The significance of the wall echo shadow triad on ultrasonography: a case series

Abstract

Background The wall echo shadow (WES) triad, also known as the double-arc-shadow sign consists of a welldefined near wall, echos from stones immediately beneath the wall, and posterior shadowing caused by strong echoes from stones in the gallbladder fossa. It has been used for over 20 years as a nonspecific finding suggestive of a gallbladder lumen filled with either multiple stones or one large stone (Miller et al. J Emerg Med 30(1):69-74, 2006; Blaivas et al. Acad Emerg Med 10(6):1020-1023, 1999; Raptopoulos et al. AJR Am J Roentgenol 138(2): [275][276][277][278] 1982). In the past, the WES triad has been correlated with underlying chronic cholecystitis. However, there are no studies that compare clinical findings to a gold standard such as surgical pathology. Case reports Three cases of the WES triad were reviewed at New York Medical Hospital of Queens over a 16-month period. Case reports Case 1A 79-year-old female presented to the Emergency Department (ED) with right upper quadrant (RUQ) abdominal pain radiating to the right flank for 2 weeks. Symptoms were associated with subjective fevers and anorexia. The patient denied nausea or vomiting. Her past medical history was significant for hypertension, hyperlipidemia and hypothyroidism. Vital signs were normal. Laboratory tests including white blood cell count, total bilirubin and liver function tests were all normal. A RUQ ultrasound was remarkable for echogenic shadowing seen from the level of the gallbladder fossa representing a gallbladder filled with stones ( Fig. 1). No sonographic Murphy's sign was elicited. There was no gallbladder wall thickening. The patient had resolution of her abdominal pain and was discharged with outpatient surgical followup. 19 days later, an elective laparoscopic cholecystectomy was performed. The pathology report was consistent with a diagnosis of acute and chronic cholecystitis. Case 2A 29-year-old male presented to the Emergency Department with RUQ pain associated with nausea and vomiting. The patient had no significant past medical history. The vital signs were normal. The physical exam was significant only for RUQ tenderness. The patient was discharged from the Emergency Department diagnosed with cholelithiasis after evaluation with normal laboratory results, normal computed tomography (CT) scan of the abdomen and an ultrasound that demonstrated the WES triad. The patient returned to the Emergency Department 1 month later with