J Gandhara Med Dent Sci

April - June 2026

ORIGINAL ARTICLE

PREVALENCE OF BILIARY DILATATION IN PATIENTS WITH PANCREATITIS ON MDCT AND ITS

CORRELATION WITH CT SEVERITY INDEX

Ashfaq Ahmad qu ayed

, Ummara Siddi e Umer

, Ghulam Ghaus

, Hira S

, Muhammad Hasnat

, Mohsin Khan

Hadia Abid

ABSTRACT

OBJECTIVES

This study aimed to determine the prevalence of biliary dilatation in patients

with pancreatitis on multidetector computed tomography (MDCT) and to

evaluate its association with the CT Severity Index (CTSI).

METHODOLOGY

Analytical cross-sectional study. Department of Radiology, Rehman Medical

Institute, Peshawar, from 1st August 2022 to 31st July 2023. A total of 146

adult patients with clinically suspected or conrmed pancreatitis who

underwent contrast-enhanced MDCT were included through non-probability

consecutive sampling. Patients with prior hepatobiliary surgery, pancreatic

or hepatobiliary malignancy, or incomplete imaging were excluded. Biliary

dilatation was dened as a common bile duct diameter >7 mm in patients

<60 years and >8 mm in those ≥60 years. The CT Severity Index (CTSI) was

calculated using the Balthazar grading system. Image interpretation was

performed independently by two experienced radiologists, and interobserver

agreement was assessed using Cohen’s kappa statistic. The association

between biliary dilatation and CTSI categories was analyzed using the Chi-

square test for trend. Prevalence estimates were reported with 95%

condence intervals (CI). Statistical analysis was performed using SPSS

version 26.0, with p < 0.05 considered signicant.

RESULTS

The mean age of patients was 43.68 ± 11.20 years, and 79 (54.1%) were

females. Biliary dilatation was observed in 54 patients (37.0%; 95% CI:

29.30-44.9). According to CTSI classication, 47 (32.2%) patients had mild,

45 (30.8%) moderate, and 54 (37.0%) severe pancreatitis. The proportion of

biliary dilatation increased with disease severity, occurrin g in 13 (27.7%)

mild, 15 (33.3%) moderate, and 26 (48.1%) severe cases. Although this trend

suggested increasing biliary involvement with greater disease severity, the

association did not reach statistical signicance (p = 0.086). Interobserver

agreement for CT interpretation demonstrated substantial reliability (κ =

0.82).

CONCLUSION

Biliary dilatation is a relatively common MDCT nding in patients with

pancreatitis and shows an increasing trend with higher CTSI categories.

Although the association was not statistically signicant, careful CT

evaluation of the biliary system may help identify patients who may benet

from further biliary assessment or targeted clinical management.

KEYWORDS: Pancreatitis, Biliary Dilatation, Multidetector Computed

Tomography, CT Severity Index, Balthazar Classication

How to cite this article

Ahmad A, Umer US, Ghaus G, Sayed

H, Hasnat M, Khan M, Abid H.

Prevalence of Biliary Dilatation in

Patients With Pancreatitis on MDCT

and its Correlation with CT Severity

Index. J Gandhara Med Dent Sci.

2025;13(2):29-33

Date of Submission: 13-02-2025

Date Revised: 27-05-2025

Date Acceptance: 05-06-2025

Professor, Department of Radiology,

Rehman Medical Institute, Peshawar

Professor, Department of Radiology,

Rehman Medical Institute, Peshawar

Postgraduate Resident, Department of

Radiology, Rehman Medical Institute,

Peshawar

Consultant, Department of Radiology,

Rehman Medical Institute, Peshawar

Correspondence

Ashfaq Ahmad, Postgraduate

Resident, Department of Radiology,

Rehman Medical Institute, Peshawar

+92-307-2605270

ashfaqaa323229@gmail.com

INTRODUCTION

Acute pancreatitis is an inammatory disorder of the

pancreas characterized by a spectrum of clinical and

morphological manifestations ranging from mild

interstitial edema to severe necrotizing disease with

systemic complications. It remains one of the most

common causes of acute abdominal emergencies

requiring hospital admission worldwide. Early

diagnosis and accurate assessment of disease severity

are essential for guiding clinical management,

predicting complications, and improving patient

outcomes.¹ Radiological imaging plays a central role in

the evaluation of pancreatitis. Among available imaging

modalities, multidetector computed tomography

(MDCT) is considered the cornerstone for assessing

pancreatic inammation, detecting local complications,

and evaluating disease severity due to its rapid

acquisition, high spatial resolution, and ability to

visualize both pancreatic and peripancreatic structures.²

https://doi.org/10.37762/jgmds.13-2.807

J Gandhara Med Dent Sci

April - June 2026

MDCT also allows comprehensive assessment of

adjacent hepatobiliary anatomy, which may be involved

in the pathophysiology or complications of

pancreatitis.³ Biliary abnormalities are frequently

encountered in patients with pancreatitis. Biliary

dilatation may occur due to various mechanisms,

including obstruction from choledocholithiasis,

inammatory compression of the distal common bile

duct by edematous pancreatic tissue, or pressure eects

from peripancreatic uid collections and pseudocysts.⁴

These changes may reect underlying biliary pathology

or secondary eects of pancreatic inammation.

