Influence of coronary stenosis location on diagnostic performance of machine learning-based fractional flow reserve from CT angiography

BackgroundCompared with invasive fractional flow reserve (FFR), coronary CT angiography (cCTA) is limited in detecting hemodynamically relevant lesions. cCTA-based FFR (CT-FFR) is an approach to overcome this insufficiency by use of computational fluid dynamics. Applying recent innovations in computer science, a machine learning (ML) method for CT-FFR derivation was introduced and showed improved diagnostic performance compared to cCTA alone. We sought to investigate the influence of stenosis location in the coronary artery system on the performance of ML-CT-FFR in a large, multicenter cohort.MethodsThree hundred and thirty patients (75.2% male, median age 63 years) with 502 coronary artery stenoses were included in this substudy of the MACHINE (Machine Learning Based CT Angiography Derived FFR: A Multi-Center Registry) registry. Correlation of ML-CT-FFR with the invasive reference standard FFR was assessed and pooled diagnostic performance of ML-CT-FFR and cCTA was determined separately for the following stenosis locations: RCA, LAD, LCX, proximal, middle, and distal vessel segments.ResultsML-CT-FFR correlated well with invasive FFR across the different stenosis locations. Per-lesion analysis revealed improved diagnostic accuracy of ML-CT-FFR compared with conventional cCTA for stenoses in the RCA (71.8% [95% confidence interval, 63.0%–79.5%] vs. 54.8% [45.7%–63.8%]), LAD (79.3 [73.9–84.0] vs. 59.6 [53.5–65.6]), LCX (84.1 [76.0–90.3] vs. 63.7 [54.1–72.6]), proximal (81.5 [74.6–87.1] vs. 63.8 [55.9–71.2]), middle (81.2 [75.7–85.9] vs. 59.4 [53.0–65.6]) and distal stenosis location (67.4 [57.0–76.6] vs. 51.6 [41.1–62.0]).ConclusionIn a multicenter cohort with high disease prevalence, ML-CT-FFR offered improved diagnostic performance over cCTA for detecting hemodynamically relevant stenoses regardless of their location.     

Thinned-out skin paddle versus collagen matrix as an optimized peri-implant soft tissue following fibula osteoseptocutaneous free flap: 3-year retrospective study

The objective of this study was to compare the implant longevity following two methods of peri-implant soft tissue optimization following free fibula flap (FFF): thinning of skin paddle (SP) and collagen matrix (CM). All patients who underwent rehabilitation with dental implants after mandibular reconstruction with FFF between June 2009 to May 2014 were retrospectively reviewed. Two methods of peri-implant soft tissue optimization were applied: (1) SP group, (2) CM group. Outcome measurements were: modified plaque index (mPI), modified sulcus bleeding index (mSBI), probing depth (PD), marginal bone loss (MBL), implant success rate and complication rates. A total of 24 patients with 69 implants were included in the study, with 8.7% (n = 6) of implants lost in 3 years. No statistically significant difference was found regarding the outcome measurements in both groups. Failed implants presented with statistically significant higher mPI, mSBI, PD and MBL scores during prosthesis delivery and subsequent follow-ups (P<0.03). In the SP group, one patient experienced SP necrosis which later underwent soft tissue optimization using CM. CM is an alternative peri-implant soft tissue, while thinning of SP is feasible if thickness is well controlled.     

液晶数字显示角度仪在全髋关节置换术中的应用价值

目的:探讨在全髋关节置换术中使用液晶数字显示角度仪控制前倾角的应用价值。方法:回顾分析自2018年1月至2019年12月83例行初次全髋关节置换术的患者,其中男28例,女55例;年龄42~81(70.4±7.9)岁。股骨颈骨折63例,股骨头缺血性坏死20例。所有患者术中使用液晶数显角度仪控制髋臼杯假体的前倾角,术后采用CT扫描,测量髋臼杯的前倾角,两者进行比较,了解使用液晶数显角度仪的准确性。结果:术后CT测量提示患者的髋臼前倾角均位于Lewinnek提倡的安全区内,术中使用液晶数显角度仪测量髋臼杯的前倾角度中位数为14.20°(12.80~15.40)°,术后CT扫描测量的髋臼杯的前倾角中位数为14.20°(13.40~15.50)°,两者比较差异无统计学意义(Z=-1.725,P=0.085)。结论:应用液晶数显角仪器对术中控制髋臼杯的前倾角是一种准确可靠的方法,具有良好的辅助参考价值。     

青年人群近距离工作后眼部参数的变化及恢复时间

目的：观察青年人群近距离用眼后眼部生理及功能性参数的变化及恢复时间。

方法：前瞻性研究。随机选取2019-12/2020-06在我院进行医学验光的患者69例138眼，根据主觉验光结果分为正视组(+0.75D≤等效球镜度≤-0.50D，18例36眼)、低度近视组(-0.75D≤等效球镜度≤-3.00D，25例50眼)和中度近视组(-3.25D≤等效球镜度≤-6.00D，26例52眼)。所有受试者近距离阅读20min后远眺放松20min，分别于近距离用眼前、近距离用眼20min后、远眺5、10、15、20min时测量受试者眼部生理性参数\〖前房深度(ACD)、眼轴长度(AL)\〗和功能性参数\〖正相对调节(PRA)、调节反应(BCC)\〗，分析各参数的达极时间和恢复时间。

结果：近距离用眼后眼轴变长，前房变浅，PRA绝对值变大，BCC无明显变化，75%(52/69)的受试者AL在近距离用眼20min后达极，87%(60/69)的受试者ACD在远眺5min时达极，96%(66/69)的受试者PRA在近距离用眼20min后达极，且以上参数均在远眺10min后逐渐恢复至初始状态。

结论：近距离用眼后眼部参数发生改变，眼轴变长，前房变浅，PRA绝对值增大，但均在远眺放松过程中逐渐回退，且均需要10min以上才能恢复至初始状态。