Prognostic role of preoperative fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography with an image-based harmonization technique: A multicenter retrospective study.

Objectives: Despite the prognostic impacts of preoperative fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography examination, fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography-based prognosis prediction has not been used clinically because of the disparity in data between institutions. By applying an image-based harmonized approach, we evaluated the prognostic roles of fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters in clinical stage I non-small cell lung cancer. Methods: We retrospectively examined 495 patients with clinical stage I non-small cell lung cancer who underwent fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography examinations before pulmonary resection between 2013 and 2014 at 4 institutions. Three different harmonization techniques were applied, and an image-based harmonization, which showed the best-fit results, was used in the further analyses to evaluate the prognostic roles of fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters. Results: Cutoff values of image-based harmonized fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters, maximum standardized uptake, metabolic tumor volume, and total lesion glycolysis were determined using receiver operating characteristic curves that distinguish pathologic high invasiveness of tumors. Among these parameters, only the maximum standardized uptake was an independent prognostic factor in recurrence-free and overall survivals in univariate and multivariate analyses. High image-based maximum standardized uptake value was associated with squamous histology or lung adenocarcinomas with higher pathologic grades. In subgroup analyses defined by ground-glass opacity status and histology or by clinical stages, the prognostic impact of image-based maximum standardized uptake value was always the highest compared with other fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters. Conclusions: The image-based fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography harmonization was the best fit, and the image-based maximum standardized uptake was the most important prognostic marker in all patients and in subgroups defined by ground-glass opacity status and histology in surgically resected clinical stage I non-small cell lung cancers.

Prognostic significance of the harmonized maximum standardized uptake value of 18F-FDG-PET/CT in patients with resectable oral tongue squamous cell carcinoma: a multicenter study.

OBJECTIVES: To investigate the usefulness of harmonized 18F-FDG-PET/CT parameters for predicting the postoperative recurrence and prognosis of oral tongue squamous cell carcinoma (OTSCC). METHODS: We retrospectively analyzed the cases of 107 OTSCC patients who underwent surgical resection at four institutions in Japan in 2010-2016 and evaluated the harmonized PET parameters of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for the primary tumor as the pSUVmax, pMTV, and pTLG. For lymph node metastasis, we used harmonized PET parameters of nodal-SUVmax, nodal-total MTV (tMTV), and nodal-total TLG (tTLG). The associations between the harmonized PET parameters and the patients' relapse-free survival (RFS) and overall survival (OS) were evaluated by the Kaplan-Meier method and Cox proportional hazard regression analysis for model 1 (preoperative stage) and model 2 (preoperative + postoperative stages). RESULTS: The harmonized SUVmax values were significantly lower than those before harmonization (p=0.012). The pSUVmax was revealed as a significant preoperative risk factor for RFS and OS. Nodal-SUVmax, nodal-tMTV, and nodal-tTLG were significant preoperative risk factors for OS. The combination of pSUVmax + nodal-SUVmax significantly stratified the patients into a low-risk group (pSUVmax <3.97 + nodal-SUVmax <2.85 or ≥2.85) and a high-risk group (pSUVmax ≥3.97 + nodal-SUVmax <2.85 or pSUVmax ≥3.97 + nodal-SUVmax ≥2.85) for recurrence and prognosis (RFS: p=0.001; OS: p<0.001). CONCLUSIONS: The harmonized pSUVmax is a significant prognostic factor for the survival of OTSCC patients. The combination of pSUVmax and nodal-SUVmax identified OTSCC patients at high risk for recurrence and poor prognosis at the preoperative stage.

Comparison of Slow-Infusion Magnetic Resonance Angiography with Sequential K-Space Filling and Computed Tomography Angiography to Detect the Adamkiewicz Artery.

