation dose reduction of 31.7%, as well as better image quality and diagnostic confidence. [ABSTRACT FROM AUTHOR]

Evaluation of hepatic fibrosis is essential to prevent liver-related morbidity and mortality. Although various types of ultrasound shear wave elastography (SWE) have been used and validated, there are limited studies on the relatively newer technique, two-dimensional SWE (2D-SWE). Therefore, this study aimed to compare the diagnostic performances of 2D-SWE and point SWE (p-SWE) for evaluating liver fibrosis using histology as the reference standard. To measure liver stiffness (LS) values, 87 patients underwent 2D-SWE and p-SWE using the same machine. Technical failures and unreliable measurements were also evaluated. The diagnostic performances of 2D-SWE and p-SWE were compared using area under the receiver operating characteristic (AUROC) curve analysis. No technical failures were observed in either method; however, unreliable measurements were less frequent in 2D-SWE (1/87 [1.1%]) than in p-SWE (8/87 [9.2%]) (p < 0.001). The AUROC of the LS values of 2D-SWE were significantly higher than those of p-SWE for diagnosing significant fibrosis (0.965 vs. 0.872, p = 0.022) and cirrhosis (0.994 vs. 0.886, p = 0.042). In conclusion, 2D-SWE is more reliable and accurate than p-SWE for diagnosing hepatic fibrosis. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the feasibility of HU histogram analysis (HUHA) to assess proximal femoral fragility fractures with respect to BMD. Methods: This retrospective study included 137 patients with femoral fragility fractures who underwent hip CT and 137 control patients without fractures who underwent abdominal CT between January 2018 and February 2019. HUHA was calculated with the 3D volume of interest from the femoral head to the lesser trochanter. HUHAfat (percentage of negative HU values) and HUHAbone (percentage of HU values ≥ 125 HU) were assumed to be fat and bone components, respectively. Statistical significance was assessed using the area under the receiver operating characteristic curve (AUC), Spearman correlation (ρ), and odds ratio. Results: HUHAfat was strongly positively correlated (ρ = 0.56) and BMD was moderately negatively correlated with fragility fractures (ρ = − 0.37). AUC of HUHAfat (0.82, 95% CI [0.77, 0.87]) significantly differed from that of BMD (0.69, 95% CI [0.63, 0.75]) (p <.001). The cutoff value was 15.8% for HUHAfat (sensitivity: 90.4%; specificity: 67.7%) and 0.709 g/cm2 for BMD (sensitivity: 87.5%; specificity: 51.5%), with higher HUHAfat and lower BMD values indicating fragility fractures. The odds ratio of HUHAfat was 19.5 (95% CI [9.9, 38.2], p <.001), which was higher than that of BMD, 7.4 (95% CI [4.0, 13.6], p <.001). Conclusion: HUHAfat revealed better performance than BMD and demonstrated feasibility in assessing proximal femoral fragility fractures. Key Points: • HUHAfat showed a strong positive correlation (Spearman ρ = 0.56, p <.001), and BMD showed a moderate negative correlation (Spearman ρ = − 0.37, p <.001) with proximal femoral fragility fractures. • HUHAfat (AUC = 0.82) performed significantly better than BMD in assessing proximal femoral fragility fractures (AUC = 0.69) (p <.001). • The odds ratio of HUHAfat for proximal femoral fragility fractures was higher than that of BMD (19.5 and 7.4, respectively; p <.001). [ABSTRACT FROM AUTHOR]

Objectives: To compare the osteoporosis-predicting ability of computed tomography (CT) indexes in abdomen-pelvic CT using the proximal femur and the reliability of measurements in two- and three-dimensional analyses. Methods: Four hundred thirty female patients (age range, 50–96 years) who underwent dual-energy X-ray absorptiometry and abdominal-pelvic CT within 1 month were retrospectively selected. The volumes of interest (VOIs) from the femoral head to the lesser trochanter and the femoral neck were expressed as 3DFemur. Round regions of interest (ROIs) of image plane drawn over the femoral neck touching the outer cortex were determined as 2Dcoronal. In HU histogram analysis (HUHA), the percentages of HU histogram ranges