Differential centiloid scale normalization techniques: comparison between hybrid PET/MRI and independently acquired MRI.

OBJECTIVE: Centiloid (CL) scales play an important role in semiquantitative analyses of amyloid-ß (Aß) PET. CLs are derived from the standardized uptake value ratio (SUVR), which needs Aß positron emission tomography (PET) normalization processing. There are two methods to collect the T1-weighted imaging (T1WI) for normalization: (i) anatomical standardization using simultaneously acquired T1WI (PET/MRI), usually adapted to PET images from PET/MRI scanners, and (ii) T1WI from a separate examination (PET + MRI), usually adapted to PET images from PET/CT scanners. This study aimed to elucidate the correlations and differences in CLs between when using the above two T1WI collection methods. METHODS: Among patients who underwent Aß PET/MRI (using 11C-Pittuberg compound B (11C-PiB) or 18F-flutemetamol (18F-FMM)) at our institution from 2015 to 2023, we selected 49 patients who also underwent other additional MRI examinations, including T1WI for anatomic standardization within 3 years. Thirty-one of them underwent 11C-PiB PET/MRI, and 18 participants underwent 18F-FMM PET/MRI. Twenty-five of them, additional MRI acquisition parameters were identical to simultaneous MRI during PET, and 24 participants were different. After normalization using PET/MRI or PET + MRI method each, SUVR was measured using the Global Alzheimer's Association Initiative Network cerebral cortical and striatum Volume of Interest templates (VOI) and whole cerebellum VOI. Subsequently, CLs were calculated using the previously established equations for each Aß PET tracer. RESULTS: Between PET/MRI and PET + MRI methods, CLs correlated linearly in 11C-PiB PET (y = 1.00x - 0.11, R2 = 0.999), 18F-FMM PET (y = 0.97x - 0.12, 0.997), identical additional MRI acquisition (y = 1.00x + 0.33, 0.999), different acquisition (y = 0.98x - 0.43, 0.997), and entire study group (y = 1.00x - 0.24, 0.999). Wilcoxon signed-rank test revealed no significant differences: 11C-PiB (p = 0.49), 18F-FMM (0.08), and whole PET (0.46). However, significant differences were identified in identical acquisition (p = 0.04) and different acquisition (p = 0.02). Bland-Altman analysis documented only a small bias between PET/MRI and PET + MRI in 11C-PiB PET, 18F-FMM PET, identical additional MRI acquisition, different acquisition, and whole PET (- 0.05, 0.67, - 0.30, 0.78, and 0.21, respectively). CONCLUSIONS: Anatomical standardizations using PET/MRI and using PET + MRI can lead to almost equivalent CL. The CL values obtained using PET/MRI or PET + MRI normalization methods are consistent and comparable in clinical studies.

Risk Stratification Using Right Ventricular Longitudinal Strain Ratio Derived from 13N-Ammonia PET in Patients with Ischemic Heart Disease.

Purpose To investigate whether right ventricular (RV) myocardial strain ratio (RVMSR) assessed using nitrogen 13 ammonia (13N-NH3) PET can predict cardiovascular events in patients with ischemic heart disease (IHD). Materials and Methods This retrospective study included 480 consecutive patients (mean age, 66 years ± 12 [SD]; 334 males and 146 females) with IHD who underwent 13N-NH3 PET. RVMSR was defined as the ratio of RV strain during stress to that at rest. The primary end point was major adverse cardiac events (MACEs), defined as cardiac death or heart failure hospitalization. The ability of RVMSR to predict MACE was assessed using receiver operating characteristic (ROC) curve and Kaplan-Meier analyses. Cox proportional hazards regression analysis was used to calculate hazard ratios (HRs) with 95% CIs. Results ROC curve analysis identified a sensitivity and specificity of 84% and 82%, respectively, for predicting MACE from RVMSR. Patients with reduced RVMSR (<110.2) displayed a significantly higher rate of MACE than those with a preserved RVMSR (34 of 240 vs four of 240; P < .001). Cox proportional hazards regression analysis of imaging parameters, including myocardial flow reserve, indicated that RVMSR was an independent predictor of MACE (HR, 0.94 [95% CI: 0.92, 0.97]; P < .001). Conclusion RVMSR was an independent predictor of MACE and has potential to aid in the risk stratification of patients with IHD. Keywords: Right Ventricular Myocardial Strain Ratio, Myocardial Flow Reserve, Ischemic Heart Disease, 13N-Ammonia Positron Emission Tomography Supplemental material is available for this article. © RSNA, 2024.