BACKGROUND: Radiographic detection of the Adamkiewicz artery (AKA) before aortic surgery helps to avoid spinal cord ischemia (SCI). We applied magnetic resonance angiography (MRA) using gadolinium enhancement (Gd-MRA) by means of the slow-infusion method with sequential k-space filling and compared AKA detectability with that of computed tomography angiography (CTA). METHODS: A total of 63 patients with thoracic or thoracoabdominal aortic disease (30 with aortic dissection [AD] and 33 with aortic aneurysm) who underwent both CTA and Gd-MRA to detect AKA were evaluated. The detectability of the AKA using Gd-MRA and CTA were compared among all patients and subgroups based on anatomical features. RESULTS: The detection rates of the AKAs using Gd-MRA and CTA were higher in all 63 patients (92.1% vs. 71.4%, P = 0.003). In AD cases, the detection rates using Gd-MRA and CTA were higher in all 30 patients (93.3% vs. 66.7%, P = 0.01) as well as in 7 patients whose AKA originated from false lumens (100% vs. 0%). In aneurysm cases, the detection rates using Gd-MRA and CTA were higher in 22 patients whose AKA originated from the nonaneurysmal parts (100% vs. 81.8%, P = 0.03). In clinical, SCI was observed in 1.8% of cases after open or endovascular repair. CONCLUSIONS: Despite the longer examination time and more complicated imaging techniques compared to those of CTA, the high spatial resolution of slow-infusion MRA may be preferable for detecting AKA before performing various thoracic and thoracoabdominal aortic surgeries.

Early and post-treatment imaging findings in perineural spread: a pathway to diffuse muscle metastasis in recurrent bladder carcinoma.

Perineural spread (PNS) from pelvic carcinoma has been regarded as a pathway to muscle and bone metastasis. However, few cases have been reported, especially in patients with bladder carcinoma. In the present report, we discuss a case of diffuse cancer involvement in the muscle 5 years after radical cystectomy for advanced bladder carcinoma. Careful observation of temporal changes on medical images confirmed PNS as the pathway to muscle metastasis (i.e., primary PNS). Our report presents early and post-treatment CT, MRI and FDG-PET/CT findings of PNS from the bladder carcinoma.

A Scoring System That Predicts Difficult Lipoma Resection: Logistic Regression and Tenfold Cross-Validation Analysis.

INTRODUCTION: Most lipomas are readily dissected and removed. However, some cases can pose surgical difficulties. This retrospective study sought to identify clinical and radiological risk factors that predict difficult lipoma resection and can be used in a clinically useful scoring system that predicts difficulty preoperatively. METHODS: The study cohort consisted of all consecutive patients who underwent resection of pathology-confirmed lipoma during 2016-2018 at a tertiary care referral center in Tokyo, Japan. Surgical difficulty was defined as difficulty separating some/all of the tumor from the surrounding tissue by hand and inability to extract the tumor in one piece. Descriptive, univariate, and multivariate logistic regression analyses were conducted to identify predictive factors. The predictive accuracy of the scoring system that included these factors was assessed by tenfold cross-validation analysis. Receiver-operating curve (ROC) analysis was conducted to identify the optimal cutoff score for predicting surgical difficulty. RESULTS: Of the 86 cases, 36% involved surgical difficulty. Multivariate analysis showed that subfascial intramuscular location (odds ratio 42.7, 95% confidence interval 3.0-608.0), broad touching of underlying structures (46.5, 3.7-586.0), in-flowing blood vessels (9.3, 1.1-78.5), and unclear boundaries (109.0, 1.1-1110.0) significantly predicted surgical difficulty. These factors were used to construct a 0-4 point scoring system (with one point per variable). On cross-validation, the accuracy of the scoring system was 82.4% (Cohen's kappa of 0.57). ROC analysis showed that scores ≥ 2 predicted surgical difficulty with sensitivity and specificity of 55% and 98%, respectively. CONCLUSIONS: Our scoring system accurately predicted lipoma resection difficulty and may help operators prepare, thereby facilitating surgery.

Hemodynamic changes during the obliteration process for cerebral arteriovenous malformations after radiosurgery.

