Diagnostic Accuracy of Dual-Layer Spectral CT Using Electron Density Images to Detect Post-Traumatic Prevertebral Hematoma of the Cervical Spine

Abstract

Purpose To investigate the diagnostic value of dual-layer spectral detector computed tomography (SDCT) in detecting posttraumatic prevertebral hematoma of the cervical spine by including electron density images. Methods 38 patients with post-traumatic imaging of the cervical spine were included in this study and received both SDCT and MRI examinations. MRI was set as the reference and combined conventional/electron density (C + ED) images were compared to conventional CT (CCT) images alone. Results A total of 18 prevertebral hematomas were identified. Reader 1 identified 14 of 18 and reader 2 15 of 18 prevertebral hematomas by using C + ED reconstructions. Readers 1 and 2 detected 6 and 9 of 18 hematomas on CCT, respectively. CCT showed a sensitivity of 33–50 % and a specificity of 75–80 %, while for C + ED reconstructed images the sensitivity was 77–83 % and the specificity was 85–90 %. Accuracy increased from 55–66 % to 84 % by using C + ED images. The minimum thickness for detecting hematoma on C + ED images was 3 mm. The sizes of prevertebral hematoma on CCT/C + ED were not significantly under- or overestimated compared to the MRI reference. There was a significant difference between the two readers for measuring hematoma sizes on CCT (p = 0.04). Readers showed an excellent inter-rater reliability (kappa = 0.82) for C + ED images and a moderative inter-rater reliability (kappa = 0.44) for CCT. Conclusion With SDCT, the diagnostic accuracy for detecting post-traumatic prevertebral hematoma is improved by using combined conventional and electron density reconstructions compared to conventional images alone. Key Points: Citation Format

Noncontrast Myocardial Characterization in Acute Myocardial Infarction Using Electron Density Imaging

“…11,[13][14][15] Conversely, the usefulness of ED imaging, though validated against different calibration phantoms, has been scarcely explored. 4,16 The present retrospective cohort comprises the first report showing the potential usefulness of ED imaging for the identification of myocardial tissue changes related to AMI. Furthermore, to the best of our knowledge, it represents the first in vivo evidence indicating that noncontrast CT might be able to detect AMI.…”

“…Nonetheless, research involving spectral CT has mainly focused on contrast-enhanced examinations, showing improved tissue characterization, particularly regarding myocardial perfusion and late iodine enhancement 11,13–15 . Conversely, the usefulness of ED imaging, though validated against different calibration phantoms, has been scarcely explored 4,16 …”

“…2 Nonetheless, HU values are also related to the effective atomic number and the material density within the x-ray spectrum. 3 Recent studies have shown improved diagnostic accuracy of ED imaging for tissue characterization compared with conventional CT. [4][5][6][7] By using two different energies, dual-energy CT improves the ability to estimate ED directly and decreases the deviation from the true nominal values.…”

救急外来でdual energy CTによる診断を行った高齢者脊椎骨折の3例(Three cases of vertebral fractures in elderly patients diagnosed by dual energy CT in the emergency department)

“…DECTでは，カルシウム，電子密度，実効原子番号画像など，多くの物質分解画像を再構成することができ，特徴的な画像を再構成して様々な疾患の診断に利用している。これらを当院ではプロトコール化してDECTを撮像している。本報告例に用いたEDは，電子密度を画像化したものである。電子密度は人の骨において骨密度が高くなると増加し，骨髄中の脂肪組織の割合が高くなると減少する。また血腫部位のヘモグロビン量の増加は，当該部位の電子密度を増加させる。これらを用いて，EDは急性期外傷の診断に利用されている報告はある 16)が，電子密度と骨髄浮腫との関連は明確でない。今回経験した5例は，いずれも骨折部で電子密度の増加が見られており，脊椎骨折の診断に利用できる可能性があると考えている。…”

Thrombus discrimination with electron density: potential implications for non-contrast computed tomography imaging

“…Few reports suggested a better visualization of thrombus and hematoma using ED imaging, although the potential clinical usefulness of ED, other than for radiotherapy planning, remains unknown ( 5 - 7 ). We therefore sought to explore in vitro whether ED imaging could improve thrombus identification compared to conventional imaging among material aspirated during mechanical thrombectomy for acute ischemic stroke.…”