Magnetic resonance imaging-based risk factors of hepatocellular carcinoma after direct-acting antiviral therapy: A multicenter observational study.

AIM: To determine risk factors associated with hepatocellular carcinoma (HCC) development following direct-acting antiviral (DAA) therapy. METHODS: We enrolled patients with chronic hepatitis C who underwent direct-acting antiviral therapy and achieved sustained virologic response at 12 weeks between 2012 and 2018. Subsequently, patients were followed up. The primary endpoint was the development of HCC or the date of the last follow up when the absence of HCC was confirmed. Uni- and multivariate Cox proportional hazards models were used to identify factors contributing to HCC development, including gadoxetic acid-enhanced magnetic resonance imaging findings. The cumulative incidence rates of HCC development were calculated using the Kaplan-Meier method, and differences between groups were assessed using the log-rank test. RESULTS: The final study cohort comprised 482 patients (median age 70.5 years; 242 men). The median follow-up period was 36.8 months. Among 482 patients, 96 developed HCC (19.9%). The 1-, 3-, and 5-year cumulative rates of HCC development were 4.9%, 18.6%, and 30.5%, respectively. Multivariate analysis revealed that age, male sex, history of HCC, and hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were independent risk factors significantly associated with HCC development (p < 0.001-0.04). The highest risk group included patients with both a history of HCC and the presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement (the 1- and 3-year cumulative HCC development rates were 14.2% and 62.2%, respectively). CONCLUSION: History of HCC and presence of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement were strong risk factors for HCC development following direct-acting antiviral therapy.

Human estimates of descending objects' motion are more accurate than those of ascending objects regardless of gravity information.

Humans can accurately estimate and track object motion, even if it accelerates. Research shows that humans exhibit superior estimation and tracking performance for descending (falling) than ascending (rising) objects. Previous studies presented ascending and descending targets along the gravitational and body axes in an upright posture. Thus, it is unclear whether humans rely on congruent information between the direction of the target motion and gravity or the direction of the target motion and longitudinal body axes. Two experiments were conducted to explore these possibilities. In Experiment 1, participants estimated the arrival time at a goal for both upward and downward motion of targets along the longitudinal body axis in the upright (both axes of target motion and gravity congruent) and supine (both axes incongruent) postures. In Experiment 2, smooth pursuit eye movements were assessed while tracking both targets in the same postures. Arrival time estimation and smooth pursuit eye movement performance were consistently more accurate for downward target motion than for upward motion, irrespective of posture. These findings suggest that the visual experience of seeing an object moving along an observer's leg side in everyday life may influence the ability to accurately estimate and track the descending object's motion.

Pancreatic cancer detection with dual-energy CT: diagnostic performance of 40 keV and 70 keV virtual monoenergetic images.

PURPOSE: To compare the diagnostic performance of 40 keV and 70 keV virtual monoenergetic images (VMIs) generated from dual-energy CT in the detection of pancreatic cancer. METHODS: This retrospective study included patients who underwent pancreatic protocol dual-energy CT from January 2019 to August 2022. Four radiologists (1-11 years of experience), who were blinded to the final diagnosis, independently and randomly interpreted 40 keV and 70 keV VMIs and graded the presence or absence of pancreatic cancer. For each image set (40 keV and 70 keV VMIs), the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. The diagnostic performance of each image set was compared using generalized estimating equations. RESULTS: Overall, 137 patients (median age, 71 years; interquartile range, 63-78 years; 77 men) were included. Among them, 62 patients (45%) had pathologically proven pancreatic cancer. The 40 keV VMIs had higher specificity (75% vs. 67%; P < .001), PPV (76% vs. 71%; P < .001), and accuracy (85% vs. 81%; P = .001) than the 70 keV VMIs. On the contrary, 40 keV VMIs had lower sensitivity (96% vs. 98%; P = .02) and NPV (96% vs. 98%; P = .004) than 70 keV VMIs. However, the diagnostic confidence in patients with (P < .001) and without (P = .001) pancreatic cancer was improved in 40 keV VMIs than in 70 keV VMIs. CONCLUSIONS: The 40 keV VMIs showed better diagnostic performance in diagnosing pancreatic cancer than the 70 keV VMIs, along with higher reader confidence.

Determination of arterial invasion in pancreatic ductal adenocarcinoma: what is the best diagnostic criterion on CT?