related to the ROI or VOI were classified as HUHAFat (<0 HU) and HUHABone (126 HU≤). Diagnostic performance, correlation analysis and measurement reliability were analyzed by receiver operating characteristic curves, correlation coefficient and interobserver correlation coefficient (ICC), respectively. Results: AUCs of each HUHA and mean-HU measurement on 2D-ROI and 3D-VOI were 0.94 or higher (P < 0.001). Both 3DFemur-Mean-HU and 3DFemur-HUHABone showed the highest AUC (0.96). The cut-off value of 3DFemur-Mean-HU was 231HU or less, (sensitivity: 94.8%; specificity: 85.0%; correlation coefficient: −0.65; P <0.001) for diagnosis of osteoporosis. There was no superiority between AUCs in 2D-ROI and 3D-VOI measurements (P > 0.05). Reliability of the 3D-VOI measurement showed perfect agreement (ICC ≥ 0.94), and 2D-ROI showed moderate to good agreement (ICC range: 0.63~0.84). Conclusions: CT indexes on 3D-VOI for predicting femoral osteoporosis showed similar diagnostic accuracy with better reproducibility of measurement, compared with 2D-ROI. [ABSTRACT FROM AUTHOR]

Background: Osteoporosis has increased and developed into a serious public health concern worldwide. Despite the high prevalence, osteoporosis is silent before major fragility fracture and the osteoporosis screening rate is low. Abdomen-pelvic CT (APCT) is one of the most widely conducted medical tests. Artificial intelligence and radiomics analysis have recently been spotlighted. This is the first study to evaluate the prediction performance of femoral osteoporosis using machine-learning analysis with radiomics features and APCT. Materials and methods: 500 patients (M: F = 70:430; mean age, 66.5 ± 11.8yrs; range, 50–96 years) underwent both dual-energy X-ray absorptiometry and APCT within 1 month. The volume of interest of the left proximal femur was extracted and 41 radiomics features were calculated using 3D volume of interest analysis. Top 10 importance radiomic features were selected by the intraclass correlation coefficient and random forest feature selection. Study cohort was randomly divided into 70% of the samples as the training cohort and the remaining 30% of the sample as the validation cohort. Prediction performance of machine-learning analysis was calculated using diagnostic test and comparison of area under the curve (AUC) of receiver operating characteristic curve analysis was performed between training and validation cohorts. Results: The osteoporosis prevalence of this study cohort was 20.8%. The prediction performance of the machine-learning analysis to diagnose osteoporosis in the training and validation cohorts were as follows; accuracy, 92.9% vs. 92.7%; sensitivity, 86.6% vs. 80.0%; specificity, 94.5% vs. 95.8%; positive predictive value, 78.4% vs. 82.8%; and negative predictive value, 96.7% vs. 95.0%. The AUC to predict osteoporosis in the training and validation cohorts were 95.9% [95% confidence interval (CI), 93.7%-98.1%] and 96.0% [95% CI, 93.2%-98.8%], respectively, without significant differences (P = 0.962). Conclusion: Prediction performance of femoral osteoporosis using machine-learning analysis with radiomics features and APCT showed high validity with more than 93% accuracy, specificity, and negative predictive value. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the reliability of 3D image analysis and the effect of an iodine contrast agent on the computed tomography (CT) Hounsfield unit (HU) values of the proximal femur. Materials and methods: Fifty female patients (mean age, 61.3 years; age range, 50–79 years) who underwent both pre- and post-enhancement abdominopelvic CT scans were included in this retrospective study. Whole 3D volumes of the left proximal femur from the head to the lesser trochanter were extracted using the regional growth technique with commercial 3D software. Total volume, mean HU, and HU histogram analysis (HUHA) values of the extracted femur were calculated. HUHA distribution was classified into HUHAfat for the assumed fatty marrow (percentage of negative HU values) and HUHAdense-bone (percentage of HU values ≥ 126 HU). Reliability