Acute abdominal pain is a common clinical presentation in the pediatric age group, accounting for approximately 5% to 10% of emergency department visits among children worldwide [1]. Unlike adults, children often present with nonspecific symptoms and have limited ability to articulate the severity, location, or nature of the pain, making diagnosis particularly challenging [2].

The differential diagnosis of acute abdomen in children ranges from benign self-limiting conditions to life-threatening surgical emergencies such as acute appendicitis, intestinal obstruction, volvulus, or perforation peritonitis [3]. Prompt and accurate diagnosis is essential to prevent complications, reduce morbidity, and optimize outcomes. Delays in diagnosis or inappropriate referrals can significantly increase the risk of morbidity in this vulnerable age group [4].

Among various diagnostic tools, ultrasonography (USG) has emerged as the modality of choice for initial imaging in suspected cases of pediatric acute abdomen due to its non-invasiveness, lack of ionizing radiation, real-time capability, and relatively low cost [5]. USG is especially valuable in resource-limited settings and for evaluating abdominal pathologies such as appendicitis, intussusception, cholecystitis, and hydronephrosis [6].

USG has demonstrated high sensitivity and specificity, particularly for diagnosing acute appendicitis, with values reported as high as 85–90% and 90–95%, respectively, in multiple pediatric studies [7,8]. Its diagnostic performance can further be enhanced by employing high-frequency transducers, using graded compression techniques, and ensuring adequate fasting to reduce bowel gas interference [9].

However, the diagnostic accuracy of ultrasonography is operator-dependent, and its effectiveness may vary based on the clinical scenario and underlying etiology [10]. In certain cases, findings may be equivocal or non-specific, necessitating further evaluation through cross-sectional imaging or surgical exploration [11].

In this context, the present study was conducted to evaluate the diagnostic performance of ultrasonography in assessing interventional and surgical causes of acute abdominal pain in children aged 1 to 18 years, correlating sonographic findings with final surgical or histopathological diagnoses. This study aims to validate the utility of USG as a frontline modality in pediatric acute abdomen and to contribute to the growing evidence supporting its role in clinical decision-making.

Study Design

This is a prospective observational study conducted in the Department of Radiodiagnosis, Kalinga Institute of Medical Sciences (KIMS), Bhubaneswar.

Study Duration

The study was carried out over a period of two years, from January 2023 to December 2025.

Source of Data

Paediatric patients aged 1–18 years presenting with acute abdominal pain and referred for ultrasonography (USG) to the Department of Radiodiagnosis, KIMS, were included in the study.

Sample Size

A total of 50 to 100 consecutive cases fulfilling the inclusion and exclusion criteria during the study period were enrolled.

Method of Data Collection

• The study commenced after obtaining approval from the Institutional Ethics Committee and Institutional Review Board (IRB).
• Written informed consent was obtained from parents/guardians of all participants.
• Sociodemographic data such as age, sex, height, weight, and educational status were recorded.
• A detailed clinical history was obtained, including:

o             Duration and onset of abdominal pain

o             Associated symptoms (fever, vomiting, nausea, changes in bowel habits)

o             Past medical and surgical history

o             History of cardiovascular malformations, prior hospitalizations, and current medications

• General physical examination, anthropometric measurements, and local abdominal examination were conducted to determine site and character of pain.
• Laboratory investigations included:

o             Complete Blood Count (CBC)

o             Peripheral Smear

o             C-Reactive Protein (CRP)

o             Blood Grouping and Blood Culture

o             Additional investigations as per clinical requirement

Ultrasonographic Examination

• Ultrasonography (USG) of the abdomen and pelvis was performed using:

o             GE Voluson S6

o             GE Voluson S10

o             Philips Affiniti 30

• Transducers used:

o             1–5 MHz curvilinear probe

o             8–12 MHz linear probe

• All scans were performed after a minimum of 6 hours of fasting to minimize bowel gas artifacts.