Collagen triple helix repeat-containing protein 1 is a novel biomarker of right ventricular involvement in pulmonary hypertension.

BACKGROUND: Pulmonary hypertension leads to right ventricular failure, which is a major determinant of prognosis. Circulating biomarkers for right ventricular function are poorly explored in pulmonary hypertension. This study aimed to clarify the significance of collagen triple helix repeat-containing protein 1 (CTHRC1) as a biomarker of right ventricular failure in pulmonary hypertension. METHODS: A monocrotaline-induced pulmonary hypertension rat model was used to evaluate right ventricular CTHRC1 expression and its relationship with fibrosis. Next, human plasma CTHRC1 levels were measured in controls (n = 20), pulmonary arterial hypertension (n = 46), and chronic thromboembolic pulmonary hypertension (CTEPH) patients (n = 64) before the first and after the final balloon pulmonary angioplasty. RESULTS: CTHRC1 expression was higher in the right ventricles of rats with monocrotaline-induced pulmonary hypertension than in those of controls. CTHRC1 was co-localized with vimentin and associated with fibrosis in the right ventricles. Plasma CTHRC1 levels were higher in human pulmonary arterial hypertension (P = 0.006) and CTEPH patients (P = 0.011) than in controls. Plasma CTHRC levels were correlated with B-type natriuretic peptide (R = 0.355, P < 0.001), tricuspid lateral annular peak systolic velocity (R = -0.213, P = 0.029), and right ventricular fractional area change (R = -0.225, P = 0.017). Finally, plasma CTHRC1 levels were decreased after the final balloon pulmonary angioplasty (P < 0.001) in CTEPH. CONCLUSIONS: CTHRC1 can be a circulating biomarker associated with right ventricular function and fibrosis in pulmonary hypertension and might reflect the therapeutic efficacy of balloon pulmonary angioplasty in CTEPH.

Complete response to tremelimumab plus durvalumab treatment in hepatocellular carcinoma with a bile duct tumor thrombus: A case report.

Tremelimumab plus durvalumab (Dur/Tre) is the first-line treatment for advanced hepatocellular carcinoma (HCC) worldwide. The present report describes the case of a 68-year-old man diagnosed with advanced HCC and a bile duct tumor thrombus (BDTT) who achieved a complete response to Dur/Tre therapy. The BDTT progressed to the bifurcation of the left and right hepatic ducts. Over time, both the tumors and BDTT progressively decreased in size, and a complete response was confirmed using the Response Evaluation Criteria in Solid Tumors (version 1.1.) 6 months after treatment administration. Subsequently, immune-related adverse events, including type 1 diabetes mellitus and diabetic ketoacidosis, emerged, leading to treatment discontinuation. The patient was undergoing outpatient follow-up in a drug-free state with no signs of recurrence 290 days after the initial administration of Dur/Tre. Although long-term and meticulous observations are required, the present findings could influence the choice of systemic chemotherapy for advanced HCC.

Impact of iodine contrast media on gamma camera-based GFR and factors affecting the difference between serum creatinine-based estimated GFR and Gate's GFR.

OBJECTIVE: We aimed to elucidate the factors underlying the difference between estimated glomerular filtration rate (eGFR) calculated from serum creatinine and Gate's GFR (gGFR) measured using technetium-99m diethylene triamine pentaacetic acid ( 99m Tc-DTPA) scintigraphy. METHODS: This study was based on consecutive patients who underwent 99m Tc-DTPA scintigraphy at our hospital between January 2021 and December 2022 and whose blood serum creatinine data were obtained on the same day as the 99m Tc-DTPA scintigraphy. Relationships between the ratio of gGFR and eGFR (gGFR/eGFR) and age, sex, BMI, visceral fat, psoas muscle index (PMI), serum blood urea nitrogen, and creatinine level were investigated based on 75 patients. Additionally, for 44 patients who had two or more follow-up DTPA studies, we compared gGFR values for studies that used iodine contrast media (ICM) for computed tomography before same-day 99m Tc-DTPA studies and those that did not in the same patients. RESULTS: Weak correlations were observed between gGFR/eGFR and PMI ( r  = 0.30), BMI ( r  = 0.24), and the visceral fat area ( r  = 0.33). Multi-regression analyses showed that gGFR/eGFR was correlated with PMI ( ß â€…= 0.34, P  < 0.01) and approached significance with the visceral fat area ( ß â€…= 0.24, P  = 0.05). A significant difference was observed in gGFR between patients who received ICM before the 99m Tc-DTPA renogram and those who did not ( P  < 0.001, eGFR 80.5 ±â€…19.0 vs. 91.7 ±â€…27.8 ml/min). CONCLUSION: ICM administration temporarily decreased gGFR, and increased muscle mass increased the difference between eGFR and gGFR values.

