The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging(MRI). Prior to apicoectomy, 11 patients with...The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging(MRI). Prior to apicoectomy, 11 patients with radiographically confirmed periapical lesions underwent dental MRI, including fat-saturated T2-weighted(T2 wFS) images, non-contrast-enhanced T1-weighted images with and without fat saturation(T1 w/T1 wFS), and contrast-enhanced fat-saturated T1-weighted(T1 wFS+C) images. Two independent observers performed structured image analysis of MRI datasets twice. A total of 15 diagnostic MRI criteria were evaluated, and histopathological results(6 granulomas and 5 cysts) were compared with MRI characteristics. Statistical analysis was performed using intraclass correlation coefficient(ICC), Cohen’s kappa(κ), Mann–Whitney U-test and Fisher’s exact test. Lesion identification and consecutive structured image analysis was possible on T2 wFS and T1 wFS+C MRI images. A high reproducibility was shown for MRI measurements of the maximum lesion diameter(intraobserver ICC = 0.996/0.998; interobserver ICC = 0.997), for the "peripheral rim" thickness(intraobserver ICC = 0.988/0.984; interobserver ICC = 0.970), and for all non-quantitative MRI criteria(intraobserver-κ = 0.990/0.995; interobserver-κ = 0.988). In accordance with histopathological results, six MRI criteria allowed for a clear differentiation between cysts and granulomas:(1) outer margin of lesion,(2) texture of "peripheral rim" in T1 wFS+C,(3)texture of "lesion center" in T2 wFS,(4) surrounding tissue involvement in T2 wFS,(5) surrounding tissue involvement in T1 wFS+C and(6) maximum "peripheral rim" thickness(all: P < 0.05). In conclusion, this pilot study indicates that radiation-free dental MRI enables a reliable differentiation between periapical cysts and granulomas in vivo. Thus, MRI may substantially improve treatment strategies and help to avoid unnecessary surgery in apical periodontitis.展开更多
Dear Editor,I write to present the results of a study on the correlation between the ultrasound energy consumed during phacoemulsification with various preoperative parameters,including best corrected distance visual ...Dear Editor,I write to present the results of a study on the correlation between the ultrasound energy consumed during phacoemulsification with various preoperative parameters,including best corrected distance visual acuity（BCDVA）,the signal to noise ratio（SNR）obtained by partial coherence laser interferometry and primarily,lens spikes measurements derived by A-scan ultrasound biometry.Quantification of crystalline lens hardness before cataract removal has been attempted by several researchers in the past.These have been in humans and in animals,in vivo and in vitro,and have used a variety of imaging modalities.展开更多
基金supported by a grant from the Dietmar Hopp Foundation (grant number: 23011228 grant holders: A.J. and S.H.)receive funding from a postdoctoral fellowship of the Medical Faculty of the University of Heidelberg
文摘The purpose of this pilot study was to evaluate whether periapical granulomas can be differentiated from periapical cysts in vivo by using dental magnetic resonance imaging(MRI). Prior to apicoectomy, 11 patients with radiographically confirmed periapical lesions underwent dental MRI, including fat-saturated T2-weighted(T2 wFS) images, non-contrast-enhanced T1-weighted images with and without fat saturation(T1 w/T1 wFS), and contrast-enhanced fat-saturated T1-weighted(T1 wFS+C) images. Two independent observers performed structured image analysis of MRI datasets twice. A total of 15 diagnostic MRI criteria were evaluated, and histopathological results(6 granulomas and 5 cysts) were compared with MRI characteristics. Statistical analysis was performed using intraclass correlation coefficient(ICC), Cohen’s kappa(κ), Mann–Whitney U-test and Fisher’s exact test. Lesion identification and consecutive structured image analysis was possible on T2 wFS and T1 wFS+C MRI images. A high reproducibility was shown for MRI measurements of the maximum lesion diameter(intraobserver ICC = 0.996/0.998; interobserver ICC = 0.997), for the "peripheral rim" thickness(intraobserver ICC = 0.988/0.984; interobserver ICC = 0.970), and for all non-quantitative MRI criteria(intraobserver-κ = 0.990/0.995; interobserver-κ = 0.988). In accordance with histopathological results, six MRI criteria allowed for a clear differentiation between cysts and granulomas:(1) outer margin of lesion,(2) texture of "peripheral rim" in T1 wFS+C,(3)texture of "lesion center" in T2 wFS,(4) surrounding tissue involvement in T2 wFS,(5) surrounding tissue involvement in T1 wFS+C and(6) maximum "peripheral rim" thickness(all: P < 0.05). In conclusion, this pilot study indicates that radiation-free dental MRI enables a reliable differentiation between periapical cysts and granulomas in vivo. Thus, MRI may substantially improve treatment strategies and help to avoid unnecessary surgery in apical periodontitis.
文摘Dear Editor,I write to present the results of a study on the correlation between the ultrasound energy consumed during phacoemulsification with various preoperative parameters,including best corrected distance visual acuity（BCDVA）,the signal to noise ratio（SNR）obtained by partial coherence laser interferometry and primarily,lens spikes measurements derived by A-scan ultrasound biometry.Quantification of crystalline lens hardness before cataract removal has been attempted by several researchers in the past.These have been in humans and in animals,in vivo and in vitro,and have used a variety of imaging modalities.
