Dual-energy ct angiography for detection of pulmonary emboli: incremental benefit of iodine maps

Nguyen Thi Thanh, Vu Thanh Trung1, Nguyen Cong Tien1, Pham Minh Thong1
1 Bach Mai Hospital

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Abstract

Purpose: To determine if there is an added benefit of using iodine maps from dual-energy (DECT) in addition to conventional CT angiography images to diagnose pulmonary embolism (PE).
Materials and Methods: In this retrospective analysis, 49 consecutive dual-energy CT angiography examinations performed from August through July 2020 at Bach Mai Hospital to evaluate for PE were reviewed. The 49 examinations included 49 patients (mean age, 59.73 years; range, 22–99 years). First, the location, level, and type (occlusive vs nonocclusive) of PEs on conventional CT angiograms were recorded. Iodine maps were then reviewed for defects suggestive of PE. Last, CT angiograms were rereviewed to detect additional PEs suggested by the iodine map.
Results: 19/49 (38.8%) patients were diagnosed with PE, a total of 247 PEs were detected at initial review. After review of the DECT iodine map, 16 additional PEs were found on 8 of 49 (16.3%) patients in which 2 of 49 (4 %) patients had a new diagnosis of PE after review of the DECT iodine maps, 4/49 (8%) patients were diagnosed PE before. Of the 16 additional PEs, 8 (50%) were segmental, 8 (50%) were subsegmental, 3 (18.8 %) were occlusive, and 13 (81.2%) were nonocclusive
Conclusion: Dual-energy CT iodine maps show a small incremental benefit for the detection of occlusive segmental and subsegmental pulmonary emboli.

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References

1. Wiener RS, Schwartz LM, Woloshin S. Time trends in pulmonary embolism in the United States: evidence of overdiagnosis. Arch Intern Med. 2011;171(9):831-837. doi:10.1001/archinternmed.2011.178
2. Simonneau G, Sors H, Charbonnier B, et al. A comparison of low-molecular-weight heparin with unfractionated heparin for acute pulmonary embolism. The THESEE Study Group. Tinzaparine ou Heparine Standard: Evaluations dans l’Embolie Pulmonaire. N Engl J Med. 1997;337(10):663-669. doi:10.1056/NEJM199709043371002
3. Goldhaber SZ, Visani L, De Rosa M. Acute pulmonary embolism: clinical outcomes in the International Cooperative Pulmonary Embolism Registry (ICOPER). Lancet. 1999;353(9162):1386-1389. doi:10.1016/s0140-6736(98)07534-5
4. Schenzle JC, Sommer WH, Neumaier K, et al. Dual energy CT of the chest: how about the dose? Invest Radiol. 2010;45(6):347-353. doi:10.1097/RLI.0b013e3181df901d
5. Weidman EK, Plodkowski AJ, Halpenny DF, et al. Dual-Energy CT Angiography for Detection of Pulmonary Emboli: Incremental Benefit of Iodine Maps. Radiology. 2018;289(2):546-553. doi:10.1148/radiol.2018180594
6. Okada M, Kunihiro Y, Nakashima Y, et al. Added value of lung perfused blood volume images using dual-energy CT for assessment of acute pulmonary embolism. Eur J Radiol. 2015;84(1):172-177. doi:10.1016/j.ejrad.2014.09.009
7. Thieme SF, Ashoori N, Bamberg F, et al. Severity assessment of pulmonary embolism using dual energy CT - correlation of a pulmonary perfusion defect score with clinical and morphological parameters of blood oxygenation and right ventricular failure. Eur Radiol. 2012;22(2):269-278. doi:10.1007/s00330-011-2267-3
8. García SG, Ruiz AM, Prieto A, et al. Dual-energy CT (DECT) pulmonary angiography in acute pulmonary thromboembolism (PTE): causes, semiology and potential diagnostic pitfalls. ECR 2016 EPOS. Published March 2, 2016. Accessed June 8, 2020. https://epos.myesr.org/poster/esr/ecr2016/C-1598
9. Geyer LL, Scherr M, Körner M, et al. Imaging of acute pulmonary embolism using a dual energy CT system with rapid kVp switching: initial results. Eur J Radiol. 2012;81(12):3711-3718. doi:10.1016/j.ejrad.2011.02.043
10. Sheh SH, Bellin E, Freeman KD, Haramati LB. Pulmonary embolism diagnosis and mortality with pulmonary CT angiography versus ventilation-perfusion scintigraphy: evidence of overdiagnosis with CT? AJR Am J Roentgenol. 2012;198(6):1340-1345. doi:10.2214/AJR.11.6426
11. Pena E, Dennie C. Acute and chronic pulmonary embolism: an in-depth review for radiologists through the use of frequently asked questions. Semin Ultrasound CT MR. 2012;33(6):500-521. doi:10.1053/j.sult.2012.06.001
12. Kang M-J, Park CM, Lee C-H, Goo JM, Lee HJ. Dual-Energy CT: Clinical Applications in Various Pulmonary Diseases. RadioGraphics. 2010;30(3):685-698. doi:10.1148/rg.303095101