Comparison of CT Pulmonary Angiography Quality at Low Tube Voltage (80 Kvp) With Standard Conditions (100 Kvp) Among the Patients with Suspected Pulmonary Embolism

Mohammad Davoodi, Mohammad Gharibvand, Goodarz Shahrami Babakan

Abstract


Background: Pulmonary embolism (PE) is a common and potentially devastating cardiovascular complication with a high mortality rate, worldwide. The diagnosis based solely on the presence of clinical features remains challenging due to heterogeneity of the nonspecific manifestations of the disease. CT pulmonary angiography (CTPA) is a fast, accurate and cost effective diagnostic test of PE, as the radiation exposure to the patient is the major disadvantage of this technique. Since voltage drop result in reduce radiation exposure, comparison of image quality at different tube voltages may provide an optimum and secure voltage for patients.

Aim: Comparison of CTPA quality at low tube voltage (80 kVp) with standard conditions (100 kVp) among the patients with suspected pulmonary embolism, referred to the Golestan Hospital, Ahvaz

Materials and methods: In this triple-blind clinical trial, 92 patients with suspected PE already admitted to the Golestan Hospital, randomly divided into two equal groups and CTPA was performed at 2 different dose protocols: group A (80 kVp) and group B (100 kVp). The groups were then compared based on the image quality scores reported by two radiologists, along with the image quality parameters (SNR, and CNR) and the radiation dose (DLP).

Results: The overall image quality score of in-group A was higher than that in-group B (p = 0.002). Although group A was also superior (P < 0.0001) to group B with regard to image noise, but the signal-to-noise ratio (SNR) and the carrier-to-noise ratio (CNR) values were similar at different contrast levels for both groups. In addition, the radiation dose (DLP) was lower in-group A than in-group B.

Conclusion: The results indicated that a reduction in tube voltage from 100 kV to 80 kV in CTPA could both reduce the radiation dose and improve the diagnostic image quality.

Key words: CT pulmonary angiography, Voltage, Image quality, Radiation


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References


Bĕlohlávek J, Dytrych V, Linhart A. Pulmonary embolism, part I: Epidemiology, risk factors and risk stratification, pathophysiology, clinical presentation, diagnosis and nonthrombotic pulmonary embolism. Experimental & Clinical Cardiology. 2013;18(2):129.

Mostafazadeh B, Ahmad EF, Zavvareh HT, Gharadaghi J, Saleki S. Prevalence of pulmonary thromboemboli among referred cadavers having hospitalization records to Tehran Legal Medicine Center. Journal of forensic and legal medicine. 2008 Jul 31;15(5):322-4.

J. E. Dalen, “Pulmonary embolism: what have we learned since Virchow? Natural history, pathophysiology, and diagnosis,” Chest, vol. 122, no. 4, pp. 1440–1456, 2002

Doğan H, de Roos A, Geleijins J, Huisman MV, Kroft LJ. The role of computed tomography in the diagnosis of acute and chronic pulmonary embolism. Diagnostic and Interventional Radiology. 2015 Jul;21(4):307.

Marshall PS, Matthews KS, Siegel MD. Diagnosis and management of life-threatening pulmonary embolism. Journal of intensive care medicine. 2011 May 23:0885066610392658.

Brenner DJ, Hall EJ. Computed tomography—an increasing source of radiation exposure. New England Journal of Medicine. 2007 Nov 29;357(22):2277-84.

Kalra MK, Prasad S, Saini S, Blake MA, Varghese J, Halpern EF, Thrall JH, Rhea JT. Clinical comparison of standard-dose and 50% reduced-dose abdominal CT: effect on image quality. AJR Am J Roentgenol 2002;179:1101-6.

Schueller-Weidekamm C, Schaefer-Prokop CM, Weber M, Herold CJ, Prokop M. CT angiography of pulmonary arteries to detect pulmonary embolism: improvement of vascular enhancement with low kilovoltage settings 1. Radiology. 2006 Dec;241(3):899-907.

Heyer CM, Mohr PS, Lemburg SP, et al. Image Quality and Radiation Exposure at Pulmonary CT Angiography with 100- or 120-kVp Protocol: Prospective Randomized Study. Radiology 2007; 245(2):577-83.

Szucs-Farkas Z, Schaller C, Bensler S, et al. Detection of Pulmonary Emboli With CT Angiography at Reduced Radiation Exposure and Contrast Material Volume: Comparison of 80 kVp and 120 kVp Protocols in a Matched Cohort. Investigative Radiology 2009; 44(12):793-99.

Gill MK, Vijayananthan A, Kumar G, Jayarani K, Ng KH, Sun Z. Use of 100 kV versus 120 kV in computed tomography pulmonary angiography in the detection of pulmonary embolism: effect on radiation dose and image quality. Quantitative imaging in medicine and surgery. 2015 Aug;5(4):524.

Zamboni GA, Guariglia S, Bonfante A, Martino C, Cavedon C, Mucelli RP. Low voltage CTPA for patients with suspected pulmonary embolism. European journal of radiology. 2012 Apr 30;81(4):e580-4.

Viteri-Ramírez G, Garcia-Lallana A, Simon-Yarza I, Broncano J, Ferreira M, Pueyo JC, Villanueva A, Bastarrika G. Low radiation and low-contrast dose pulmonary CT angiography: Comparison of 80 kVp/60 ml and 100 kVp/80 ml protocols. Clinical radiology. 2012 Sep 30;67(9):833-9.

Bogot NR, Fingerle A, Shaham D, Nissenbaum I, Sosna J. Image quality of low-energy pulmonary CT angiography: comparison with standard CT. American Journal of Roentgenology. 2011 Aug;197(2):W273-8.

Qi L, Yan’E Z, Zhou CS, Spearman JV, Renker M, Schoepf UJ, Zhang LJ, Lu GM. Image quality and radiation dose of lower extremity CT angiography at 70 kVp on an integrated circuit detector dual-source computed tomography. Acta Radiologica. 2014 Jun 11:0284185114535391.

Yilmaz Ö, Üstün ED, Kayan M, Kayan F, Aktaş AR, Unlu EN, Degirmenci B, Çetin M. Diagnostic quality of CT pulmonary angiography in pulmonary thromboembolism: A comparison of three different kV values. Medical science monitor: international medical journal of experimental and clinical research. 2013;19:908.


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