Color Doppler and Microvascular Flow Imaging to Evaluate the Degree of Inflammation in a Case of Hidradenitis Suppurativa

Microvascular Flow Imaging is a new ultrasound technique with better ability than Color Doppler Imaging to identify small vessels that have slow blood flow, and it permits better evaluation of the features, especially microvascular architecture, of various lesions. We describe a case of inguinal hidradenitis suppurativa in a patient with positive risk factors (young age, female, smoker, and obese), diagnosed by ultrasonography using B-Mode, Color Doppler, and finally also with Microvascular Flow Imaging. Our aim is to demonstrate the usefulness of this new technique in characterization of lesions.

Veno-Arterial Index (VAI)—A Promising Tool For Identifying Renal Transplant Rejection

The objective of this study is to evaluate the veno-arterial index (VAI) as a predictor of renal rejection in kidney transplant patients. A diagnostic test study was conducted between January 2014 and May 2018. Renal transplant patients who underwent percutaneous renal biopsy were included. The VAI was obtained by measuring the flow velocity in the renal segmental vein and dividing this value by the peak systolic velocity of the segmental artery in this same location. The records of 77 patients were analyzed. Among these patients, 32 (42%) were positive for transplant rejection and 29 presented with acute rejection. In patients with renal rejection, the median VAI was 0.67 (interquartile range [IQR] = 0.56-0.87), and in kidneys with a negative biopsy for rejection, the median VAI was 0.41 (IQR = 0.27-0.57), with a statistically significant difference ( P = .007) and a value much higher than that obtained for the general population of 0.30 (IQR = 0.18-0.44). Subacute and acute rejected kidneys had an even higher VAI of 0.725 (IQR = 0.57-0.87; P = .0001). Although the resistive index has a good correlation with glomerular filtration, it is not possible by that index to differentiate among the multiple causes that can lead to graft dysfunction. The results of this study show that the VAI might be a useful parameter, which when elevated could predict renal transplant rejection.

A Possible Role for Arterial Duplex and Hand Acceleration Time in Diagnosing and Managing Shock

Shock represents a state when arterial perfusion is inadequate to supply the needs of cellular respiration, leading to anerobic metabolism, acidosis, and cell death. Although typically described in terms of blood pressure and heart rate, these measures can both lead to delayed recognition of shock and under appreciation of the severity of end-organ malperfusion. Recently, there has been increased interest in monitoring peripheral perfusion both to detect early shock and monitor the response to treatment. However, current methods are variable and, in some cases, require specialized equipment. We present a case in which duplex ultrasound assessment of peripheral palmar acceleration time identified a post-hemorrhagic shock state before it was clinically apparent. Bedside arterial duplex and hand acceleration time may provide a simple tool to assess the degree of shock and response to intervention.

Development of a Duplex Ultrasound Protocol for Baseline and Follow-Up Imaging of a Branched Aortic Endoprosthesis

Branched endoprostheses for endovascular repair of pararenal and thoracoabdominal aortic aneurysms are undergoing evaluation in prospective clinical trials. Duplex ultrasound has been a cornerstone of surveillance for vascular reconstructions. This paper describes the development and deployment of a standardized duplex imaging protocol to evaluate individuals who have undergone endovascular repair of their thoracoabdominal aortic aneurysm. Ultrasound imaging is performed after an 8 to 12 hour fast to minimize the presence of bowel gas and allow for optimal imaging of abdominal vascular structures. Doppler measurements of peak systolic and end diastolic velocity are made at specific arterial segments in the aorta and the celiac, superior mesenteric, and renal arteries. Resistive indices are also recorded in the segmental and arcuate arteries of both kidneys. Pulsed-wave Doppler is used to record spectral Doppler data and color Doppler is used to image all arterial segments and ensure proper placement of the Doppler sample volume and ensure correct angle of interrogation. Implementation of a standardized duplex ultrasound imaging protocol can be used to image and follow individuals who have received the Thoracoabdominal Branch Endoprosthesis (TAMBE) device and branched endovascular aneurysm repair (BEVAR). Ultrasound may provide complementary findings and may add information to the computed tomography angiography imaging for following these individuals.