Akira Yamada

Objectives The purpose of this study was to investigate the clinical and imaging features of solid pseudopapillary neoplasms (SPNs) in men and to compare with those in women. Methods One hundred twenty-two patients (38 men and 84 women) with histologically confirmed SPNs from seven institutions were retrospectively analyzed. Clinical data, including demographics and preoperative diagnoses, were reviewed, and imaging characteristics on computed tomography, magnetic resonance imaging, and ¹⁸F-fluorodeoxyglucose positron emission tomography were assessed. Clinical and imaging characteristics were compared between men and women. Results Men were significantly older than women (mean age: 43.7 years vs. 31.1 years, p < 0.001) and had smaller tumors (mean size: 28.5 mm vs. 38.5 mm, p = 0.014). Regarding preoperative diagnosis, SPN was suspected less frequently in men (p < 0.001), with a higher rate of biopsy (p = 0.006). Imaging characteristics revealed that SPNs in men had fewer hemorrhagic changes (p = 0.035), more frequent internal calcifications (p = 0.003), and a higher proportion of solid components (p = 0.009). In women, tumor size (ρ = − 0.292, p = 0.007) and the proportion of solid components (ρ = − 0.276, p = 0.011) negatively correlated with age, whereas no correlations were observed in men. Conclusion SPNs in men exhibit distinct clinical and imaging characteristics, including older age, smaller size, a greater proportion of solid components, and fewer degenerative features compared with those in women. Recognizing these sex-specific differences is important for improving diagnostic accuracy and guiding the optimal management of patients with SPNs. Graphical Abstract

Purpose: The study aimed to evaluate the incidence and features of the follicle-preserving sign (FPS) and investigate its usefulness in differentiating the grades of malignancy of ovarian tumors using magnetic resonance imaging (MRI). Materials and methods: This retrospective study examined 234 patients of reproductive age with a confirmed diagnosis of ovarian lesions at Shinshu University Hospital between January 2014 and December 2023. Preoperative MR images of each patient were independently evaluated by two radiologists. First, 20 patients with malignant ovarian tumors were randomly selected. To define the MR findings of normal follicles, we observed the contralateral unaffected ovary. Next, the presence of FPS in the affected ovaries was examined in all patients. Finally, the FPS frequency was statistically analyzed in relation to patient age, maximum tumor diameter, tumor malignancy, MRI magnetic field strength, MRI slice thickness (MRIST), and histological subtype. Results: Among 276 ovarian lesions (benign, 146; borderline, 51; malignant, 79), the follicle-preserving sign (FPS) was significantly more frequent in benign tumors than in malignant tumors ( p < 0.001), while no significant difference was observed between borderline tumors and the other two groups. Multivariate analysis identified patient age, tumor diameter, and MRIST as independent factors associated with FPS, with MRIST exerting the greatest influence (OR = 0.75, p = 0.006). Compared with malignant tumors, benign tumors tended to be smaller and were imaged with thinner slices, contributing to a higher FPS incidence. Importantly, even after stratification by MRIST, benign tumors consistently showed a significantly higher FPS rate than malignant tumors across all subgroups ( p < 0.05). FPS frequency also varied by histological subtype, being frequent in serous/seromucinous borderline tumors and immature teratomas, but uncommon in mucinous tumors irrespective of malignancy status. Conclusion: The incidence of FPS was significantly higher in benign tumors than malignant tumors. However, it should be noted that FPS expression is affected by MRIST.

