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Takahashi, Naoki

0000-0002-7946-6078

Mayo Clinic

Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.

Citations 55

Fully Automated Deep Learning Model to Detect Clinically Significant Prostate Cancer at MRI

Radiology | August 6, 2024 | Volume: 312 | Issue: 2 | Pages: No page available

10.1148/radiol.232635 | PMID 39105640

The performance of a deep learning model was not different from that of radiologists in the detection of clinically significant prostate cancer at MRI, and gradient-weighted class activation maps localized the tumor.
Long-Term Outcomes and Risk of Pancreatic Cancer in Intraductal Papillary Mucinous Neoplasms

JAMA Network Open | October 17, 2023 | Volume: 6 | Issue: 10 | Pages: e2337799

10.1001/jamanetworkopen.2023.37799 | PMID 37847503

ImportanceIntraductal papillary mucinous neoplasms (IPMNs) are pancreatic cysts that can give rise to pancreatic cancer (PC). Limited population data exist on their prevalence, natural history, or risk of malignant transformation (IPMN-PC).ObjectiveTo fill knowledge gaps in epidemiology of IPMNs and associated PC risk by estimating population prevalence of IPMNs, associated PC risk, and proportion of IPMN-PC.Design, Setting, and Participants: This retrospective cohort study was conducted in Olmsted County, Minnesota. Using the Rochester Epidemiology Project (REP), patients aged 50 years and older with abdominal computed tomography (CT) scans between 2000 and 2015 were randomly selected (CT cohort). All patients from the REP with PC between 2000 and 2019 were also selected (PC cohort). Data were analyzed from November 2021 through August 2023.Main outcomes and MeasuresCIs for PC incidence estimates were calculated using exact methods with the Poisson distribution. Cox models were used to estimate age, sex, and stage–adjusted hazard ratios for time-to-event end points.ResultsThe CT cohort included 2114 patients (1140 females [53.9%]; mean [SD] age, 68.6 [12.1] years). IPMNs were identified in 231 patients (10.9%; 95% CI, 9.7%-12.3%), most of which were branch duct (210 branch-duct [90.9%], 16 main-duct [6.9%], and 5 mixed [2.2%] IPMNs). There were 5 Fukuoka high-risk (F-HR) IPMNs (2.2%), 39 worrisome (F-W) IPMNs (16.9%), and 187 negative (F-N) IPMNs (81.0%). After a median (IQR) follow-up of 12.0 (8.1-15.3) years, 4 patients developed PC (2 patients in F-HR and 2 patients in F-N groups). The PC incidence rate per 100 person years for F-HR IPMNs was 34.06 incidents (95% CI, 4.12-123.02 incidents) and not significantly different for patients with F-N IPMNs compared with patients without IPMNs (0.16 patients; 95% CI, 0.02-0.57 patients vs 0.11 patients; 95% CI, 0.06-0.17 patients; P = .62). The PC cohort included 320 patients (155 females [48.4%]; mean [SD] age, 72.0 [12.3] years), and 9.8% (95% CI, 7.0%-13.7%) had IPMN-PC. Compared with 284 patients with non-IPMN PC, 31 patients with IPMN-PC were older (mean [SD] age, 76.9 [9.2] vs 71.3 [12.5] years; P = .02) and more likely to undergo surgical resection (14 patients [45.2%] vs 60 patients [21.1%]; P = .003) and more-frequently had nonmetastatic PC at diagnosis (20 patients [64.5%] vs 130 patients [46.8%]; P = .047). Patients with IPMN-PC had better survival (adjusted hazard ratio, 0.62; 95% CI, 0.40-0.94; P = .03) than patients with non-IPMN PC.Conclusions and RelevanceIn this study, CTs identified IPMNs in approximately 10% of patients aged 50 years or older. PC risk in patients with F-N IPMNs was low and not different compared with patients without IPMNs; approximately 10% of patients with PC had IPMN-PC, and they had better survival compared with patients with non-IPMN PC.
Muscle loss during cancer therapy is associated with poor outcomes in advanced ovarian cancer