• Organs examined included:

o             Liver, gallbladder, biliary tract

o             Pancreas, spleen, kidneys

o             Bowel loops, appendix

o             Pelvic organs (in female patients)

• The findings were documented in real-time and interpreted by qualified radiologists.
• Patients were followed up until interventional or surgical procedures (with or without histopathological examination) were performed, and USG findings were correlated with final diagnoses.

Inclusion Criteria

• Children aged 1 to 18 years presenting with acute abdominal pain
• Patients with a history of recurrent acute abdominal pain
• Patients who underwent intervention/surgery and/or histopathological examination

Exclusion Criteria

• Patients aged below 1 year or above 18 years
• Patients with abdominal trauma
• Patients managed conservatively without surgical or interventional procedures

Ethical Considerations

• Ethical clearance was obtained from the Institutional Ethics Committee and IRB of KIMS, Bhubaneswar.
• Informed consent was obtained from parents or legal guardians.
• Participation was voluntary, and refusal to participate did not affect the patient’s medical care.
• Patient data were anonymized and used solely for research purposes.

Statistical Analysis

• Data were entered into Microsoft Excel and analyzed using SPSS version 21.0.
• Categorical variables were summarized using frequencies and percentages.
• Continuous variables were expressed as mean ± standard deviation (SD) or median with interquartile range (IQR) based on data distribution.
• Normality of data was assessed using the Kolmogorov–Smirnov test.
• Chi-square test (with or without Yate’s correction) or Fisher’s exact test was used for comparison of proportions.
• A p-value < 0.05 was considered statistically significant.

Table No. 1: Gender and Age Distribution of Study Participants (n = 75)

TABLE NO. 2: DISTRIBUTION ACCORDING TO SIGNIFICANT PAST HISTORY

TABLE NO. 3: DISTRIBUTION ACCORDING TO THE USG ABDOMEN DIAGNOSES

*Subtypes of IO, hence its frequency and percentage calculated out of total no. of IO according to the USG abdomen diagnosis- n=13.

TABLE NO. 4: DISTRIBUTION ACCORDING TO OPERATIVE/HPE DIAGNOSES

Table No. 5: Correlation of Clinical and USG Findings with Final Diagnosis (n = 75)

TABLE NO. 6: COMPARISON OF CLINICAL, USG, OPERATIVE/HPE DIAGNOSIS

Table No.7: Association of Clinical Diagnosis with USG Findings and Correlation between Clinical & USG Diagnoses (n = 75)

Part A: Cross-tabulation of Clinical Diagnosis vs. USG Diagnosis

• Chi-square value (χ²): 731
• p-value: 0.002
• Interpretation: There is a statistically significant association between clinical diagnosis and ultrasonographic findings, validating USG as a reliable modality for evaluating pediatric acute abdominal conditions.

Part B: Association Between Clinical and USG Correlation

• Chi-square value (χ²): 31.7
• Degrees of freedom (df): 1
• p-value: < 0.001

TABLE NO.8: PREDICTIVE VALUES OF USG FOR EACH CLINICAL CONDITION

The findings of the present study reinforce the diagnostic utility of ultrasonography (USG) in evaluating interventional and surgical causes of acute abdominal pain in the pediatric population. Acute abdominal pain in children is often a diagnostic challenge due to vague symptomatology and communication barriers [1,2]. Timely and accurate imaging plays a vital role in preventing unnecessary delays in diagnosis and management.

In this study, acute appendicitis was the most frequently identified condition on USG (44%), aligning closely with operative and histopathological confirmation. This is consistent with existing literature, where USG has demonstrated high sensitivity and specificity for acute appendicitis—ranging from 85% to 90% and 90% to 95%, respectively [7,8]. The positive predictive value (PPV) and diagnostic accuracy observed in our study were 95.2% and 88%, respectively, confirming the high reliability of sonographic findings for appendicitis in children.

Similarly, intestinal obstruction was detected in 17.3% of cases via USG, with a diagnostic accuracy of 86%. Various subtypes such as intussusception, volvulus, and atresia were well visualized, affirming that USG is a crucial tool in detecting mechanical causes of obstruction [6,9]. The use of graded compression and high-frequency probes, as advocated in the literature, improves diagnostic clarity, especially in cases with minimal gas interference [9].

