Advanced zoomed diffusion-weighted imaging vs. full-field-of-view diffusion-weighted imaging in prostate cancer detection: a radiomic features study.

OBJECTIVES: We aimed to compare the efficiency of prostate cancer (PCa) detection using a radiomics signature based on advanced zoomed diffusion-weighted imaging and conventional full-field-of-view DWI. METHODS: A total of 136 patients, including 73 patients with PCa and 63 without PCa, underwent multi-parametric magnetic resonance imaging (mp-MRI). Radiomic features were extracted from prostate lesion areas segmented on full-field-of-view DWI with b-value = 1500 s/mm2 (f-DWIb1500), advanced zoomed DWI images with b-value = 1500 s/mm2 (z-DWIb1500), calculated zoomed DWI with b-value = 2000 s/mm2 (z-calDWIb2000), and apparent diffusion coefficient (ADC) maps derived from both sequences (f-ADC and z-ADC). Single-imaging modality radiomics signature, mp-MRI radiomics signature, and a mixed model based on mp-MRI and clinically independent risk factors were built to predict PCa probability. The diagnostic efficacy and the potential net benefits of each model were evaluated. RESULTS: Both z-DWIb1500 and z-calDWIb2000 had significantly better predictive performance than f-DWIb1500 (z-DWIb1500 vs. f-DWIb1500: p = 0.048; z-calDWIb2000 vs. f-DWIb1500: p = 0.014). z-ADC had a slightly higher area under the curve (AUC) value compared with f-ADC value but was not significantly different (p = 0.127). For predicting the presence of PCa, the AUCs of clinical independent risk factors model, mp-MRI model, and mixed model were 0.81, 0.93, and 0.94 in training sets, and 0.74, 0.92, and 0.93 in validation sets, respectively. CONCLUSION: Radiomics signatures based on the z-DWI technology had better diagnostic accuracy for PCa than that based on the f-DWI technology. The mixed model was better at diagnosing PCa and guiding clinical interventions for patients with suspected PCa compared with mp-MRI signatures and clinically independent risk factors. KEY POINTS: • Advanced zoomed DWI technology can improve the diagnostic accuracy of radiomics signatures for PCa. • Radiomics signatures based on z-calDWIb2000 have the best diagnostic performance among individual imaging modalities. • Compared with the independent clinical risk factors and the mp-MRI model, the mixed model has the best diagnostic efficiency.

Evaluation of Quiescent-Interval Single-Shot Magnetic Resonance Angiography in Diabetic Patients With Critical Limb Ischemia Undergoing Digital Subtraction Angiography: Comparison With Contrast-Enhanced Magnetic Resonance Angiography With Calf Compression at 3.0 Tesla.

PURPOSE: To assess the diagnostic performance of quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) at 3 tesla in diabetic patients with critical limb ischemia (CLI) vs contrast-enhanced MR angiography (CE-MRA) using digital subtraction angiography (DSA) as the standard of reference. METHOD: Thirty-seven consecutive diabetic patients (mean age 71.8±7.2 years; 30 men) with CLI (Fontaine stage III-IV) underwent QISS-MRA and CE-MRA with calf compression; DSA was the standard. Image quality (5-point Likert-type scale) and stenosis severity (5-point grading) for QISS-MRA and CE-MRA were evaluated by 2 blinded readers in 1147 and 654 vessel segments, respectively. Per-segment and per-region (pelvis, thigh, calf) sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS: Image quality of QISS-MRA was lower compared with CE-MRA in the pelvic region (p<0.001 in both readers) and thigh region (p=0.033 in reader 1 and p=0.018 in reader 2), whereas in the calf region, the image quality of QISS-MRA was better than CE-MRA (p=0.009 in reader 1 and p=0.001 in reader 2). In segment-based analyses, there was no difference between QISS-MRA and CE-MRA in sensitivity [89.5% vs 90.3% in reader 1 (p=0.774) and 87.6% vs 90.6% in reader 2 (p=0.266)] or specificity [94.2% vs 92.9% in reader 1 (p=0.513) and 92.9% vs 92.9% in reader 2 (p>0.999)]. In region-based analyses, QISS-MRA and CE-MRA yielded similar sensitivity and specificity in all areas but the pelvic region for reader 2 (specificity 95.5% vs 84.8%, p=0.041). CONCLUSION: QISS-MRA performed very well in diabetic patients with CLI and was a good alternative for patients with contraindications to CE-MRA.

Morphological characteristics of chronic total occlusion: predictors of different strategies for long-segment femoral arterial occlusions.

