Gagliardi J A, Chung E M, Chandnani V P, Kesling K L, Christensen K P, Null R N, Radvany M G, Hansen M F
Department of Radiology, Tripler Army Medical Center, Honolulu, HI 96859-5000.
AJR Am J Roentgenol. 1994 Sep;163(3):629-36. doi: 10.2214/ajr.163.3.8079858.
Chondromalacia patellae is a condition characterized by softening, fraying, and ulceration of patellar articular cartilage. We compare the sensitivity, specificity, and accuracy of conventional MR imaging, MR arthrography, and CT arthrography in detecting and staging this abnormality.
Twenty-seven patients with pain in the anterior part of the knee were prospectively examined with MR imaging, including T1-weighted (650/16), proton density-weighted (2000/20), T2-weighted (2000/80), and spoiled two-dimensional gradient-recalled acquisition in the steady state (SPGR/)/35 degrees (51/10) with fat saturation pulse sequences. All were also examined with T1-weighted MR imaging after intraarticular injection of dilute gadopentetate dimeglumine and with double-contrast CT arthrography. Each imaging technique was evaluated independently by two observers, who reached a consensus interpretation. The signal characteristics of cartilage on MR images and contour abnormalities noted with all imaging techniques were evaluated and graded according to a modification of the classification of Shahriaree. Twenty-six of the 54 facets examined had chondromalacia shown by arthroscopy, which was used as the standard of reference. The sensitivity, specificity, and accuracy of each imaging technique in the diagnosis of each stage of chondromalacia patellae were determined and compared by using the McNemar two-tailed analysis.
Arthroscopy showed that 28 facets were normal. Grade 1 chondromalacia patellae was diagnosed only with MR and CT arthrography in two (29%) of seven facets. Intermediate (grade 2 or 3) chondromalacia patellae was detected in two (13%) of 15 facets with T1-weighted and SPGR MR imaging, in three (20%) of 15 facets with proton density-weighted MR imaging, in seven (47%) of 15 facets with T2-weighted MR imaging, in 11 (73%) of 15 facets with CT arthrography, and in 12 (80%) of 15 facets with MR arthrography. Grade 4 was detected in three (75%) of four facets with T1-, proton density-, and T2-weighted MR imaging, two (50%) of four facets with SPGR MR imaging, and four (100%) of four facets with MR and CT arthrography. Thus, all imaging techniques were insensitive to grade 1 lesions and highly sensitive to grade 4 lesions, so that no significant difference among the techniques could be shown.
All imaging techniques studied had high specificity and accuracy in the detection and grading of chondromalacia patella; however, both MR arthrography and CT arthrography were more sensitive than T1-weighted, proton density-weighted, and SPGR with fat saturation MR imaging for showing intermediate grades of chondromalacia patellae. Although the arthrographic techniques were not significantly better than T2-weighted imaging, the number of false-positive diagnoses was greatest with T2-weighted MR imaging.
髌骨软化症是一种以髌骨关节软骨软化、磨损及溃疡为特征的病症。我们比较了传统磁共振成像（MR）、磁共振关节造影及CT关节造影在检测和分期该异常病变方面的敏感性、特异性及准确性。
对27例膝前部疼痛患者进行前瞻性MR成像检查，包括T1加权像（650/16）、质子密度加权像（2000/20）、T2加权像（2000/80）以及采用脂肪饱和脉冲序列的稳态扰相梯度回波序列（SPGR）/35°（51/10）。所有患者还接受了关节腔内注射稀释钆喷酸葡胺后的T1加权MR成像及双对比CT关节造影检查。两名观察者独立评估每种成像技术，并达成共识解读。根据Shahriaree分类法的改良版，对MR图像上软骨的信号特征及所有成像技术所发现的轮廓异常进行评估和分级。54个关节面中有26个经关节镜检查显示有髌骨软化，以此作为参考标准。采用McNemar双侧分析确定并比较每种成像技术在诊断髌骨软化症各阶段的敏感性、特异性及准确性。
关节镜检查显示28个关节面正常。在7个关节面中的2个（29%），仅通过MR和CT关节造影诊断出1级髌骨软化症。在15个关节面中的2个（13%），通过T1加权和SPGR MR成像检测到中度（2级或3级）髌骨软化症；在15个关节面中的3个（20%），通过质子密度加权MR成像检测到；在15个关节面中的7个（47%），通过T2加权MR成像检测到；在15个关节面中的11个（73%），通过CT关节造影检测到；在15个关节面中的12个（80%），通过MR关节造影检测到。在4个关节面中的3个（75%），通过T1加权、质子密度加权和T2加权MR成像检测到4级病变；在4个关节面中的2个（50%），通过SPGR MR成像检测到；在4个关节面中的4个（1），通过MR和CT关节造影检测到。因此，所有成像技术对1级病变均不敏感，对4级病变高度敏感，故各技术之间无显著差异。
所研究的所有成像技术在检测和分级髌骨软化症方面均具有高特异性和准确性；然而，对于显示中度髌骨软化症，MR关节造影和CT关节造影均比T1加权、质子密度加权及脂肪饱和SPGR MR成像更敏感。尽管关节造影技术并不比T2加权成像显著优越，但T2加权MR成像的假阳性诊断数量最多。
