CTPA with a conventional CT at 100 kVp vs. a spectral-detector CT at 120 kVp: Comparison of radiation exposure, diagnostic performance and image quality.
Eur J Radiol Open
; 7: 100234, 2020.
Article
en En
| MEDLINE
| ID: mdl-32420413
PURPOSE: To compare CT pulmonary angiographies (CTPAs) as well as phantom scans obtained at 100 kVp with a conventional CT (C-CT) to virtual monochromatic images (VMI) obtained with a spectral detector CT (SD-CT) at equivalent dose levels as well as to compare the radiation exposure of both systems. MATERIAL AND METHODS: In total, 2110 patients with suspected pulmonary embolism (PE) were examined with both systems. For each system (C-CT and SD-CT), imaging data of 30 patients with the same mean CT dose index (4.85 mGy) was used for the reader study. C-CT was performed with 100 kVp and SD-CT was performed with 120 kVp; for SD-CT, virtual monochromatic images (VMI) with 40, 60 and 70 keV were calculated. All datasets were evaluated by three blinded radiologists regarding image quality, diagnostic confidence and diagnostic performance (sensitivity, specificity). Contrast-to-noise ratio (CNR) for different iodine concentrations was evaluated in a phantom study. RESULTS: CNR was significantly higher with VMI at 40 keV compared to all other datasets. Subjective image quality as well as sensitivity and specificity showed the highest values with VMI at 60 keV and 70 keV. Hereby, a significant difference to 100 kVp (C-CT) was found for image quality. The highest sensitivity was found using VMI at 60 keV with a sensitivity of more than 97 % for all localizations of PE. For diagnostic confidence and subjective contrast, highest values were found with VMI at 40 keV. CONCLUSION: Higher levels of diagnostic performance and image quality were achieved for CPTAs with SD-CT compared to C-CT given similar dose levels. In the clinical setting SD-CT may be the modality of choice as additional spectral information can be obtained.
BMI, body mass index; C-CT, conventional spiral CT; CNR, contrast-to-noise ratio; CT, computed tomography; CTDIVOL, volume-weighted CT dose index; CTPA, CT pulmonary angiography; Computed tomography angiography; DE-CT, dual-Energy CT; DLP, dose length product; DS-CT, dual-Source CT; ED, effective dose; HU, Hounsfield Units; IQ, image quality; PE, pulmonary embolism; Patient safety; Pulmonary embolism; ROI, region of interest; Radiation exposure; Radiologic; SD-CT, spectral-detector CT; Technology; VMI, virtual monochromatic images; kVp, peak kilovoltage; keV, kilo-electronvolt
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Eur J Radiol Open
Año:
2020
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Reino Unido