Sorbonne University, AP-HP, Pitié Salpêtrière - Charles Foix Hospital, Department of Neuroradiology, F75013, Paris, France.
Sorbonne University, AP-HP, Pitié Salpêtrière - Charles Foix Hospital, Department of Orthopaedic Surgery, F75013, Paris, France.
Eur Radiol. 2021 Jul;31(7):4690-4699. doi: 10.1007/s00330-020-07654-3. Epub 2021 Jan 15.
Preoperative embolization of hypervascular spinal metastases (HSM) is efficient to reduce perioperative bleeding. However, intra-arterial digital subtraction angiography (IA-DSA) must confirm the hypervascular nature and rule out spinal cord arterial feeders. This study aimed to evaluate the reliability and accuracy of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) in assessing HSM prior to embolization.
All consecutive patients referred for preoperative embolization of an HSM were prospectively included. TR-CE-MRA sequences and selective IA-DSA were performed prior to embolization. Two readers independently reviewed imaging data to grade tumor vascularity (using a 3-grade and a dichotomized "yes vs no" scale) and identify the arterial supply of the spinal cord. Interobserver and intermodality agreements were estimated using kappa statistics.
Thirty patients included between 2016 and 2019 were assessed for 55 levels. Interobserver agreement was moderate (κ = 0.52; 95% CI [0.09-0.81]) for TR-CE-MRA. Intermodality agreement between TR-CE-MRA and IA-DSA was good (κ = 0.74; 95% CI [0.37-1.00]). TR-CE-MRA had a sensitivity of 97.9%, a specificity of 71.4%, a positive predictive value of 95.9%, a negative predictive value of 83.3%, and an overall accuracy of 94.6%, for differentiating hypervascular from non-hypervascular SM. The arterial supply of the spine was assessable in 2/30 (6.7%) cases with no interobserver agreement (κ < 0).
TR-CE-MRA can reliably differentiate hypervascular from non-hypervascular SM and thereby avoid futile IA-DSAs. However, TR-CE-MRA was not able to evaluate the vascular supply of the spinal cord at the target levels, thus limiting its scope as a pretherapeutic assessment tool.
• TR-CE-MRA aids in distinguishing hypervascular from non-hypervascular spinal metastases. • TR-CE-MRA could avoid one-quarter of patients referred for HSM embolization to undergo futile conventional angiography. • TR-CE-MRA's spatial resolution is insufficient to replace IA-DSA in the pretherapeutic assessment of the spinal cord vascular anatomy.
术前对富血管性脊柱转移瘤（HSM）进行栓塞可有效减少围手术期出血。然而，必须通过数字减影血管造影（IA-DSA）来确认富血管特性并排除脊髓动脉供血。本研究旨在评估时间分辨对比增强磁共振血管造影（TR-CE-MRA）在栓塞前评估 HSM 的可靠性和准确性。
所有连续因 HSM 术前栓塞而被转介的患者均前瞻性纳入研究。在栓塞前进行 TR-CE-MRA 序列和选择性 IA-DSA。两位观察者独立地对图像数据进行分级评估肿瘤血管生成（使用 3 级和“是/否”二分制）和识别脊髓的动脉供应。采用 Kappa 统计来评估观察者间和模式间的一致性。
2016 年至 2019 年间，对 30 名患者的 55 个节段进行了评估。TR-CE-MRA 的观察者间一致性为中等（κ=0.52；95%CI [0.09-0.81]）。TR-CE-MRA 与 IA-DSA 之间的模式间一致性良好（κ=0.74；95%CI [0.37-1.00]）。TR-CE-MRA 对区分富血管性和非富血管性 SM 的敏感性为 97.9%，特异性为 71.4%，阳性预测值为 95.9%，阴性预测值为 83.3%，总准确率为 94.6%。对于评估脊髓的动脉供应，2/30（6.7%）例中无法进行观察者间评估（κ<0）。
TR-CE-MRA 可以可靠地区分富血管性和非富血管性 SM，从而避免进行无效的 IA-DSA。然而，TR-CE-MRA 无法评估目标水平的脊髓血管供应，从而限制了其作为治疗前评估工具的范围。
TR-CE-MRA 有助于区分富血管性和非富血管性脊柱转移瘤。
TR-CE-MRA 可以避免四分之一的因 HSM 栓塞而转介的患者进行无效的常规血管造影。
TR-CE-MRA 的空间分辨率不足以替代 IA-DSA 来评估脊髓血管解剖结构。
