Final Pr. ID: Poster #: SCI-013
Idiopathic thickening of the pyloric muscle can occur in young infants, causing projectile vomiting, electrolyte abnormalities, and necessity for surgical intervention to relieve the gastric outlet obstruction. Case reports have been published describing infants with HPS who also have portal venous gas (PVG) visualized within the liver. The presence of PVG in other clinical scenarios often indicates a severe and potentially life threatening bowel condition. The purpose of this study was to determine the incidence of infants with hypertrophic pyloric stenosis (HPS) and concurrent portal venous gas (PVG), as well as whether there are unique clinical features or different outcomes in the HPS patients with PVG versus without PVG. Read More
Final Pr. ID: Poster #: EDU-001 (R)
Background: Infantile hypertrophic pyloric stenosis (IHPS) is a condition affecting young infants in which the circular muscle layer of pylorus becomes thickened, leading to narrowing and elongation of the pyloric channel. The pyloric mucosa becomes redundant and appears hypertrophic. On ultrasound, the thickened pylorus is often seen adjacent to the gallbladder and anteromedial to the right kidney. Infants with IHPS are asymptomatic at birth but, in the first few weeks of life, develop nonbilious forceful vomiting described as “projectile emesis” and present with partial gastric outlet obstruction. Surgical pyloromyotomy is curative.
Standard sonographic criteria include measurement of pyloric muscle >3 mm and elongation of pyloric canal >14 mm. Normal pyloric muscle thickness measures <2 mm. When pyloric muscle thickness measures between 2-3 mm, the exam is called as equivocal or borderline. Factors leading to equivocal exam may include incorrect technique that involves over measuring the pyloric muscle thickness, obliquely oriented section of pylorus and transient pylorospasm.
Purpose: The goals of this exhibit are-
1. To review the sonographic anatomy of normal and abnormal pylorus.
2. To illustrate our technical approach to diagnose IHPS with specific attention on how to accurately measure the muscle thickness and channel length.
3. To describe tips and tricks to minimize equivocal exams. Read More
Final Pr. ID: Poster #: SCI-083
Hypertrophic pyloric stenosis (HPS) is a frequent cause of vomiting in young infants, with an incidence of 1.5 – 4 per 1000 live births, depending on demographic group. The gold standard diagnostic test is abdominal ultrasound targeting the pylorus, and the measurement thresholds for determining an abnormal pylorus are well established. The objective of this study was to assess whether visual, subjective assessment of the pylorus was as accurate in diagnosing HPS as traditional formal measurements.
Final Pr. ID: Poster #: EDU-025
To retrospectively review the imaging planes performed, the number pyloric layers visible and the location of measurements taken, in infants with suspected (HPS). Read More
Final Pr. ID: Poster #: SCI-015
To evaluate false positive rate of community hospital ultrasound (US) diagnosis of hypertrophic pyloric stenosis (HPS) Read More
Final Pr. ID: Poster #: EDU-007
Hypertrophic pyloric stenosis (HPS) is a common surgical condition in infants characterized by idiopathic thickening of the gastric pyloric musculature that results in progressive gastric outlet obstruction and non-bilious emesis in infants between the ages of 2 weeks and 3 months. Ultrasound is the best imaging modality in the diagnosis of HPS as it allows for clear delineation of the thickened pyloric muscle and elongated pyloric channel, as well shows associated findings including gastric distention and lack of normal gastric emptying. To the untrained eye however, lack of knowledge of normal anatomy complicated by intermittent antral contraction may make it difficult to confidently exclude HPS. Several fun and helpful radiologic signs have been created to help radiologists and especially radiology trainees recognize the ultrasound findings of HPS (e.g. antral nipple sign and cervix sign). This poster discusses a new radiologic sign called the "eating duck sign" that can be helpful in distinguishing the normal gastric pylorus. In this sign, the distal stomach and antrum appear as the body and head of the duck, the normal gastric pylorus appears as the bill of the duck, and the duodenal bulb appears as the turnip or beet shaped snack of the duck. Read More
Authors: Fenlon Edward
Final Pr. ID: Poster #: EDU-033
IHPS has a history that is intimately related to the evolution of Ultrasound(US). US was first used to diagnose IHPS as far back as 1977 (Teele and Smith), and as US technology advanced, the diagnosis of IHPS became more refined. We can make precise measurements for the pyloric muscle wall thickness (MWT), pyloric canal length (CL), and transverse pyloric diameter (TPD), and we have highly sensitive and specific signs (i.e. target, shoulder, double-track signs, etc) to aid us in the diagnosis of IHPS (Hernanz-Schulman 1998).
Why: IHPS is the most common cause of gastric outlet obstruction and one of the most common conditions requiring surgery in infants. The exact pathogenesis of IHPS is unknown, but it is an acquired, gradual and progressive disorder.
Who: The classic picture is 5 to 8-week old Caucasian male (4:1 M:F) who presents with non-bloody, non-bilious projectile vomiting. Classic physical exam findings including visible peristalsis and palpable pyloric olive are present in less than 50% cases. Delay in diagnosis can cause serious consequences.
When: We can typically do US at any age at the time of the next feed and as the baby is being bottle fed (ideally).
How: We use a linear 12-5 or curved 8-5 transducer, with 2D and cine imaging. The baby is placed in supine position, and we begin scanning at the epigastric region. We find the gastroesophageal junction and trace the lesser curvature of the stomach medially to find the pylorus.
What: Once we find it; we measure the MWT, CL, and TDP, and look for all the signs. One way to remember the normal limits is our “Rule of 4s”. In IHPS, MWT is more than 4mm, CL is 4x4 = 16mm, and TDP is 4+4+4 = 12+mm. The signs include target sign (hypertrophied hypoechoic muscle surrounding echogenic mucosa), shoulder/nipple sign (bulging of hypertrophied pyloric muscle into the lumen of the antrum), and double-track sign (elongated pylorus with hypoechoic lumen, sandwiched between echogenic mucosa). If the measurements do not meet our “rule of 4s” and there are none of the signs, we can confidently rule out IHPS, or we may consider another differential diagnosis, like pylorospasm and mucosal hypertrophy due to other causes like prostaglandins. We’ve come a long way with refining and defining US diagnosis of IHPS until finally ultrasound is now the gold standard diagnostic modality for IHPS. Read More