OBJECTIVE: The process of cerebral arteriovenous malformation (AVM) obliteration following radiosurgery is poorly understood. Authors of this retrospective study aimed to assess the changes in AVM hemodynamics after stereotactic radiosurgery (SRS) by using 3D flow magnetic resonance imaging (MRI) to elucidate the process of AVM obliteration. METHODS: Twenty-four patients with AVMs treated with SRS between July 2015 and December 2017 were included in this study and classified into two groups depending on the duration of AVM obliteration: group A, obliteration within 3 years (n = 15); and group B, obliteration taking more than 3 years or no obliteration (n = 9). Blood flow (ml/min) in the largest feeding artery was measured before and after SRS by using time-averaged 3D flow MRI. The decreasing rate of blood flow in the feeding artery after SRS was calculated as the percent change from baseline blood flow. A Wilcoxon rank-sum test was used to compare the decreasing blood flow rate between the two groups at 4 and 12 months after SRS. RESULTS: For the entire cohort, the mean decrease in blood flow in the feeding artery from baseline was 29% at 4 months and 71% at 12 months after SRS. In general, blood flow after SRS decreased faster in group A and slower in group B. The decreasing rates in blood flow at 4 and 12 months after SRS were significantly different between the two groups (p = 0.02 and < 0.001, respectively). CONCLUSIONS: Tracking changes in AVM hemodynamics after SRS may be useful for assessing the progress of AVM obliteration and the therapeutic effects of SRS, possibly contributing to the prediction of subsequent obliteration outcome.

Reproducibility of Standardized Uptake Values Including Volume Metrics Between TOF-PET-MR and TOF-PET-CT.

Purpose: To investigate the reproducibility of tracer uptake measurements, including volume metrics, such as metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) obtained by TOF-PET-CT and TOF-PET-MR. Materials and Methods: Eighty consecutive patients with different oncologic diagnoses underwent TOF-PET-CT (Discovery 690; GE Healthcare) and TOF-PET-MR (SIGNA PET-MR; GE Healthcare) on the same day with single dose-18F-FDG injection. The scan order, PET-CT following or followed by PET-MR, was randomly assigned. A spherical volume of interest (VOI) of 30 mm was placed on the liver in accordance with the PERCIST criteria. For liver, the maximum and mean standard uptake value for body weight (SUV) and lean body mass (SUL) were obtained. For tumor delineation, VOI with a threshold of 40 and 50% of SUVmax was used (VOI40 and VOI50). The SUVmax, SUVmean, SUVpeak, MTV and TLG were calculated. The measurements were compared between the two scanners. Results: In total, 80 tumor lesions from 35 patients were evaluated. There was no statistical difference observed in liver regions, whereas in tumor lesions, SUVmax, SUV mean, and SUVpeak of PET-MR were significantly underestimated (p < 0.001) in both VOI40 and VOI50. Among volume metrics, there was no statistical difference observed except TLG on VOI50 (p = 0.03). Correlation between PET-CT and PET-MR of each metrics were calculated. There was a moderate correlation of the liver SUV and SUL metrics (r = 0.63-0.78). In tumor lesions, SUVmax and SUVmean had a stronger correlation with underestimation in PET-MR on VOI 40 (SUVmax and SUVmean; r = 0.92 and 0.91 with slope = 0.71 and 0.72, respectively). In the evaluation of MTV and TLG, the stronger correlations were observed both on VOI40 (MTV and TLG; r = 0.75 and 0.92) and VOI50 (MTV and TLG; r = 0.88 and 0.95) between PET-CT and PET-MR. Conclusion: PET metrics on TOF-PET-MR showed a good correlation with that of TOF-PET-CT. SUVmax and SUVpeak of tumor lesions were underestimated by 16% on PET-MRI. MTV with % threshold can be regarded as identical volumetric markers for both TOF-PET-CT and TOF-PET-MR.

Hemodynamic Parameters for Cardiovascular System in 4D Flow MRI: Mathematical Definition and Clinical Applications.