OBJECTIVES: To investigate the diagnostic performance and interobserver variability in the determination of arterial invasion in pancreatic ductal adenocarcinoma (PDAC) and determine the best CT imaging criterion. METHODS: We retrospectively evaluated 128 patients with PDAC (73 men and 55 women) who underwent preoperative contrast-enhanced CT. Five board-certified radiologists (expert) and four fellows (non-expert]) independently assessed the arterial invasion (celiac, superior mesenteric, splenic, and common hepatic arteries) using a 6-point score: 1, no tumor contact; 2, hazy attenuation ≤ 180°; 3, hazy attenuation > 180°; 4, solid soft tissue contact ≤ 180°; 5, solid soft tissue contact > 180°; and 6, contour irregularity. ROC analysis was performed to evaluate the diagnostic performance and determine the best diagnostic criterion for arterial invasion, with pathological or surgical findings as references. Interobserver variability was assessed using Fleiss's ĸ statistics. RESULTS: Among the 128 patients, 35.2% (n = 45/128) received neoadjuvant treatment (NTx). Solid soft tissue contact ≤ 180° was the best diagnostic criterion for arterial invasion as defined by the Youden Index both in patients who did and did not receive NTx (sensitivity, 100% vs. 100%; specificity, 90% vs. 93%; and AUC, 0.96 vs. 0.98, respectively). Interobserver variability among the non-expert was not inferior to that among the expert (ĸ = 0.61 vs 0.61; p = .39 and ĸ = 0.59 vs 0.51; p < .001 in patients treated with and without NTx, respectively). CONCLUSIONS: Solid soft tissue contact ≤ 180° was the best diagnostic criterion for the determination of arterial invasion in PDAC. Considerable interobserver variability was seen among the radiologists. KEY POINTS: • Solid soft tissue contact ≤ 180° was the best diagnostic criterion for the determination of arterial invasion in pancreatic ductal adenocarcinoma. • Interobserver agreement among non-expert radiologists was almost comparable to that among expert radiologists.

Deep learning image reconstruction algorithm for pancreatic protocol dual-energy computed tomography: image quality and quantification of iodine concentration.

OBJECTIVES: To evaluate the image quality and iodine concentration (IC) measurements in pancreatic protocol dual-energy computed tomography (DECT) reconstructed using deep learning image reconstruction (DLIR) and compare them with those of images reconstructed using hybrid iterative reconstruction (IR). METHODS: The local institutional review board approved this prospective study. Written informed consent was obtained from all participants. Thirty consecutive participants with pancreatic cancer (PC) underwent pancreatic protocol DECT for initial evaluation. DECT data were reconstructed at 70 keV using 40% adaptive statistical iterative reconstruction-Veo (hybrid-IR) and DLIR at medium and high levels (DLIR-M and DLIR-H, respectively). The diagnostic acceptability and conspicuity of PC were qualitatively assessed using a 5-point scale. IC values of the abdominal aorta, pancreas, PC, liver, and portal vein; standard deviation (SD); and coefficient of variation (CV) were calculated. Qualitative and quantitative parameters were compared between the hybrid-IR, DLIR-M, and DLIR-H groups. RESULTS: The diagnostic acceptability and conspicuity of PC were significantly better in the DLIR-M group compared with those in the other groups (p < .001-.001). The IC values of the anatomical structures were almost comparable between the three groups (p = .001-.9). The SD of IC values was significantly lower in the DLIR-H group (p < .001) and resulted in the lowest CV (p < .001-.002) compared with those in the hybrid-IR and DLIR-M groups. CONCLUSIONS: DLIR could significantly improve image quality and reduce the variability of IC values than could hybrid-IR. KEY POINTS: Image quality and conspicuity of pancreatic cancer were the best in DLIR-M. DLIR significantly reduced background noise and improved SNR and CNR. The variability of iodine concentration was reduced in DLIR.

Prediction of overall survival in patients with pancreatic ductal adenocarcinoma: histogram analysis of ADC value and correlation with pathological intratumoral necrosis.

