The cervix sign and other sonographic signs of hypertrophic pyloric stenosis

Excerpt

In the presence of hypertrophic pyloric stenosis (HPS), the sonographic resemblance of the thickened and elongated pylorus to the normal ultrasound appearance of the uterine cervix on longitudinal views has been termed the “cervix sign” (Figure 1A) [1]. An orthogonal image of this process with the hypoechoic muscle surrounding the echogenic mucosa yields the “target” sign, also known as the “donut” or “bull’s eye” sign (Figure 1C]) [2]. Prominent hyperechoic mucosa projecting into the antrum is known as the antral nipple sign [Figure 1B] [1]. Although muscle wall thickness of >3 mm is the most definitive criteria for HPS on sonography [3], cervix sign [Figure 1A], antral nipple sign [Figure 1B], and target sign [Figure 1C] are associated sonographic appearances. Pyloric canal length is variable, ranging from ~14 to 20 mm. These classical appearances were seen in a 5-month-old male infant who presented with progressive bouts of projectile vomiting for 10 days. He underwent surgical pyloromyotomy with absolute relief from complaints. The closest differential diagnosis for thickened pyloric canal is pylorospasm. Muscle measurements in pylorospasm may overlap with HPS, but variability in morphology and measurement during the study helps in the diagnosis of pylorospasm [1, 4].

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