OBJECTIVES: To investigate morphological characteristics used to predict recanalisation strategies in long-segment (>10 cm) femoral chronic total occlusion (LSF-CTO) angioplasty. METHODS: We retrospectively evaluated a range of morphological CTA and DSA features in patients who underwent recanalisation of LSF-CTO. The stage of CTO was classified into early (3-12 months) and late (>12 months) according to estimated duration. Characteristics including stump morphology, lesion length and calcification, proximal side branches, collaterals circulation, runoff vessels and concomitant arterial occlusion were used as predictors, and multivariate logistic regression analysis was performed to identify variables associated with late-stage CTO and retrograde technique. RESULTS: A total of 119 patients with 137 CTOs in 137 limbs were enrolled. Overall, successful recanalisation was achieved in 122 CTOs (89.1%). Flush occlusion [odds ratio (OR) 2.958; 95% confidence interval (CI) 1.172-7.465; p = 0.022], large collateral (OR 2.778; 95% CI 1.201-6.427; p = 0.017) and TransAtlantic Inter-Society Consensus II class D (TASC D) lesion (OR 1.743; 95% CI 1.019-2.981; p = 0.042) were predictors for late-stage CTO. Flush occlusion (OR 75.278; 95% CI 10.664-531.384; p < 0.001) and large collateral (OR 23.213; 95% CI 3.236-166.523; p = 0.002) were associated with high likelihood for retrograde approach. CONCLUSIONS: Flush occlusion and large collateral were associated with a CTO at late-stage which may require retrograde recanalisation. KEY POINTS: • CTO morphological characteristics help estimate lesion duration and optimise recanalisation strategies. • Flush occlusion and large collateral is associated with late-stage CTO and retrograde recanalisation. • Application of anterograde and retrograde recanalisation for long-segment femoral CTO is effective.

Correction to: Morphological characteristics of chronic total occlusion: predictors of different strategies for long-segment femoral arterial occlusions.

The original version of this article unfortunately contained mistakes. The legends to Figs. 2-4 were incorrectly interchanged. The correct versions are given below. The original article has been corrected.

String-like lumen in below-the-knee chronic total occlusions on contrast-enhanced magnetic resonance angiography predicts intraluminal recanalization and better blood flow restoration.

OBJECTIVES: To determine whether string-like lumina (SLs) on contrast-enhanced magnetic resonance angiography (CE-MRA) predict better outcomes in diabetic patients with below-the-knee (BTK) chronic total occlusions (CTOs). METHODS: This study involved 317 long-segment (>5 cm) BTK CTOs of 245 patients that were examined using CE-MRA and treated using endovascular angioplasty. An SL with a CTO was slowly filled with blood on conventional CE-MRA. Univariate and multivariate analyses were performed to identify predictors of procedural success, recanalisation method and immediate blood flow restoration. The target-lesion patency and limb-salvage rates were assessed. RESULTS: SL-positive CTOs (n = 60) achieved a higher technique success rate, preferred intraluminal angioplasty and better blood flow restoration than SL-negative CTOs (n = 257, P < 0.05). Multivariate analyses revealed that lesion length was the independent predictor of procedural success (P = 0.028). SL was a predictor of intraluminal angioplasty (P < 0.001) and good blood-flow restoration (P = 0.004). Kaplan-Meier analyses at 12 months revealed a higher target lesion patency rate (P = 0.04) and limb-salvage rate (P = 0.35) in SL-positive CTOs. CONCLUSIONS: In patients with BTK CTOs, SL predicted intraluminal angioplasty and good blood-flow restoration for BTK CTOs. KEY POINTS: • Intraluminal recanalisation was more frequently used for BTK-CTOs with SLs than without • CTO length was the only independent predictor of successful CTO recanalisation • SL was the only predictor of intraluminal angioplasty for BTK-CTOs • SL and CTO length were predictors of good blood-flow restoration after recanalisation • Restenosis-free and limb-salvage rates were better for SL-positive CTOs than SL-negative CTOs.

Rendezvous technique for recanalization of long-segmental chronic total occlusion above the knee following unsuccessful standard angioplasty.

PURPOSE: To assess the technical feasibility and efficacy of the rendezvous technique, a type of subintimal retrograde wiring, for the treatment of long-segmental chronic total occlusions above the knee following unsuccessful standard angioplasty. METHODS: The rendezvous technique was attempted in eight limbs of eight patients with chronic total occlusions above the knee after standard angioplasty failed. The clinical symptoms and ankle-brachial index were compared before and after the procedure. At follow-up, pain relief, wound healing, limb salvage, and the presence of restenosis of the target vessels were evaluated. RESULTS: The rendezvous technique was performed successfully in seven patients (87.5%) and failed in one patient (12.5%). Foot pain improved in all seven patients who underwent successful treatment, with ankle-brachial indexes improving from 0.23 ± 0.13 before to 0.71 ± 0.09 after the procedure (P < 0.001). At the end of the follow-up period, the visual analogue scale improved from 6.86 ± 1.57 to 1.57 ± 1.27 (P < 0.001). Non-healing ulcers in three patients either healed (n = 2) or improved (n = 1). No major amputation was necessary. Kaplan-Meier analyses revealed that stenosis-free rate was 83.3% at six months and 41.7% at 12 months. CONCLUSION: The rendezvous technique is a feasible and effective treatment for chronic total occlusions above the knee when standard angioplasty fails.

