Name : Hamidreza
Affiliation : Radiology department,ShohadaTajrish Hospital,SBMU
Academic Degree: Associate professor of Radiology
Resident : Ramin Pourghorban, Hamid Jafarzadeh
Gender : Male
Age : 38
Uroradiology & Genital Male Imaging
38 years old male with gross hematuria
Imaging Procedures and Findings
A 38 years old male was referred with gross hematuria. No history of prior trauma or percutaneous biopsy was revealed. On longitudinal gray scale ultrasound exam (image-1), a simple round anechoic structure is shown in the middle pole of the left kidney. On color doppler study (image-2) the mentioned lesion shows turbulent internal vascular flow. High-velocity, low-impedance pulsatile flow was detected on doppler duplex study (image-3). Abdominal CT after contrast medium administration (images4-6) demonstrates tortuous left renal artery accompanied by dilatation of intrarenal veins.Notice that left renal artery and vein are opacified simultaneously consistent with cirsoid arteriovenous malformation. Also noted is delayed contrast excretion of left kidney compared to the right one.
The prevalence of congenital renal AVM is less than 0.04%. Congenital renal AVMs of the kidney are sometimes called cirsoid AVMs. These tortuous, varixlike vessels are immediately beneath the urothelium and lead to hematuria as the presenting finding in up to 72% of cases. They account for slightly less than one-quarter of all renal AVMs. In contrast, acquired lesions are aneurysmal, typically with a solitary communication between the artery and vein. They account for almost three-quarters of all renal AVMs and have been associated with renal biopsy (the most common cause), other renal surgical procedures (eg, nephrectomy, heminephrectomy, nephrolithotomy), trauma (usually penetrating), and malignant tumors. Idiopathic lesions are also aneurysmal, with a single cavernous channel and well-defined arterial and venous elements. They account for 3%??5% of all renal AVMs. Acquired and idiopathic lesions cause increased venous return and high cardiac output, and are more likely to result in cardiovascular signs and symptoms. Multidetector CT is useful in evaluating renal AVM and fistula. Unenhanced scans show only renal caliceal or pelvic hemorrhage and cortical atrophy. On early phase scans obtained with the bolus injection technique, renal AVM is clearly seen as a vascular-attenuation mass located in the renal sinus and surrounding the pelvicaliceal system. Delayed phase CT scans commonly show renal AVM to have the same attenuation as the inferior vena cava. In addition, the renal and left gonadal veins are often dilated; however, definition of the communicating renal artery and draining vein is often poor. Color Doppler US is the first-line imaging procedure for renal AVM because of its low cost, less invasive nature, and wide availability. Color Doppler US is reported to have successfully demonstrated a small, mosaiclike vascular area with posterior color spots (representing tissue vibration) in a patient with renal AVM. Yokoyama and Tsuji concluded that color Doppler US is excellent for demonstrating turbulent blood flow within the kidney. Takebayashi et al reported that color Doppler US revealed a small peripheral malformation that was indistinct at selective angiography; however, they concluded that it was difficult to distinguish arteriovenous fistula from aneurysm at color Doppler US, and that flow in normal vessels grouped in the renal hilum obscures the lighter-colored flow in a small central renal AVM.
Cirsoid Renal AVM
Muraoka N,Sakai T, Kimura H, et al. Rare Causes of Hematuria Associated with Various Vascular Diseases Involving the Upper Urinary Tract. RadioGraphics 2008; 28: 855Ã¢??867.