Simultaneous vessel size and blood volume measurement in a human tumor outside the brain

The interest in MRI methods that are capable of non-invasively measuring the microvascular structure of tumors has grown steadily over the past years [1,2]. As shown in a previous work, we have developed an approach to joint blood volume and vessel size assessment via simultaneous R2 and R2* quantification pre and post injection of a super-paramagnetic blood pool agent [3]. Preclinical studies have validated the technique against histology and have demonstrated its sensitivity to subtle microvascular changes during anti-angiogenic / anti-vascular treatments [4]. This work reports from the experience in a patient with a pleomorphic sarcoma in the pubic bone and thus presents, to our knowledge, the first vessel size map outside the brain. It further proposes a protocol for fast and robust abdominal vascularization measurements, which accounts for the rapid washout of clinical contrast agents.