Runoff detected by magnetic resonance angiography as an indicator for better recanalization outcomes in below-the-knee chronic total occlusions in diabetic patients.

PURPOSE: To compare the feasibility and efficacy of recanalizing below-the-knee (BTK) chronic total occlusions (CTOs) between patients with good or poor distal runoff based on magnetic resonance angiography (MRA) scans. METHODS: Two hundred long-segment BTK CTOs in 171 limbs of 113 diabetic patients (58 men; mean age 69.8±1.9 years) were divided into good distal runoff (GDR: 119 lesions, 98 limbs) or poor distal runoff groups (PDR: 81 lesions, 73 limbs) based on baseline MRA findings. After angioplasty, modified thrombolysis in myocardial ischemia (mTIMI) grades and ankle-brachial index (ABI) were used to assess immediate outcomes. Regularly scheduled duplex or MRA imaging was performed in follow-up. The restenosis and limb salvage rates were compared. RESULTS: The success rates were 93.3% and 87.7% in the GDR and PDR groups, respectively (p=0.21); subintimal angioplasty was more common in the PDR group (93.0% vs. 63.1%, p<0.01). Completion angiography indicated an mTIMI grade 3 blood flow in 71.2% lesions in the GDR patients and in 52.1% in the PDR (p=0.01) group. Improvement in the ABI was greater in the GDR limbs (p<0.001 vs. PDR). Mean imaging follow-up was 10.8±6.9 months in the GDR group and 11.1±6.6 months in the PDR group. Kaplan-Meier analysis showed a better restenosis-free rate in the GDR group (80.6% vs. 61.7%; p=0.02) at 12 months and for lesions with mTIMI grade 3 flow (p<0.01). At 24 months, Kaplan-Meier analysis revealed a better limb salvage rate in the GDR group (84.2% vs. 54.6%; p=0.02). CONCLUSION: Distal runoff detected using MRA could be a predictor for successful intraluminal recanalization, better distal tissue perfusion, improved long-term patency, and better limb salvage for patients with BTK CTOs.

Patency of runoff detected by MR angiography at 3.0 T with cuff-compression: a predictor of successful endovascular recanalization below the knee.

OBJECTIVES: Our aim was to assess the reliability of detecting distal runoff vessels using contrast-enhanced MR angiography (CE-MRA) that were occult on digital subtraction angiography (DSA) for predicting the outcome of endovascular recanalization (ER). METHODS: This retrospective analysis comprised 63 patients with diabetes (98 limbs) who underwent ER for infrapopliteal lesions. Before ER, they underwent CE-MRA and DSA for peripheral arterial disease; runoff vessels were detected with CE-MRA, but not with DSA. Immediate and follow-up postoperative outcomes were assessed. Univariate analysis was performed to identify variables associated with successful ER. RESULTS: Successful ER was achieved in 85.7 % of limbs, and runoff score was significantly lower than in failure limbs (5.1 ± 1.1 vs. 6.2 ± 1.3; P < 0.05). During follow-up, sustained ankle-brachial index (ABI) improvement was found in 76.6 % claudication patients, and walking distance improvement in 86.5 %; pain was relieved in 70.6 % of critical limb ischemia (CLI) limbs, ulceration healed in 81.3 %, and limb-salvage rate was 100 %. Restenosis/occlusion rate was higher for patients with CLI at 12 months (48.8 % vs. 96.3 % in claudication; P < 0.01). Runoff score was associated with a significantly higher likelihood of ER success (odds ratio = 4.096, 95 % confidence interval: 2.056-8.158; P < 0.001). CONCLUSION: Runoff vessels detected using CE-MRA could indicate immediate success and better outcome of ER for infrapopliteal occlusions. KEY POINTS: • 3-T MRA with cuff compression displayed distal below-the-knee (BTK) runoffs better than DSA • Detected runoffs indicate high recanalization rate and good clinical outcome • Runoff display provides potential opportunity to perform other backup recanalization strategies.

Outcomes of antiplatelet therapy for haemorrhage patients after thrombolysis: a prospective study based on susceptibility-weighted imaging.

