History
A 33-year-old male patient, complaining of a small mass on the right wrist, came to the hospital for a check-up. He noticed the mass a month ago and was asymptomatic. The mass was occasionally painful and he reported no history of trauma or injury. An ultrasound examination revealed a subcutaneous angiomatous
lesion. It was however unclear as to the vascular origin and involvement. A CT angiography (CTA) was requested for pre-operative evaluation.
Diagnosis
CTA images showed a mass on the palm-radial side of the right wrist, measuring 2.0 x 2.5 cm in size. The
nidus was ill-defined, heterogeneously enhanced, fed by two small arteries branching off the radial artery
and drained through the cephalic vein, the radial vein and the median antebrachial vein. No signs of lesion invasion into the muscular compartments or bones were seen. A diagnosis of a subcutaneous arteriovenous malformation (AVM) was suggested. Subsequently, the lesion was surgically removed, and the patient recovered uneventfully.
Fig. 1: cVRT images, using different presets, show an overview of the subcutaneous AVM.
Fig. 2: cVRT images, with three different oblique views, show the nidus, two feeding arteries (arrows) branching off the radial artery and the draining veins.
Comments
An AVM is classified as a high-flow vascular malformation. High-flow lesions comprise approximately 10%
of peripheral vascular malformations. Treatment strategy is based upon lesion characteristics such as subtype, depth, invasion of adjacent structures, as well as inflow and outflow vessels. Hereby, imaging examinations play a critical role in characterizing the lesions. In this case, an ultrasound examination depicts the angiomatous lesion, is however unable to visualize the two feeding arteries which are short and hidden. CTA is capable of delineating the feeding arteries, nidus, draining veins and lesion extent then providing important information to the physicians for a confident diagnosis and treatment planning. To improve the contrast-to-noise ratio and reduce the radiation exposure, a lower kV setting of 80 kV is applied in combination with standard dose reduction techniques, such as CARE Dose4D (automatic controlled tube current modulation) and ADMIRE (Advanced Modeled Iterative Reconstruction), achieving a dose value as low as 1.2 mGy. An advanced cinematic volume rendering technique is used to enable a lifelike three-dimensional image demonstration facilitating an easy communication between physicians as well as to the patient.