BACKGROUND: To evaluate the utility of histogram analysis (HA) of apparent diffusion coefficient (ADC) values to predict the overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDAC) and to correlate with pathologically evaluated massive intratumoral necrosis (MITN). MATERIALS AND METHODS: Thirty-nine patients were included in this retrospective study with surgically resected PDAC who underwent preoperative magnetic resonance imaging. Twelve patients received neoadjuvant chemotherapy. HA on the ADC maps were performed to obtain the tumor HA parameters. Using Cox proportional regression analysis adjusted for age, time-dependent receiver-operating-characteristic (ROC) curve analysis, and Kaplan-Meier estimation, we evaluated the association between HA parameters and OS. The association between prognostic factors and pathologically confirmed MITN was assessed by logistic regression analysis. RESULTS: The median OS was 19.9 months. The kurtosis (P < 0.001), entropy (P = 0.013), and energy (P = 0.04) were significantly associated with OS. The kurtosis had the highest area under the ROC curve (AUC) for predicting 3-year survival (AUC 0.824) among these three parameters. Between the kurtosis and MITN, the logistic regression model revealed a positive correlation (P = 0.045). Lower survival rates occurred in patients with high kurtosis (cutoff value > 2.45) than those with low kurtosis (≤ 2.45) (P < 0.001: 1-year survival rate, 75.2% versus 100%: 3-year survival rate, 14.7% versus 100%). CONCLUSIONS: HA derived kurtosis obtained from tumor ADC maps might be a potential imaging biomarker for predicting the presence of MITN and OS in patients with PDAC.

Optimized Bolus Threshold for Dual-Energy CT Angiography with Monoenergetic Images: A Randomized Clinical Trial.

Background The bolus-tracking technique from single-energy CT has been applied to dual-energy CT (DECT) without optimization or validation. Further optimization is imperative because of a paucity of literature and differences in the attenuation profile of virtual monoenergetic images (VMIs). Purpose To determine the optimal trigger threshold with bolus-tracking technique for DECT angiography (DECTA) in a phantom study and assess the feasibility of an optimized threshold for bolus-tracking technique in DECTA at 40 keV with a 50% reduced iodine dose in human participants. Materials and Methods A phantom study with rapid kilovoltage-switching DECT was performed to determine the optimal threshold for each kiloelectron-volt VMI. In a prospective study, consecutive participants who underwent whole-body CT angiography (CTA) from August 2018 to July 2019 were randomized into three groups: single-energy CTA (SECTA) with standard iodine dose (600 mg of iodine per kilogram), DECTA with 50% reduced iodine dose (300 mg of iodine per kilogram) by using a conventional threshold, and DECTA with 300 mg of iodine per kilogram by using an optimized threshold. A trigger threshold of 100 HU at 120 kVp was used as a reference for comparison. Injected iodine doses and aortic CT numbers were compared among the three groups using Kruskal-Wallis test. Results Ninety-six participants (mean age ± standard deviation, 72 years ± 9; 80 men) were evaluated (32 participants in each group). The optimized threshold for VMIs at 40 keV was 30 HU. The median iodine dose was lower in the optimized DECTA group (13 g) compared with conventional DECTA (19 g) and SECTA (26 g) groups (P < .017 for each comparison). The median aortic CT numbers were higher in the order corresponding to conventional DECTA (655-769 HU), optimized DECTA (543-610 HU), and SECTA (343-359 HU) groups (P < .001). Conclusion The optimized trigger threshold of 30 HU for bolus-tracking technique during dual-energy CT angiography at 40 keV achieved lower iodine load while maintaining aortic enhancement. ©RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Malayeri in this issue.

A human voice, but not human visual image makes people perceive food to taste better and to eat more: "Social" facilitation of eating in a digital media.

Food tastes better and people eat more when eating with others compared to eating alone. Although previous research has shown that watching television facilitates eating, the influencing factors regarding video content are unclear. We compared videos of a person speaking with those of only objects (food and a cell phone) in Experiment 1, and videos of groups of four people talking in Experiment 2. Half of these videos presented human voices (including the objects-only video), while the other half had no audio. Results showed participants rated the popcorn as tasting better and consumed more when eating alone while listening to someone talking, irrespective of whether the person was present or absent in the video in Experiment 1. A similar result was found in Experiment 2, irrespective of the increased number of people talking in the video. In Experiment 3, we assessed to what extent human voices contributed to an increase in food intake and the perceived taste of food by substituting sine-wave speech (SWS) for human voices used in Experiment 1 and found that the perceived taste of food and food intake were not facilitated when participants watched videos with SWS. The present study indicates that the human voice plays a crucial role in the perceived taste of food and consumption amount when people eat alone while watching television. Suggestions to improve food enjoyment when dining alone are discussed.