Current Roles of Ramucirumab in the Sequential Treatment of Unresectable Hepatocellular Carcinoma.

BACKGROUND/AIM: The treatment algorithm for systemic therapies for advanced hepatocellular carcinoma (HCC) has changed dramatically; however, the therapeutic landscape for sequential second-line or later-line treatments, including ramucirumab, remains controversial. This study aimed to investigate the role of ramucirumab for treating HCC. PATIENTS AND METHODS: We retrospectively analyzed data from 17 patients with advanced HCC who received ramucirumab, and 8 of them who received lenvatinib re-administration after ramucirumab treatment failure. RESULTS: The median overall survival of 17 patients treated with ramucirumab was 11.5 months. The median ratios of the 1-month post-treatment α-fetoprotein (AFP) levels and albumin-bilirubin (ALBI) scores to the pre-treatment AFP levels and ALBI scores following ramucirumab treatment were 0.880 and 0.965, respectively. The median ratios of the 1-month post-treatment AFP and ALBI levels to the pre-treatment levels were 1.587 and 0.970 for mALBI grade 1/2a, and 1.313 and 0.936 for mALBI grade 2b/3, respectively. Six of the eight patients who received lenvatinib rechallenge treatment exhibited a decrease in AFP levels one month post-lenvatinib treatment. Deterioration of liver function 3 months post-lenvatinib treatment was noted in five of the eight patients who received lenvatinib rechallenge treatment after ramucirumab. CONCLUSION: Ramucirumab may be equally useful in patients with unresectable HCC who have poor liver function or whose liver function is aggravated by other therapies. Rechallenge treatment with lenvatinib after ramucirumab may be a valid treatment option for HCC.

The Albumin-bilirubin Grade as Prognostic Indicator for Recurrent Hepatocellular Carcinoma Needing Repeat Liver Resection.

BACKGROUND/AIM: This study aimed to evaluate the utility of the albumin-bilirubin grade for predicting the prognosis after repeat liver resection for patients with recurrent hepatocellular carcinoma. PATIENTS AND METHODS: Ninety patients with intrahepatic recurrent hepatocellular carcinoma who underwent repeat liver resection at our institution between 2005 and 2019 were retrospectively analyzed. Cox proportional-hazards regression models evaluated independent preoperative prognostic factors, including the albumin-bilirubin grade. Prognosis differences between patients with albumin-bilirubin grades 1 and 2 were analyzed using the Kaplan-Meier method. RESULTS: Cox proportional-hazards regression analysis revealed that albumin-bilirubin grade 2 (p=0.003) and early recurrence within one year from the initial surgery (p=0.001) were independently associated with poor recurrence-free survival, and albumin-bilirubin grade 2 (p=0.020) was independently associated with poor overall survival. The five-year recurrence-free (31% and 17%, respectively) and overall (86% and 60%, respectively) survival rates after repeat liver resection for patients with albumin-bilirubin grades 1 and 2 were significantly different between groups (both p=0.003). CONCLUSION: The albumin-bilirubin grade is useful for preoperatively predicting favorable survival rates after repeat liver resection for patients with recurrent hepatocellular carcinoma. Patients with an albumin-bilirubin grade 1 are better candidates for surgical treatment of recurrent hepatocellular carcinoma.

Optimal cutoff values of drain amylase for predicting pancreatic fistula are different between open and laparoscopic distal pancreatectomy.

