双能量CT成像鉴别诊断淋巴瘤与转移性淋巴结

目的 探究双源双能量CT成像在淋巴瘤与转移性淋巴结诊断及鉴别诊断中的价值。 方法 回顾性分析18例淋巴瘤(44个淋巴结)及20例肿瘤淋巴结转移患者(38个淋巴结)的双能量CT资料,通过后处理得到动静脉期碘图及40~190 keV单能量图像,利用能量成像定量分析功能测量病变淋巴结的能量参数及各期CT值,并进行统计学分析。 结果 淋巴瘤与转移性淋巴结平扫CT值分别为(41.09±9.10)HU和(35.08±9.28)HU,动脉期与平扫CT差值分别为(28.34±15.97)HU和(12.92±9.22)HU,静脉期与平扫CT差值分别为(41.55±16.19)HU和(20.17±10.93)HU(P均<0.05);淋巴瘤与转移性淋巴结在碘图上动脉期碘覆盖值分别为(31.86±11.98)HU和(11.53±10.43)HU,静脉期碘覆盖值分别为(40.09±10.68)HU和(20.64±13.17)HU,动脉期碘浓度分别为(1.75±0.77)mg/ml和(0.60±0.46)mg/ml,静脉期碘浓度分别为(2.18±0.66)mg/ml和(0.92±0.57)mg/ml,动脉期碘浓度均一化比值分别为0.20±0.13和0.73±0.06,静脉期碘浓度均一化比值分别为0.41±0.18和0.24±0.16(P均<0.05);淋巴瘤与转移性淋巴结动静脉期平均碘浓度差值分别为(0.43±0.37)mg/ml和(0.32±0.16)mg/ml(P>0.05)。两组病变淋巴结动脉期在40~120 keV单能谱下CT值差异有统计学意义(P均<0.05),且在40~190 keV下的能量衰减曲线不同。 结论 双源CT的单能量图像、碘图及碘物质定量分析技术对淋巴瘤与转移性淋巴结的鉴别诊断有一定价值;联合应用多种衍生序列能够提高诊断准确性。

Dual-energy CT in differential diagnosis of lymphoma and metastatic lymph nodes

Objective To assess the value of dual-energy CT in the diagnosis and differentiation of lymphoma and metastatic lymph nodes. Methods Dual-energy CT data of 18 patients with lymphoma (44 lymph nodes) and 20 patients with malignant tumor (38 lymph nodes) were retrospectively analyzed. The iodine density images of arterial and portal venous phase and a series of 40-190 keV monoenergetic imaging were obtained. Different parameters and CT attenuation of lymph node of every protocol were measured and analyzed statistically. Results The plain CT attenuation, arterial reinforcement attenuation, portal venous reinforcement attenuation of the lymphoma and metastatic lymph nodes respectively were (41.09±9.10)HU, (28.34±15.97)HU, (41.55±16.19)HU and (35.08±9.28)HU, (12.92±9.22)HU, (20.17±10.93)HU (all P<0.05), respectively. The concentration of arterial phase iodine map and portal venous phase iodine map between the lymphoma and metastatic lymph nodes were (31.86±11.98)HU, (40.09±10.68)HU and (11.53±10.43)HU, (20.64±13.17)HU, respectively, and the iodine content of arterial and portal venous phase between the lymphoma and metastatic lymph nodes were (1.75±0.77)mg/ml, (2.18±0.66)mg/ml and (0.60±0.46)mg/ml, (0.92±0.57) mg/ml, respectively (all P<0.05). The average iodine concentration difference (ICD) of the lymphoma and metastatic lymph nodes was (0.43±0.37)mg/ml and (0.32±0.16)mg/ml (P>0.05). The iodine content of the arterial and venous phase homogenization ratio in the lymphoma and metastatic lymph nodes lesions separately were 0.20±0.13, 0.41±0.18 and 0.73±0.06, 0.24±0.16 (all P<0.05). There were significant difference in CT attenuation of 40-120 keV mono-energetic imaging between the other diseases (all P<0.05). The energy spectral curves of lymphoma and metastatic lymph nodes were different of 40-190 keV. Conclusion Integrated application of mono-energetic imaging, iodine density imaging and the measurement of iodine concentrations can improve the sensitivity and accuracy of the detection and differential diagnosis of metastatic lymph nodes and lymphoma.