Long-term Multidisciplinary Rehabilitation Efficacy in Older Patients After Traumatic Brain Injury: Assessed by the Functional Independence Measure.

Instances of traumatic brain injury (TBI) in the elderly have been increasing along with the aging of popula-tions. In the present study, we examined the effect of aging on long-term multidisciplinary in-patient rehabili-tation efficacy after TBI. Sixty-three patients with physical and cognitive impairments after TBI were enrolled in this study. Patients were divided into 4 age groups (≤ 24, 25-44, 45-64, ≥ 65 years) and the clinical charac-teristics and rehabilitation efficacy of each age group were determined. Functional disability was evaluated using motor and cognitive Functional Independence Measure (FIM) scores. Rehabilitation efficacy was assessed by FIM gains during rehabilitation and compared among the groups. There were no statistically significant dif-ferences in motor and cognitive FIM gains among the age groups. However, cognitive FIM gain was limited in a subset of ≥ 65 patients, and initial cognitive measures could not predict cognitive FIM improvement. These results indicate that chronological age is insufficient to accurately predict rehabilitation efficacy in older TBI patients, and that such patients should be considered candidates for intensive rehabilitation programs based on these results. Accurate prognostication of rehabilitation efficacy with continuing data collection is important when using rehabilitation resources for older TBI patients.

[Points to Note about Neuropsychological Impairment in the Acute Management of Traumatic Brain Injury].

Neuropsychological impairment after traumatic brain injury(TBI)is occasionally difficult to diagnose and called "invisible or hidden impairment," especially when physical impairment is mild. Patients and their family do not recognize the impairment during hospitalization and even after discharge. However, they manifest many problems when they return to real life and society. Here, we have presented the characteristics and tips to diagnose neuropsychological impairment after TBI that are important for clinical neurosurgeons working at acute care hospitals. They are as follows: 1)In the emergency room, accurate evaluation of the consciousness state is the first step. 2)In the acute phase after TBI, do not mix up acute symptomatic seizure and post-traumatic epilepsy. 3)Soon after stabilization of the general condition, detailed radiological examinations should be performed to detect organic brain damages with MRI including DWI, FLAIR, T2*, and SWI. 4)At discharge, it is necessary to provide information about neuropsychological impairment to the patients and their family members. Neurosurgeons should diagnose and treat the patients with accurate understanding of neuropsychological impairment in the acute management of TBI.

Humans detect snakes more accurately and quickly than other animals under natural visual scenes: a flicker paradigm study.

Threat detection is crucial to survival. Studies using unnatural visual scene settings (i.e. visual search tasks) have shown that humans and primates are able to identify snakes more quickly than they are able to identify other animals. The present study employed a flicker paradigm task to assess whether humans detect snakes more accurately and rapidly than they do other reptiles in natural scene settings. Participants watched a long series of images, consisting of pairs of complex natural scenes. A blank interval was inserted between the two versions of the scene, showing only the scene and the scene plus an added animal (snake or lizard). Participants detected scene changes featuring the snake targets more accurately and rapidly than those with lizard targets. This finding supports the view that there were evolutionary pressures for a visual system which prioritised human detection of snakes.

Correlation of quantitative pancreatic T1 value and HbA1c value in subjects with normal and impaired glucose tolerance.