BACKGROUND: Drainage fluid amylase (DFA) is useful for predicting clinically relevant postoperative pancreatic fistula (CR-POPF) after distal pancreatectomy (DP). However, difference in optimal cutoff value of DFA for predicting CR-POPF between open DP (ODP) and laparoscopic DP (LDP) has not been investigated. This study aimed to identify the optimal cutoff values of DFA for predicting CR-POPF after ODP and LDP. METHODS: Data for 294 patients (ODP, n = 127; LDP, n = 167) undergoing DP at Kobe University Hospital between 2010 and 2021 were reviewed. Propensity score matching was performed to minimize treatment selection bias. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff values of DFA for predicting CR-POPF for ODP and LDP. Logistic regression analysis for CR-POPF was performed to investigate the diagnostic value of DFA on postoperative day (POD) three with identified cutoff value. RESULTS: In the matched cohort, CR-POPF rates were 24.7% and 7.9% after ODP and LDP, respectively. DFA on POD one was significantly lower after ODP than after LDP (2263 U/L vs 4243 U/L, p < 0.001), while the difference was not significant on POD three (543 U/L vs 1221 U/L, p = 0.171). ROC analysis revealed that the optimal cutoff value of DFA on POD one and three for predicting CR-POPF were different between ODP and LDP (ODP, 3697 U/L on POD one, 1114 U/L on POD three; LDP, 10564 U/L on POD one, 6020 U/L on POD three). Multivariate analysis showed that DFA on POD three with identified cutoff value was the independent predictor for CR-POPF both for ODP and LDP. CONCLUSIONS: DFA on POD three is an independent predictor for CR-POPF after both ODP and LDP. However, the optimal cutoff value for it is significantly higher after LDP than after ODP. Optimal threshold of DFA for drain removal may be different between ODP and LDP.

Investigation of factors affecting CT attenuation and glucose metabolism of bone marrow as seen on PET/CT scans.

The aim of this study is to determine the factors affecting the CT attenuation of bone marrow, and its correlation with 18F-FDG uptake. The mean standardized uptake value (SUV) of vertebral bone marrow (Vertebral-SUV) and femoral bone marrow (Femoral-SUV) as well as CT number of bone marrow (BM-CT number) were measured in 243 patients who had undergone 18F-FDG PET/CT. The correlations among BM-CT number, Femoral-SUV, and Vertebral-SUV were investigated. The relationships of Femoral-SUV, Vertebral-SUV, and BM-CT number with blood parameters, age, blood sugar, and body weight were analyzed by correlation and multi-regression analyses. The Mann-Whitney U test and chi-square test and Binomial logistic analysis were used to examine the relationships between high BM-CT number (≥ 0 HU) and the above parameters. Significant correlations were observed between: BM-CT number and Femoral-SUV (r = 0.73, P < 0.01); Vertebral-SUV and Femoral-SUV (r = 0.78, P < 0.01); and BM-CT number and Vertebral-SUV (r = 0.52, P < 0.01). BM-CT number was correlated with patients' age in both univariable (r = -0.27) and multivariable analyses (ß = -0.20). Positive BM-CT number correlated with WBC in both univariable (P = 0.04) and multivariable (P < 0.01) analyses. Bone marrow glucose metabolism had a tendency to decrease with age, was increased in patients with elevated CRP. In conclusion, CT attenuation of bone marrow correlated well with bone marrow metabolism and also tended to decrease with age. High bone marrow attenuation (≥ 0 HU) could predict elevated serum WBC.

Association between tumor morphology and efficacy of atezolizumab plus bevacizumab for advanced hepatocellular carcinoma.

AIM: The IMbrave150 trial revealed that atezolizumab plus bevacizumab (AtezoBv) showed a higher objective response rate (ORR) in patients with advanced hepatocellular carcinoma (HCC). Although conversion therapy after AtezoBv has been recently reported, markers predictive of its efficacy, particularly radiological imaging markers, have not yet been identified. The present study focused on tumor morphological appearance on radiological imaging and evaluated whether it could be associated with AtezoBv efficacy. METHODS: Ninety-five intrahepatic lesions in 74 patients who were given AtezoBv for advanced HCC were recruited for evaluation. The lesions were divided into two groups, simple nodular (SN group) and non-simple nodular (non-SN group), based on the gross morphology on pretreatment imaging, and retrospectively evaluated for treatment response and other relevant clinical outcomes. RESULTS: Assessing the size of individual tumors after treatment, waterfall plots showed that tumor shrinkage in the non-SN group including 56 lesions was higher than that in the SN group comprising 39 lesions. The ORR was significantly higher in the non-SN group (39.3% vs. 15.4%, p = 0.012). Additionally, the median time to nodular progression was longer in the non-SN group (21.0 months vs. 8.1 months, p = 0.119) compared to the SN group. Six patients with non-SN lesions underwent sequential local therapy. CONCLUSIONS: Atezolizumab plus bevacizumab may show increased therapeutic efficacy in patients with tumors with a higher potential for aggressive oncological behavior, such as non-SN lesions. Treatment strategies focusing on conversion therapy may be crucial in patients with non-SN lesions.

