Original Article

Evaluating the Performance of Unenhanced Computed Tomography in the Diagnosis of Pulmonary Embolism

Abstract

Background: Computed tomography pulmonary angiography (CTPA) as the gold-standard examination in the detection of pulmonary embolism (PE) is contraindicated or unavailable in certain cases. The current study aimed to assess the accuracy of unenhanced CT in the diagnosis of PE.

Methods: This cohort study was conducted between October 2020 and March 2021 in Birjand, Iran, on 195 participants with clinical suspicion of PE examined with multidetector computed tomography (MDCT) scanning and CTPA. The patients were categorized into 2 groups based on the diagnosis PE in CTPA results. Imaging variables in unenhanced CT scans, including hyper/hypodense intraluminal signs, pulmonary trunk enlargements, peripheral wedge-shaped opacities, and pleural effusions, were independently reviewed by 2 radiologists and then compared between the groups.

Results: There were 82 men (42.1%) and 113 women (57.9%) at a mean age ± standard deviation of 56.00±0.24 years. Based on CTPA results, PE was diagnosed in 24.1% of the study population (47/195). However, only 20 cases (42.5%) were detected by MDCT: 17 cases (85.0%) with central PE and 3 cases (15.0%) with peripheral PE. Concerning the intraluminal clot density, 12 patients (60.0%) had hyperdense signs, 3 (15.0%) had hypodense signs, and 5 (25.0%) had mixed hyper/hypodense signs. There was a significant difference between central PE and peripheral PE detected by MDCT. Intraluminal signs had the highest specificity and sensitivity (98.6% and 42.5%, area under the curve =0.734).

Conclusion: Unenhanced MDCT has a remarkable performance in detecting PE, specifically central clots, and can, therefore, be considered an alternative modality when CTPA is not available or indicated.

1. Duffett L, Castellucci LA, Forgie MA. Pulmonary embolism: update on management and controversies. BMJ 2020;370:m2177.
2. Turetz M, Sideris AT, Friedman OA, Triphathi N, Horowitz JM. Epidemiology, pathophysiology, and natural history of pulmonary embolism. Semin Intervent Radiol 2018;35:92-98.
3. Carson JL, Kelley MA, Duff A, Weg JG, Fulkerson WJ, Palevsky HI, Schwartz JS, Thompson BT, Popovich J, Jr, Hobbins TE. The clinical course of pulmonary embolism. N Engl J Med 1992;326:1240-1245.
4. Cobelli R, Zompatori M, De Luca G, Chiari G, Bresciani P, Marcato C. Clinical usefulness of computed tomography study without contrast injection in the evaluation of acute pulmonary embolism. J Comput Assist Tomogr 2005;29:6-12.
5. Tatco VR, Piedad HH. The validity of hyperdense lumen sign in non-contrast chest CT scans in the detection of pulmonary thromboembolism. Int J Cardiovasc Imaging 2011;27:433-440.
6. Chien CH, Shih FC, Chen CY, Chen CH, Wu WL, Mak CW. Unenhanced multidetector computed tomography findings in acute central pulmonary embolism. BMC Med Imaging 2019;19:65.
7. Ghaye B, Szapiro D, Mastora I, Delannoy V, Duhamel A, Remy J, Remy-Jardin M. Peripheral pulmonary arteries: how far in the lung does multi-detector row spiral CT allow analysis? Radiology 2001;219:629-636.
8. Goodman LR, Curtin JJ, Mewissen MW, Foley WD, Lipchik RJ, Crain MR, Sagar KB, Collier BD. Detection of pulmonary embolism in patients with unresolved clinical and scintigraphic diagnosis: helical CT versus angiography. AJR Am J Roentgenol 1995;164:1369-1374.
9. Reinert D, Mönnings P, Schneider R, Lukas C. Hyperdense pulmonary artery sign - detection of pulmonary embolism in patients with suspected COVID-19 using non-contrast chest CT. Radiol Case Rep 2021;16:1815-1818.
10. Cobelli R, Zompatori M, Bresciani P, De Luca G. Visualization of hypoattenuation clots on unenhanced CT of the thorax. AJR Am J Roentgenol 2004;182:530-531.
11. New PF, Aronow S. Attenuation measurements of whole blood and blood fractions in computed tomography. Radiology 1976;121(3 Pt. 1):635-640.
12. Foster M, Nolan RL, Lam M. Prediction of anemia on unenhanced computed tomography of the thorax. Can Assoc Radiol J 2003;54:26-30.
13. Collins AJ, Gillespie S, Kelly BE. Can computed tomography identify patients with anaemia? Ulster Med J 2001;70:116-118.
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IssueVol 16 No 4 (2021): J Teh Univ Heart Ctr QRcode
SectionOriginal Article(s)
DOI https://doi.org/10.18502/jthc.v16i4.8601
Keywords
Pulmonary embolism Multidetector computed tomography Contrast media Computed tomography angiography Sensitivity and specificity
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How to Cite
1.
Ehsanbakhsh A, Hatami F, Valizadeh N, Khorashadizadeh N, Norouzirad F. Evaluating the Performance of Unenhanced Computed Tomography in the Diagnosis of Pulmonary Embolism. J Tehran Heart Cent. 2021;16(4):156-161.