Prenatal radiographic evaluation of congenital transverse limb deficiencies: A scoping review

Table 2 The radiographic pearls and pitfalls as identified by our literature search and our institutional musculoskeletal radiology experts

Pearl or pitfall	Reasoning and evidence
Use the appropriate classification system	Many classification systems exist[25,26]. However, the most recent classification system by Gold et al[27] provides improved communication. When these fail, description of the location and use of modifiers can be helpful to radiologists and non-radiologists, alike
Prenatal ultrasound pearl	Three-dimensional ultrasonography using both maximum intensity projection (MIP), thick slabs with MIP, or surface rendering greatly complements the examination using two-dimensional ultrasound. Scanning with new generation high-frequency broad band probes (up to 22 MHz in some cases) allows greater confidence in the identification of amniotic bands compared to standard obstetrical probes[11]
Prenatal fetal MRI pearl	MRI is not superior to ultrasound for imaging fetal bones. However, it may prove useful in cases where ultrasonography windows are limited, such as maternal obesity, advanced gestational age, oligohydramnios, and unfavorable fetal position. It also provides an additional opportunity to diagnose associated congenital anomalies for which MRI is more sensitive than ultrasound (i.e., CNS anomalies)
Prenatal CT	Current literature supports the use of low-dose CT with 3D reconstruction for the evaluation of skeletal dysplasias[30]. The use of CT for the evaluation of transverse limb deficiencies has not been fully evaluated. The use of CT may be considered when both ultrasound and MRI failed to characterize the phenotype and only after thorough evaluation of benefits versus risks in individual cases

MRI: Magnetic resonance imaging; CT: Computed tomography.