Mutations in the SARS-CoV-2 spike proteins affected the ACE2-binding affinity during the development of Omicron pandemic variants.

Mutations in SARS-CoV-2 caused multiple waves of pandemics. To identify the function of such mutations, we investigated the binding affinity of the S protein with its receptor, ACE2. Omicron BA.1 showed significantly lower binding affinity with human ACE2 than prototype SARS-CoV-2 and Alpha strain, indicating that pre-Omicron to Omicron transition was not mediated by increasing the ACE2-binding affinity. Meanwhile, the later Omicron variants, BA.5 and XBB.1.5, showed significantly higher ACE2-binding affinity, suggesting that the increased ACE2-binding could be involved in the variant transition within Omicron strains. Furthermore, Alpha and Omicron variants, but not prototype SARS-CoV-2, bound mouse ACE2, which lead to a hypothesis that early Omicron strains evolved from Alpha strain by acquiring multiple mutations in mice.

Outcomes of embolization procedures for type II endoleaks following endovascular abdominal aortic repair.

OBJECTIVE: The objective of this study was to investigate the mid-term outcomes of embolization procedures for type II endoleak after endovascular abdominal aortic repair, and clarify the risk factors for aneurysm enlargement after embolization procedures. METHODS: This was a retrospective multicenter registry study enrolling patients who underwent embolization procedures for type II endoleaks after EVAR from January 2012 to December 2018 at 19 Japanese centers. The primary end point was the rate of freedom from aneurysm enlargement, more than 5 mm in the aortic maximum diameter, after an embolization procedure. Demographic, procedural, follow-up, and laboratory data were collected. Continuous variables were summarized descriptively, and Kaplan-Meier analyses and a Cox regression model were used for statistical analyses. RESULTS: A total of 315 patients (248 men and 67 women) were enrolled. The average duration from the initial embolization procedure to the last follow-up was 31.6 ± 24.6 months. The rates of freedom from aneurysm enlargement at 3 and 5 years were 55.4 ± 3.8% and 37.0 ± 5.2%, respectively. A multivariate analysis revealed that a larger aortic diameter at the initial embolization procedure and the presence of a Moyamoya endoleak, defined as heterogeneous contrast opacity with an indistinct faint border, were associated with aneurysm enlargement after embolization management. CONCLUSIONS: The embolization procedures were generally ineffective in preventing further expansion of abdominal aortic aneurysms in patients with type II endoleaks after EVAR, especially in patients with a large abdominal aortic aneurysm and/or a presence of a Moyamoya endoleak.

Intranodal dynamic contrast-enhanced CT lymphangiography and dynamic contrast-enhanced MR lymphangiography in microminipig.

OBJECTIVES: To evaluate the feasibility and image quality of intranodal dynamic contrast-enhanced CT lymphangiography (DCCTL) and dynamic contrast-enhanced MR lymphangiography (DCMRL) in microminipigs. METHODS: Our institution's committee for animal research and welfare provided approval. Three microminipigs underwent DCCTL and DCMRL after inguinal lymph node injection of 0.1 mL/kg contrast media. Mean CT values on DCCTL and signal intensity (SI) on DCMRL were measured at the venous angle and thoracic duct (TD). The contrast enhancement index (CEI; increase in CT values pre- to post-contrast) and signal intensity ratio (SIR; SI of lymph divided by SI of muscle) were evaluated. The morphologic legibility, visibility, and continuity of lymphatics were qualitatively evaluated using a 4-point scale. Two microminipigs underwent DCCTL and DCMRL after lymphatic disruption and the detectability of lymphatic leakage was evaluated. RESULTS: The CEI peaked at 5-10 min in all microminipigs. The SIR peaked at 2-4 min in two microminipigs and at 4-10 min in one microminipig. The peak CEI and SIR values were 235.6 HU and 4.8 for venous angle, 239.4 HU and 2.1 for upper TD, and 387.3 HU and 2.1 for middle TD. The visibility and continuity of upper-middle TD scores were 4.0 and 3.3-3.7 for DCCTL, and 4.0 and 4.0 for DCMRL. In the injured lymphatic model, both DCCTL and DCMRL demonstrated lymphatic leakage. CONCLUSIONS: DCCTL and DCMRL in a microminipig model enabled excellent visualization of central lymphatic ducts and lymphatic leakage, indicating the research and clinical potential of both modalities. KEY POINTS: • Intranodal dynamic contrast-enhanced computed tomography lymphangiography showed a contrast enhancement peak at 5-10 min in all microminipigs. • Intranodal dynamic contrast-enhanced magnetic resonance lymphangiography showed a contrast enhancement peak at 2-4 min in two microminipigs and at 4-10 min in one microminipig. • Both intranodal dynamic contrast-enhanced computed tomography lymphangiography and dynamic contrast-enhanced magnetic resonance lymphangiography demonstrated the central lymphatic ducts and lymphatic leakage.

