Targeted ultrasound is the procedure of choice for detecting rudimentary branchial cysts causing jugular and subclavian vein thrombosis.

The aim of this study was to facilitate the imaging diagnosis of branchial cysts leading to combined jugular and subclavian vein thrombosis during ovarian hyperstimulation syndrome (OHSS). Three women developed combined jugular and subclavian vein thrombosis following OHSS related to assisted reproductive technologies. The imaging modalities used for diagnosis were a bimode Doppler ultrasound, MRI of the neck in two women, computed tomography (CT) angiography and venography in one. Targeted ultrasound identified the rudimentary cysts in all patients, whereas CT angiography performed with contrast material failed to detect the cyst, which resembled a vessel with thrombus in the lumen. MRI performed at the same level did detect the cyst; however, MRI of the neck requires special attention using a dedicated cystic protocol at the base of the neck. Venography was performed in one patient; it demonstrated the thrombosed vein possibly with some extrinsic compression, but it could not define a cyst. Targeted ultrasound is the simplest and best imaging modality for discerning rudimentary cysts in pregnant women with OHSS who present with jugular and subclavian vein thrombosis following assisted reproductive technology. A search for the cyst at the time of OHSS is important, as early detection could decrease the risk of developing thrombosis.