Utility of plasma D-dimer for diagnosis of venous thromboembolism after hepatectomy.

BACKGROUND: Venous thromboembolism (VTE) is a potentially fatal complication of hepatectomy. The use of postoperative prophylactic anticoagulation in patients who have undergone hepatectomy is controversial because of the risk of postoperative bleeding. Therefore, we hypothesized that monitoring plasma D-dimer could be useful in the early diagnosis of VTE after hepatectomy. AIM: To evaluate the utility of monitoring plasma D-dimer levels in the early diagnosis of VTE after hepatectomy. METHODS: The medical records of patients who underwent hepatectomy at our institution between January 2017 and December 2020 were retrospectively analyzed. Patients were divided into two groups according to whether or not they developed VTE after hepatectomy, as diagnosed by contrast-enhanced computed tomography and/or ultrasonography of the lower extremities. Clinicopathological factors, including demographic data and perioperative D-dimer values, were compared between the two groups. Receiver operating characteristic curve analysis was performed to determine the D-dimer cutoff value. Univariate and multivariate analyses were performed using logistic regression analysis to identify significant predictors. RESULTS: In total, 234 patients who underwent hepatectomy were, of whom (5.6%) were diagnosed with VTE following hepatectomy. A comparison between the two groups showed significant differences in operative time (529 vs 403 min, P = 0.0274) and blood loss (530 vs 138 mL, P = 0.0067). The D-dimer levels on postoperative days (POD) 1, 3, 5, 7 were significantly higher in the VTE group than in the non-VTE group. In the multivariate analysis, intraoperative blood loss of > 275 mL [odds ratio (OR) = 5.32, 95% confidence interval (CI): 1.05-27.0, P = 0.044] and plasma D-dimer levels on POD 5 ≥ 21 µg/mL (OR = 10.1, 95%CI: 2.04-50.1, P = 0.0046) were independent risk factors for VTE after hepatectomy. CONCLUSION: Monitoring of plasma D-dimer levels after hepatectomy is useful for early diagnosis of VTE and may avoid routine prophylactic anticoagulation in the postoperative period.

Spontaneous rupture of splenic hilar lymph node metastasis from hepatocellular carcinoma.

Spontaneous rupture of a primary hepatocellular carcinoma (HCC) is a frequently observed and fatal complication. However, the rupture of lymph node (LN) metastases from HCC is rare. A 79 year-old male with hepatitis B underwent three liver resections for HCC. Two years and 6 months after the last liver resection, enhanced computed tomography (CT) revealed a nodule with a diameter of 3 cm in the lower pole of the spleen. Splenic metastasis of HCC was suspected, and splenectomy was scheduled. During our hospital stay for a urinary tract infection before the scheduled operation, he complained of acute left-sided abdominal pain, and CT showed intra-abdominal hemorrhage due to rupture of the splenic tumor. Emergency splenectomy was performed, and the postoperative course was uneventful. Histopathological examination revealed a poorly differentiated HCC in the lower splenic pole lesion, which contained LN structures. The ruptured lesion was diagnosed as splenic hilar LN metastasis of HCC. Although laparoscopic partial liver resection was performed for intrahepatic recurrence, and atezolizumab plus bevacizumab therapy was administered for peritoneal metastases, the patient was alive 25 months after the splenectomy. Our case suggests that emergency surgery for LN metastatic rupture can achieve hemostasis and lead to improved survival outcomes.

Prognostic significance of left atrial strain combined with left ventricular strain using cardiac magnetic resonance feature tracking in patients with heart failure with preserved ejection fraction.

We aimed to evaluate the prognostic value of left ventricular global longitudinal strain (LVGLS) and left atrial strain (LAS) obtained from magnetic resonance imaging (MRI) feature tracking in patients with heart failure with preserved ejection fraction (HFpEF). We retrospectively enrolled consecutive patients with HFpEF admitted to our hospital who underwent cardiac MRI. LVGLS and LAS were obtained from cine MRI by feature tracking. The end point was defined as a composite of all-cause death, myocardial infarction, and hospitalization due to decompensated HF. One-hundred patients with HFpEF were enrolled. Mean LVGLS and LAS were - 13.7 ± 3.7% and 22.5 ± 11.6%, respectively. During follow-up of 4.4 ± 1.9 years, 24 events occurred. Multivariate Cox proportional hazards model analysis demonstrated LAS was independently associated with adverse cardiac events. Kaplan-Meier curve analysis revealed that the patients with both LVGLS and LAS worse than the median (LVGLS ≥ - 12.2% and LAS ≤ 13.8%) had a significantly lower event-free rate compared to those with preserved strain (Log-rank P < 0.001). Simultaneous assessment of LVGLS and LAS using MRI was useful for risk stratification in the patients with HFpEF.