was assessed by calculating intra- and interobserver correlation coefficients (ICCs) and by drawing Bland–Altman plots. The effect of contrast medium administration was evaluated by the paired t-test. Results: All intra- and interobserver ICCs of 3D volume measurements showed excellent reproducibility (all ICCs > 0.90). On Bland–Altman analysis of two observers' 3D volume measurements, the differences in the mean total volume, HUHAfat, HUHAdense-bone, and mean HU were 2.4 cm3, 0.17%, 0.6%, and 1.9 HU, respectively. The mean difference in HU after contrast agent administration (-2.2 HU) was not significant (P = 0.27). The mean difference in HUHAfat and HUHAdense-bone after contrast agent administration were -1.1% and -2.2%, respectively, on the Bland–Altman plot. HUHAfat and HUHAdense-bone showed significant differences (P < 0.05). The 95% limits of agreement for HUHAfat, HUHAdense-bone, and mean HU were -3.6% to 1.3%, -6.5% to 2.1%, and -30.0 to 25.5 HU, respectively. Conclusion: Image analysis based on 3D volume measurement of the proximal femur showed excellent reliability, with the contrast agent administration showing negligible influence on the mean HU. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the diagnostic performance of Hounsfield unit histogram analysis (HUHA) of precontrast abdominal-pelvic CT scans for predicting osteoporosis.Materials and Methods: The study included 271 patients who had undergone dual X-ray absorptiometry (DXA) and abdominal-pelvic CT within 1 month. HUHA was measured using commercial 3D analysis software (Aquarius iNtuition v4.4.12Ⓡ, TeraRecon) and expressed as a percentage of seven HU range categories related to the ROI: A < 0, 0 ≤ B < 25, 25 ≤ C < 50, 50 ≤ D < 75, 75 ≤ E < 100, 100 ≤ F < 130, and 130 ≤ G. A coronal reformatted precontrast CT image containing the largest Ward's triangle was selected and then the ROI was drawn over the femoral neck. Correlation (r) and ROC curve analyses were used to assess diagnostic performance in predicting osteoporosis using the femur T-score as the reference standard.Results: When the femur T-score was used as the reference, the rs of HUHA-A and HUHA-G were 0.74 and -0.57, respectively. Other HUHA values had moderate to weak correlations (r = -0.33 to 0.27). The correlation of HUHA-A was significantly higher than that of HUHA-G (p = 0.03). The area under the curve (0.95) of HUHA-A differed significantly from that of HUHA-G (0.90; p < 0.01). A HUHA-A threshold ≥ 27.7% was shown to predict osteoporosis based on a sensitivity and specificity of 95.6% and 81.7%, respectively.Conclusion: The HUHA-A value of the femoral neck is closely related to osteoporosis and may help predict osteoporosis.Key Points: • HUHA correlated strongly with the DXA femur T-score (HUHA-A, r = 0.74). • The diagnostic performance of HUHA for predicting osteoporosis (AUC = 0.95) was better than that of the average CT HU value (AUC = 0.91; p < 0.05). • HUHA may help predict osteoporosis and enable semi-quantitative measurement of changes in bone mineral density. [ABSTRACT FROM AUTHOR]

Purpose: Objective of this study was to evaluate the effectiveness of the iterative reconstruction of high-pitch dual-source chest CT (IR-HP-CT) scanned with low radiation exposure compared with low dose chest CT (LDCT). Materials and methods: This study was approved by the institutional review board. Thirty healthy adult volunteers (mean age 44 years) were enrolled in this study. All volunteers underwent both IR-HP-CT and LDCT. IR-HP-CT was scanned with 120 kVp tube voltage, 30 mAs tube current and pitch 3.2 and reconstructed with sinogram affirmed iterative reconstruction. LDCT was scanned with 120 kVp tube voltage, 40 mAs tube current and pitch 0.8 and reconstructed with B50 filtered back projection. Image noise, and signal to noise ratio (SNR) of the infraspinatus muscle, subcutaneous fat and lung parenchyma were calculated. Cardiac motion artifact, overall image quality and artifacts was rated by two blinded readers using 4-point scale. The dose-length product (DLP) (mGy∙cm) were obtained from each CT dosimetry