BACKGROUND: Signal intensity on T1 -weighted images (T1 WI) is associated with pancreatic fibrosis and HbA1c levels. PURPOSE: To evaluate the feasibility of the pancreatic T1 value for assessment of subjects with normal and impaired glucose tolerance (IGT). STUDY TYPE: A prospective single-institution study. POPULATION: In all, 95 consecutive patients with a known or suspected pancreatic disease. FIELD STRENGTH/SEQUENCES: 3T/fast pancreatic T1 mapping using a modified Look-Locker sequence. ASSESSMENT: Following the American Diabetes Association criteria, patients were classified into three groups, as follows: no-diabetes subject, HbA1c < 5.7%; prediabetes, 5.7% ≤ HbA1c < 6.5%; and type 2 diabetes mellitus (T2DM), HbA1c ≥ 6.5%. Pancreatic T1 value and signal intensity ratio (SIR = SIpancreas /SImuscle ) using T1 WI were compared with the HbA1c values. STATISTICAL TESTS: Quantitative data were assessed with one-way analysis of variance, Fisher's and Mann-Whitney U tests, and receiver-operating characteristic analysis. RESULTS: The pancreatic T1 value was significantly longer in T2DM than in no-diabetes and prediabetes subjects (P < 0.05) and was significantly longer in prediabetes than in no-diabetes subjects (P < 0.05). The mean pancreatic T1 value was significantly lower in the low-value group (HbA1c < 5.7%) (906.3 msec) compared with the high-value group (HbA1c ≥ 6.5%) (993.8 msec) (P < 0.0001). SIR on T1 WI was significantly higher in the low-value group compared with the high-value group (P = 0.029). The sensitivities, specificities, and area under the receiver-operating characteristic curve (AUCs) for differentiating the low- and high-value groups were 74.1%, 83.8%, and 0.82 in the pancreatic T1 values and 77.8%, 54.4%, and 0.63 in SIR on T1 WI, respectively. The specificity (P < 0.0001) and AUC (P = 0.0020) were significantly higher in the pancreatic T1 values than in SIR on T1 WI. DATA CONCLUSION: Pancreatic T1 value has the potential of being an imaging biomarker for the assessment of IGT. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:711-718.

Prognostic evaluation of pancreatic ductal adenocarcinoma: Associations between molecular biomarkers and CT imaging findings.

OBJECTIVES: To investigate association between molecular biomarkers and computed tomography (CT) imaging findings in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: Fifty-three consecutive patients with PDAC (34 men and 19 women; mean age, 70.6 ±â€¯8.1 years; range, 56-86 years) who underwent dynamic contrast-enhanced CT prior to pancreatectomy were included. The Ki-67 index and expressions of E-cadherin, Vimentin, and TWIST were immunohistochemically evaluated. Qualitative image analysis and histogram analysis of CT numbers were conducted. Clinical and molecular biomarkers were tested as possible prognostic factors for overall survival (OS) using Kaplan-Meier method and Cox proportional hazards regression. In addition, associations between CT imaging findings and significant molecular biomarkers were investigated. RESULTS: The TNM stage (P = 0.018) and E-cadherin expression status (P = 0.018) were independently associated with OS. E-cadherin-negative PDACs had a worse prognosis than E-cadherin-positive PDACs (hazard ratio: 2.21). Irregular tumor margin was observed more frequently in E-cadherin-negative PDACs (54.7%) than in E-cadherin-positive PDACs (45.3%) (P = 0.00054). The kurtosis of CT number during the pancreatic parenchymal phase was significantly higher in E-cadherin-negative PDACs than in E-cadherin-positive PDACs (P = 0.035). CONCLUSIONS: E-cadherin suppression was found to be a prognostic factor for OS in patients with PDAC, and irregular tumor margin and kurtosis of CT numbers during the pancreatic parenchymal phase could be indicators for E-cadherin suppression.

Simultaneous acquisition of MR angiography and diagnostic images of abdomen at view-sharing multiarterial phases and comparing the effect of two different contrast agents.

BACKGROUND: Simultaneous acquisition of magnetic resonance angiography (MRA) and diagnostic images is challenging in contrast-enhanced upper abdominal MRI. PURPOSE: To evaluate the image quality of MRA of the abdomen acquired simultaneously with diagnostic MR images, and to compare the contrast effect, conspicuity of aortic branches, and pancreatic lesions in MRA between gadobutrol and gadoterate meglumine. STUDY TYPE: Prospective. POPULATION: Eighty-eight patients with known and suspected upper abdominal disease. FIELD STRENGTH/SEQUENCES: 3T/4D-eTHRIVE (T1 -weighted fat-suppressed 3D fast gradient echo) for multiarterial phase imaging. ASSESSMENT: The artery-to-muscle signal intensity ratio (SIR), conspicuity of aortic branches on the axial, maximum intensity projection (MIP), and volume-rendered (VR) images, and conspicuity of focal pancreatic lesions were compared between gadobutrol and gadoterate meglumine. The diameters of aortic branches were measured on axial MRA and computed tomography angiography (CTA) images and then compared. STATISTICAL TESTS: Quantitative and qualitative data were assessed with the Mann-Whitney U-test. The diameters of aortic branches between MRA and CTA were compared with a Spearman rank correlation test. RESULTS: View-sharing multiarterial phase imaging was successfully performed in all patients. The SIRs of common hepatic artery (P = 0.0051) and left renal artery (RA) (P = 0.045), vascular conspicuities of right and left hepatic arteries (P = 0.010 and 0.030) and right and left RAs on axial (P = 0.0065 and 0.036), and that of gastroduodenal artery on MIP (P = 0.039) with gadobutrol were significantly higher than those with gadoterate meglumine. The conspicuity of focal pancreatic lesions were comparable between the gadobutrol and gadoterate meglumine (P = 0.73). The vascular diameters on MRA and CTA were strongly correlated in all aortic branches (r = 0.842-0.942, P < 0.0001). DATA CONCLUSION: High-quality MRA of the abdomen was obtained simultaneously with the diagnostic MR images using view-sharing multiarterial phase imaging that also demonstrated comparable image quality between gadobutrol and gadoterate meglumine. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2017.