The sensitivity and specificity of USG in diagnosing cholelithiasis/cholecystitis (86% and 85%, respectively) further support its applicability beyond appendiceal pathologies. These values correspond to previous studies that highlight USG as the first-line modality for gallbladder evaluation in pediatric populations due to its accuracy and non-invasiveness [5,6].

Mesenteric lymphadenitis, although less frequent, was detected with moderate sensitivity and specificity (84% and 82.3%, respectively). While it is a self-limiting condition, its differentiation from acute appendicitis is clinically important and achievable via high-resolution USG [5].

Importantly, our study demonstrated a statistically significant correlation between clinical diagnosis and USG findings (p = 0.002), as well as a strong association between USG and final diagnoses (p < 0.001). These findings underscore the pivotal role of USG in bridging clinical suspicion and definitive diagnosis [10,11].

However, operator dependency remains a recognized limitation of ultrasonography. While we attempted to minimize inter-observer variability by involving experienced radiologists, the inherent subjective interpretation of findings can occasionally lead to false positives or negatives [10]. Moreover, conditions with overlapping clinical and sonographic features may still require further imaging (e.g., CT/MRI) for confirmation [11].

The study also highlighted that USG failed to detect certain less common or complex conditions, including mesenteric ischemia, necrotizing enterocolitis, and follicular hyperplasia, emphasizing the need for comprehensive evaluation in atypical or equivocal cases.

Overall, the high sensitivity, specificity, and diagnostic accuracy of USG across multiple abdominal conditions confirm its value as a frontline imaging modality in the pediatric age group, consistent with previous global findings [5–9]. Its non-invasive nature and real-time assessment capability make it particularly advantageous in emergency and resource-limited settings [5].

The present study highlights the high diagnostic utility of ultrasonography (USG) in evaluating interventional and surgical causes of acute abdominal pain in the pediatric population. With an overall diagnostic accuracy of 80–88% for conditions such as acute appendicitis, intestinal obstruction, cholelithiasis, and mesenteric lymphadenitis, USG proves to be a reliable, non-invasive, and radiation-free first-line imaging modality. The significant correlation between clinical, sonographic, and operative/histopathological findings emphasizes its effectiveness in guiding timely clinical decision-making and surgical intervention. Despite its operator dependency, USG remains indispensable, especially in resource-limited settings, for the prompt and accurate diagnosis of pediatric acute abdomen. Therefore, its use should be encouraged and optimized in routine pediatric emergency evaluations.

1. Bundy DG, Byerley JS, Liles EA, Perrin EM, Katznelson J, Rice HE. Does this child have appendicitis? JAMA. 2007;298(4):438–451.
2. Fecteau A. Acute abdominal pain in children. Pediatr Clin North Am. 1999;46(6):1291–1309.
3. Di Saverio S, et al. Diagnosis and treatment of acute appendicitis: 2020 update. World J Emerg Surg. 2020;15(1):27.
4. Becker T, Kharbanda A, Bachur R. Atypical clinical features of pediatric appendicitis. Acad Emerg Med. 2007;14(2):124–129.
5. Hernanz-Schulman M. Ultrasound of the appendix. Semin Roentgenol. 2008;43(1):22–32.
6. Slovis TL, et al. Pediatric abdominal ultrasonography. Radiol Clin North Am. 1997;35(6):1149–1165.
7. Doria AS, et al. US or CT for diagnosis of appendicitis in children and adults? A meta-analysis. Radiology. 2006;241(1):83–94.
8. Khan RA, et al. Acute appendicitis in children: USG and clinical correlation. J Indian Assoc Pediatr Surg. 2010;15(4):131–133.
9. Puylaert JB. Acute appendicitis: US evaluation using graded compression. Radiology. 1986;158(2):355–360.
10. Trout AT, Towbin AJ. Pediatric abdominal ultrasound: what every radiologist needs to know. Radiol Clin North Am. 2013;51(5):1039–1056.
11. Sivit CJ. Imaging the acute abdomen in children. Radiol Clin North Am. 1997;35(4):815–832.