Obstetrics and Gynecology Department, CHU Bocage, University of Burgundy, Dijon, France.
Ultrasound Obstet Gynecol. 2013 Aug;42(2):161-8. doi: 10.1002/uog.12298. Epub 2013 Jul 14.
(1) To study the use and diagnostic value, as a complement to ultrasound, of helical computed tomography (helical CT) to differentiate normal fetuses from cases of skeletal dysplasia; (2) to define the most relevant indications for helical CT; and (3) to evaluate its diagnostic performance with respect to radiological criteria considered discriminatory.
This was a retrospective study from 2005 to 2008 in 67 pregnant women who underwent helical CT after 26 weeks of gestation for suspected fetal skeletal dysplasia due to fetal shortened long bones on ultrasound (≤ 10(th) percentile), either alone or associated with other bone abnormalities. The results were compared with pediatric examinations in 41 cases and with fetal autopsy findings after elective termination of pregnancy in the others.
Helical CT had a sensitivity of 82%, specificity of 91% and positive and negative predictive values of 90% and 83%, respectively, for diagnosis of fetal skeletal dysplasia. An etiological diagnosis that had not been suspected at ultrasound was specified in 15% of cases and diagnoses suspected at ultrasound were confirmed in 24% and discounted in 43% of cases. The prevalence of skeletal dysplasia was increased in cases of micromelia < 3(rd) percentile or if there was a combination of bone signs. Helical CT showed 69% sensitivity in identifying individual predefined pathological bone signs which were confirmed on fetal autopsy findings.
Helical CT is a key examination, in combination with ultrasound, in the diagnosis of fetal skeletal dysplasia from 26 weeks of gestation. It should be reserved for cases with severe micromelia below the 3(rd) percentile and for those with micromelia ≤ 10(th) percentile associated with another bone sign. A checklist of discriminatory signs is proposed.
（1）研究螺旋 CT（helical CT）在超声检查的基础上的应用及其对骨骼发育不良胎儿的诊断价值；（2）明确螺旋 CT 的最佳适应证；（3）评估其在具有鉴别意义的影像学标准下的诊断性能。
本研究为 2005 年至 2008 年的回顾性研究，共纳入 67 例孕妇，这些孕妇因超声检查发现胎儿长骨缩短（<第 10 百分位数）而在妊娠 26 周后接受螺旋 CT 检查，怀疑存在骨骼发育不良，这些长骨缩短要么单独存在，要么与其他骨骼异常同时存在。将检查结果与 41 例儿科检查结果进行比较，并与其余病例因选择性终止妊娠而进行的胎儿尸检结果进行比较。
螺旋 CT 对胎儿骨骼发育不良的诊断具有 82%的敏感性、91%的特异性、90%的阳性预测值和 83%的阴性预测值。在 15%的病例中，螺旋 CT 可以明确超声检查未怀疑的病因诊断，在 24%的病例中证实了超声检查怀疑的诊断，在 43%的病例中排除了超声检查怀疑的诊断。当超声检查发现胎儿长骨缩短<第 3 百分位数或存在骨骼异常的组合时，骨骼发育不良的发生率增加。螺旋 CT 对胎儿尸检结果中确认的 69%的个体病理性骨骼异常具有较高的识别能力。
从妊娠 26 周开始，螺旋 CT 结合超声检查是诊断胎儿骨骼发育不良的关键检查。对于长骨缩短<第 3 百分位数的严重病例，以及长骨缩短≤第 10 百分位数且伴发其他骨骼异常的病例，应保留螺旋 CT 检查。本研究提出了一套鉴别性骨骼异常的检查表。