Assessing Chemotherapeutic Response in Pancreatic Ductal Adenocarcinoma: Histogram Analysis of Iodine Concentration and CT Number in Single-Source Dual-Energy CT.

OBJECTIVE: The objective of this study was to evaluate the feasibility of histographic analysis of iodine concentration (IC) and CT number on single-source dual-energy CT (DECT) to assess response to first-line chemotherapy in patients with pancreatic ductal adenocarcinoma (PDAC) who received first-line chemotherapy but not radiation therapy. SUBJECTS AND METHODS: This prospective study was approved by our institutional review board, and patients gave written informed consent. Sixty consecutive patients with PDAC undergoing first-line chemotherapy underwent DECT during the pancreatic parenchymatous phase (PPP) and the equilibrium phase (EP). The IC and CT number of PDAC were measured using PPP and EP iodine-based material decomposition and monochromatic images (65 keV), respectively. Histographic parameters for the IC and CT number of PDACs were obtained, and differences in mean IC (ΔIC) and CT number (ΔHU) between the PPP and the EP were calculated. These parameters were then compared between the response (partial response or stable disease) and nonresponse (progressive disease) groups. RESULTS: Among the histographic parameters, the kurtosis of IC during the PPP (p = 0.018) and ΔIC (p = 0.0004) were identified as significant for differentiating between the two groups. IC diagnostic factor was calculated using the following coefficients of logistic regression analysis: 0.52 - (1.45 × kurtosis of IC during PPP) + (0.69 × ΔIC). The sensitivity, specificity, and area under the ROC curve for differentiating between the two groups were 97.7%, 70.6%, and 0.889, respectively. CONCLUSION: The IC diagnostic factor is a potential biomarker for assessing chemotherapeutic response in patients with PDAC.

Modified National Comprehensive Cancer Network Criteria for Assessing Resectability of Pancreatic Ductal Adenocarcinoma.

OBJECTIVE: The objective of our study was to assess the preoperative resectability of pancreatic ductal adenocarcinoma (PDAC) using the National Comprehensive Cancer Network (NCCN) guideline, the general rules of the Japan Pancreas Society (JPS), and both of them combined. MATERIALS AND METHODS: Eighty-six consecutive patients with PDAC (50 men and 36 women; mean age ± SD, 70.8 ± 9.0 years; age range, 49-86 years) underwent dynamic contrast-enhanced CT. Following the NCCN guideline, the degree of vascular invasion was evaluated to determine the NCCN score: 0 points for absence of vascular invasion, 1 point for tumor contact ≤ 180°, and 2 points for tumor contact > 180°. Direct invasion to adjacent structures was rated according to the general rules of JPS to determine the JPS score: 0 points for absence and 1 point for presence. The NCCN score, JPS score, and sum of the two scores, which we refer to as the "combined score," were compared with histopathologic or intraoperative findings as well as for the differentiation of R0 resection (negative resection margins) from R1 (microscopic tumor infiltration) and R2 (macroscopic residual tumor) using ROC curve analysis. RESULTS: The sensitivities, specificities, and areas under the ROC curves (AUCs) for the differentiation of R0 from R1 and R2 were 100.0%, 40.0%, and 0.725, respectively, with the NCCN score; 63.9%, 84.0%, and 0.824 with the JPS score; and 86.9%, 68.0%, and 0.874 with the combined score. The AUC of the combined score was significantly greater than that of the NCCN score (p = 0.0059). CONCLUSION: The assessment of resectability of PDAC based on the combined criteria of the NCCN guideline and general rules of JPS was superior to that based on either criterion alone.

