Ultrasound International Open – Recently Published

Strain Elastography – How to do it? 

Christoph F. Dietrich, Richard G. Barr, André Farrokh, Manjiri Dighe, Michael Hocke, Christian Jenssen, Yi Dong, Adrian Saftoiu, Roald Flesland Havre

doi:10.1055/s-0043-119412

Tissue stiffness assessed by palpation for diagnosing pathology has been used for thousands of years. Ultrasound elastography has been developed more recently to display similar information on tissue stiffness as an image. There are two main types of ultrasound elastography, strain and shear wave. Strain elastography is a qualitative technique and provides information on the relative stiffness between one tissue and another.

Fig. 4 Soft tissue above stiff lesion shows more strain (red coloring) than adjacent tissue at the same depth (green coloring).

Sonographic Venous Velocity Index Identifies Patients with Chronic Kidney Disease and Severe Diastolic Dysfunction 

Markus Meier, Wolfram Johannes Jabs, Maria Guthmann, Gesa Geppert, Ali Aydin, Martin Nitschke

doi:10.1055/a-0684-9483

Diagnosing cardiorenal syndrome (CRS) in patients with chronic kidney disease (CKD) continues to remain challenging in outpatient practice. Patients with CRS (n = 30), CKD (n = 30), and NRF (n = 30) were included in the study. For each patient, duplex ultrasound scans of intrarenal segmental veins were retrospectively analyzed. The VVI was calculated from the renal venous doppler curve as the ratio of the maximal positive venous velocity to the maximal negative venous velocity. Patients with CRS were compared to age-matched controls with NRF and to GFR-matched controls with CKD.

Fig. 3 Exemplary kidney duplex ultrasound investigations of a patient with CKD. Venous Doppler spectrum of a patient with ADPKD a shows a monophasic negative flow pattern, whereas a patient with nephrosclerosis shows a biphasic flow pattern b. Calculation of the venous duplex index (VVI) in patient A (no positive flow): VVI = 0; patient B: VVI = V1 / V2 = 0.16.

Evaluation of Peak Reflux Velocities with Vector Flow Imaging and Spectral Doppler Ultrasound in Varicose Veins 

Thor Bechsgaard, Kristoffer Lindskov Hansen, et al.

doi:10.1055/a-0643-4430

Spectral Doppler ultrasound (SDUS) is used for quantifying reflux in lower extremity varicose veins. The technique is angle-dependent opposed to the new angle-independent Vector Flow Imaging (VFI) method. 64 patients with chronic venous disease were scanned with VFI and SDUS in the great or the small saphenous vein, and reflux velocities were compared to three assessment tools for chronic venous disease. A flow rig was used to assess the accuracy and precision of the two methods.

Fig. 1 a Longitudinal SDUS scan of superficial lower extremity vein with valve incompetence causing reflux. The range gate covers the vessel without including vessel boundaries and 30° beam steering is applied reducing the insonation angle from 90° to 60°. The spectrogram for the SDUS data is shown at the bottom of the figure. b Corresponding longitudinal VFI scan. The VFI region of interest was placed corresponding to the position of the SDUS range gate. A 2D vector velocity map is displayed with VFI to depict the directions and magnitudes of the blood flow. A color wheel is provided and superimposed arrows on the color-coded pixels ease the velocity interpretation. Velocity curve for VFI data is shown at the bottom of the figure.