Low flow vascular malformations of the head and neck: a study on brightness mode, color coded duplex and spectral Doppler sonography

The clinical presentation of low flow vascular malformations of the head and neck (LFVM) can range from a birthmark to severe disfigurement, functional impairment or relevant hemorrhage. The values of Brightness mode (B-mode) ultrasound and Doppler sonography in the investigation, identifying and differentiating of these lesions has been sparingly documented in the literature. This study evaluates the sonografic features of different morphological subtypes of LFVM. This is a 2-year retrospective study of 51 patients who presented with LFVM based on routine ultrasound exam in the context of their clinical consultation. Diagnosis was based on the clinical and histological findings. B-mode, color coded duplex and spectral Doppler measurements were performed for venous, lymphatic, capillary, and mixed venous-lymphatic lesions of the head and neck. The echogenicity of the majority of venous malformations was heterogenic, of most lymphatic malformations hypoechoic, and of all capillary malformations isoechoic. Blood flow was detected in only 11 cases (36.7%) of venous malformations with a monophasic pattern. There was a statistical significant difference in the mean minimum and maximum Doppler shifts between venous and lymphatic malformation for cases when the blood flow was evident. No statistical significant difference in Doppler parameters existed between capillary and lymphatic, neither between venous and capillary nor mixed malformations. Phleboliths were present in eight cases (26.7%) of venous malformations and were not detectable in any other subtype of LFVM. The detection of flow in ultrasound was only possible in a small portion of LFVM. When considering differentiating among LFVM, features such as the echogenecity, spectral Doppler wave forms, and the evidence of phleboliths contribute to establish the correct diagnosis.