Recognition of biliary dilatation on CT imaging is

clinically important because it may prompt further

evaluation of the biliary system and guide decisions

regarding additional diagnostic or therapeutic

procedures such as magnetic resonance

cholangiopancreatography (MRCP) or endoscopic

retrograde cholangiopancreatography (ERCP).

5,6

The

CT Severity Index (CTSI), originally proposed by

Balthazar and later modied, is a widely used

radiological scoring system for grading the severity of

acute pancreatitis. It combines morphological grading

of pancreatic inammation with the extent of pancreatic

necrosis to generate a score ranging from 0 to 10.

Higher CTSI scores have been associated with

increased risk of complications, prolonged

hospitalization, and higher morbidity and mortality.

7,8

While CTSI is well established for evaluating

pancreatic parenchymal involvement and peripancreatic

complications, its relationship with biliary changes such

as bile duct dilatation has not been extensively

investigated. Although biliary dilatation may be

observed in pancreatitis, the available literature

addressing its prevalence and its relationship with CT-

based severity indices remains limited. Most studies

have focused primarily on pancreatic necrosis and

peripancreatic complications rather than on

hepatobiliary alterations visible on CT. A clearer

understanding of the association between biliary

dilatation and pancreatitis severity may provide

additional radiologic indicators of disease burden and

help identify patients who require closer clinical

monitoring or further biliary evaluation. Therefore, the

present study aimed to determine the prevalence of

biliary dilatation on MDCT in patients with pancreatitis

and to assess its association with the CT Severity Index

(CTSI). We hypothesized that biliary dilatation would

be more frequently observed in patients with higher

CTSI categories, reecting greater inammatory

involvement and potential biliary compression.

METHODOLOGY

This analytical cross-sectional study was conducted in

the Department of Radiology at Rehman Medical

Institute, Peshawar, from 1st August 2022 to 31st July

2023, after obtaining Institutional Ethical Review

Board approval. Written informed consent was obtained

from all participants prior to inclusion in the study. The

sample size was calculated using the WHO sample size

calculator, with a reported prevalence of biliary

dilatation in pancreatitis patients of 38.6%, a 95%

confidence level, and an absolute precision of 8%.

Based on these parameters, the minimum required

sample size was calculated to be 146 patients, who were

enrolled in the study. Patients aged 18 years or above

with clinically suspected or conrmed pancreatitis who

underwent contrast-enhanced multidetector computed

tomography (MDCT) of the abdomen were included in

the study. Participants were recruited using non-

probability consecutive sampling. Patients with a

history of prior hepatobiliary surgery, known

hepatobiliary or pancreatic malignancy, or incomplete

or poor-quality imaging studies were excluded. All CT

examinations were performed using a 128-slice

multidetector CT scanner with a standard pancreatic

imaging protocol. Non-ionic iodinated contrast medium

was administered intravenously at a dose of 1 mL/kg

body weight through an 18-gauge intravenous cannula

using a pressure injector at a rate of 3-4 mL/sec.

Imaging was acquired during the arterial and portal

venous phases to evaluate the pancreatic parenchyma

and surrounding structures adequately. Biliary

dilatation was dened as a common bile duct (CBD)

diameter greater than 7 mm in patients younger than 60

years and greater than 8 mm in patients aged 60 years

or older, measured at the intrapancreatic portion of the

duct. The CT Severity Index (CTSI) was calculated

using the Balthazar grading system, which assigns

scores for pancreatic inammation (Grades A-E) and

pancreatic necrosis, yielding a total score of 0-10.

Based on the CTSI score, pancreatitis severity was

categorized as mild (0-3), moderate (4-6), and severe

(7-10). Two experienced radiologists independently

reviewed all CT images, each having more than seven

years of experience in abdominal imaging. Both

radiologists interpreted the scans independently and

were blinded to each other‘s assessments. In cases of

disagreement, a consensus interpretation was reached.

Interobserver agreement between the radiologists was

assessed using Cohen‘s kappa statistic. Data were

analyzed using IBM SPSS Statistics for Windows,

Versi on 26.0 (IBM Corp., Armonk, NY, USA).