Blood flow imaging becomes an emerging trend in cardiology with the recent progress in computer technology. It not only visualizes colorful flow velocity streamlines but also quantifies the mechanical stress on cardiovascular structures; thus, it can provide the detailed inspections of the pathophysiology of diseases and predict the prognosis of cardiovascular functions. Clinical applications include the comprehensive assessment of hemodynamics and cardiac functions in echocardiography vector flow mapping (VFM), 4D flow MRI, and surgical planning as a simulation medicine in computational fluid dynamics (CFD).For evaluation of the hemodynamics, novel mathematically derived parameters obtained using measured velocity distributions are essential. Among them, the traditional and typical parameters are wall shear stress (WSS) and its related parameters. These parameters indicate the mechanical damages to endothelial cells, resulting in degenerative intimal change in vascular diseases. Apart from WSS, there are abundant parameters that describe the strength of the vortical and/or helical flow patterns. For instance, vorticity, enstrophy, and circulation indicate the rotating flow strength or power of 2D vortical flows. In addition, helicity, which is defined as the cross-linking number of the vortex filaments, indicates the 3D helical flow strength and adequately describes the turbulent flow in the aortic root in cases with complicated anatomies. For the description of turbulence caused by the diseased flow, there exist two types of parameters based on completely different concepts, namely: energy loss (EL) and turbulent kinetic energy (TKE). EL is the dissipated energy with blood viscosity and evaluates the cardiac workload related to the prognosis of heart failure. TKE describes the fluctuation in kinetic energy during turbulence, which describes the severity of the diseases that cause jet flow. These parameters are based on intuitive and clear physiological concepts, and are suitable for in vivo flow measurements using inner velocity profiles.

A data-driven ultrasound approach discriminates pathological high grade prostate cancer.

Accurate prostate cancer screening is imperative for reducing the risk of cancer death. Ultrasound imaging, although easy, tends to have low resolution and high inter-observer variability. Here, we show that our integrated machine learning approach enabled the detection of pathological high-grade cancer by the ultrasound procedure. Our study included 772 consecutive patients and 2899 prostate ultrasound images obtained at the Nippon Medical School Hospital. We applied machine learning analyses using ultrasound imaging data and clinical data to detect high-grade prostate cancer. The area under the curve (AUC) using clinical data was 0.691. On the other hand, the AUC when using clinical data and ultrasound imaging data was 0.835 (p = 0.007). Our data-driven ultrasound approach offers an efficient tool to triage patients with high-grade prostate cancers and expands the possibility of ultrasound imaging for the prostate cancer detection pathway.

Four-dimensional flow magnetic resonance imaging is useful for assessing hemolytic anemia following surgical repair of type A aortic dissection.

BACKGROUND: Four-dimensional flow magnetic resonance imaging (4D flow MRI) can directly estimate turbulent kinetic energy (TKE) which is associated with pressure loss that are not assessable by other imaging modalities. METHODS AND RESULTS: A 55-year-old woman developed hemolytic anemia after emergency ascending aortic replacement for acute type A aortic dissection. Although computed tomographic angiography or doppler echocardiography could not identify the culprit stenotic legion, 4D flow MRI revealed jet flow and highly elevated TKE at the highly stenosed proximal anastomosis of a replaced ascending aorta. CONCLUSION: Our findings suggest that 4D flow MRI evaluation and TKE estimation enable more accurate and detailed assessment of abnormal flow dynamics than conventional imaging modalities.

Factors Influencing Long-Term Blood Flow in Extracranial-to-Intracranial Bypass for Symptomatic Internal Carotid Artery Occlusive Disease: A Quantitative Study.

BACKGROUND: Maintaining the patency of extracranial-to-intracranial (EC-IC) bypass is critical for long-term stroke prevention. However, reports on the factors influencing long-term bypass patency and quantitative assessments of bypass patency are limited. OBJECTIVE: To quantitatively evaluate blood flow in EC-IC bypass using four-dimensional (4D) flow magnetic resonance imaging (MRI) and investigate factors influencing the long-term patency of EC-IC bypass. METHODS: Thirty-six adult Japanese patients who underwent EC-IC bypass for symptomatic internal carotid or middle cerebral artery occlusive disease were included. We examined the relationships between decreased superficial temporal artery (STA) blood flow volume and perioperative complications, long-term ischemic complications, patient background, and postoperative antithrombotic medications in patients for whom STA flow could be quantitatively assessed for at least 5 months using 4D flow MRI. RESULTS: The mean follow-up time was 54.7 ± 6.1 months. One patient presented with a stroke during the acute postoperative period that affected postoperative outcomes. No recurrent strokes were recorded during long-term follow-up. Two patients died of malignant disease. Seven cases of reduced flow occurred in the STA, which were correlated with single bypass (P = .0294) and nonuse of cilostazol (P = .0294). STA occlusion was observed in 1 patient during the follow-up period. Hypertension, age, smoking, dyslipidemia, and diabetes mellitus were not correlated with reduced blood flow in the STA. CONCLUSION: Double anastomoses and cilostazol resulted in long-term STA blood flow preservation. No recurrence of cerebral infarction was noted in either STA hypoperfusion or occlusion cases.

