Naslov
CT and MR angiography in evaluation of renovascular hypertension

Autori
Šunjara, Vice ; Štern Padovan, Ranka ; Hrabak Paar, Maja ; Lušić, Mario

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
5th Central European Meeting on Hypertension, Final Programme and Abstract Book / - , 2009

Skup
5th Central European Meeting on Hypertension

Mjesto i datum
Zagreb, Hrvatska, 22.10.2009. - 25.10.2009

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
renovascular hypertension; CT angiography; MR angiography

Sažetak
In a small but important subset of hypertensive patients the disease is caused by the stenosis of renal artery. A number of radiological examination methods are used to assess the degree of stenosis and to prepare the patient for possible endovascular or surgical intervention. Color doppler sonography is often used as a first-line method but it has a number of limitations. Digital subtraction angiography (DSA) is invasive and is now usually performed as a part of endovascular intervention. Non-invasive evaluation of renal artery stenosis is performed using computed tomography (CTA) and magnetic resonance (MRA) angiography. CTA is unsurpassed in terms of both spatial resolution and speed. The spatial resolution, while less important in patients with mostly ostial atherosclerotic stenosis, is of crucial importance in those with fibromuscular dysplasia where the affected vessels are often segmental. The visualization of calcified plaques with CTA is both a blessing and a curse. It can be useful to ascertain the nature of atherosclerotic plaques causing the stenosis when planning the endovascular intervention, however, the calcium often makes it difficult to assess the remaining artery lumen, leading to overestimation of stenosis. CTA involves the application of a relatively large quantity of iodinated contrast, making it unsuitable for patients with decreased renal function. Its radiation dose is also quite high, necessitating caution in younger patients and those in need of repeated examinations. MRA of the renal arteries is commonly performed with contrast application. MRA still lags behind CTA in terms of the necessary time-resolution compromise. Artefacts can be more pronounced in MRA, especially if the imaging takes place too early or late after contrast application. The strength of MRA is its ability to depict only the arterial lumen, without calcified plaques which could hinder the accurate assessment of renal artery stenosis, thus increasing specificity. The contrast used in MRA is safer and linked to a lower rate of side effects than the iodinated contrast used in CTA, but it can cause nephrogenic systemic fibrosis, a rare but serious complication. There is no ionizing radiation, making repeat examinations in younger patients possible. On the other hand, MRA is contraindicated in patients with pacemakers and certain other metallic implants, and it is often impossible to perform in severely claustrophobic patients. Both methods result in poor images in uncooperative patients unable to hold their breath, but here CTA may be less artefact-prone. In conclusion, each method has several advantages and disadvantages compared to the other. Together, they are able to assess the stenosis in almost all patients with both the specificity and sensitivity of over 90%. However, it is important to remember that renal artery stenosis can be present without arterial hypertension and may not be the underlying cause of hypertension even if present.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

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