Continuous variables, such as age and CBD diameter,

were reported as mean ± standard deviation (SD),

whereas categorical variables were presented as

frequencies and percentages. The prevalence of biliary

dilatation was reported with 95% condence intervals

(CI). The association between biliary dilatation and

CTSI categories was assessed using the Chi-square test

for trend. A p-value < 0.05 was considered statistically

Prevalence of Biliary Dilatation in Patients with Pancreatitis

J Gandhara Med Dent Sci

April - June 2026

significant.

RESULTS

A total of 146 patients with pancreatitis who underwent

contrast-enhanced MDCT were included in the

analysis. The mean age of the study population was

43.68 ± 11.20 years, and the mean common bile duct

(CBD) diameter was 6.56 ± 2.41 mm. Among the

participants, 67 (45.9%) were males, and 79 (54.1%)

were females. Biliary dilatation was observed in 54

(37.0%; 95% CI: 29.3-44.9) patients, whereas 92

(63.0%) patients had no evidence of biliary dilatation

on MDCT (Table 1). Based on the CT Severity Index

(CTSI) classication, 47 (32.2%) patients had mild

pancreatitis, 45 (30.8%) had moderate pancreatitis, and

54 (37.0%) had severe pancreatitis. When biliary

dilatation was evaluated across CTSI categories, it was

present in 13 (27.7%) patients with mild pancreatitis, 15

(33.3%) with moderate pancreatitis, and 26 (48.1%)

with severe pancreatitis. Among patients without biliary

dilatation, 34 (72.3%) were in the mild category, 30

(66.7%) in the moderate category, and 28 (51.9%) in

the severe category (Table 2). The Chi-square test for

trend showed an increasing proportion of biliary

dilatation across CTSI categories; however, the

association between biliary dilatation and pancreatitis

severity did not reach statistical signicance (p =

0.086). Interobserver agreement between the two

radiologists for CT interpretation demonstrated

substantial reliability, with a Cohen‘s kappa value of

0.82, indicating strong agreement in the evaluation of

biliary dilatation and CTSI grading.

Table 1: Demographic and Clinical Characteristics of Study

Participants (n = 146)

Variable Category n (%) / Mean ± SD

Age (years) Mean ± SD 43.68 ± 11.20

CBD Diameter(mm)

Mean ± SD 6.56 ± 2.41

Gender Male 67 (45.9)

Female 79 (54.1)

Biliary Dilatation Y es 54 (37.0) (95% CI 29.3-4

44.9)

No 92 (63.0) (95% CI 55.1-

70.7)

CTSI Category Mild (0-3) 47 (32.2)

Moderate (4-6) 45 (30.8)

Severe (7-10) 54 (37.0)

Table 1: Association Between Biliary Dilatation and CT Severity

Index (CTSI) Categories (n = 146)

Biliary

Dilatat

ion

CT Severity Index (CTSI)

Categories

Total n

(%)

value

Mild n

(%)

Modera

te n (%)

Severe n

(%)

Yes 13 (27.7) 15

(33.3)

26 (48.1) 54

(37.0)

0.086

No 34 (72.3) 30

(66.7)

28 (51.9) 92

(63.0)

Total 47 (100) 45 (100) 54 (100) 146

(100)

DISCUSSION

The present study evaluated the prevalence of biliary

dilatation in patients with pancreatitis using

multidetector computed tomography (MDCT) and

examined its association with the CT Severity Index

(CTSI). Biliary dilatation was identied in 54 (37.0%)

patients, indicating that hepatobiliary involvement is a

relatively frequent imaging nding in pancreatitis.

Although the proportion of biliary dilatation increased

across CTSI categories from 13 (27.7%) in mild, 15

(33.3%) in moderate, to 26 (48.1%) in severe

pancreatitis, the association did not reach statistical

signicance (p = 0.086). Nevertheless, this trend

suggests that increasing inammatory severity of

pancreatitis may contribute to secondary biliary

changes. The prevalence observed in our study is

comparable to that reported in the literature, which

documents biliary dilatation or biliary involvement in

approximately 30-45% of pancreatitis cases. Such

biliary changes are often attributed to underlying

gallstone disease, pancreatic head inammatory edema,

or compression of the distal common bile duct by

peripancreatic uid collections or pseudocysts.