Delayed diagnosis of Lemierre's syndrome in a patient with severe coronavirus disease 2019: importance of comprehensive oral and neck examination - a case report.

BACKGROUND: Given the widespread prevalence of the coronavirus disease 2019 (COVID-19), oral and neck examinations tend to be avoided in patients with suspected or confirmed COVID-19. This might delay the diagnosis of conditions such as Lemierre's syndrome, which involves symptoms resembling COVID-19-related throat manifestations. CASE PRESENTATION: A 24-year-old man without any underlying conditions was diagnosed with COVID-19 7 days before presentation. He was admitted to another hospital 1 day before presentation with severe COVID-19 and suspected bacterial pneumonia; accordingly, he was started on treatment with remdesivir and meropenem. Owing to bacteremic complications, the patient was transferred to our hospital for intensive care. On the sixth day, the patient experienced hemoptysis; further, a computed tomography (CT) scan revealed new pulmonary artery pseudoaneurysms. Successful embolization was performed to achieve hemostasis. In blood cultures conducted at the previous hospital, Fusobacterium nucleatum was isolated, suggesting a cervical origin of the infection. A neck CT scan confirmed a peritonsillar abscess and left internal jugular vein thrombus; accordingly, he was diagnosed with Lemierre's syndrome. The treatment was switched to ampicillin/sulbactam, based on the drug susceptibility results. After 6 weeks of treatment, the patient completely recovered without complications. CONCLUSION: This case highlights the significance of thorough oral and neck examinations in patients with suspected or diagnosed COVID-19 for the detection of throat and neck symptoms caused by other conditions.

[A Case of Refractory Lymphatic Leakage after Robot-Assisted Radical Cystectomy].

A 78-year-old male visited the referring hospital because of asymptomatic gross hematuria. The patient was diagnosed with bladder cancer, clinical stage T3aN2M0, after multiple tumors were found in the bladder by cystoscopy and bilateral obturator lymph node metastases were found by contrast-enhanced thoracoabdominal-pelvic computed tomography. After neoadjuvant chemotherapy, the patient underwent robot-assisted radical cystectomy and pelvic lymph node dissection, followed by bilateral ureterocutaneostomy for urinary diversion. Postoperatively, the drainage volume from the pelvic drain ranged from 1,000 to 3,000 ml/day. We suspected lymphatic leakage based on the results of biochemical tests of the drainage fluid. Lymphangiography was conducted to confirm the diagnosis of lymphatic leakage, and lymphatic embolization was performed simultaneously. The patient underwent lymphangiography four times, but the lymphatic leakage persisted. Surgical treatment was considered, and lymphangioscintigraphy was conducted to search for areas of lymphatic leakage that could not be delineated by lymphangiography. Ascites decreased significantly after lymphangioscintigraphy.