Dual-VENC 4D Flow MRI Can Detect Abnormal Blood Flow in the Left Atrium That Potentially Causes Thrombosis Formation after Left Upper Lobectomy.

PURPOSE: The purpose of the current study was to clarify the blood flow pattern in the left atrium (LA), potentially causing the formation of thrombosis after left upper lobectomy (LUL). The blood flow in the LA was evaluated and compared between LUL patients with and without thrombosis. For the evaluation, we applied highly accelerated 4D flow MRI with dual-velocity encoding (VENC) scheme, which was expected to be able to capture slow flow components in the LA accurately. METHODS: Eight volunteers and 18 patients subjected to LUL underwent dual-VENC 4D Flow MRI. Eight patients had a history of thrombosis. We measured the blood flow velocity and stasis ratio (proportion in the volume that did not exceed 10 cm/s in any cardiac phase) in the LA and left superior pulmonary vein (LSPV) stump. For visual assessment, the presence of each collision of the blood flow from pulmonary veins and vortex flow in the LA were evaluated. Each acquired value was compared between healthy participants and LUL patients, and in LUL patients with and without thrombosis. RESULTS: In LUL patients, blood flow velocity near the inflow part of the left superior pulmonary vein (Lt Upp) and mean velocity in the LA were lower, and stasis ratio in the LA was higher compared with healthy volunteers (Lt Upp 9.10 ± 3.09 vs.13.23 ± 14.19 cm/s, mean velocity in the LA 9.81 ± 2.49 vs. 11.40 ± 1.15 cm/s, and stasis ratio 25.28 ± 18.64 vs. 4.71 ± 3.03%, P = 0.008, 0.037, and < 0.001). There was no significant difference in any quantification values between LUL patients with and without thrombosis. For visual assessment, the thrombus formation was associated with no collision pattern (62.5% vs. 10%, P = 0.019) and not with vortex flow pattern (50% vs. 30%, P = 0.751). CONCLUSION: The net blood flow velocity was not associated with the thrombus formation. In contrast, a specific blood flow pattern, the absence of blood flow collision from pulmonary veins, correlates to the thrombus formation in the LA.

Utility of 4D Flow MRI in Thoracic Aortic Diseases: A Literature Review of Clinical Applications and Current Evidence.

Despite the recent technical developments, surgery on the thoracic aorta remains challenging and is associated with significant mortality and morbidity. Decisions about when and if to operate are based on a balance between surgical risk and the hazard of aortic rupture. These decisions are sometimes difficult in elective cases of thoracic aortic diseases, including aneurysms and dissections. Abnormal wall stress derived from flow alterations influences disease progression. Therefore, a better understanding of the complex hemodynamic environment inside the aortic lumen will facilitate patient-specific risk assessments of complications, which enable clinicians to provide timely prophylactic interventions. Time-resolved 3D phase-contrast (4D flow) MRI has many advantages for the in vivo assessment of flow dynamics. Recent developments in 4D flow imaging techniques has led to significant advances in our understanding of physiological flow dynamics in healthy subjects and patients with thoracic aortic diseases. In this clinically focused review of thoracic aortic diseases, we demonstrate the clinical advances acquired with 4D flow MRI from published studies. We provide a systematic overview of key evidences and considerations regarding normal thoracic aortas, thoracic aortic aneurysms, aortic dissections, and thoracic aortas with prosthetic graft replacement.

Ring finger protein 213 c.14576G>A mutation is not involved in internal carotid artery and middle cerebral artery dysplasia.

