超低剂量CT+1024矩阵+深度学习重建使肺穿刺辐射剂量降低约82%且图像质量具有非劣效性:一项非随机对照试验OA

Objective To address cumulative radiation exposure from repeated scans during CT-guided percutaneous lung biopsy,this study evaluated the impact of low-dose and ultra-low-dose CT combined with a 1024×1024 matrix and deep learning reconstruction algorithms on image quality and radiation dose,investigating the clinical feasibility of this protocol in meeting localization requirements for puncture procedures.Methods In this prospective non-randomized controlled trial,100 consecutive patients undergoing CT-guided thoracic biopsy were enrolled at the Department of Radiology,First Affiliated Hospital of Dalian Medical University,between April and December 2025.Multiple repeated localizations were performed during the procedure.The standard-dose(CD)protocol utilized 120 kV,180 mA,a 512×512 reconstruction matrix,and ClearView reconstruction at 60%strength(CD-CV60 group).Low-dose(LD)protocols employed 120 kV with automatic tube current modulation(O-Dose coefficient 1.0),a 1024×1024 matrix,and ClearInfinity reconstruction at 40%,60%,and 80%strength(LD-CI40,LD-CI60,LD-CI80 groups).Ultra-low-dose(ULD)protocols used 120 kV with automatic tube current modulation(O-Dose coefficient 0.7),a 1024×1024 matrix,and ClearInfinity reconstruction at 40%,60%,and 80%strength(ULD-CI40,ULD-CI60,ULD-CI80 groups);Except for the tube-current setting and reconstruction parameters,all other scanning parameters remained identical across protocols.CT attenuation values and standard deviation(SD)of the aorta and chest wall fat were measured to calculate signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR).Subjective image quality,including lesion margin delineation,homogeneity of lesion density,and artifact severity,was assessed using a 5-point Likert scale.Volume CT dose index(CTDIvol),dose-length product(DLP),effective dose(ED),and size-specific dose estimate(SSDE)were recorded.Results Interobserver agreement for lesion-margin delineation,lesion-density homogeneity,and artifact severity was good,with linearly weighted κ values of 0.801(95%CI:0.753 to 0.844),0.758(95%CI:0.709 to 0.805),and 0.815(95%CI:0.768 to 0.859),respectively.Mean CTDIvol for CD,LD,and ULD protocols were 11.13 mGy,3.98 mGy,and 2.01 mGy,respectively;the corresponding DLP values were 389.55,139.13,and 70.35 mGy/cm;the ED values were 5.45,1.95,and 0.98 mSv;and corresponding SSDE values were 14.37 mGy,5.27 mGy,and 2.60 mGy.Compared to the CD protocol,CTDIvol was reduced by 64.2%and 81.9%in the LD and ULD protocols,respectively,DLP was reduced by 64.2%and 81.9%,ED by 64.2%and 82.0%,and SSDE by 63.3%and 81.9%,respectively.Regarding objective quality,background SD progressively decreased with increasing ClearInfinity strength in LD and ULD protocols,whereas SNR and CNR generally increased.SNR and CNR in LD-CI60,LD-CI80,ULD-CI60,and ULD-CI80 groups were significantly higher than those in the CD-CV60 group(P<0.05).For subjective quality,most metrics initially improved then declined as ClearInfinity strength increased.Among LD and ULD protocols,images reconstructed with 60%ClearInfinity demonstrated superior subjective scores;notably,lesion density homogeneity in the LD-CI60 group was significantly higher than in CD-CV60(P<0.05),while other 60%reconstruction groups showed no statistically significant differences compared to CD-CV60.These 60%reconstruction images consistently outperformed their respective 40%and 80%counterparts within the same dose protocol(P<0.05).The mean difference in patient-level composite image-quality scores between the ULD-CI60 and CD-CV60 groups(ULD-CI60-CD-CV60)was-0.002 points(95%CI:-0.100 to 0.097),and the lower limit of the 95%CI was higher than the prespecified noninferiority margin of-0.5 points.Postoperative complications occurred in 33 patients(33.0%),comprising isolated pneumothorax(14 cases,14.0%),isolated pulmonary hemorrhage(12 cases,12.0%),and combined pneumothorax with hemorrhage(7 cases,7.0%);no severe complications such as air embolism occurred.Conclusion During CT-guided percutaneous lung biopsy,the ULD-CI60 protocol achieves image quality sufficient for puncture localization and path planning while reducing radiation dose by approximately 81.9%.