Objectives: This study aimed to develop a clinically applicable harmonization method for the hepatocellular uptake index (HUI), a quantitative liver function index, using gadoxetate disodium-enhanced (EOB)-MRI, to ensure consistency across diverse MR systems. Materials and methods: This retrospective study, approved by our institutional review board, included consecutive patients who underwent three-dimensional gradient-echo T1-weighted EOB-MRI, HUI measurements, indocyanine green disappearance rate (ICG-PDR), and albumin-bilirubin linear predictor (ALBI-LP) between April 2011 and June 2024. Six different MR systems were used for HUI measurements. A harmonization method using ALBI-LP was developed and validated for estimating liver reserves corresponding to ICG-PDR through statistical analysis of residuals. Results: A total of 498 patients (mean age, 68.0 years ± 11.6; 320 men) were evaluated. A statistically significant linear correlation was observed between HUI, ICG-PDR, and ALBI-LP in each MR system, leading to the determination of conversion factors for HUI harmonization. The harmonizing equation, harmonized HUI (h-HUI) = HUI･(Slope2’/−1.425)･0.955, was derived, with Slope2’ representing the regression slope between HUI and ALBI-LP for each MR system. The standard deviation of the estimation error for ICG-PDR was significantly smaller using h-HUI by ALBI-LP (0.051, [0.048–0.054]) compared to non-harmonized HUI (0.060, [0.056–0.063]) or ALBI-LP (0.060, [0.057–0.064]), and equivalent to h-HUI by ICG-PDR (0.051, [0.045, 0.055]). Conclusion: The HUI harmonized by the ALBI-LP is a clinically applicable method for ensuring the comparability of MR devices in quantitative liver reserve prediction using gadoxetate disodium-enhanced MR imaging. Key Points: Question The accurate prediction of quantitative liver function by hepatocyte-specific contrast-enhanced MRI necessitates the harmonization of MR systems. However, no established method has yet been identified. Findings In quantitative hepatic function assessment, albumin-bilirubin linear predictor can be employed to achieve harmonization between MR systems equivalent to the indocyanine green clearance test. Clinical relevance Quantitative liver function, as measured by the indocyanine green clearance test, can be accurately estimated using the hepatocellular uptake index, harmonized with the albumin-bilirubin linear predictor, across diverse MR systems. Graphical

Purpose: To evaluate the predictive ability of ^99mTc-galactosyl human serum albumin SPECT/CT quantitative parameters for posthepatectomy liver failure (PHLF). Methods: Sixty-eight patients who underwent ^99mTc-galactosyl human serum albumin scintigraphy as a preoperative examination for hepatectomy between July 2021 and December 2023 were prospectively evaluated. The patients were divided into PHLF and non-PHLF groups. The clearance index (HH15) and receptor index (LHL15) were calculated from planar images. Quantitative parameters for the total liver (SUV_max, SUV_mean, peak SUV [SUV_peak], functional liver volume [FLV], SUV_mean × FLV), remnant liver (r-SUV_max, r-SUV_mean, r-SUV_peak, r-FLV, and r-SUV_mean × r-FLV), and r-FLV/FLV were calculated from SPECT/CT images. The areas under the curve (AUCs) of parameters from planar images and SPECT/CT parameters of the total and remnant livers were calculated to evaluate the predictive ability of PHLF. Results: PHLF occurred in 9 patients. AUC of r-FLV was significantly higher than that of HH15 (0.93; 95% confidence interval [CI], 0.84–0.99 vs 0.66; 95% CI, 0.46–0.84; P = 0.026) and LHL15 (0.93; 95% CI, 0.84–0.99 vs 0.72; 95% CI, 0.55–0.86; P = 0.043). AUC of r-SUV_mean × r-FLV was significantly higher than that of HH15 (0.90; 95% CI, 0.80–0.97 vs 0.66; 95% CI, 0.46–0.84; P = 0.037). There were no significant differences between the AUC of other SPECT/CT, r-FLV/FLV, and planar image parameters. Conclusions: r-FLV can predict PHLF more accurately than HH15 or LHL15.