table. Scan length was calculated from the DLP results. The DLP parameter was a metric of radiation output, not of patient dose. Size-specific dose estimation (SSDE, mGy) was calculated using the sum of the anteroposterior and lateral dimensions and effective radiation dose (ED, mSv) were calculated using CT dosimetry index. Results: Approximately, mean 40% of SSDE (2.1 ± 0.2 mGy vs. 3.5 ± 0.3 mGy) and 34% of ED (1.0 ± 0.1 mSv vs. 1.5 ± 0.1 mSv) was reduced in IR-HP-CT compared to LDCT (P < 0.0001). Image noise was reduced in the IR-HP-CT (16.8 ± 2.8 vs. 19.8 ± 3.4, P = 0.0001). SNR of lung and aorta of IR-HP-CT showed better results compared with that of LDCT (22.2 ± 5.9 vs. 33.0 ± 7.8, 1.9 ± 0.4 vs 1.1 ± 0.3, P < 0.0001). The score of cardiac pulsation artifacts were significantly reduced on IR-HP-CT (3.8 ± 0.4, 95% confidence interval, 3.7‒4.0) compared with LDCT (1.6 ± 0.6, 95% confidence interval, 1.3‒1.8) (P < 0.0001). SNR of muscle and fat, beam hardening artifact and overall subjective image quality of the mediastinum, lung and chest wall were comparable on both scans (P ≥ 0.05). Conclusion: IR-HP-CT with 120 kVp and 30 mAs tube setting in addition to an iterative reconstruction reduced cardiac motion artifact and radiation exposure while representing similar image quality compared with LDCT. [ABSTRACT FROM AUTHOR]

Objective: To evaluate DW MR tumour volumetry and post-CRT ADC in rectal cancer as predicting factors of CR using high b values to eliminate perfusion effects.Methods: One hundred rectal cancer patients who underwent 1.5-T rectal MR and DW imaging using three b factors (0, 150, and 1,000 s/mm(2)) were enrolled. The tumour volumes of T2-weighted MR and DW images and pre- and post-CRT ADC150-1000 were measured. The diagnostic accuracy of post-CRT ADC, T2-weighted MR, and DW tumour volumetry was compared using ROC analysis.Results: DW MR tumour volumetry was superior to T2-weighted MR volumetry comparing the CR and non-CR groups (P < 0.001). Post-CRT ADC showed a significant difference between the CR and non-CR groups (P = 0.001). The accuracy of DW tumour volumetry (Az = 0.910) was superior to that of T2-weighed MR tumour volumetry (Az = 0.792) and post-CRT ADC (Az = 0.705) in determining CR (P = 0.015). Using a cutoff value for the tumour volume reduction rate of more than 86.8 % on DW MR images, the sensitivity and specificity for predicting CR were 91.4 % and 80 %, respectively.Conclusion: DW MR tumour volumetry after CRT showed significant superiority in predicting CR compared with T2-weighted MR images and post-CRT ADC. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the impact of the different region-of-interest (ROI) methods of 2-D shear wave elastography (2-D SWE) on hepatic fibrosis diagnosis. In this retrospective study, 83 patients who underwent 2-D SWE with three ROI methods (a circle ROI, a box ROI and multiple ROIs in an elastogram) and transient elastography (TE) were included. Liver stiffness (LS) was measured five times with each ROI method. These LS values were compared, and their correlation with those obtained from TE was evaluated. The LS values obtained using the three different ROI methods differed statistically (p < 0.001). However, the LS values obtained using each ROI method of 2-D SWE were highly correlated with those obtained using TE (r > 0.7, p < 0.001). All three ROI methods of 2-D SWE had high areas under the receiver operating characteristic curve in diagnosing significant fibrosis and cirrhosis (0.841, 0.820 and 0.840, respectively; 0.962, 0.946 and 0.945, respectively). There were no significant differences in area under the receiver operating characteristic curve among the ROI methods of 2-D SWE. Regardless of the ROI method, 2-D SWE had high performance in diagnosing hepatic fibrosis. [ABSTRACT FROM AUTHOR]