PURPOSE: The authors evaluated the effect of susceptibility-weighted imaging (SWI) for antiplatelet therapy on post-thrombolysis microbleeds (MB). MATERIALS AND METHODS: A total of 146 patients without symptomatic intracranial haemorrhage on computed tomography after thrombolysis were allocated to two groups: group A (n = 72) received antiplatelets 24 h after recombinant tissue plasminogen activator, regardless of SWI-detected haemorrhage; group B (n = 74) received antiplatelets for patients without SWI-visualised haemorrhage. RESULTS: Haemorrhage was detected by SWI in 22 and 28 patients in groups A and B, respectively. The difference in mean NIHSS (National Institutes of Health Stroke Scale) score in group A between baseline and 6, 24 h, 7, 14 days was -1.6, -1.7, -3.6, -5.9, respectively; in group B, the difference in mean NIHSS score between baseline and 6, 24 h, 7, 14 days was -2.6, -3.3, -5.4, -8.7, respectively. The difference between groups in reduction of mean NIHSS score from baseline was 1.0 (p < 0.001) at 6 h, 1.6 (p < 0.001) at 24 h, 1.8 (p = 0.001) at 7 days and 2.8 (p < 0.001) at 14 days. NIHSS scores at 7, 14 days and modified Rankin scale at 90 days were significantly lower in haemorrhage patients in groups B than in A, whereas the hospital stay was shorter and the rate of favourable outcome at 90 days was higher. CONCLUSION: Our results indicated that SWI was an effective approach for the guidance of antiplatelet therapy in post-thrombolysis MB.

Automated deep-learning system in the assessment of MRI-visible prostate cancer: comparison of advanced zoomed diffusion-weighted imaging and conventional technique.

BACKGROUND: Deep-learning-based computer-aided diagnosis (DL-CAD) systems using MRI for prostate cancer (PCa) detection have demonstrated good performance. Nevertheless, DL-CAD systems are vulnerable to high heterogeneities in DWI, which can interfere with DL-CAD assessments and impair performance. This study aims to compare PCa detection of DL-CAD between zoomed-field-of-view echo-planar DWI (z-DWI) and full-field-of-view DWI (f-DWI) and find the risk factors affecting DL-CAD diagnostic efficiency. METHODS: This retrospective study enrolled 354 consecutive participants who underwent MRI including T2WI, f-DWI, and z-DWI because of clinically suspected PCa. A DL-CAD was used to compare the performance of f-DWI and z-DWI both on a patient level and lesion level. We used the area under the curve (AUC) of receiver operating characteristics analysis and alternative free-response receiver operating characteristics analysis to compare the performances of DL-CAD using f- DWI and z-DWI. The risk factors affecting the DL-CAD were analyzed using logistic regression analyses. P values less than 0.05 were considered statistically significant. RESULTS: DL-CAD with z-DWI had a significantly better overall accuracy than that with f-DWI both on patient level and lesion level (AUCpatient: 0.89 vs. 0.86; AUClesion: 0.86 vs. 0.76; P < .001). The contrast-to-noise ratio (CNR) of lesions in DWI was an independent risk factor of false positives (odds ratio [OR] = 1.12; P < .001). Rectal susceptibility artifacts, lesion diameter, and apparent diffusion coefficients (ADC) were independent risk factors of both false positives (ORrectal susceptibility artifact = 5.46; ORdiameter, = 1.12; ORADC = 0.998; all P < .001) and false negatives (ORrectal susceptibility artifact = 3.31; ORdiameter = 0.82; ORADC = 1.007; all P ≤ .03) of DL-CAD. CONCLUSIONS: Z-DWI has potential to improve the detection performance of a prostate MRI based DL-CAD. TRIAL REGISTRATION: ChiCTR, NO. ChiCTR2100041834 . Registered 7 January 2021.

Glutamate level detection by magnetic resonance spectroscopy in patients with post-stroke depression.

In recent studies, the glutamate (Glu) level has been quantified using the modified STEAM sequence on 3T MRI. We enrolled 15 healthy volunteers and a group of 51 patients who experienced stroke for the first time and had a good prognosis. The patients with infarction were divided into three groups according to their scores by using the DSM-IV diagnostic criteria for major depressive disorder and the 17-item Hamilton Depression Rating Scale (HDRS). We studied the association between post-stroke depression and (1)H-MRS measurements in unaffected frontal lobes. Single-voxel proton magnetic resonance spectroscopy ((1)H-MRS) was performed to assess N-acetylaspartate/creatine (NAA)/Cr, (Glu)/Cr, choline (Cho)/Cr, and myoinositol (mI)/Cr ratios in stroke patients. The 11 patients (21.5%) who met the criteria for depression and 9 patients (17.6%) who had a high score for HDRS, (>14) but were not depressed, had a significantly higher Glu/Cr ratio than patients who scored ≤14 on HDRS and control groups (p < 0.001). No differences were found in NAA/Cr, Cho/Cr, or mI/Cr between the groups after stroke. These findings suggest that post-stroke depression is accompanied by changes in glutamate levels in the frontal lobe.

