TY - JOUR
T1 - Adrenal incidentaloma triage with single-source (fast-kilovoltage switch) dual-energy CT
AU - Glazer, Daniel I.
AU - Maturen, Katherine E.
AU - Kaza, Ravi K.
AU - Francis, Isaac R.
AU - Keshavarzi, Nahid R.
AU - Parker, Robert A.
AU - Platt, Joel F.
PY - 2014/8
Y1 - 2014/8
N2 - OBJECTIVE. The purpose of this article is to evaluate single-source dual-energy CT (DECT) for distinguishing benign and indeterminate adrenal nodules, with attention to the effects of phase of IV contrast enhancement. MATERIALS AND METHODS. A retrospective review revealed 273 contrast-enhanced abdominal DECT examinations from November 2009 through March 2012. Fifty adrenal nodules 0.8 cm or larger were identified in 41 patients (22 women and 19 men; average age, 66 years; age range, 36-88 years). CT postprocessing and measurements were independently performed by two radiologists (readers 1 and 2) for each nodule, as follows: attenuation (in Hounsfield units) on true unenhanced images; contrast-enhanced attenuation (in Hounsfield units) on monochromatic spectral images at 40, 75, and 140 keV; and contrast-enhanced material density (in milligrams per milliliter) on virtual unenhanced images. Nodules were classified as benign (< 10 HU) and indeterminate (≥ 10 HU) according to true unenhanced images. RESULTS. Interreader agreement regarding benign and indeterminate nodules was high (κ = 0.92; 95% CI, 0.8-1.0). At 140 keV, the attenuation of benign nodules was significantly lower (reader 1, 7.0 ± 12.5 HU; reader 2, 7.8 ± 9.2 HU) than that of indeterminate nodules (reader 1, 15.7 ± 20.5 HU [ p = 0.004]; reader 2, 17.5 ± 13.4 HU [ p < 0.0001]). On virtual unenhanced images, benign nodules had significantly lower material density (reader 1, 992.4 ± 9.9 mg/mL; reader 2, 992.7 ± 9.6 mg/mL) than did indeterminate nodules (reader 1, 1001.1 ± 20.5 mg/mL [ p = 0.038]; reader 2, 1007.6 ± 13.4 mg/mL [ p < 0.0001]). CONCLUSION. DECT tools can mathematically subtract iodine or minimize its effects in high-energy reconstructions, approximating unenhanced imaging and potentially reducing the need for additional studies to triage adrenal nodules detected on contrast-enhanced DECT examinations.
AB - OBJECTIVE. The purpose of this article is to evaluate single-source dual-energy CT (DECT) for distinguishing benign and indeterminate adrenal nodules, with attention to the effects of phase of IV contrast enhancement. MATERIALS AND METHODS. A retrospective review revealed 273 contrast-enhanced abdominal DECT examinations from November 2009 through March 2012. Fifty adrenal nodules 0.8 cm or larger were identified in 41 patients (22 women and 19 men; average age, 66 years; age range, 36-88 years). CT postprocessing and measurements were independently performed by two radiologists (readers 1 and 2) for each nodule, as follows: attenuation (in Hounsfield units) on true unenhanced images; contrast-enhanced attenuation (in Hounsfield units) on monochromatic spectral images at 40, 75, and 140 keV; and contrast-enhanced material density (in milligrams per milliliter) on virtual unenhanced images. Nodules were classified as benign (< 10 HU) and indeterminate (≥ 10 HU) according to true unenhanced images. RESULTS. Interreader agreement regarding benign and indeterminate nodules was high (κ = 0.92; 95% CI, 0.8-1.0). At 140 keV, the attenuation of benign nodules was significantly lower (reader 1, 7.0 ± 12.5 HU; reader 2, 7.8 ± 9.2 HU) than that of indeterminate nodules (reader 1, 15.7 ± 20.5 HU [ p = 0.004]; reader 2, 17.5 ± 13.4 HU [ p < 0.0001]). On virtual unenhanced images, benign nodules had significantly lower material density (reader 1, 992.4 ± 9.9 mg/mL; reader 2, 992.7 ± 9.6 mg/mL) than did indeterminate nodules (reader 1, 1001.1 ± 20.5 mg/mL [ p = 0.038]; reader 2, 1007.6 ± 13.4 mg/mL [ p < 0.0001]). CONCLUSION. DECT tools can mathematically subtract iodine or minimize its effects in high-energy reconstructions, approximating unenhanced imaging and potentially reducing the need for additional studies to triage adrenal nodules detected on contrast-enhanced DECT examinations.
KW - Adrenal adenoma
KW - Adrenal glands
KW - Dual-energy CT
KW - Incidentaloma
KW - Low-kilovoltage CT
UR - http://www.scopus.com/inward/record.url?scp=84906516440&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84906516440&partnerID=8YFLogxK
U2 - 10.2214/AJR.13.11811
DO - 10.2214/AJR.13.11811
M3 - Article
C2 - 25055267
AN - SCOPUS:84906516440
SN - 0361-803X
VL - 203
SP - 329
EP - 335
JO - American Journal of Roentgenology
JF - American Journal of Roentgenology
IS - 2
ER -