Abstract：
OBJECTIVE: To compare the diagnostic performance of conventional non-contrast CT, dual-energy spectral CT, and chemical-shift MRI (CS-MRI) in discriminating lipid-poor adenomas (> 10-HU on non-contrast CT) from non-adenomas.
METHODS: A total of 110 patients (69 men; 41 women; mean age 66.5 ± 13.4 years) with 80 lipid-poor adenomas and 30 non-adenomas who underwent non-contrast dual-layer spectral CT and CS-MRI were retrospectively identified. For each lesion, non-contrast attenuation on conventional 120-kVp images, ΔHU-index ([attenuation difference between virtual monoenergetic 140-keV and 40-keV images]/conventional attenuation × 100), and signal intensity index (SI-index) were quantified. Each parameter was compared between adenomas and non-adenomas using the Mann-Whitney U-test. The area under the receiver operating characteristic curve (AUC) and sensitivity to achieve > 95% specificity for adenoma diagnosis were determined.
RESULTS: Conventional non-contrast attenuation was lower in adenomas than in non-adenomas (22.4 ± 8.6 HU vs 32.8 ± 48.5 HU), whereas ΔHU-index (148.0 ± 103.2 vs 19.4 ± 25.8) and SI-index (41.6 ± 19.6 vs 4.2 ± 10.2) were higher in adenomas (all, p < 0.001). ΔHU-index showed superior performance to conventional non-contrast attenuation (AUC: 0.919 [95% CI: 0.852-0.963] vs 0.791 [95% CI: 0.703-0.863]; sensitivity: 75.0% [60/80] vs 27.5% [22/80], both p < 0.001), and near equivalent to SI-index (AUC: 0.952 [95% CI: 0.894-0.984], sensitivity 85.0% [68/80], both p > 0.05). Both the ΔHU-index and SI-index provided a sensitivity of 96.0% (48/50) for hypoattenuating adenomas (≤ 25 HU). For hyperattenuating (> 25 HU) adenomas, SI-index showed higher sensitivity than ΔHU-index (66.7% [20/30] vs 40.0% [12/30], p = 0.022).
CONCLUSIONS: Non-contrast spectral CT and CS-MRI outperformed conventional non-contrast CT in distinguishing lipid-poor adenomas from non-adenomas. While CS-MRI demonstrated superior sensitivity for adenomas measuring > 25 HU, non-contrast spectral CT provided high discriminative values for adenomas measuring ≤ 25 HU.
CONCLUSIONS: Spectral attenuation analysis improves the diagnostic performance of non-contrast CT in discriminating lipid-poor adrenal adenomas, potentially serving as an alternative to CS-MRI and obviating the necessity for additional diagnostic workup in indeterminate adrenal incidentalomas, particularly for lesions measuring ≤ 25 HU.
CONCLUSIONS: Incidental adrenal lesion detection has increased as abdominal CT use has become more frequent. Non-contrast spectral CT and CS-MRI differentiated lipid-poor adenomas from non-adenomas better than conventional non-contrast CT. For lesions measuring ≤ 25 HU, spectral CT may obviate the need for additional evaluation.
METHODS: A total of 110 patients (69 men; 41 women; mean age 66.5 ± 13.4 years) with 80 lipid-poor adenomas and 30 non-adenomas who underwent non-contrast dual-layer spectral CT and CS-MRI were retrospectively identified. For each lesion, non-contrast attenuation on conventional 120-kVp images, ΔHU-index ([attenuation difference between virtual monoenergetic 140-keV and 40-keV images]/conventional attenuation × 100), and signal intensity index (SI-index) were quantified. Each parameter was compared between adenomas and non-adenomas using the Mann-Whitney U-test. The area under the receiver operating characteristic curve (AUC) and sensitivity to achieve > 95% specificity for adenoma diagnosis were determined.
RESULTS: Conventional non-contrast attenuation was lower in adenomas than in non-adenomas (22.4 ± 8.6 HU vs 32.8 ± 48.5 HU), whereas ΔHU-index (148.0 ± 103.2 vs 19.4 ± 25.8) and SI-index (41.6 ± 19.6 vs 4.2 ± 10.2) were higher in adenomas (all, p < 0.001). ΔHU-index showed superior performance to conventional non-contrast attenuation (AUC: 0.919 [95% CI: 0.852-0.963] vs 0.791 [95% CI: 0.703-0.863]; sensitivity: 75.0% [60/80] vs 27.5% [22/80], both p < 0.001), and near equivalent to SI-index (AUC: 0.952 [95% CI: 0.894-0.984], sensitivity 85.0% [68/80], both p > 0.05). Both the ΔHU-index and SI-index provided a sensitivity of 96.0% (48/50) for hypoattenuating adenomas (≤ 25 HU). For hyperattenuating (> 25 HU) adenomas, SI-index showed higher sensitivity than ΔHU-index (66.7% [20/30] vs 40.0% [12/30], p = 0.022).
CONCLUSIONS: Non-contrast spectral CT and CS-MRI outperformed conventional non-contrast CT in distinguishing lipid-poor adenomas from non-adenomas. While CS-MRI demonstrated superior sensitivity for adenomas measuring > 25 HU, non-contrast spectral CT provided high discriminative values for adenomas measuring ≤ 25 HU.
CONCLUSIONS: Spectral attenuation analysis improves the diagnostic performance of non-contrast CT in discriminating lipid-poor adrenal adenomas, potentially serving as an alternative to CS-MRI and obviating the necessity for additional diagnostic workup in indeterminate adrenal incidentalomas, particularly for lesions measuring ≤ 25 HU.