The multilobated morphology is still a better prognosis factor of diffuse large B-cell lymphoma in the R-CHOP era.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of B-cell lymphoma. Although the multilobated subtype of DLBCL has been observed since the 1970s, little is known about the clinical significance of this unique variant in the era of rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin, prednisone/prednisolone (R-CHOP) therapy. In this study, the retrospective clinicopathological analysis of 312 patients diagnosed with DLBCL showed that the multilobated DLBCL group comprised 11% of the cases and was predominantly male (p = 0.027), achieved complete remission in the first therapy (p = 0.023), and exhibited germinal center B-cell phenotypes in the Hans algorithm (p = 0.025). The multilobated DLBCL groups had a better prognosis in overall survival (OS) and progression-free survival (PFS) than the non-multilobated DLBCL group (OS, p = 0.006; PFS, p = 0.010). In the multivariate Cox regression analyses for OS, independent prognosis factors were high soluble IL-2 receptor (p = 0.025), high risk of International Prognostic Index, and multilobated morphology (p = 0.031). The most characteristic copy number gains found in more than 50% of the cases were located at 1q, 3p, 10q, 12q, and 14q. Overall, the multilobated morphology in DLBCL exhibits a good outcome in the R-CHOP era.

Risk factors for lower respiratory tract disease and outcomes in allogeneic hematopoietic stem cell transplantation recipients with influenza virus infection.

INTRODUCTION: Influenza virus infection (IVI) is frequent in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, and reports from several countries indicate high morbidity and mortality from progression to lower respiratory tract disease (LRTD). However, there have been no reports on IVI clinical characteristics, treatment outcomes, and risk factor for progression to LRTD among allo-HSCT recipients in Japan. METHODS: We retrospectively reviewed the medical charts of allo-HSCT recipients who developed IVI between 2012 and 2019. RESULTS: Forty-eight cases of IVI following allo-HSCT were identified at our institution. The median age was 42 years, and median time from allo-HSCT to IVI was 25 months. Thirty-seven patients (77.1%) were administered neuraminidase inhibitors (NAIs) as antiviral therapy within 48 h of symptom onset (early therapy), whereas 11 (22.9%) received NAI over 48 h after onset (delayed therapy). Subsequently, 12 patients (25.0%) developed LRTD after IVI. Multivariate analysis identified older age (hazard ratio [HR], 7.65; 95% confidence interval [CI], 2.22-26.3) and bronchiolitis obliterans (HR, 5.74; 95% CI, 1.57-21.0) as independent risk factors for progression to LRTD. Moreover, land-mark analysis showed that early therapy prevented progression to LRTD (11.8% vs. 45.5%, P = 0.013). The IVI-related mortality rate was 2.1%. CONCLUSIONS: Early NAI treatment is recommended for reducing the risk of LRTD progression due to IVI in allo-HSTC recipients, particularly for older patients and those with bronchiolitis obliterans.

Association between measurable residual disease kinetics and outcomes of Philadelphia chromosome-positive acute lymphoblastic leukemia.

The prognosis of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) has improved dramatically. Although measurable residual disease (MRD) kinetics during pretransplant treatment has been recently reported to correlate with patient outcomes, it is unclear whether prognosis is better if the MRD falls below the detection sensitivity soon after induction therapy. We retrospectively analyzed data of 37 Ph + ALL patients who were treated with autologous or allogeneic stem cell transplantation (auto-SCT, allo-SCT) at our institute from 2003 to 2019. Based on MRD kinetics, patients were divided into three groups: early responders (MRD became negative after induction therapy [n = 10, 27.0%]); late responders (MRD remained positive after induction therapy and became negative just before SCT [n = 12, 32.4%]); and poor responders (MRD was positive until just before SCT [n = 15, 40.5%]). The 5-year disease-free survival (DFS) rates for the three groups were 80.0%, 60.0%, and 29.9%, respectively (P = 0.037). The 5-year overall survival rates were not significantly different. The 5-year relapse rates were 0.0%, 31.7%, and 49.5%, respectively (P = 0.045). Non-relapse mortality (NRM) rates were similar among the three groups. Subgroup analysis for the cases that received posttransplantation tyrosine kinase inhibitor maintenance therapy revealed that DFS was similarly dependent on MRD kinetics (P = 0.022). This study clarified that MRD kinetics was a significant prognosticator for DFS and relapse rate in Ph + ALL.

