UHF Ultrasound Imaging for Preventative Medicine

Submitted by Dr. Frida Dangardt, Physician and Medical Researcher, University of Gothenburg, Sweden.

With improving treatment, the survival rate of children with different types of chronic disease has increased substantially in the last decade. Therefore, there is now an emerging problem of cardiovascular disease (CVD) affecting those who reach adulthood, as many of these diseases are known to have an adverse impact on the cardiovascular system. This holds true especially for children with type 1 diabetes (T1D) and chronic kidney disease (CKD), where cardiovascular changes are severe and CVD represents a large part of the increased mortality seen in these groups. In children with cystic fibrosis (CF), which could be considered an inflammatory disease, very little is known about the development of CVD, however, some studies in adults suggest that there are vascular changes involved. A program allowing a thorough characterisation of the different parts of the cardiovascular system (including vascular morphology and function, autonomic regulation and cardiorespiratory fitness) may facilitate prevention strategies and treatment optimisation to proactively minimise the cardiovascular consequences already in childhood.

New, ultra high frequency (UHF) ultrasound techniques are now available to enable visualisation of the separate layers of the vessel wall (intima, media and adventitia). This allows us to establish in which part of the vessel wall the initial changes appear, as well as possibly identifying changes at an earlier stage than with the composite measurement of IMT by conventional methods. We are then able to differ between the atherosclerotic changes in the intima driven by inflammation and lipids and the pressure driven changes in the smooth muscle of the media, or medial calcification as seen in patients with kidney disease (1). Using UHF B-mode ultrasound with technology from FUJIFILM VisualSonics, Inc. (under special ethics approval) with discrimination power of 30 μm, the feasibility of measuring intimal thickness (IT) of the radial and dorsal pedal arteries separately from medial thickness (MT) even in children has been demonstrated (2-4), and gender differences exist already early on (4). Increased IT has also been demonstrated in children with obesity (2). This may prove useful for treatment monitoring and for following disease progression.

1. Shroff R, Long D and Shanahan C. Mechanistic Insights into Vascular Calcification in CKD. JASN 2013; 24: 179-189.

2. Dangardt F, Osika W, Volkmann R, Gan LM, Friberg P. Obese children show increased intimal wall thickness and decreased pulse wave velocity. Clin Physiol Funct Imaging. 2008;28(5):287–93.

3. Osika W, Dangardt F, Gronros J, Lundstam U, Myredal A, Johansson M, et al. Increasing Peripheral Artery Intima Thickness From Childhood to Seniority. Arterioscler Thromb Vasc Biol. 2007;27(3):671–6.

4. Osika W, Dangardt F, Montgomery SM, Volkmann R, Gan LM, Friberg P. Sex differences in peripheral artery intima, media and intima media thickness in children and adolescents. Atherosclerosis. 2009;203(1):172–7.

Dr. Dangardt is a physician and medical researcher at the University of Gothenburg, Sweden. Her research has primarily focused on cardiovascular and metabolic conditions in children. Above, she discusses her current work on the cardiovascular effects of chronic childhood disease. This type of preventative research has the potential to help alleviate the burden caused by cardiovascular and metabolic disorders. It is also a great example of the utility of our Vevo imaging technology in the field of preventative medicine.