JNCI Monographs | February 18, 2023 | Volume: 2023 | Issue: 61 | Pages: 43-48

10.1093/jncimonographs/lgad007 | PMID 37139982

Abstract Data evaluating change in body composition during treatment of advanced cancer are limited. Here we evaluated computed tomography (CT)–based changes in muscle mass during treatment for advanced ovarian cancer (OC) and association with outcomes. We analyzed the preoperative and posttreatment skeletal muscle index (SMI), skeletal muscle area normalized for height of 109 patients with advanced OC who underwent primary surgery and platinum-based chemotherapy from 2006 to 2016. Based on an SMI less than 39 cm2/m2, 54.1% of patients were never sarcopenic, 24.8% were sarcopenic on both CT scans, and 21.1% were newly sarcopenic upon treatment completion. Patients who lost muscle during treatment had the worst survival of the 3 groups identified: median survival 2.6 years vs 4.6 years if sarcopenic on both CT scans and 4.8 years if never sarcopenic. Loss of muscle portends a poor prognosis among patients with OC. Additional research is needed to better understand and best mitigate these changes.
Combined Drainage and Protocolized Necrosectomy Through a Coaxial Lumen-apposing Metal Stent for Pancreatic Walled-off Necrosis

Annals of Surgery | November 4, 2021 | Volume: 277 | Issue: 5 | Pages: e1072-e1080

10.1097/sla.0000000000005274 | PMID 35129503

Objective: We evaluated a protocolized endoscopic necrosectomy approach with a lumen-apposing metal stent (LAMS) in patients with large symptomatic walled-off pancreatic necrosis (WON) comprising significant necrotic content, with or without infection. Summary Background Data: Randomized trials have shown similar efficacy of endoscopic treatment compared with surgery for infected WON. Design: We conducted a regulatory, prospective, multicenter single-arm clinical trial examining the efficacy and safety of endoscopic ultrasound -guided LAMS with protocolized necrosectomy to treat symptomatic WON ≥6 cm in diameter with >30% solid necrosis. After LAMS placement, protocolized WON assessment was conducted and endoscopic necrosectomy was performed for insufficient WON size reduction and persistent symptoms. Patients with radiographic WON resolution to ≤ 3 cm and/or 60-day LAMS indwell had LAMS removal, then 6-month follow-up. Primary endpoints were probability of radiographic resolution by 60 days and procedure-related serious adverse events. Results: Forty consecutive patients were enrolled September 2018 to March 2020, of whom 27 (67.5%) were inpatients and 19 (47.5%) had clinical evidence of infection at their index procedure. Mean WON size was 15.0 ± 5.6 cm with mean 53.2% ± 16.7% solid necrosis. Radiographic WON resolution was seen in 97.5% (95% CI, 86.8%, 99.9%) by 60 days, without recurrence in 34 patients with 6-month follow-up data. Mean time to radiographic WON resolution was 34.1 ± 16.8 days. Serious adverse events occurred in 3 patients (7.5%), including sepsis, vancomycin-resistant enterococcal bacteremia and shock, and upper gastrointestinal bleeding. There were no procedure-related deaths. Conclusions: Endoscopic ultrasound-guided drainage with protocolized endoscopic necrosectomy to treat large symptomatic or infected walled-off necrotic pancreatic collections was highly effective and safe. Clinicaltrials.-gov no: NCT03525808.
Abnormal body composition in patients with adrenal adenomas

European Journal of Endocrinology | August 18, 2021 | Volume: 185 | Issue: 5 | Pages: 653-662

10.1530/eje-21-0458 | PMID 34406976

Objective Increased visceral fat and sarcopenia are cardiovascular risk factors that may explain increased cardiovascular morbidity and frailty in patients with adrenal adenomas. Our objective was to compare body composition measurement of patients with adrenal adenomas to referent subjects without adrenal disease. Design Cross-sectional study, 2014–2018. Methods Participants were adults with nonfunctioning adrenal tumor (NFAT), mild autonomous cortisol secretion (MACS), and Cushing syndrome (CS) and age, sex, and BMI 1:1 matched referent subjects without adrenal disorders. Main outcome measures were body composition measurements calculated from abdominal CT imaging. Intra-abdominal adipose tissue and muscle mass measurements were performed at the third lumbar spine level. Results Of 227 patients with adrenal adenomas, 20 were diagnosed with CS, 76 with MACS, and 131 with NFAT. Median age was 56 years (range: 18–89), and 67% were women. When compared to referent subjects, patients with CS, MACS, and NFAT demonstrated a higher visceral fat (odds ratio (OR): 2.2 (95% CI: 0.9–6.5), 2.0 (1.3–3.2), and 1.8 (1.2–2.7) and a lower skeletal muscle area (OR: 0.01 (95% CI: 0–0.09), 0.31 (0.18–0.49), and 0.3 (1.2–2.7)) respectively. For every 1 µg/dL cortisol increase after overnight dexamethasone, visceral fat/muscle area ratio increased by 2.3 ( P = 0.02) and mean total skeletal muscle area decreased by 2.2 cm 2 ( P = 0.03). Conclusion Patients with adrenal adenomas demonstrate a lower muscle mass and a higher proportion of visceral fat when compared to referent subjects, including patients with NFAT. Even a subtle abnormality in cortisol secretion may impact health of patients with adenomas.
Obesity, venous capacitance, and venous compliance in heart failure with preserved ejection fraction

