Pulmonar ARFI elastography and ultrasonography of canine fetal hydrops: case report

M.C Maronezi,G.M Madruga,A.R Assis,R.A.R Uscategui,C.A Cintra,A.P.R Simões,P Silva,W.R.R Vicente,M.G.K Rodrigues,M.A.R Feliciano

doi:10.1590/1678-4162-10001

Abstract

ABSTRACT This case report describes diagnostic and prognostic applicability of pulmonary acoustic radiation force impulse elastography and ultrasonography in canine hydrops fetalis. We also explore these methods’ potential in prediction of postnatal respiratory dysfunction. Two pregnant bitches (English bulldog [case 1] and French bulldog [case 2]) were referred for sonographic evaluation in their last week of pregnancy. Ultrasound showed that in each bitch, one fetus presented with lung alterations (hyperechogenicity, irregular surface, and pleural effusion) and anasarca. The other fetuses of the litter were normal, and they were observed as light gray and dark blue on pulmonary elastography. Their shear-wave velocity was 0.75m/s. Fetuses with hydrops were observed as medium gray and dark blue, and the average shear-wave velocities were 1.05m/s (case 1) and 1.12m/s (case 2). Findings were compatible with increased lung rigidity. Six neonates of English bulldog and two of French bulldog showed no signs of clinical abnormalities during neonatal assessment. One puppy in each gestation presented with anasarca and respiratory distress, and died approximately 24 hours after birth. Novel ultrasound techniques (elastography) for assessing pulmonary tissues in abnormal fetuses in veterinary obstetrics can promote early, safe, and non-invasive diagnosis of canine prenatal and neonatal alterations.

Highlights

INTRODUCTIONCanine hydrops fetalis is a congenital abnormality caused by hemostatic imbalance of fluids in the fetus, leading to the fluid accumulation in subcutaneous tissues (anasarca), the central nervous system (hydrocephalus), fetal membranes (hydroallantois or hydramnios), and cavities (peritoneal, pericardial, and pleural effusions) (Assis et al, 2013; Feliciano et al, 2013)
Canine hydrops fetalis is a congenital abnormality caused by hemostatic imbalance of fluids in the fetus, leading to the fluid accumulation in subcutaneous tissues, the central nervous system, fetal membranes, and cavities (Assis et al, 2013; Feliciano et al, 2013)
Acoustic radiation force impulse (ARFI) elastography is an ultrasound imaging technique used for the assessment of tissue elasticity (Feliciano et al, 2014)

Summary

INTRODUCTION

Canine hydrops fetalis is a congenital abnormality caused by hemostatic imbalance of fluids in the fetus, leading to the fluid accumulation in subcutaneous tissues (anasarca), the central nervous system (hydrocephalus), fetal membranes (hydroallantois or hydramnios), and cavities (peritoneal, pericardial, and pleural effusions) (Assis et al, 2013; Feliciano et al, 2013). One fetus presented with lung hyperechogenicity (compared with the other fetuses), irregular pulmonary surface (pulmonary retraction), pleural effusion, subcutaneous thickening, and an anechoic band between the skin and muscle layer (Figure 1) These findings were compatible with hydrops fetalis. Qualitative and quantitative analysis of the fetal pulmonary structures in normal fetuses and those with hydrops were performed using the VTIQ method of ARFI (virtual touch tissue imaging quantification, 2D shear-wave elastography technique) (Feliciano et al, 2014; Tang et al, 2015). Fetuses with hydrops were observed as medium gray and dark blue, and their average shear-wave velocities were 1.05m/s (case 1) and 1.12m/s (case 2) These findings were compatible with increased lung rigidity (Figures 2 and 3).

DISCUSSION

CONCLUSION