| Objectives: To evaluate the image quality and diagnostic performance of grayscale inversion based on zero echo time and grayscale inversion based on T1-weighted imaging compared with computed tomography(CT)in patients with bone lesions of lower extremities.Methods: Fifty patients with pathological and imaging confirmation of musculoskeletal tumors or tumor-like diseases of lower extremities between April 2020 and July 2022 in Affiliated Hospital of Qingdao University,1.5-T MR imaging was applied including T1-weighted fast spin echo sequence and ZTE sequence as the basis for CT-like images.Three radiologists independently interpreted these images as well as CT images in a random order with an interval of at least 10 days between assessments of each imaging modality.Differences in image quality were calculated using Mann-Whitney U test in combination with four-point Likert scale.Median and IQR were used to evaluate the central and discrete tendency of the image quality scores.The radiologists calculated the Contrastto-Noise Ratio(CNR)of the three imaging and used the paired-sample t-test for statistical analysis.The recorded signs were(1)size(maximum mass diameter in centimeters),(2)lesion number(solitary or multiple),(3)location(central,intracortical,periosteal,or parosteal),(4)sclerotic rim(absent,partial,or total),(5)penetration of cortex(absent,thinning,or total penetration),(6)periosteal reaction(absent,non-invasive,or invasive),(7)expanded shell(absent,≤1 cm,or > 1 cm),(8)destruction pattern(geographic,moth-eaten,or permeative),and(9)matrix mineralization(absent,chondrogenic,osteogenic,or ground glass).The intraclass correlation coefficient(ICC)was used to analyze the agreement of lesion parameters between CT and MR sequences,as well as the interobserver reliability.A p value < 0.05 was considered statistically significant.Results: Image quality score was significantly higher for CT images than TIWI images[radiologist 1: 4(0)vs 4(1),p<0.001;radiologist 2: 4(0)vs 4(1),p=0.001;radiologist 3:4(0)vs 3(1),p<0.001].Except for radiologist 3[4(0)vs 4(1),p=0.026],there was no significant difference in scores between CT and ZTE [radiologist 1: 4(0)vs 4(0),p = 0.133;radiologist 2: 4(0)vs 4(0),p = 0.085)].The CNR(69.19±18.50)of CT was higher than that of T1WI(48.66±16.55)and ZTE(50.93±19.24).There were statistically significant differences between CT and T1 WI or ZTE(t=7.73,t=6.34;P<0.001).There was good – excellent agreement between both MR sequences and CT for size,lesion number,location,sclerotic rim,expanded shell,destruction pattern,and matrix mineralization for both radiologists(ICC:0.636-1.000).For periosteal reaction and penetration of cortex,ZTE provided clearer displayed details,while T1 WI missed these cortical bone abnormalities in some cases.The consistency of periosteal reaction and penetration of the cortex was fair to good(ICC:0.481-0.729)between T1 WI and CT and good to excellent between ZTE and CT(ICC:0.682-0.852).Conclusions: Both ZTE and T1 WI could provide “CT-like” contrast.ZTE images showed high inter-modality agreement with CT images for the display of bone lesions,and the image quality is comparable,which can offer more bone morphology abnormalities details than T1 WI images. |
PDF Full Text Request