European Journal of Heart Failure | May 30, 2021 | Volume: 23 | Issue: 10 | Pages: 1648-1658

10.1002/ejhf.2254 | PMID 34053158

Abstract Aims Circulating blood volume is functionally divided between the unstressed volume, which fills the vascular space, and stressed blood volume (SBV), which generates vascular wall tension and intravascular pressure. With decreases in venous capacitance, blood functionally shifts to the SBV, increasing central venous pressure and pulmonary venous pressures. Obesity is associated with both elevated venous pressure and heart failure with preserved ejection fraction (HFpEF). To explore the mechanisms underlying this association, we evaluated relationships between blood volume distribution, venous compliance, and body mass in patients with and without HFpEF. Methods and results Subjects with HFpEF ( n = 62) and non‐cardiac dyspnoea (NCD) ( n = 79) underwent invasive haemodynamic exercise testing with echocardiography. SBV was estimated (eSBV) from measured haemodynamic variables fit to a comprehensive cardiovascular model. Compared to NCD, patients with HFpEF displayed a leftward‐shifted central venous pressure–dimension relationship, indicating reduced venous compliance. eSBV was 81% higher at rest and 69% higher during exercise in HFpEF than NCD (both P < 0.0001), indicating reduced venous capacitance. Despite greater augmented eSBV with exercise, the increase in cardiac output was reduced in HFpEF, suggesting operation on the plateau of the Starling curve. Exercise eSBV was directly correlated with higher body mass index (r = 0.77, P < 0.0001) and inversely correlated with right ventricular–pulmonary arterial coupling (r = −0.57, all P < 0.0001). Conclusions Patients with HFpEF display reductions in systemic venous compliance and increased eSBV related to reduced venous capacitance, abnormalities in right ventricular–pulmonary artery interaction, and increased body fat. These data provide new evidence supporting an important role of venous dysfunction in obesity‐related HFpEF and suggest that therapies that improve venous function may hold promise to improve clinical status in this cohort.
Pathophysiologic importance of visceral adipose tissue in women with heart failure and preserved ejection fraction

European Heart Journal | September 22, 2020 | Volume: 42 | Issue: 16 | Pages: 1595-1605

10.1093/eurheartj/ehaa823 | PMID 33227126

Abstract Aims Central obesity is a major risk factor for heart failure with preserved ejection fraction (HFpEF), particularly in women, but the mechanisms remain unclear. We hypothesized that sex-specific differences in visceral adipose tissue (VAT) content would differentially relate to haemodynamic severity of HFpEF in women and men. Methods and results Abdominal computed tomography (CT) and invasive haemodynamic exercise testing were performed in 105 subjects with HFpEF (63 women) and 105 age-, sex-, and body mass index-matched controls. Visceral adipose tissue area was quantified by CT. As compared with control women, VAT area was 34% higher in women with HFpEF (186 ± 112 vs. 139 ± 72 cm2, P = 0.006), while VAT area was not significantly different in men with or without HFpEF (294 ± 158 vs. 252 ± 92 cm2, P = 0.1). During exercise, pulmonary capillary wedge pressure (PCWP) increased markedly and to similar extent in both men and women with HFpEF. Women with increased VAT area displayed 33% higher PCWP during exercise compared with women with normal VAT area (28 ± 10 vs. 21 ± 10 mmHg, P = 0.001), whereas exercise PCWP was similar in men with or without excess VAT (24 ± 9 vs. 25 ± 6, P = 0.89). In women, each 100 cm2 increase in VAT area was associated with a 4.0 mmHg higher PCWP (95% CI 2.1, 6.0 mmHg; P &lt; 0.0001), but there was no such relationship in men (interaction P = 0.009). Conclusions These data suggest that accumulation of excess VAT plays a distinct and important role in the pathophysiology of HFpEF preferentially in women. Further research is needed to better understand the mechanisms and treatment implications for visceral fat in HFpEF.
Complete abdomen and pelvis segmentation using U‐net variant architecture