Objectives:With the aging population, the number of elderly patients diagnosed with gastric cancer is increasing. However, determining treatment strategies for elderly patients with gastric cancer is controversial. The aim of this study is to evaluate the usefulness of surgical treatment on elderly patients aged ≥80 years with advanced gastric cancer. Methods:A total of 147 elderly patients who were diagnosed with advanced gastric cancer from August 2001 to December 2015 were retrospectively analyzed. We compared the clinicopathological features and prognoses of 94 elderly patients (80–85 years) and 53 extreme-elderly patients (≥86 years) according to treatment modalities. Results:In the elderly group, the 3-year overall survival (OS) rates of the surgical resection group and supportive care group were 42.1% and 4.0%, respectively (p < .001). In the extreme-elderly group, the 3-year OS rates of the surgical resection group and supportive care group were 36.4% and 8.0%, respectively (p = .028). The post-operative mortality rate of the elderly group and extreme-elderly group was 5.6% and 9.1%, respectively. In the analysis of risk factors associated with survival, surgical resection was a significantly good prognostic factor in the elderly group (hazard ratio [HR] = 0.277;p = .003) compared with supportive care. In the extreme-elderly group, surgical resection was associated with good prognosis but did not reach statistical significance (HR = 0.491;p = .099). Conclusions:These results suggest that elderly patients aged 80–85 years with advanced gastric cancer could expect a better prognosis with surgical resection. However, extreme-elderly patients aged ≥86 years should consider the risks and benefits of surgical treatment. [ABSTRACT FROM AUTHOR]

Purposes: To determine the maximum tolerated dose (MTD), recommended dose (RD), and activity of combined oxaliplatin, irinotecan, and S-1 chemotherapy for metastatic or recurrent gastrointestinal (GI) cancer.Methods: Oxaliplatin and irinotecan were administered intravenously on day 1, and S-1 was administered orally on days 1-7, every 2 weeks. This phase I study used the following dose levels for oxaliplatin/irinotecan/S-1: level 1, 85/120/60 mg/m2; level 2, 85/120/80 mg/m2; level 3, 85/120/100 mg/m2; level 4, 85/150/100 mg/m2; and level 5, 85/180/100 mg/m2. Treatment was repeated for a maximum of 12 cycles, until disease progression, or until unacceptable toxicity.Results: Twenty-four patients were enrolled between October 2012 and February 2014 (median age 59 years). During the first cycle, one of the six patients in levels 1, 3, and 4 developed a dose-limiting toxicity (grade 3 febrile neutropenia), and none of the three patients in level 5 developed a dose-limiting toxicity. As the planned maximum dose did not reach the MTD, the level 5 dose was defined as the RD. Twenty-one patients were evaluated for response, which included 2 cases of complete response and 8 cases of partial response, with an overall response rate of 47.6 %.Conclusions: The combination of oxaliplatin, irinotecan, and S-1 provided an acceptable toxicity profile and modest clinical benefits in patients with advanced GI cancer. The RD was 85 mg/m2 of oxaliplatin, 180 mg/m2 of irinotecan, and 100 mg/m2 of S-1 every 2 weeks. [ABSTRACT FROM AUTHOR]

Background. This retrospective study aimed to assess the efficacy and toxicities of second-line chemotherapy with irinotecan, leucovorin, and 5-fluorouracil (5-FU) in metastatic gastric cancer (MGC) patients previously treated with docetaxel and S-1 with or without oxaliplatin (DS/DOS). Patients and Methods. We reviewed the data of patients who had previously been treated with first-line DS/DOS and received biweekly irinotecan-based chemotherapy (FOLFIRI/IFL) between October 2004 and November 2011. Results. A total of 209 cycles were administered to 35 patients, with a median of 4 (range, 1–22) cycles each. The overall response rate in 29 response-assessable patients was 17.2%, including 2 complete and 3 partial responses. The median progression-free and overall survivals were 3.81 (95% confidence interval [CI], 1.82–5.80) months and 6.24 (95% CI, 1.44–11.04) months, respectively. The major grade 3/4 toxicity was neutropenia (8.6%). Conclusion. FOLFIRI/IFL chemotherapy showed modest antitumour activity and tolerable toxicities in DS/DOS-treated MGC patients. [ABSTRACT FROM AUTHOR]