Thin-slab maximum intensity projection of CT angiography for collateral score and clot burden score evaluation: comparison with conventional CT angiography.

BACKGROUND: This study aimed to exam the effects of thin-slab maximum intensity projection (TS-MIP) of computed tomography angiography (CTA) for collateral score (CS) and clot burden score (CBS) evaluation in patients with large-vessel-occlusion (LVO) stroke in the anterior circulation. METHODS: Of 241 consecutive patients with LVO stroke admitted to our center between August 2015 and June 2020, 187 patients were enrolled. CS and CBS were evaluated on conventional CTA and TS-MIP separately. Outcome at 90 days was classified as good if modified Rankin scale (mRS) was ≤2 and as poor if mRS was >2. The correlations between CS and CBS and clinical outcomes were assessed. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic values of CS and CBS. Multivariate logistic regression analysis was performed to identify the independent predictors of 90-day good clinical outcomes. RESULTS: The correlation coefficient for clinical outcomes was significantly better for CS based on TS-MIP than that based on conventional CTA (-0.444 vs. -0.285, P=0.039); no significant difference was found in the CBS evaluation (TS-MIP: -0.356 vs. conventional CTA: -0.320, P=0.348). For predicting good clinical outcomes, TS-MIP-based CS was associated with larger area under the curve (AUC) (0.709 vs. 0.609, P=0.004) and higher sensitivity (69.1% vs. 42.0%, P=0.001) than CS based on CTA. In multivariable logistic regression analysis, the factors independently associated with good outcomes were National Institutes of Health Stroke Scale (NIHSS) score at admission (OR =1.147; P<0.001), TS-MIP-based CS (OR =0.326; P<0.001), final modified treatment in cerebral infarction (mTICI) score of 2b/3 (OR =0.098; P<0.001), and hemorrhagic transformation (OR =3.662; P<0.001). CONCLUSIONS: TS-MIP-CTA is superior to conventional CTA for evaluation CS and CBS, and TS-MIP-based CS may be a useful predictor of clinical outcome.

Adversarial training for prostate cancer classification using magnetic resonance imaging.

Background: To use adversarial training to increase the generalizability and diagnostic accuracy of deep learning models for prostate cancer diagnosis. Methods: This multicenter study retrospectively included 396 prostate cancer patients who underwent magnetic resonance imaging (development set, 297 patients from Shanghai Jiao Tong University Affiliated Sixth People's Hospital and Eighth People's Hospital; test set, 99 patients from Renmin Hospital of Wuhan University). Two binary classification deep learning models for clinically significant prostate cancer classification [PM1, pretraining Visual Geometry Group network (VGGNet)-16-based model 1; PM2, pretraining residual network (ResNet)-50-based model 2] and two multiclass classification deep learning models for prostate cancer grading (PM3, pretraining VGGNet-16-based model 3; PM4: pretraining ResNet-50-based model 4) were built using apparent diffusion coefficient and T2-weighted images. These models were then retrained with adversarial examples starting from the initial random model parameters (AM1, adversarial training VGGNet-16 model 1; AM2, adversarial training ResNet-50 model 2; AM3, adversarial training VGGNet-16 model 3; AM4, adversarial training ResNet-50 model 4, respectively). To verify whether adversarial training can improve the diagnostic model's effectiveness, we compared the diagnostic performance of the deep learning methods before and after adversarial training. Receiver operating characteristic curve analysis was performed to evaluate significant prostate cancer classification models. Differences in areas under the curve (AUCs) were compared using Delong's tests. The quadratic weighted kappa score was used to verify the PCa grading models. Results: AM1 and AM2 had significantly higher AUCs than PM1 and PM2 in the internal validation dataset (0.84 vs. 0.89 and 0.83 vs. 0.87) and test dataset (0.73 vs. 0.86 and 0.72 vs. 0.82). AM3 and AM4 showed higher κ values than PM3 and PM4 in the internal validation dataset {0.266 [95% confidence interval (CI): 0.152-0.379] vs. 0.292 (95% CI: 0.178-0.405) and 0.254 (95% CI: 0.159-0.390) vs. 0.279 (95% CI: 0.163-0.396)} and test set [0.196 (95% CI: 0.029-0.362) vs. 0.268 (95% CI: 0.109-0.427) and 0.183 (95% CI: 0.015-0.351) vs. 0.228 (95% CI: 0.068-0.389)]. Conclusions: Using adversarial examples to train prostate cancer classification deep learning models can improve their generalizability and classification abilities.