Natural History of Unruptured Visceral Artery Aneurysms Due to Segmental Arterial Mediolysis and Efficacy of Transcatheter Arterial Embolization: A Retrospective Multiinstitutional Study in Japan.

OBJECTIVE. The purpose of this study was to clarify the natural history of unruptured visceral artery aneurysms due to segmental arterial mediolysis and the efficacy of transcatheter arterial embolization. MATERIALS AND METHODS. Patients with a pathologic or clinical diagnosis of visceral artery aneurysms due to segmental arterial mediolysis between 2005 and 2015 were enrolled. For patients with clinical diagnoses, images were collected and assessed by central radiologic review. To clarify the natural history of unruptured aneurysms, the morphologic changes were assessed. The efficacy and safety of transcatheter arterial embolization for aneurysms due to segmental arterial mediolysis were evaluated. RESULTS. Forty-five patients with 123 aneurysms due to segmental arterial mediolysis were enrolled. Among the 123 aneurysms, 70 unruptured aneurysms were evaluated for natural history. Forty-five of the 70 (64%) aneurysms had no change in morphology. Among the other 25 aneurysms, nine (13% of the 70) were reduced in size, 13 (19%) disappeared, and three (4%) were newly found at follow-up. Aneurysms of the middle colic artery were ruptured in 10 of 11 (91%) cases. Transcatheter arterial embolization was performed on 45 aneurysms and was successful in all cases but caused slight arterial injury in three cases (6.7%). CONCLUSION. At initial diagnosis, unruptured aneurysms due to segmental arterial mediolysis are likely to be stable or to resolve, but the risk of rupture of aneurysms of the middle colic artery appears high. Transcatheter arterial embolization is a useful treatment, but careful manipulation is necessary.

Preoperative CT Findings for Predicting Acute Exacerbation of Interstitial Pneumonia After Lung Cancer Surgery: A Multicenter Case-Control Study.

BACKGROUND. Acute exacerbation (AE) is a life-threatening complication of inter-stitial pneumonia (IP). Thoracic surgery may trigger AE. OBJECTIVE. The purpose of this study is to explore the role of preoperative CT findings in predicting postoperative AE in patients with IP and lung cancer. METHODS. This retrospective case-control study included patients from 22 institutions who had IP and underwent thoracic surgery for lung cancer. AE was diagnosed on the basis of symptoms and imaging findings noted within 30 days after surgery and the absence of alternate causes. For each patient with AE, two control patients without AE were identified. After exclusions, the study included 92 patients (78 men and 14 women; 31 with AE [the AE group] and 61 without AE [the no-AE group]; mean age, 72 years). Two radiologists independently reviewed preoperative thin-slice CT examinations for pulmonary findings and resolved differences by consensus. The AE and no-AE groups were compared using the Fisher exact and Mann-Whitney U tests. Multivariable logistic regression was performed. Interreader agreement was assessed by kappa coefficients. RESULTS. A total of 94% of patients in the AE group underwent segmentectomy or other surgery that was more extensive than wedge resection versus 75% in the no-AE group (p = .046). The usual IP pattern was present in 58% of the AE group versus 74% of the no-AE group (p = .16). According to subjective visual scoring, the mean (± SD) ground-glass opacity (GGO) extent was 6.3 ± 5.4 in the AE group versus 3.9 ± 3.8 in the no-AE group (p = .03), and the mean consolidation extent was 0.5 ± 1.2 in the AE group versus 0.1 ± 0.3 in the no-AE group (p = .009). Mean pulmonary trunk diameter was 28 ± 4 mm in the AE group versus 26 ± 3 mm in the no-AE group (p = .02). In a model of CT features only, independent predictors of AE (p < .05) were GGO extent (odds ratio [OR], 2.8), consolidation extent (OR, 9.4), and pulmonary trunk diameter (OR, 4.2); this model achieved an AUC of 0.75, a PPV of 71%, and an NPV of 77% for AE. When CT and clinical variables were combined, undergoing segmentectomy or more extensive surgery also independently predicted AE (OR, 8.2; p = .02). CONCLUSION. The presence of GGO, consolidation, and pulmonary trunk enlargement on preoperative CT predicts AE in patients with IP who are undergoing lung cancer surgery. CLINICAL IMPACT. Patients with IP and lung cancer should be carefully managed when predictive CT features are present. Wedge resection, if possible, may help reduce the risk of AE in these patients. TRIAL REGISTRATION. University Hospital Medical Information Clinical Trial Registry UMIN000029661.