Flow-metabolism uncoupling in the cervical spinal cord of ALS patients.

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease. In ALS, both glucose consumption and neuronal intensity reportedly decrease in the cerebral motor cortex when measured by positron emission tomography (PET). In this study, we evaluated cervical spinal glucose metabolism, blood flow, and neuronal intensity of 10 ALS patients with upper extremity (U/E) atrophy both with 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) PET and 11C-flumazenil (11C-FMZ) PET. On the ipsilateral side of C5 and T1 levels, 18F-FDG uptake increased significantly (*p < 0.05), and was correlated with the rate of progression of the ALS FRS-R-U/E score (R = 0.645, *p = 0.041). Despite this hyperglucose metabolism, the 11C-FMZ PET study did not show a coupled increase of spinal blood flow even though neuronal intensity did not decrease. These results indicate a strong correlation between hyperglucose metabolism and ALS progression alongside the uncoupling of flow-metabolism. This mechanism, which could result in subsequent motor neuronal death, may be a potential therapeutic target for ALS.

Expression of 58-kD Microspherule Protein (MSP58) is Highly Correlated with PET Imaging of Tumor Malignancy and Cell Proliferation in Glioma Patients.

BACKGROUND/AIMS: The nucleolar 58-kDa microspherule protein (MSP58) has important transcriptional regulation functions and plays a crucial role in the tumorigenesis and progression of cancers. 3'-deoxy-3'-[18F]fluorothymidine (FLT) has emerged as a promising positron emission tomography (PET) tracer for evaluating tumor malignancy and cell proliferation. METHODS: In the present study, the expression of MSP58 was evaluated by immunohistochemistry and the corresponding PET image was examined using FLT-PET in 55 patients with various grades of gliomas. RESULTS: The immunoreactivity score (IRS) of MSP58 increased with tumor grade with grade IV gliomas exhibiting the highest expression and showed a highly significant positive correlation with the Ki-67 index (r = 0.65, P < 0.001). The IRS of MSP58 in the tumor showed a highly significant positive correlation with corresponding FLT uptake value (r = 0.61, P < 0.001). The correlation between MSP58 expression and glioma malignancy was also confirmed by immunofluorescence, RT-PCR and western blot analysis. FLT uptake value also exhibited a highly significant positive correlation with the Ki-67 index (r = 0.59, P < 0.001). Kaplan-Meier analysis revealed that MSP58 expression has a significant prognostic ability for the overall survival time similar to that found in the uptake value of FLT-PET. CONCLUSION: These results indicate that MSP58 plays an important role in cell proliferation and will be one of the potential candidates of molecular therapy targeting proliferation. FLT-PET might be used as an early measure of treatment response in the proliferation-targeted therapy.

Diffusion kurtosis imaging of the pancreas for the assessment of HbA1c levels.

PURPOSE: To evaluate the feasibility of diffusion kurtosis (DK) imaging of the pancreas for the assessment of hemoglobin (Hb) A1c values. MATERIALS AND METHODS: Our Institutional Review Board approved this prospective study and written informed consent was obtained. In all, 102 consecutive patients with suspected pancreatic disease underwent magnetic resonance imaging (MRI), including DK imaging. Patients were classified into three groups according to American Diabetes Association criteria: HbA1c < 5.7% (group 1), 5.7% ≤ HbA1c < 6.5% (group 2), and HbA1c ≥ 6.5% (group 3). Mean kurtosis (MK) and apparent diffusion coefficient (ADC) of pancreatic parenchyma were computed. MRI measurements and HbA1c values were then compared. RESULTS: HbA1c values positively correlated with MK (r = 0.66, P < 0.0001). Group 3 was significantly (P < 0.05) higher (P < 0.05) in MK than groups 1 and 2. The sensitivity, specificity, and area under the ROC curve of the MK for the detection of group 3 were 90%, 88%, and 0.92, respectively. CONCLUSION: The MK measurement on DK imaging of the pancreas could be a potential biomarker for assessing HbA1c level.