The ring finger protein 213 (RNF213) susceptibility gene has been detected in more than 80% of Japanese and Korean patients with moyamoya disease (MMD), a bilateral internal carotid artery (ICA) occlusion. Furthermore, RNF213 has been detected in more than 20% of East Asians with atherosclerotic ICA stenosis. In this study, we evaluated the frequency of RNF213 mutations in congenital occlusive lesions of the ICA system. This case series was conducted jointly at four university hospitals. Patients with a family history of MMD, quasi-MMD, or related diseases were excluded. Ten patients were diagnosed with abnormal ICA or middle cerebral artery (MCA) angiogenesis. Patients with neurofibromatosis were excluded. Finally, nine patients with congenital vascular abnormalities were selected; of these, five had ICA deficiency and four had twig-like MCA. The RNF213 c.14576G > A mutation was absent in all patients. Therefore, the RNF213 c.14576G > A mutation may not be associated with ICA and MCA congenital dysplasia-rare vascular anomalies making it difficult to study a large number of cases. However, an accumulation of cases is required for accurate determination. The results of this study may help differentiate congenital vascular diseases from MMD.

RNF213 c.14576G>A Is Associated with Intracranial Internal Carotid Artery Saccular Aneurysms.

A mutation in RNF213 (c.14576G>A), a gene associated with moyamoya disease (>80%), plays a role in terminal internal carotid artery (ICA) stenosis (>15%) (ICS). Studies on RNF213 and cerebral aneurysms (AN), which did not focus on the site of origin or morphology, could not elucidate the relationship between the two. However, a report suggested a relationship between RNF213 and AN in French-Canadians. Here, we investigated the relationship between ICA saccular aneurysm (ICA-AN) and RNF213. We analyzed RNF213 expression in subjects with ICA-AN and atherosclerotic ICS. Cases with a family history of moyamoya disease were excluded. AN smaller than 4 mm were confirmed as AN only by surgical or angiographic findings. RNF213 was detected in 12.2% of patients with ICA-AN and 13.6% of patients with ICS; patients with ICA-AN and ICS had a similar risk of RNF213 mutation expression (odds ratio, 0.884; 95% confidence interval, 0.199-3.91; p = 0.871). The relationship between ICA-AN and RNF213 (c.14576G>A) was not correlated with the location of the ICA and bifurcation, presence of rupture, or multiplicity. When the etiology and location of AN were more restricted, the incidence of RNF213 mutations in ICA-AN was higher than that reported in previous studies. Our results suggest that strict maternal vessel selection and pathological selection of AN morphology may reveal an association between genetic mutations and ICA-AN development. The results of this study may form a basis for further research on systemic vascular diseases, in which the RNF213 (c.14576G>A) mutation has been implicated.

Cross-Comparison of 4-Dimensional Flow Magnetic Resonance Imaging and Intraoperative Middle Cerebral Artery Pressure Measurements Before and After Superficial Temporal Artery-Middle Cerebral Artery Bypass Surgery.

BACKGROUND: The hemodynamic changes after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery are unclear. OBJECTIVE: To clarify the hemodynamics by comparing flow parameters obtained by 4-dimensional (4D) flow magnetic resonance imaging (MRI) and intraoperative MCA pressure measurement. METHODS: We recruited 23 patients who underwent STA-MCA bypass surgery for internal carotid artery (ICA) or MCA stenosis. We monitored intraoperative MCA, STA, and radial artery (RA) pressure. All patients underwent 4D flow MRI preoperatively and 3 wk after surgery to quantify the blood flow volume (BFV) of the ipsilateral ICA (BFViICA), contralateral ICA (BFVcICA), basilar artery (BFVBA), ipsilateral STA (BFViSTA), and contralateral STA (BFVcSTA). The sum of intracranial BFV was defined as BFVtotal. We compared BFV parameters and intraoperative pressure. RESULTS: BFViSTA significantly increased after surgery (P < .001). BFViICA and BFVBA significantly decreased after surgery (BFViICAP = .005; BFVBAP = .02). No significant difference was observed between BFVcICA before and after surgery. As a result, BFVtotal postoperatively increased by 6.8%; however, no significant difference was observed. Flow direction at M1 changed from antegrade to unclear after surgery in 5 patients. Intraoperative MCA pressure and MCA/RA pressure ratio significantly increased after surgery (P < .001). We found a stronger positive correlation between MCA pressure increase ratio and BFVtotal increase ratio in patients with lower pre-MCA pressure (r = 0.907, P < .001). CONCLUSION: The visual and quantitative assessment of 4D flow MRI revealed that intracranial blood flow changes complementarily after STA-MCA bypass surgery. 4D flow MRI may detect the improvement of cerebral perfusion pressure.

