Department of Neurosurgery, Presbyterian Medical Center and Christian Medical Research Center, Jeonju, Korea.
Pain Med. 2011 Jan;12(1):36-44. doi: 10.1111/j.1526-4637.2010.00993.x. Epub 2010 Nov 18.
Pressure-controlled manometric discography is used by clinicians to evaluate discogenic pain. However, some would improve diagnostic accuracy. The goal of this study was to investigate potential confounding factors that might affect discographic results. Pressure differences depending on different speed of injection, lengths of connecting tubing and locations of sensors were evaluated using an in vitro model system.
Two sets of automated discography devices were arranged to record post-syringeal pressure pressures (PSPs) and intradiscal pressures (IDPs) in an "air chamber disk model" representing intradiscal pressure. PSPs and IDPs were measured simultaneously while varying injection speeds, and using intrasyringeal and extrasyringeal pressure sensors and contrast medium-filled tubing of different lengths. All pressure/volume curves were collected and viewed dynamically, and stored for further analysis.
At injection speed of 0.1 cc/second, the mean pressure difference (mean ΔP) between PSP and IDP was 38.1 psi. As injection speed was reduced, mean ΔP was proportionally decreased. Mean ΔP was 5.3 psi at injection speed of 0.01 cc/second and 0.7 psi at 0.005 cc/second. Mean ΔP values were significantly higher when pressures were recorded using intrasyringeal sensor: at injection speed of 0.1 cc/second, PSP and IDP values were 82.9 and 30.1 psi, respectively, compared with 50.6 and 12.5 psi measured by extrasyringeal sensor. Mean ΔP due to increased length of tubing was not significant.
Discography can be better performed with low speed injection (≤0.01 cc/second), using an extrasyringeal sensor. Difference of length of connecting tubings did not cause significant pressure differences. These data suggest that automated discography is a helpful adjunct to improve diagnostic accuracy, due to extrasyringeal location of pressure sensor and greater control of injection speed.
压力控制测压椎间盘造影术被临床医生用于评估椎间盘源性疼痛。然而，一些因素可能会提高诊断准确性。本研究旨在探讨可能影响椎间盘造影结果的潜在混杂因素。使用体外模型系统评估了不同注射速度、连接管长度和传感器位置对测压盘差异的影响。
两组自动椎间盘造影设备被安排在“气室盘模型”中记录针后压力（PSP）和椎间盘内压力（IDP），以代表椎间盘内压力。同时改变注射速度，使用针内和针外压力传感器以及不同长度的充满对比剂的连接管，测量 PSP 和 IDP。收集并动态查看所有压力/体积曲线，并存储以备进一步分析。
在 0.1cc/秒的注射速度下，PSP 和 IDP 之间的平均压力差（mean ΔP）为 38.1psi。随着注射速度的降低，mean ΔP 成比例降低。在 0.01cc/秒的注射速度下，mean ΔP 为 5.3psi，在 0.005cc/秒的注射速度下为 0.7psi。使用针内传感器记录压力时，mean ΔP 值显著更高：在 0.1cc/秒的注射速度下，PSP 和 IDP 值分别为 82.9 和 30.1psi，而使用针外传感器测量值分别为 50.6 和 12.5psi。连接管长度增加导致的平均压力差并不显著。
使用低速注射（≤0.01cc/秒）和针外传感器，可以更好地进行椎间盘造影术。连接管长度的差异不会导致显著的压力差异。这些数据表明，由于压力传感器位于针外以及对注射速度的更好控制，自动椎间盘造影术是一种有助于提高诊断准确性的辅助手段。
