Diagnostic Department, Division of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211, Geneva 14, Switzerland.
Surgery Department, Division of Plastic, Reconstructive and Aesthetic Surgery, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211, Geneva 14, Switzerland.
Skeletal Radiol. 2021 Jan;50(1):231-237. doi: 10.1007/s00256-020-03564-z. Epub 2020 Aug 5.
To evaluate the value of synthetic magnetic resonance imaging (MRI) and T2 mapping in distinguishing between different types of fillers in soft tissues.
Ex vivo fillers of buttock soft tissues (silicone, collagen, and different types of hyaluronic acid) were scanned using a synthetic MRI sequence at 1.5 and 3 T and an optimized T2 mapping sequence to measure the T2 relaxation times of the fillers ex vivo. Three patients addressed to assess complications with buttock fillers underwent MRI with the standard morphological sequences and an additional synthetic MRI sequence; T2 mapping was not performed for the patients. Two patients had silicone fillers, whereas the exact filler composition for the third patient was unknown.
Measurements of T1 and T2 relaxation times of ex vivo fillers at 1.5 and 3 T using synthetic MRI showed that the silicone, collagen, and hyaluronic acid had distinct relaxation time characteristics. In vivo, the synthetic MRI correctly identified silicone in the two patients with known silicone fillers, showing low T1 and T2 values, whereas in the third patient with an unknown filler type, the synthetic MRI suggested a collagen filler, with intermediate relaxation time values.
Quantitative sequences have the potential to differentiate between filler types in a noninvasive fashion.
评估合成磁共振成像（MRI）和 T2 映射在区分软组织中不同类型填充物的价值。
使用合成 MRI 序列在 1.5 和 3 T 以及优化的 T2 映射序列对臀部软组织的外源性填充物（硅胶、胶原蛋白和不同类型的透明质酸）进行扫描，以测量填充物的 T2 弛豫时间。三位患者因臀部填充物并发症而接受 MRI 检查，包括标准形态学序列和附加的合成 MRI 序列；患者未进行 T2 映射。两名患者有硅胶填充物，而第三名患者的确切填充物成分未知。
使用合成 MRI 对 1.5 和 3 T 下的外源性填充物的 T1 和 T2 弛豫时间进行测量，结果表明硅胶、胶原蛋白和透明质酸具有独特的弛豫时间特征。在体内，两名已知硅胶填充物的患者中，合成 MRI 正确识别了硅胶，显示出低 T1 和 T2 值，而在第三例未知填充物类型的患者中，合成 MRI 提示为胶原蛋白填充物，具有中等弛豫时间值。
定量序列有可能以非侵入性的方式区分填充物类型。