Efficacy of S-1 Adjuvant Chemotherapy for Resected Biliary Tract Cancer: A Retrospective Propensity-Matched Analysis.

INTRODUCTION: Surgical resection is considered an effective cure for biliary tract cancer (BTC); however, the prognosis is unsatisfactory despite improved surgical techniques and perioperative management. The recurrence rate remains high even after curative resection. The efficacy of adjuvant chemotherapy in pancreatic and gastric cancers has been previously reported, and the feasibility of adjuvant therapy with S-1 has recently been reported in patients with resected BTC. We aimed to retrospectively investigate the effects of adjuvant chemotherapy with S-1 on resected advanced BTC. METHODS: We included data from 438 BTC patients who underwent resection between 2001 and 2020. After excluding patients with pTis-pT1 (n = 112) and other exclusion criteria, 266 patients were included in the analysis. RESULTS: After propensity score matching, 48 patients received S-1 adjuvant chemotherapy (S-1 group), and 48 patients received non-S1 adjuvant chemotherapy or underwent surgery alone (Non-S-1 group). The patients in the S-1 group had significantly better overall survival (OS) than those in the non-S-1 group (MST 51 vs 37 months, hazard ratio [HR]:.54, 95% confidence interval [CI]:.30-.98, P = .04). The S-1 group had a significantly better recurrence-free survival (RFS) than the non-S-1 group (94 vs 21 months, HR: .57, 95% CI: .33-.97, P = .03). Subgroup analyses for OS and RFS exhibited the benefits of S-1 in patients aged <75 years and in patients with primary sites of extrahepatic and perineural invasion and curability of R0. DISCUSSION: S-1 adjuvant therapy is promising for improving the postoperative survival of patients with resected advanced BTC, positive nerve invasion, and R0 resection.

Predictive Value of Aortic Valve Calcium Volume Measured by Computed Tomography for Paravalvular Leakage After Transcatheter Aortic Valve Implantation.

Paravalvular leakage (PVL) is a complication of transcatheter aortic valve implantation (TAVI) for aortic stenosis, leading to an adverse prognosis. We investigated whether aortic valve calcium volume (Ca-Vol) measured by preoperative cardiac computed tomography had a predictive value for PVL after TAVI using a third-generation self-expandable valve.We retrospectively analyzed 59 consecutive patients who underwent TAVI using a third-generation self-expandable valve. We measured Ca-Vol in the aortic valve and each cusp (non-coronary cusp [NCC], right-coronary cusp [RCC], and left-coronary cusp [LCC]). We divided the patients into 2 groups: a PVL group (32.2%) and a non-PVL group (67.8%). Total Ca-Vol was significantly higher in the PVL group than in the non-PVL group (P < 0.001). Ca-Vol in each cusp was also significantly higher in the PVL group ([NCC] P < 0.001, [RCC] P = 0.001, [LCC] P < 0.001). Univariate logistic regression analysis for PVL indicated that the total and per-cusp Ca-Vols were predictors for PVL (total, odds ratio [OR] 4.0, P < 0.001; NCC, OR 12.5, P = 0.002; RCC, OR 16.0, P = 0.008; LCC, OR 44.5, P < 0.001).Receiver operating characteristic curve analysis of Ca-Vol for predicting PVL revealed the optimal cut-off values of Ca-Vol were 2.4 cm3 for the total, 0.74 cm3 for NCC, 0.73 cm3 for RCC, and 0.56 cm3 for LCC (area under the curve, 0.85, 0.79, 0.76, and 0.83, respectively).Preoperative total, NCC, RCC, and LCC calcium volumes were significant predictors for PVL after TAVI using third-generation self-expandable valves.

A Novel Method Using Gadolinium-Ethoxybenzyl Diethylenetriamine Pentaacetate Acid-Enhanced Magnetic Resonance Imaging for Predicting Post-Hepatectomy Liver Failure in Hepatocellular Carcinoma Patients with a Major Portal Vein Tumor Thrombus.