CONCLUSIONS: Incidental adrenal lesion detection has increased as abdominal CT use has become more frequent. Non-contrast spectral CT and CS-MRI differentiated lipid-poor adenomas from non-adenomas better than conventional non-contrast CT. For lesions measuring ≤ 25 HU, spectral CT may obviate the need for additional evaluation.
摘要：
目的：比较常规非对比CT的诊断性能，双能谱CT,和化学位移MRI（CS-MRI）可区分低脂腺瘤（非造影CT>10-HU）与非腺瘤。
方法：回顾性分析了110例患者（男69例，女41例，平均年龄66.5±13.4岁），其中80例贫脂腺瘤和30例非腺瘤患者接受了非对比双层能谱CT和CS-MRI检查。对于每个病变，常规120kVp图像上的非对比衰减，ΔHU指数（[虚拟单能140-keV和40-keV图像之间的衰减差]/常规衰减×100），并对信号强度指数(SI指数)进行定量。使用Mann-WhitneyU检验在腺瘤和非腺瘤之间比较每个参数。确定受试者工作特征曲线下面积(AUC)和实现腺瘤诊断的>95%特异性的敏感性。
结果：腺瘤的常规非对比剂衰减低于非腺瘤（22.4±8.6HUvs32.8±48.5HU），而腺瘤中的ΔHU指数（148.0±103.2vs19.4±25.8）和SI指数（41.6±19.6vs4.2±10.2）较高（所有，p<0.001)。ΔHU指数表现优于常规非对比衰减（AUC：0.919[95%CI：0.852-0.963]vs0.791[95%CI：0.703-0.863]；灵敏度：75.0%[60/80]vs27.5%[22/80]，两者p<0.001)，接近SI指数（AUC：0.952[95%CI：0.894-0.984]，灵敏度85.0%[68/80]，两者p>0.05)。ΔHU指数和SI指数对减弱腺瘤（≤25HU）的敏感性均为96.0％（48/50）。对于超衰减（>25HU）腺瘤，SI指数显示出比ΔHU指数更高的灵敏度（66.7％[20/30]对40.0％[12/30]，p=0.022)。
结论：非对比能谱CT和CS-MRI在区分低脂腺瘤和非腺瘤方面优于常规非对比CT。虽然CS-MRI对测量>25HU的腺瘤表现出优异的敏感性，非对比能谱CT为测量≤25HU的腺瘤提供了很高的鉴别值。
结论：谱衰减分析提高了非造影CT对鉴别贫脂肾上腺腺瘤的诊断效能，可能作为CS-MRI的替代方案，并消除了在不确定的肾上腺偶发瘤中进行额外诊断检查的必要性，特别是对于测量≤25HU的病变。
结论：随着腹部CT的使用越来越频繁，偶然发现的肾上腺病变增加。非对比能谱CT和CS-MRI对非腺瘤的鉴别低脂腺瘤优于常规非对比CT。对于测量≤25HU的病变，谱CT可以消除额外评估的需要。
方法：回顾性分析了110例患者（男69例，女41例，平均年龄66.5±13.4岁），其中80例贫脂腺瘤和30例非腺瘤患者接受了非对比双层能谱CT和CS-MRI检查。对于每个病变，常规120kVp图像上的非对比衰减，ΔHU指数（[虚拟单能140-keV和40-keV图像之间的衰减差]/常规衰减×100），并对信号强度指数(SI指数)进行定量。使用Mann-WhitneyU检验在腺瘤和非腺瘤之间比较每个参数。确定受试者工作特征曲线下面积(AUC)和实现腺瘤诊断的>95%特异性的敏感性。
结果：腺瘤的常规非对比剂衰减低于非腺瘤（22.4±8.6HUvs32.8±48.5HU），而腺瘤中的ΔHU指数（148.0±103.2vs19.4±25.8）和SI指数（41.6±19.6vs4.2±10.2）较高（所有，p<0.001)。ΔHU指数表现优于常规非对比衰减（AUC：0.919[95%CI：0.852-0.963]vs0.791[95%CI：0.703-0.863]；灵敏度：75.0%[60/80]vs27.5%[22/80]，两者p<0.001)，接近SI指数（AUC：0.952[95%CI：0.894-0.984]，灵敏度85.0%[68/80]，两者p>0.05)。ΔHU指数和SI指数对减弱腺瘤（≤25HU）的敏感性均为96.0％（48/50）。对于超衰减（>25HU）腺瘤，SI指数显示出比ΔHU指数更高的灵敏度（66.7％[20/30]对40.0％[12/30]，p=0.022)。
结论：非对比能谱CT和CS-MRI在区分低脂腺瘤和非腺瘤方面优于常规非对比CT。虽然CS-MRI对测量>25HU的腺瘤表现出优异的敏感性，非对比能谱CT为测量≤25HU的腺瘤提供了很高的鉴别值。
结论：谱衰减分析提高了非造影CT对鉴别贫脂肾上腺腺瘤的诊断效能，可能作为CS-MRI的替代方案，并消除了在不确定的肾上腺偶发瘤中进行额外诊断检查的必要性，特别是对于测量≤25HU的病变。
结论：随着腹部CT的使用越来越频繁，偶然发现的肾上腺病变增加。非对比能谱CT和CS-MRI对非腺瘤的鉴别低脂腺瘤优于常规非对比CT。对于测量≤25HU的病变，谱CT可以消除额外评估的需要。