Dynamic contrast-enhanced computed tomography lymphangiography with intranodal injection of water-soluble iodine contrast media in microminipig: imaging protocol and feasibility.

OBJECTIVES: To evaluate the optimal imaging protocol and the feasibility of intranodal dynamic contrast-enhanced computed tomography lymphangiography (DCCTL) in microminipigs. METHODS: The Committee for Animal Research and Welfare provided university approval. Five female microminipigs underwent DCCTL after inguinal lymph node injection of 0.1 mL/kg of iodine contrast media at a rate of 0.3 mL/min with three different iodine concentrations: group 1, 75 mgI/mL; group 2, 150 mgI/mL; and group 3, 300 mgI/mL. The CT values of the venous angle, thoracic duct (TD), cisterna chyli, iliac lymphatic duct, and iliac lymph node were measured; increases in CT values pre- to post-contrast were assessed as the contrast-enhanced index (CEI). Multi-detector row CT (MDCT) and volume rendering images showing the highest CEI were qualitatively evaluated. RESULTS: The CEI of all lymphatics peaked at 5-10 min. The mean CEI of TD at 10 min of group 2 (193.0 HU) and group 3 (201.5 HU) were significantly higher than that of group 1 (70.7 HU) (p = 0.024). The continuity and overall diagnostic acceptability of all lymphatic system components were better in group 3 (3.6 and 3.0, respectively) than group 1 (2.6 and 1.6) and group 2 (3.0 and 2.6) (p = 0.249 and 0.204). CONCLUSIONS: The optimal imaging protocol for intranodal DCCTL could be dual-phase imaging at 5 and 10 min after the injection of 300 mgI/mL iodinated contrast media. DCCTL provided good images of lymphatics and is potentially feasible in clinical settings. KEY POINTS: • Dynamic contrast-enhanced computed tomography lymphangiography with intranodal injection of water-soluble iodine contrast media showed the highest enhancement of all lymphatics at scan delays of 5 and 10 min. • The optimal iodine concentration for intranodal dynamic contrast-enhanced computed tomography lymphangiography might be 300 mgI/mL. • Intranodal dynamic contrast-enhanced computed tomography lymphangiography provided good images of all the lymphatic system components and is potentially feasible in clinical settings.

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.

Intrahepatic portosystemic venous shunt via the right adrenal vein: treatment with vascular plug.

A 65-year-old man with hepatocellular carcinoma (HCC) due to alcohol-related liver cirrhosis had undergone transarterial chemoembolization 11 times. However, treatment for HCC was difficult to continue, due to episodic hepatic encephalopathy. He was referred to our hospital for treatment of hepatic encephalopathy, showing a Child-Pugh score of 8 despite medical therapy. Abdominal computed tomography revealed intrahepatic portosystemic venous shunt comprising two shunt tracts from the right posterior portal vein to the inferior vena cava via the right adrenal vein. The larger tract was occluded using an Amplatzer Vascular Plug (AVP) II, and the smaller tract was occluded using an original AVP. The postembolization course was uneventful. Hepatic encephalopathy improved after shunt occlusion and no recurrence had occurred as of one year after the procedure.