Aim: The purpose of this study was to evaluate whether parameters obtained from gadoxetate disodium‐enhanced magnetic resonance imaging (EOB‐MRI) could predict intrahepatic tumor recurrence in patients who underwent curative hepatectomy for hepatocellular carcinoma (HCC).Methods: This study included 208 patients who underwent EOB‐MRI before hepatectomy for HCC. The mean signal intensity of the liver (L20) and spleen (S20) was obtained from preoperative EOB‐MRI, and liver‐to‐spleen ratio (LSR) was calculated from these values as: LSR = L20/S20. The association of LSR value with intrahepatic recurrence of HCC after curative hepatectomy was analyzed.Results: Intrahepatic recurrence in the remnant liver developed in 111 (53%) patients during the median follow‐up period of 52.0 (range, 7.0–134.9) months after hepatectomy. Cumulative incidence of intrahepatic recurrence was significantly higher in patients with low LSR (p < 0.001). In multivariable analysis, low LSR was identified as an independent predictor of intrahepatic recurrence (hazard ratio, 1.83; 95% confidence interval [CI], 1.23–2.72; p = 0.002), together with multiple tumors, macroscopic vascular invasion, and high‐grade fibrosis of the background liver. Subgroup analysis according to the time of recurrence (within 1 year or more) revealed that low LSR was significantly associated with late recurrence (hazard ratio, 2.35; 95% CI, 1.40–3.94; p = 0.001), but not with early recurrence.Conclusions: Low LSR was an independent risk factor of intrahepatic recurrence after curative hepatectomy for HCC, and was especially associated with late recurrence developing more than 1 year after curative hepatectomy.

This study aimed to measure right atrial (RA) strain in the reservoir, conduit, and contraction phases and examine its clinical utility in detecting pulmonary hypertension (PH). One hundred and thirteen patients hospitalized in the intensive or coronary care units of our institution who underwent echocardiography and measurements of RA/right ventricular (RV) strain were retrospectively examined. RA strain was measured in the reservoir, conduit, and contraction phases of one cardiac cycle. PH was defined as peak tricuspid regurgitation velocity >2.8 m/s. Patients were grouped according to PH status (PH, no PH) and statistically compared. Logistic regression and receiver operating characteristic analyses were also performed. Mean age was 71.1±15.4 years and 72 were men (63.7%). The PH and no PH groups comprised 40 and 73 patients, respectively. Among the RA strain parameters, RA strain in the conduit phase was significantly lower in the PH group (–8.1±4.2% vs. –17.4±7.7%; p<0.001). In the receiver operating characteristic analysis for PH, RA strain in the conduit phase had the highest area under the curve among the RA/RV strain parameters (area under the curve, 0.88; sensitivity, 92.5%; specificity, 71.2%; p<0.001). RA strain is an echocardiographic parameter that can detect PH and should be considered when RV strain parameters are not measurable.

Purpose: To evaluate the predictive ability of combining Technetium-99m-galactosyl human serum albumin (^99mTc‑GSA) single-photon emission computed tomography (SPECT)/computed tomography (CT) volume and plasma clearance rate of indocyanine green (ICGK) for posthepatectomy liver failure (PHLF). Materials and methods: Fifty patients who underwent ^99mTc-GSA scintigraphy as a preoperative examination for segmentectomy or more from July 2021 to June 2023 were evaluated prospectively. Patients were divided into two groups according to the presence or absence of posthepatectomy liver failure (PHLF). Total functional liver volume (t-FLV) and remnant FLV (r-FLV) were measured from ^99mTc-GSA SPECT/CT image. Future liver remnant ICGK (ICGK-F) was calculated by ICGK and remnant liver volume from CT. Area under the curve (AUC) of ICGK-F, r-FLV, r-FLV/t-FLV, ICGK × r-FLV, ICGK × r-FLV/t-FLV was calculated to evaluate predictive ability of each parameter for PHLF. Results: PHLF was occurred in 7 patients. AUC of ICGK × r-FLV was significantly higher than that of ICGK-F (0.99; 95% confidence interval [CI]: 0.96–1 vs 0.82; 95%CI: 0.64–0.96; p = 0.036). There was no significant difference between the AUC of r-FLV, r-FLV/t-FLV, ICGK × r-FLV/t-FLV and that of ICGK-F, respectively. Conclusion: The combination of ^99mTc‑GSA SPECT/CT volume and ICGK can predict PHLF more accurately than ICGK-F.