Application of the newly developed stents in the treatment of benign cardia stricture: an experimental comparative study.

BACKGROUND: Retrievable temporary stent placement has recently been suggested as a potential treatment for benign esophageal stricture. OBJECTIVE: To assess the efficacy of a newly designed cardia stent for the treatment of benign cardia stricture in a canine model compared with groups that received pneumatic dilation or standard esophageal stent insertion. DESIGN: Basic experimental study. SETTING: GI interventional center. PATIENTS: Forty-eight dog models were randomly divided into a control group (no stent insertion) (n=12), a pneumatic dilation group (PDG) (n=12), a standard esophageal stent group (SESG) (n=12), and a novel cardia stent group (NCSG) (n=12). INTERVENTIONS: Pneumatic dilation, standard esophagus stent, cardia stent. MAIN OUTCOME MEASUREMENTS: Lower esophageal sphincter pressures and the 5-minute barium height were assessed before and immediately after the procedure, after 1 week, and at 1-, 3-, and 6-month follow-up. Three dogs in each group were killed for histological examination. RESULTS: Stent insertion was tolerated by all dogs, with a lower migration rate in the NCSG (0% vs 41.7% in the SESG; P=.0373). At the 6-month follow-up, the lower esophageal sphincter pressure and 5-minute barium height values in the NCSG were still stable compared with those in the PDG and SESG (P<.05). Immunohistochemistry for mouse anti-proliferating cell nuclear antigen and α-smooth muscle actin revealed a stronger inflammatory reaction peak in the PDG than in the SESG and NCSG (P<.05). Collagen proliferation was most severe after 6 months in the PDG (P<.05). LIMITATIONS: Longer follow-up studies are required to assess whether the recurrence rate is lower because of less inflammation and scarring. CONCLUSIONS: The novel cardia stent was more effective than pneumatic dilation or a standard stent in this canine model.

Batroxobin plus aspirin reduces restenosis after angioplasty for arterial occlusive disease in diabetic patients with lower-limb ischemia.

PURPOSE: Aspirin is routinely given to reduce vascular events after angioplasty. Batroxobin has been shown to effectively prevent thrombosis after angioplasty via inhibition of the fibrinogen concentration. In this randomized clinical trial, the hypothesis that batroxobin plus aspirin is more effective than aspirin alone in reducing the incidence of restenosis/reocclusion in patients with diabetes undergoing angioplasty for lower-limb ischemia. MATERIALS AND METHODS: Patients with diabetes and symptomatic arterial obstructions (N = 129) were randomized to receive aspirin 100 mg/d plus batroxobin 5 IU every other day for six doses (n = 58) or aspirin alone (n = 71). The primary outcome was restenosis documented by magnetic resonance (MR) angiography or duplex imaging at 12 months. Secondary outcomes included amputation above the ankle, death, and cumulative rate of amputation or death. Kaplan-Meier analysis was used to evaluate limb salvage and survival rates. RESULTS: After 12 months, restenosis had occurred in 43.1% and 29.7% of patients in the control and batroxobin groups, respectively (P = .0018). MR angiography and duplex imaging revealed an improved restenosis rate for infrapopliteal lesions and for lesions longer than 10 cm (P = .0016). The primary and cumulative secondary outcomes indicated significant improvements in restenosis rate, symptom relief, and amputation rates in the batroxobin group compared with the aspirin-only group. Kaplan-Meier analysis showed limb salvage and survival rates of 78.3% in the aspirin-only group and 92.2% in the batroxobin group 12 months after angioplasty (log-rank test, P = .0414). CONCLUSIONS: Batroxobin plus aspirin reduced the rate of restenosis after arterial angioplasty, particularly in lesions located below the knee and in those longer than 10 cm, with better clinical symptom relief and improved rate of limb salvage.

Calculation of Apparent Diffusion Coefficients in Prostate Cancer Using Deep Learning Algorithms: A Pilot Study.