Four-dimensional flow analysis reveals mechanism and impact of turbulent flow in the dissected aorta.

OBJECTIVES: This study aimed to explore the flow dynamics factors affecting turbulence formation in the false lumen (FL) of aortic dissection using four-dimensional flow magnetic resonance imaging (4D flow MRI). This study also aimed to uncover risk factors affecting late complications of aortic dissection. METHODS: Thirty-three aortic dissection patients were examined using 4D flow MRI for quantitative flow dynamics (gross flow, velocity and regurgitant fraction) and turbulence visualization (helix and vortex with three-point visual grading) in the FL. The incidence of late complications (rupture or prophylactic intervention) was also obtained prospectively. RESULTS: The helix grade was correlated with FL gross flow (rS = 0.55, P < 0.001) and FL velocity (rS = 0.45, P = 0.008). The vortex grade was also correlated with FL gross flow (rS = 0.70, P < 0.001) and FL velocity (rS = 0.67, P < 0.001). Comparative analysis of patients with complications and stable patients revealed that patients with complications exhibited higher FL gross flow [41.7 (interquartile range, IQR 29.1-59.7) vs 17.7 (IQR 9.0-42.0) ml/s; P = 0.01], higher helix grade [2 (IQR 1.25-2) vs 0 (IQR 0-1); P = 0.001] and higher vortex grade [2 (IQR 1-2) vs 0 (IQR 0-2); P = 0.01]. CONCLUSIONS: Using 4D flow MRI analysis, we showed that turbulence formation depends on flow volume and velocity in the FL. Patients with high-volume turbulent flow in their FL are at higher risk of late complications; therefore, close follow-up and aggressive prophylactic intervention may improve their survival. CLINICAL TRIAL REGISTRATION NUMBER: Nippon Medical School Hospital Institutional Review Board approved this observational study in September 2018 (No. 30-08-986).

Harmonized pretreatment quantitative volume-based FDG-PET/CT parameters for prognosis of stage I-III breast cancer: Multicenter study.

OBJECTIVES: This study investigated harmonized pretreatment volume-based quantitative FDG-PET/CT parameters in breast cancer patients for prognostic value. RESULTS: During a median overall follow-up period of 5.3 years, 91 patients had recurrence and 40 died. Multivariate analysis of ER-positive/HER2-negative patients showed high maximum standardized uptake value (SUVmax) (p = 0.018), high total lesion glycolysis (TLG) (p = 0.010), and clinical N-classification (p = 0.0027) as independent negative predictors of RFS, while high maximum SUVmax (p = 0.037), advanced clinical T-classification (p = 0.030), and advanced TNM stage (p = 0.0067) were independent negative predictors of OS. For recurrence and death in HER2-positive patients, high total TLG (p = 0.037, p = 0.0048, respectively) and advanced TNM stage (p = 0.048, p = 0.046, respectively) were independent prediction factors. In the triple-negative group, independent factors related to recurrence and death were high maximum SUVmax (p = 0.0014, p = 0.0003, respectively) and advanced TNM stage (p < 0.0001, p < 0.0001, respectively). MATERIALS AND METHODS: Records of 546 stage I-III invasive breast cancer patients, including 344 estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative, 110 HER2-positive, and 92 triple-negative cases, treated at four institutions were reviewed retrospectively. Harmonized primary tumor and nodal maximum SUVmax, metabolic tumor volume (MTV), and TLG indicated in pretreatment FDG-PET/CT results were analyzed. Evaluations of relationships of clinicopathological factors, volume-based quantitative parameters, recurrence-free survival (RFS), and overall survival (OS) for each subtype were performed with a Cox proportional hazards model and log-rank test. CONCLUSIONS: The results indicated that potential surrogate markers for prognosis in patients with the three main subtypes of operable breast cancer include harmonized pretreatment quantitative volume-based FDG-PET/CT parameters, particularly whole-lesion SUVmax and TLG.

