Bondioni Maria Pia, Pazzaglia Ugo Ernesto, Izzi Claudia, Di Gaetano Giuseppe, Laffranchi Francesco, Baldi Maurizia, Prefumo Federico
Pediatric Radiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, P.le Spedali Civili n. 1, 25100, Brescia, Italy.
Orthopaedic Clinic, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy.
Radiol Med. 2017 Nov;122(11):880-891. doi: 10.1007/s11547-017-0784-0. Epub 2017 Jul 3.
The purpose of the paper was to assess the morphometric parameters to improve the specificity of the ultrasound (US) signs for the early differential diagnosis between two lethal dysplasias, as thanatophoric dysplasia (TD) and osteogenesis imperfecta type 2 (OI-2).
The diaphyseal length and the bowed shape of long bones associated with vertebral body dimension assessment were investigated in a group of 14 pregnancy terminations carried out in the time period 2007-2013. The definitive diagnosis was established after pregnancy termination by means of skeletal standardized X-rays, histopathology and gene analysis.
TD and OI-2 long bones were significantly shorter than controls. No significant differences were observed between the two dysplasias. The bowing angle was higher in OI-2; a true angulation or eventually axial displacement was present only in the latter. Furthermore, they did not show any evidence of vertebral collapse. The thanatophoric dysplasia presented less bowed long bones, and never true angulation. The spine was steadily characterized by flattened anterior vertebral bodies.
Long bone shortening is not a sufficient and accurate sign for early sonographic differential diagnosis between TD and OI-2. Angled diaphysis, axial diaphyseal displacement and a conserved vertebral body height in the prenatal period support the diagnosis of osteogenesis imperfecta type 2, while moderately regular bowed diaphysis associated with platyspondyly that of thanatophoric dysplasia.
本文旨在评估形态学参数，以提高超声（US）征象在两种致死性发育异常（即致死性侏儒症（TD）和2型成骨不全症（OI-2））早期鉴别诊断中的特异性。
对2007年至2013年期间进行的14例妊娠终止病例进行研究，观察与椎体尺寸评估相关的长骨干长度和弯曲形状。妊娠终止后，通过骨骼标准化X线、组织病理学和基因分析确定最终诊断。
TD和OI-2的长骨明显短于对照组。两种发育异常之间未观察到显著差异。OI-2的弯曲角度更高；仅在OI-2中存在真正的成角或最终的轴向移位。此外，它们没有显示出任何椎体塌陷的迹象。致死性侏儒症的长骨弯曲程度较小，且从未出现真正的成角。脊柱的特征始终是椎体前部扁平。
长骨缩短并非TD和OI-2早期超声鉴别诊断的充分且准确的征象。产前时期骨干成角、骨干轴向移位以及椎体高度保持正常支持2型成骨不全症的诊断，而骨干中度规则弯曲并伴有椎体扁平则支持致死性侏儒症的诊断。
