Background

To investigate lateral lumbar spine radiography technical parameters for reduction of effective dose whilst maintaining image quality (IQ).

Methods

Thirty-six radiograms of an anthropomorphic phantom were acquired using different exposure parameters: source-to-detector distance (SDD) (100, 130 or 150 cm), tube potential (75, 85 or 95 kVp), tube current × exposure time product (4.5, 9, 18 mAs) and additional copper (Cu) filter (no filter, 0.1-, 0.2-, or 0.3-mm thickness. IQ was assessed using an objective approach (contrast-to-noise-ratio [CNR] calculation and magnification measurement) and a perceptual approach (six observers); ED was estimated using the PCXMC 2.0 software. Descriptive statistics, paired t test, and intraclass correlation coefficient (ICC) were used.

Results

The highest ED (0.022 mSv) was found with 100 cm SSD, 75 kVp, 18 mAs, and without Cu filter, whilst the highest CNR (7.23) was achieved at 130 cm SSD, 75 kVp, 18 mAs, and without Cu filter. The lowest ED and CNR were generated at 150 cm SDD, 95 kVp, 4.5 mAs, and 0.3-mm Cu filter. All observers identified the relevant anatomical structures on all images with the lowest ED and IQ. The intra-observer (0.61–0.79) and inter-observer (0.55–0.82) ICC ranged from moderate to excellent.

Conclusion

All relevant anatomical structures were identified on the lateral lumbar spine radiographs despite using low-dose protocols. The lowest ED (0.002 mSv) was obtained with 150 cm SDD, 95 kVp, 4.5 mAs, and 0.3-mm Cu filter. Further technical and clinical studies are needed to verify these preliminary findings.

中文翻译：

---

腰椎侧位X线摄影的有效剂量和图像优化：一项幻像研究。

背景

调查腰椎侧位X线摄影技术参数，以减少有效剂量，同时保持图像质量（IQ）。

方法

使用不同的曝光参数获得了拟人化体模的36幅放射线照片：源到检测器的距离（SDD）（100、130或150 cm），电子管电势（75、85或95 kVp），电子管电流×曝光时间乘积（4.5、9、18 mAs）和附加的铜（Cu）滤波器（无滤波器，厚度为0.1、0.2或0.3毫米）。使用客观方法（对比噪声比[CNR]计算）评估了IQ （放大倍数测量）和一个感知方法（六个观察者）；使用PCXMC 2.0软件估算ED，使用描述性统计量，配对t检验和类内相关系数（ICC）。

结果

使用100 cm SSD，75 kVp，18 mAs和不使用铜滤波器时，发现最高的ED（0.022 mSv），而使用130 cm SSD，75 kVp，18 mAs和不使用Cu滤波器时，可以得到最高的CNR（7.23）。ED和CNR最低的是在150 cm SDD，95 kVp，4.5 mAs和0.3 mm Cu过滤器下产生的。所有观察者都在ED和IQ最低的所有图像上确定了相关的解剖结构。观察者内部（0.61-0.79）和观察者间（0.55-0.82）的ICC从中等到极好。

结论

尽管使用了小剂量方案，但在腰椎侧位X线片上确定了所有相关的解剖结构。使用150 cm SDD，95 kVp，4.5 mAs和0.3 mm Cu过滤器可获得最低的ED（0.002 mSv）。需要进一步的技术和临床研究来验证这些初步发现。