Medical Physics | August 2, 2020 | Volume: 47 | Issue: 11 | Pages: 5609-5618

10.1002/mp.14422 | PMID 32740931

PurposeOrgan segmentation of computed tomography (CT) imaging is essential for radiotherapy treatment planning. Treatment planning requires segmentation not only of the affected tissue, but nearby healthy organs‐at‐risk, which is laborious and time‐consuming. We present a fully automated segmentation method based on the three‐dimensional (3D) U‐Net convolutional neural network (CNN) capable of whole abdomen and pelvis segmentation into 33 unique organ and tissue structures, including tissues that may be overlooked by other automated segmentation approaches such as adipose tissue, skeletal muscle, and connective tissue and vessels. Whole abdomen segmentation is capable of quantifying exposure beyond a handful of organs‐at‐risk to all tissues within the abdomen.MethodsSixty‐six (66) CT examinations of 64 individuals were included in the training and validation sets and 18 CT examinations from 16 individuals were included in the test set. All pixels in each examination were segmented by image analysts (with physician correction) and assigned one of 33 labels. Segmentation was performed with a 3D U‐Net variant architecture which included residual blocks, and model performance was quantified on 18 test cases. Human interobserver variability (using semiautomated segmentation) was also reported on two scans, and manual interobserver variability of three individuals was reported on one scan. Model performance was also compared to several of the best models reported in the literature for multiple organ segmentation.ResultsThe accuracy of the 3D U‐Net model ranges from a Dice coefficient of 0.95 in the liver, 0.93 in the kidneys, 0.79 in the pancreas, 0.69 in the adrenals, and 0.51 in the renal arteries. Model accuracy is within 5% of human segmentation in eight of 19 organs and within 10% accuracy in 13 of 19 organs.ConclusionsThe CNN approaches the accuracy of human tracers and on certain complex organs displays more consistent prediction than human tracers. Fully automated deep learning‐based segmentation of CT abdomen has the potential to improve both the speed and accuracy of radiotherapy dose prediction for organs‐at‐risk.
The 2019 American College of Rheumatology/European League Against Rheumatism Classification Criteria for IgG4‐Related Disease

Arthritis & Rheumatology | December 3, 2019 | Volume: 72 | Issue: 1 | Pages: 7-19

10.1002/art.41120 | PMID 31793250

Objective IgG4‐related disease (IgG4‐ RD ) can cause fibroinflammatory lesions in nearly any organ. Correlation among clinical, serologic, radiologic, and pathologic data is required for diagnosis. This work was undertaken to develop and validate an international set of classification criteria for IgG4‐ RD . Methods An international multispecialty group of 86 physicians was assembled by the American College of Rheumatology ( ACR ) and the European League Against Rheumatism ( EULAR ). Investigators used consensus exercises, existing literature, derivation and validation cohorts of 1,879 subjects (1,086 cases, 793 mimickers), and multicriterion decision analysis to identify, weight, and test potential classification criteria. Two independent validation cohorts were included. Results A 3‐step classification process was developed. First, it must be demonstrated that a potential IgG4‐ RD case has involvement of at least 1 of 11 possible organs in a manner consistent with IgG4‐ RD . Second, exclusion criteria consisting of a total of 32 clinical, serologic, radiologic, and pathologic items must be applied; the presence of any of these criteria eliminates the patient from IgG4‐ RD classification. Third, 8 weighted inclusion criteria domains, addressing clinical findings, serologic results, radiology assessments, and pathology interpretations, are applied. In the first validation cohort, a threshold of 20 points had a specificity of 99.2% (95% confidence interval [95% CI ] 97.2–99.8%) and a sensitivity of 85.5% (95% CI 81.9–88.5%). In the second, the specificity was 97.8% (95% CI 93.7–99.2%) and the sensitivity was 82.0% (95% CI 77.0–86.1%). The criteria were shown to have robust test characteristics over a wide range of thresholds. Conclusion ACR / EULAR classification criteria for IgG4‐ RD have been developed and validated in a large cohort of patients. These criteria demonstrate excellent test performance and should contribute substantially to future clinical, epidemiologic, and basic science investigations.
Prostatic Remnant After Prostatectomy: MR Findings and Prevalence in Clinical Practice

American Journal of Roentgenology | October 31, 2019 | Volume: 214 | Issue: 1 | Pages: W37-W43

10.2214/ajr.19.21345 | PMID 31670591