INTRODUCTION: The usefulness of gadolinium-ethoxybenzyl diethylenetriamine pentaacetate acid-enhanced magnetic resonance imaging (EOB-MRI) in assessing the functional future remnant liver volume (fFRLV) to predict post-hepatectomy liver failure (PHLF) has been previously reported. Herein, we evaluated the efficacy of this technique in patients with hepatocellular carcinoma (HCC) with a major portal vein tumor thrombus (PVTT). METHODS: This study included 21 patients with PVTT in the ipsilateral first-order branch (Vp3) and 30 patients with PVTT in the main trunk/contralateral branch (Vp4). To evaluate fFRLV, the signal intensity (SI) of the remnant liver was determined on T1-weighted images, using both conventional and newly developed methods. The fFRLV was calculated using the SI of the remnant liver and muscle, remnant liver volume, and body surface area. Preoperative factors predicting PHLF (≥grade B) in HCC patients with Vp3/4 PVTT were evaluated. RESULTS: In the Vp3 group, we found fFRLV area under the receiver-operating characteristic curves (AUCs) above 0.70 (AUC = 0.875, 0.750) using EOB-MRI results calculated using either the plot or whole method. None of the parameters in the Vp4 group had an AUC greater than 0.70. CONCLUSION: The fFRLV calculated by EOB-MRI using the whole method can be as useful as the conventional method in predicting PHLF (≥grade B) for HCC patients with Vp3 PVTT.

The Relationship Between Conventionally Obtained Serum-Based Liver Function Indices and Intravoxel Incoherent Motion Diffusion-Weighted Imaging and Magnetic Resonance Elastography in Patients With Hepatocellular Carcinoma.

OBJECTIVES: To investigate the relationship between conventionally obtained serum-based biochemical indices and intravoxel incoherent motion imaging (IVIM) parameters compared with magnetic resonance elastography (MRE). METHODS: Patients with hepatocellular carcinoma who underwent ≥2 liver magnetic resonance imaging (MRI) scan, including IVIM and MRE, between 2017 and 2020 and biochemical testing within 1 week before or after MRI were included in this study. Biochemical tests were performed to determine the albumin-bilirubin (ALBI) score and modified ALBI (mALBI) grade, aspartate aminotransferase to platelet ratio index (APRI), and fibrosis-4 index (FIB-4). The diffusion coefficient ( D ), pseudo-diffusion coefficient ( D *), fractional volume occupied by flowing spins ( f ), and apparent diffusion coefficient were calculated for IVIM. The correlations between (1) the imaging parameters and biochemical indices and (2) the changes in mALBI grades and imaging parameters were evaluated. RESULTS: This study included 98 scans of 40 patients (31 men; mean age, 67.7 years). The correlation analysis between the biochemical and IVIM parameters showed that ALBI score and D* had the best correlation ( r = -0.3731, P < 0.001), and the correlation was higher than that with MRE ( r = 0.3289, P < 0.001). However, among FIB-4, APRI, and MRI parameters, MRE outperformed IVIM parameters (MRE and FIB-4, r = 0.3775, P < 0.001; MRE and APRI, r = 0.4687, P < 0.001). There were significant differences in the changes in MRE among the 3 groups (improved, deteriorated, and unchanged mALBI groups) in the analysis of covariance ( P = 0.0434). There were no significant changes in IVIM. CONCLUSIONS: Intravoxel incoherent motion imaging has the potential to develop into a more readily obtainable method of liver function assessment.

Incidence of Bowel Wall Swelling Induced by Iodine-Contrast Media and Its Association With Gastrointestinal Manifestation.