9,10,11

These mechanisms may result in transient or persistent

obstruction of the bile duct, which can be visualized on

cross-sectional imaging modalities such as CT. MDCT

remains a cornerstone in the evaluation of pancreatitis

because it can simultaneously assess pancreatic

parenchymal inammation, peripancreatic

complications, and adjacent hepatobiliary structures.²

The increasing frequency of biliary dilatation with

higher CTSI categories observed in our study may

reect the greater degree of pancreatic inammation

and peripancreatic edema in severe disease. These

pathological processes may exert mechanical

compression on the intrapancreatic portion of the

common bile duct, resulting in upstream dilatation.¹²

Similar observations have been reported, demonstrating

that biliary abnormalities on contrast-enhanced CT

were more common in patients with moderate-to-severe

pancreatitis.¹³ Likewise, another study described that

inammatory enlargement of the pancreatic head and

surrounding tissues can lead to compression of the

distal common bile duct, even in the absence of

gallstones.¹⁴ These ndings support the concept that

biliary dilatation in pancreatitis may occur due to

inammatory changes rather than primary biliary

pathology alone. Despite the observed trend, the

association between biliary dilatation and CTSI severity

categories did not reach statistical signicance in our

study. Several factors may explain this nding. First,

pancreatitis is a heterogeneous disease with multiple

etiologies, including gallstone-related, alcohol-induced,

and idiopathic pancreatitis. Since etiological

stratication was not performed in the present study,

Prevalence of Biliary Dilatation in Patients with Pancreatitis

J Gandhara Med Dent Sci

April - June 2026

the presence of non-biliary causes of pancreatitis may

have diluted the strength of the association.¹⁵ Second,

the denition of biliary dilatation based solely on CBD

diameter may not fully reect functional biliary

obstruction, particularly in the absence of biochemical

correlation with liver function tests or direct

cholangiographic evaluation. From a clinical

perspective, recognition of biliary dilatation on CT

imaging may have practical implications.

Identication of dilated bile ducts in patients with

pancreatitis may prompt further evaluation of the

biliary tree using modalities such as magnetic

resonance cholangiopancreatography (MRCP) or

endoscopic retrograde cholangiopancreatography

(ERCP) to exclude obstructive pathology such as

choledocholithiasis or strictures.

17,18

Early detection of

such conditions may help guide therapeutic decisions

and prevent recurrent biliary pancreatitis.

The present

study has several strengths. A standardized MDCT

imaging protocol was used for all patients, and two

experienced radiologists independently interpreted CT

images. Interobserver agreement analysis demonstrated

substantial reliability (κ = 0.82), supporting the

reproducibility of the imaging ndings. Furthermore,

the use of consecutive patient inclusion helped

minimize selection bias.

LIMITATIONS

The study did not stratify patients by the underlying

etiology of pancreatitis, which may have inuenced the

prevalence of biliary dilatation. Biochemical

parameters, such as liver function tests, were not

analyzed to correlate imaging ndings with functional

biliary obstruction. A multivariable analysis adjusting

for potential confounders, such as age, gender, and

etiology, was not performed. Future prospective studies

incorporating clinical, biochemical, and endoscopic

correlation may provide a more comprehensive

understanding of the clinical signicance of biliary

dilatation in pancreatitis.

CONCLUSIONS

Biliary dilatation was observed in a substantial

proportion of patients with pancreatitis undergoing

MDCT and showed an increasing frequency across

higher CT Severity Index (CTSI) categories. Although

the association between biliary dilatation and disease

severity did not reach statistical signicance, the

observed trend suggests that biliary changes may

accompany more severe pancreatic inammatory

involvement. Careful evaluation of the biliary system

during CT assessment of pancreatitis may therefore

help clinicians identify patients who could benet from

further biliary investigation or targeted clinical

management.

CONFLICT OF INTEREST: None

FUNDING SOURCES: None

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Ashfaq Ahmad - Concept & Design; Data Acquisition; Data

Analysis/Interpretation; Drafting Manuscript; Critical

Revision; Final Approval

Ummara Siddique Umer - Concept & Design; Data

Acquisition; Drafting Manuscript; Supervision; Final Approval

Ghulam Ghaus - Concept & Design; Data Acquisition;

Drafting Manuscript; Critical Revision; Final Approval

Hira Sayed - Concept & Design; Data Acquisition; Drafting

Manuscript; Final Approval

Muhammad Hasnat - Concept & Design; Data Acquisition;

Drafting Manuscript; Final Approval

Mohsin Khan- Concept & Design; Data Acquisition; Drafting

Manuscript; Final Approval

Hadia Abid - Concept & Design; Data Acquisition; Drafting

Manuscript; Final Approval

AUTHORS CONTRIBUTION

The authors accept responsibility for all aspects of the work

and will ensure that any concerns regarding the accuracy or

integrity of any part are properly investigated and resolved.

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Prevalence of Biliary Dilatation in Patients with Pancreatitis