Variations in Measurements of the Aortic Knob in the Chest Radiograph in Normal and Hypertensive Subjects

  • Prakash Kayastha Tribhuvan University Teaching Hospital, Institute of Medicine
  • Sharma Paudel Tribhuvan University Teaching Hospital, Institute of Medicine https://orcid.org/0000-0001-7973-2711
  • Sundar Suwal Tribhuvan University Teaching Hospital, Institute of Medicine https://orcid.org/0000-0001-8534-3413
  • Binaya Adhikari Tribhuvan University Teaching Hospital, Institute of Medicine
  • Mukunda Prasad Humagain Tribhuvan University Teaching Hospital, Institute of Medicine
  • Bhawan Thapa Magar Patan Academy of Health Science
  • Krishna Prasad Adhikary Nepal Medical Council https://orcid.org/0000-0001-7162-5612
DOI: https://doi.org/10.46405/ejms.v2i2.212
Keywords: Aortic knob, chest x-ray, Chest radiograph, Measurements, Hypertensive population, Variation

Abstract

Background: Aortic knob enlarges in many cardiovascular disorders including hypertension. It can be easily evaluated in chest radiographs. The study was carried out to document and analyze measurements of aortic knob in normal and hypertensive population in chest radiograph.
Methods: This descriptive cross-sectional study was performed in the Department of Radiology and Imaging, Tribhuvan University Teaching Hospital (TUTH) and Manmohan Cardiothoracic Vascular and Transplant Center (MCVTC) from July to October 2019. Postero-anterior (PA) chest radiographs of 200 individuals (100 normal and 100 hypertensives) between the age of 18 to 70 years were evaluated. Width of aortic knob (AKW), straight length of aortic knob (AKS), curved length of aortic knob (AKC) and aortic knob index (AKI) were measured. Aortic knob index (AKI) was determined from AKC divided by AKS.
Results: The mean aortic knob index (AKI) for male and female were 1.24±0.06 and 1.20±0.07 respectively and the total mean aortic knob index (AKI) was 1.22±0.07 in normal population. In hypertensive population, aortic knob index (AKI) was 1.49±0.095 and 1.42±0.04 in male and female respectively. Total aortic knob index (AKI) for hypertensive population was 1.45±0.083. Aortic knob index in hypertensive population was significantly higher than that of normal population. Mean aortic knob index (AKI) in male was significantly higher than that in female in both normal and hypertensive population (p<0.05).
Conclusion: Aortic knob index (AKI), the index for aortic diameter, was higher in hypertensive population and male. Thus, simple measurement of aortic knob in PA chest x-ray may help in predicting cardiovascular disorder.

References

Sutton D, Gregson RHS. Arteriography and interventional angiography. In: Sutton D (ed). Textbook of Radiology and Imaging, Vol 1, 7th ed (2003). Churchill Livingstone, Edinburgh, pp 427.

Shankar N, Veeramani R, Ravindranath R, Philip B. Anatomical variations of the aortic knob in chest radiographs. European Journal of Anatomy. 2010;14(1):25-30.

Felson B. A review of over 30,000 normal chest roentgenograms. In: Chest Roentgenology. WB Saunders, Philadelphia (1973), pp 495.

Anyanwu GE, Anibeze CIP, Akpuaka FC. Transverse aortic arch diameters and relationship with heart size of Nigerians within the south east. Biomedical Research. 2007;18(2): 115-118.

Ikeme AC, Ogakwu MA, Nwakonobi FA. The significance of the enlargement of the aortic shadow in adult Nigerians. African journal of medicine and medical sciences. 1976 Sep;5(3):195-9.

Lee EJ, Han JH, Kwon KY, Kim JH, Han KH, Sung SY, Hong SR. The Relationship between Aortic Knob Width and Metabolic Syndrome. Korean Journal of Family Medicine, 2018;39(4),253–259. https://doi.org/10.4082/kjfm.17.0038

Ray A, Mandal D, Kundu P, Manna S and Mandal S. Aortic knob diameter in chest X-ray and its relation with age, heart diameter and transverse diameter of thorax in a population of Bankura District of West Bengal, India: a cross sectional study. Journal of Evolution of Medical and Dental Sciences. 2014;3(31):8595–600. DOI: 10.14260/jemds/2014/3092

Obikili EN, Okoye IJ. Aortic arch diameter in frontal chest radiographs of a normal Nigerian population. Nigerian Journal of Medicine: Journal of the National Association of Resident Doctors of Nigeria. 2004 Apr-Jun;13(2):171-174.

Afsar B, Saglam M, Yuceturk C, Agca E. The relationship between aortic knob width and various demographic, clinical, and laboratory parameters in stable hemodialysis patients. Saudi J Kidney Dis Transpl [serial online] 2014 [cited 2020 Dec 15];25:1178-85. Available from: https://www.sjkdt.org/text.asp?2014/25/6/1178/144250

Brian LR, Hillel G, Lionel HO. The chest radiograph: A useful investigation in the evaluation of hypertensive patients. American Journal of Hypertension. 2004 June;17(6):507–510. https://doi.org/10.1016/j.amjhyper.2004.02.012

Published
2020-12-30
How to Cite
1.
Kayastha P, Paudel S, Suwal S, Adhikari B, Humagain MP, Thapa Magar B, Adhikary KP. Variations in Measurements of the Aortic Knob in the Chest Radiograph in Normal and Hypertensive Subjects. Europasian J Med Sci. [Internet]. 2020Dec.30 [cited 2024May16];2(2):92-6. Available from: https://www.europasianjournals.org/ejms/index.php/ejms/article/view/212
Issue
Vol 2 No 2 (2020): EJMS | July - December Issue 4
Section
Original Articles

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