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.

Findings in pancreatic MRI associated with pancreatic fibrosis and HbA1c values.

PURPOSE: To evaluate the diagnostic performance of noncontrast-enhanced magnetic resonance imaging (MRI) to grade pancreatic fibrosis and to assess hemoglobin (Hb) A1c values. MATERIALS AND METHODS: Twenty-nine consecutive patients with pancreatic or biliary malignancy who underwent pancreatectomy were evaluated. Patients were classified into three groups: HbA1c < 5.7 (group 1), 5.7 ≤ HbA1c < 6.5 (group 2), and HbA1c ≥ 6.5 (group 3). MRI of the pancreas was performed using a 1.5T MR system. The pancreas-to-muscle signal intensity ratio (SIR) on in- and opposed-phase T1 -, T2 -, and diffusion-weighted images, as well as the apparent diffusion coefficient were calculated. MRI measurements, degrees of pancreatic fibrosis, and HbA1c values were compared using multiple regression analysis and Kruskal-Wallis test. RESULTS: The pancreatic fibrosis grade was negatively correlated with the SIR on in-phase T1 -weighted images (r = -0.67, P = 0.0002). The pancreatic fibrosis grade and HbA1c value were negatively correlated with the SIR on opposed-phase T1 -weighted images (r = -0.47, P = 0.019 and r = -0.51, P = 0.0089, respectively). SIRs on in- and opposed-phase T1 -weighted images were significantly lower in group 3 than in groups 1 and 2 (P < 0.05). CONCLUSION: The pancreas-to-muscle SIRs on in- and opposed-phase T1 -weighted images could be a potential biomarker for pancreatic fibrosis and elevated HbA1c values.

Minimally Required Iodine Dose for the Detection of Hypervascular Hepatocellular Carcinoma on 80-kVp CT.

OBJECTIVE: The objective of our study was to determine the iodine dose per unit of body weight (BW) or body surface area (BSA) that is minimally required to detect hypervascular hepatocellular carcinoma (HCC) on 80-kVp CT. SUBJECTS AND METHODS: One hundred eleven patients (78 men and 33 women; mean age, 68 years; age range, 43-85 years) with chronic hepatitis were randomized into three groups with different iodine loads (0.5, 0.4, and 0.3 g I/kg BW) and underwent contrast-enhanced CT at 80 kVp. Enhancement of the liver and of hypervascular HCCs was quantitatively and qualitatively assessed on hepatic arterial, portal venous, and equilibrium phase images and compared between the groups. Values for iodine dose per unit of BSA (g I/m(2)) were also computed and analyzed. RESULTS: No significant differences in the contrast-to-noise ratio (CNR) of hypervascular HCCs in any phase were found between the groups (p = 0.34-0.99). In the portal venous phase, the mean increase in hepatic contrast enhancement (ΔHU) of the 0.5 g I/kg group (80.3 HU) was higher than those of the 0.4 g I/kg (63.4 HU) and 0.3 g I/kg (53.3 HU) groups (p < 0.001). Linear correlation equations for the increase in hepatic contrast enhancement were as follows: ΔHU = 5.9 + 150.0 × IL(BW) (r = 0.69, p < 0.001), where IL(BW) is the iodine load per unit of BW (g I/kg), and ΔHU = 13.0 + 3.68 × IL(BSA) (r = 0.66, p < 0.001), where IL(BSA) is the iodine load pre unit of BSA (g I/m(2)). CONCLUSION: The minimal iodine dose required to achieve a tumor-to-liver CNR that is acceptable for the detection of hypervascular HCCs on 80-kVp CT was 0.3 g I/kg BW or 11.0 g I/m(2) BSA.