BACKGROUND: Apparent diffusion coefficients (ADCs) obtained with diffusion-weighted imaging (DWI) are highly valuable for the detection and staging of prostate cancer and for assessing the response to treatment. However, DWI suffers from significant anatomic distortions and susceptibility artifacts, resulting in reduced accuracy and reproducibility of the ADC calculations. The current methods for improving the DWI quality are heavily dependent on software, hardware, and additional scan time. Therefore, their clinical application is limited. An accelerated ADC generation method that maintains calculation accuracy and repeatability without heavy dependence on magnetic resonance imaging scanners is of great clinical value. OBJECTIVES: We aimed to establish and evaluate a supervised learning framework for synthesizing ADC images using generative adversarial networks. METHODS: This prospective study included 200 patients with suspected prostate cancer (training set: 150 patients; test set #1: 50 patients) and 10 healthy volunteers (test set #2) who underwent both full field-of-view (FOV) diffusion-weighted imaging (f-DWI) and zoomed-FOV DWI (z-DWI) with b-values of 50, 1,000, and 1,500 s/mm2. ADC values based on f-DWI and z-DWI (f-ADC and z-ADC) were calculated. Herein we propose an ADC synthesis method based on generative adversarial networks that uses f-DWI with a single b-value to generate synthesized ADC (s-ADC) values using z-ADC as a reference. The image quality of the s-ADC sets was evaluated using the peak signal-to-noise ratio (PSNR), root mean squared error (RMSE), structural similarity (SSIM), and feature similarity (FSIM). The distortions of each ADC set were evaluated using the T2-weighted image reference. The calculation reproducibility of the different ADC sets was compared using the intraclass correlation coefficient. The tumor detection and classification abilities of each ADC set were evaluated using a receiver operating characteristic curve analysis and a Spearman correlation coefficient. RESULTS: The s-ADCb1000 had a significantly lower RMSE score and higher PSNR, SSIM, and FSIM scores than the s-ADCb50 and s-ADCb1500 (all P < 0.001). Both z-ADC and s-ADCb1000 had less distortion and better quantitative ADC value reproducibility for all the evaluated tissues, and they demonstrated better tumor detection and classification performance than f-ADC. CONCLUSION: The deep learning algorithm might be a feasible method for generating ADC maps, as an alternative to z-ADC maps, without depending on hardware systems and additional scan time requirements.

Synthesizing High-b-Value Diffusion-weighted Imaging of the Prostate Using Generative Adversarial Networks.

PURPOSE: To develop and evaluate a diffusion-weighted imaging (DWI) deep learning framework based on the generative adversarial network (GAN) to generate synthetic high-b-value (b =1500 sec/mm2) DWI (SYNb1500) sets from acquired standard-b-value (b = 800 sec/mm2) DWI (ACQb800) and acquired standard-b-value (b = 1000 sec/mm2) DWI (ACQb1000) sets. MATERIALS AND METHODS: This retrospective multicenter study included 395 patients who underwent prostate multiparametric MRI. This cohort was split into internal training (96 patients) and external testing (299 patients) datasets. To create SYNb1500 sets from ACQb800 and ACQb1000 sets, a deep learning model based on GAN (M0) was developed by using the internal dataset. M0 was trained and compared with a conventional model based on the cycle GAN (Mcyc). M0 was further optimized by using denoising and edge-enhancement techniques (optimized version of the M0 [Opt-M0]). The SYNb1500 sets were synthesized by using the M0 and the Opt-M0 were synthesized by using ACQb800 and ACQb1000 sets from the external testing dataset. For comparison, traditional calculated (b =1500 sec/mm2) DWI (CALb1500) sets were also obtained. Reader ratings for image quality and prostate cancer detection were performed on the acquired high-b-value (b = 1500 sec/mm2) DWI (ACQb1500), CALb1500, and SYNb1500 sets and the SYNb1500 set generated by the Opt-M0 (Opt-SYNb1500). Wilcoxon signed rank tests were used to compare the readers' scores. A multiple-reader multiple-case receiver operating characteristic curve was used to compare the diagnostic utility of each DWI set. RESULTS: When compared with the Mcyc, the M0 yielded a lower mean squared difference and higher mean scores for the peak signal-to-noise ratio, structural similarity, and feature similarity (P < .001 for all). Opt-SYNb1500 resulted in significantly better image quality (P ≤ .001 for all) and a higher mean area under the curve than ACQb1500 and CALb1500 (P ≤ .042 for all). CONCLUSION: A deep learning framework based on GAN is a promising method to synthesize realistic high-b-value DWI sets with good image quality and accuracy in prostate cancer detection.Keywords: Prostate Cancer, Abdomen/GI, Diffusion-weighted Imaging, Deep Learning Framework, High b Value, Generative Adversarial Networks© RSNA, 2021 Supplemental material is available for this article.

Comparative Study on Iron Content Detection by Energy Spectral CT and MRI in MDS Patients.