PURPOSE: The aim of this study was to investigate the incidence of bowel wall swelling after iodine-contrast media injection and its relationship with gastrointestinal symptoms. METHODS: The incidence of bowel wall swelling was examined in 75 patients who showed adverse reactions to iodine-contrast media (AR[+] group) and 75 controls without adverse reactions (AR[-] group). Bowel wall swelling was identified if there was increased wall thickness on postcontrast computed tomography when compared with precontrast computed tomography. Swelling less than 2-fold of the original wall thickness was defined as grade 1 bowel angioedema, and swelling more than 2-fold was defined as grade 2. RESULTS: The incidence of bowel wall swelling was significantly higher in the AR(+) group (26.6%) than in the AR(-) group (10.6%) ( P = 0.01). Grade 1 bowel wall swelling was observed in 12.0% and 10.7% of AR(+) and AR(-) groups, respectively, whereas grade 2 was observed in 14.7% and 0%, respectively. Bowel wall swelling was observed in the duodenum and jejunum but not in the stomach, ileum, or colon in any patient in either group. In the AR(+) group, nausea and/or vomiting was observed in 15 patients, among whom bowel wall swelling was observed in 9 patients (60%). The frequency of nausea and/or vomiting was significantly higher in the patients with bowel wall swelling (45.0%, 9/20) compared with those without (10.9%, 6/55). CONCLUSION: Bowel wall swelling was more frequent and severe in patients with adverse reactions to iodine-contrast media than those without and was associated with nausea and/or vomiting.

Optimization of Intraventricular Radioactive Concentration for 13N ammonia PET with Time-of-Flight Scanner: Simplified Phantom Study with Noise Equivalent Count Rate Analysis.

Background: Myocardial blood flow quantification (MBF) is one of the distinctive features for cardiac positron emission tomography. The MBF calculation is mostly obtained by estimating the input function from the time activity curve in dynamic scan. However, there is a substantial risk of count-loss because the high radioactivity pass through the left ventricular (LV) cavity within a short period. We aimed to determine the optimal intraventricular activity using the noise equivalent count rate (NECR) analysis with simplified phantom model. Methods: Positron emission tomography computed tomography scanner with LYSO crystal and time of flight was used for phantom study. 150 MBq/mL of 13N was filled in 10 mL of syringe, placed in neck phantom to imitate end-systolic small LV. 3D list-mode acquisition was repeatedly performed along radioactive decay. Net true and random count rate were calculated and compared to the theoretical activity in the syringe. NECR curve analysis was used to determine the optimal radioactive concentration. Result: The attenuation curves showed good correlation to the theoretical activity between 20 to 370, and 370 to 740 MBq (r2=1.0 ± 0.0001, p<0.0001; r2=0.99 ± 0.0001, p<0.0001 for 20 to 370, and 370 to 740, respectively), while did not over 740 MBq (p=0.62). NECR analysis revealed that the peak rate was at 2.9 Mcps, there at the true counts were significantly suppressed. The optimal radioactive concentration was determined as 36 MBq/mL. Conclusion: Simulative analysis for high-dose of 13N using the phantom imitating small LV confirmed that the risk of count-loss was increased. The result can be useful information in assessing the feasibility of MBF quantification in clinical routine.

Myocardial Strain Derived from 13N-ammonia Positron Emission Tomography: Detection of Ischemia-Related Wall Motion Abnormality.

Background: Due to the limitation of spatial resolution, cardiac nuclear medicine images have not been applied to feature-tracking method to automatic extraction of myocardial contours. We have successfully applied the feature-tracking method to high-resolution cine 13N-ammonia positron emission tomography (PET) images to calculate the regional myocardial strains. Here, we investigate the potential of 13N-ammonia PET-derived strain to detect ischemia-related wall motion abnormality. Methods: Data of adenosine-stress/rest 13N-ammonia PET for 95 coronary artery disease patients was retrospectively analyzed. Using an original algorithm dedicated to 13N-ammonia PET, the longitudinal strain (LS) corresponding to the three main coronary artery territories [right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex coronary artery (LCX)] was calculated from semi-automatic endocardial contours extraction on cine 13N-ammonia PET images of the left ventricular long-axis. The presence of ischemia in three main territories was determined from rest and stress-perfusion images. Results: In all three coronary territories, LS at stress was significantly smaller at rest in the ischemic region RCA: -19.2±8.0% vs. -22.7±6.1%, LAD: -19.0±6.9% vs. -24.4±6.4%, LCX: -20.5%±7.6% vs. -22.6±6.9%). In contrast, in the non-ischemic region, there was no significant difference between the LS at stress and at rest. Receiver-operating-characteristic analysis revealed that using the optimal cutoff of the LS ratio of stress to rest, ischemia could be diagnosed with area under the curve of 0.82 in the RCA, 0.86 in the LAD, and 0.69 in the LCX. Conclusions: Myocardial strain derived from endocardial feature-tracking of 13N-ammonia PET cine imaging is reduced in the ischemia induced by adenosine-stress. The LS ratio of stress to rest may detect wall motion abnormality related to ischemia.