Coronal MR angiography of the IVC
Cardiovascular
Case TypeClinical Cases
AuthorsG. Giannikouris, I. Staikidou, C. Pikoulas, G. Mantzikopoulos
Patient23 years, female
The left IVC or transposition of the IVC occurs in 0.2-0.5% of the general population [1-3] as a result of an embryological disorder (persistence of the infrarenal part of the left supracardinal vein and regression of the infrarenal part of the right supracardinal vein).
The interruption of the IVC with hemiazygos or azygos continuation is a rare (0.6%), but well-described anomaly [4,5]. A more rare anomaly is the presence of a left IVC with hemiazygos continuation. In this situation there are three possible routes for the return of the blood to the right atrium [3]: (a) via the azygos vein to the SVC, (b) via the accessory hemiazygos and left superior intercostal veins to the left brachiocephalic vein, or (c) via the accessory hemiazygos and a persistent left SVC into the coronary sinus.
In this patient the blood return was via the hemiazygos vein to the azygos vein and through the SVC into the right atrium. Although there have been cases reported in the radiological literature of hemiazygos continuation of a left IVC, to our knowledge there has been no previous report of such a case investigated with contrast-enhanced MR venography demonstrating additional venous anomalies in the abdomen (which in this patient were the presence of a hypoplastic intrahepatic segment of the right IVC and anomalous venous drainage of the hepatic segments V and VI into the right renal vein).
IVC anomalies are most often detected incidentally. Recognition of these anomalies can be very important and can prevent diagnostic mistakes as well as problems when planning intervention procedures (placement of IVC filters, renal vein sampling) or abdominal surgery (aortic aneurysm repair, renal transplantation or donor evaluation, adrenalectomy, nephrectomy or left sympathectomy).
MR venography is a safe and reliable contrast-enhanced alternative to conventional or CT venography. The procedure is quick and simple and can be combined with phase contrast venography and flow direction studies.
[1] Munechika H, Cohan R, Baker M, Cooper C, Dunnick NR. Hemiazygos continuation of a left inferior vena cava: CT appearance. J Comput Assist Tomogr 1988;12(2):328-30. (PMID: 3351050)
[2] Kim HJ, Ahn IO, Park ED. Hemiazygos continuation of a left inferior vena cava draining into the right atrium via persistent left superior vena cava. Demonstration by helical computed tomography. Cardiovasc Intervent Radiol 1995;18:65-7. (PMID: 7788639)
[3] Bass JE,Redwine MD, Kramer LA, Huynh PT, Harris JH Jr. Spectrum of congenital anomalies of the inferior vena cava: Cross-sectional imaging findings. Radiographics 2000;20:639-52. (PMID: 10835118)
[4] Minniti S, Visentini S, Procacci C. Congenital anomalies of the venae cavae: embryological origin, imaging features and report of three new variants. Eur Radiol 2002;12:1869-71. (PMID: 12136323)
URL: | https://www.eurorad.org/case/2067 |
DOI: | 10.1594/EURORAD/CASE.2067 |
ISSN: | 1563-4086 |