Objective: The purpose of this study was to identify the difference between dual energy spectral computed tomography (DECT) and magnetic resonance imaging (MRI) used to detect liver/cardiac iron content in Myelodysplastic syndrome (MDS) patients with differently adjusted serum ferritin (ASF) levels. Method: Liver and cardiac iron content were detected by DECT and MRI. Patients were divided into different subgroups according to the level of ASF. The receiver operating characteristic curve (ROC) analysis was applied in each subgroup. The correlation between iron content detected by DECT/MRI and ASF was analyzed in each subgroup. Result: ROC curves showed that liver virtual iron content (LVIC) Az was significantly less than liver iron concentration (LIC) Az in the subgroup with ASF < 1,000 ng/ml. There was no significant difference between LVIC Az and LIC Az in the subgroup with 1,000 ≤ ASF < 2,500 ng/ml and 2,500 ≤ ASF < 5,000 ng/ml. LVIC Az was significantly higher than LIC Az in the subgroup with ASF <5,000 and 5,000 ≤ ASF ng/ml. In patients undergoing DECT and MRI examination on the same day, ASF was significantly correlated with LVIC, whereas no significant correlation was observed between ASF and LIC. After removing the data of ASF > 5,000 mg/L in LIC, LIC became correlated with ASF. There was no significant difference between the subgroup with 2,500 ≤ ASF < 5,000 ng/ml and 5,000 ng/ml ≤ ASF in LIC expression. Furthermore, both LIC and liver VIC had significant correlations with ASF in patients with ASF < 2,500 ng/ml, while LVIC was still correlated with ASF, LIC was not correlated with ASF in patients with 2,500 ng/ml ≤ ASF. Moreover, neither cardiac VIC nor myocardial iron content (MIC) were correlated with ASF in these subgroups. Conclusion: MRI and DECT were complementary to each other in liver iron detection. In MDS patients with high iron content, such as ASF ≥ 5,000 ng/ml, DECT was more reliable than the MRI in the assessment of iron content. But in patients with low iron content, such as ASF < 1,000 ng/ml, MRI is more reliable than DECT. Therefore, for the sake of more accurately evaluating the iron content, the appropriate detection method can be selected according to ASF.

Analysis of the influencing factors related to liver and cardiac iron overload in MDS patients detected by MRI in the real world.

OBJECTIVES: We aim to explore and analyze the related influencing factors of liver and cardiac iron overload in MDS patients detected by magnetic resonance imaging (MRI). METHODS: We have detected cardiac T2* and liver T2* by MRI in 105 MDS patients. Among them, 20 patients accepted MRI examination before and after iron chelation therapy (ICT). Results: We found that adjusted ferritin (ASF) was significantly correlated with liver T2* and cardiac T2*. RBC transfusion volume, brain natriuretic peptide (BNP) and age were the related factors of cardiac T2*, while RBC transfusion volume and erythropoietin (EPO) were related factors of liver T2*. After ICT, the changes of ASF and liver T2* were earlier than cardiac T2*. Chronic hepatitis but virus copy normal's has no significant effect on liver iron deposition. CONCLUSION: These results showed special attention should be paid to these related influencing factors of liver and cardiac T2* expression when we evaluated iron overload and detected the efficacy of ICT in MDS patients.

Retrograde transdorsal-to-plantar or transplantar-to-dorsal intraluminal re-entry following unsuccessful subintimal angioplasty for below-the-ankle arterial occlusion.

PURPOSE: To assess the technical feasibility and efficacy of transdorsal-to-plantar (TDP) or transplantar-to-dorsal (TPD) intraluminal re-entry following unsuccessful subintimal angioplasty for arterial occlusion below the ankle. METHODS: TDP or TPD retrograde intraluminal re-entry angioplasty was attempted in 8 limbs of 8 diabetic patients (5 men; mean age 74.5 ± 7.76 years, range 62-81) with chronic below-the-ankle arterial occlusive disease when standard transtibial subintimal angioplasty failed. The clinical symptoms, dorsal or plantar arterial pulse volume scores, and ankle-brachial indexes (ABI) were compared before and after the procedures. At follow-up, pain relief, wound healing, limb salvage, and the presence of any restenosis of the target vessels were evaluated. RESULTS: TDP or TPD retrograde intraluminal re-entry angioplasty was performed successfully in 5 (62.5%) patients; foot pain improved, with median pulse volume scores and ankle-brachial indexes increasing from 0.60 ± 0.55 and 0.32 ± 0.20 before to 2.40 ± 0.55 and 0.75 ± 0.12, respectively, after the procedure (p<0.01 for both). At the end of follow-up, the visual analogue scale improved from 7.40 ± 1.14 to 2.20 ± 1.48 (p=0.002). Ulcers in 2 of the successfully treated patients either healed (n=1) or improved (n=1). No amputation occurred. Restenosis of 1 target vessel was revealed by magnetic resonance angiography. CONCLUSION: TDP and TPD retrograde intraluminal re-entry techniques are feasible and effective in the treatment of foot ischemia in diabetic patients when standard below-the-ankle angioplasty has failed.