Factors Associated with Prolonged Retroperitoneal Laparoscopic Radical Nephrectomy Performed by Non-expert Surgeons.

BACKGROUND: High body mass index (BMI) and visceral obesity were reported to be associated with prolonged transperitoneal laparoscopic radical nephrectomy (LRN); however, factors that prolong retroperitoneal LRN remain unknown. We therefore investigated factors associated with prolonged retroperitoneal LRN performed by non-expert surgeons. METHODS: We defined non-experts surgeons as surgeons not certified to perform laparoscopic surgery by the Japanese Society of Endourology. We retrospectively reviewed the medical records of 59 consecutive patients with renal cell carcinoma treated with retroperitoneal LRN performed by non-experts at our hospital between 2014 and 2019. Associations of surgical duration with age, sex, BMI, visceral fat area (VFA), subcutaneous fat area (SFA), laterality and location of the tumor, length of the major tumor axis (tumor length), clinical T stage, ipsilateral adrenalectomy and specimen weight were analyzed using Spearman rank correlation coefficients. RESULTS: Surgical duration positively correlated with ipsilateral adrenalectomy (rs = 0.3162, p = 0.0147) and specimen weight (rs = 0.3103, p = 0.0168) but not with BMI (rs = 0.2016, p = 0.1257) or VFA (rs = 0.0185, p = 0.8894). CONCLUSIONS: Ipsilateral adrenalectomy and specimen weight were associated with prolonged retroperitoneal LRN, when performed by non-expert surgeons.

Harmonized pretreatment quantitative volume-based 18F-FDG PET/CT parameters for stage IV breast cancer prognosis. Multicenter study in Japan.

OBJECTIVE: The prognostic value of harmonized pretreatment volume-based quantitative fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) parameters in metastatic breast cancer patients was investigated. SUBJECTS AND METHODS: Records of 65 stage IV breast cancer patients, including 29 estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative, 23 HER2-positive, and 13 triple-negative cases, from four different institutions were retrospectively reviewed. Harmonized standardized uptake value (SUVmax) of the primary tumor (pSUVmax), highest SUVmax of all malignant lesions (wSUVmax), whole-body metabolic tumor volume (WB MTV), and whole-body total lesion glycolysis (WB TLG) shown by pretreatment 18F-FDG PET/CT imaging were calculated. Cox proportional hazards model and log-rank test results were used to evaluate relationships among clinicopathological factors, volume-based quantitative 18F-FDG PET/CT parameters, progression-free survival, and overall survival (OS). RESULTS: Disease progression occurred in 54 patients and 28 died during a median follow-up period of 52.5 months (range 2.6-133.6 months). Univariate analysis of all cases showed associations of negative ER and progesterone receptor (PR) status (P=0.0025), and high T/N stage (P=0.037/P=0.019), pSUVmax (P=0.049), WB MTV (P=0.021), and WB TLG (P=0.0010) with significantly shorter OS. Multivariate analysis confirmed negative ER and PR status (hazard ratio [HR]: 6.42, 95% confidence interval [CI]: 2.27-19.38; P=0.0054), high T stage (HR: 5.10, 95% CI:1.96-18.61, P=0.0064) and WB TLG (HR: 4.69, 95% CI:1.67-12.79, P=0.049) as independent negative OS predictors. In two groups of ER-positive/HER2-negative and triple-negative, WB TLG had a significant association with death (P=0.021 and P=0.037, respectively) on univariate analysis. In a HER2-positive group, no independent negative OS predictors were observed. CONCLUSION: In metastatic breast cancer patients, harmonized pretreatment quantitative volume-based 18F-FDG PET/CT parameters, especially whole-body TLG, are potential surrogate markers for prognosis.