Blunt abdominal trauma remains a major cause of morbidity and mortality worldwide, particularly in road traffic collisions and falls. Among abdominal injuries, small-bowel and mesenteric trauma is relatively uncommon compared with solid organ injury, but delayed diagnosis can lead to bowel ischemia, perforation, peritonitis, and sepsis [1–4].

Computed tomography (CT), particularly multidetector CT (MDCT), is the imaging modality of choice for stable patients with blunt abdominal trauma. While CT has excellent specificity for direct signs such as pneumoperitoneum, bowel wall discontinuity, and contrast extravasation, sensitivity is variable because many injuries manifest only as subtle indirect signs, including free fluid without solid organ injury, bowel wall thickening, and mesenteric fat stranding [1,2,5,6].

Most studies emphasize that CT performance improves when multiple signs are evaluated together, rather than relying on a single finding [2,6,7]. Given differences in injury mechanisms, patient population, and CT protocol, institutional data remain valuable.

This study was conducted at a tertiary care institute in South Kashmir and aims to describe the spectrum of CT findings in blunt small-bowel and mesenteric trauma, correlate imaging with operative findings, and compare institutional patterns with published literature.

MATERIALS AND METHODS

Study design and setting

A retrospective observational study was conducted at, Government Medical College, Anantnag, a tertiary care institute in South Kashmir. Imaging and clinical records were reviewed for a 5-year period (January 2020 to December 2024).

Study population

A total of 20 consecutive patients who underwent contrast-enhanced CT for blunt abdominal trauma with clinical or radiological suspicion of small-bowel or mesenteric injury were included.

Inclusion criteria

• Age ≥ 16 years
• Blunt abdominal trauma
• CT performed with intravenous contrast
• Imaging and clinical records available

Exclusion criteria

• Penetrating trauma
• Patients with isolated solid organ injury and no suspicion of bowel/mesenteric injury
• Incomplete CT study or missing records

CT protocol

CT was performed using MDCT (128-slice) with intravenous contrast (portal venous phase minimum). Axial and coronal reconstructions were routinely generated with thin slices. Oral contrast was not routinely administered due to emergency setting and time constraints.

Image analysis and CT signs recorded

Two radiologists reviewed all CT scans in consensus using a structured checklist. The following CT signs were recorded:

Indirect signs

• Free intraperitoneal fluid (any)
• Free fluid without solid organ injury
• Bowel wall thickening
• Abnormal bowel wall enhancement (hyper/hypo)
• Mesenteric fat stranding
• Mesenteric hematoma
• Interloop fluid
• Localized bowel dilatation / focal ileus
• Peritoneal enhancement

Direct signs

• Free intraperitoneal air
• Bowel wall defect/discontinuity
• Active contrast extravasation
• Pneumatosis intestinalis

CT overall impression grading

CT was graded as follows:

CT was considered positive if Grade 3 or Grade 4.

Reference standard

The reference standard was:

• Operative findings in patients who underwent laparotomy
• Clinical follow-up in conservatively managed patients (minimum 30-day follow-up documented)

Surgically significant injury included:

• Small bowel perforation or transection
• Duodenal rent
• Mesenteric tear with devascularization
• Mesenteric hematoma requiring operative management

Statistical analysis

Data were summarized as frequencies and percentages. Diagnostic accuracy measures were calculated: sensitivity, specificity, PPV, and NPV.

RESULTS

Demographic profile

A total of 20 patients were included.

• Mean age: 34.5 years (range 18–62)
• Sex: 16 males (80%), 4 females (20%)

Mechanism of injury

• Road traffic collision: 12 (60%)
• Fall from height: 5 (25%)
• Other blunt trauma: 3 (15%)

Frequency of CT findings

The most frequent CT findings were:

• Free intraperitoneal fluid: 14/20 (70%)
• Mesenteric fat stranding: 13/20 (65%)
• Bowel wall thickening: 10/20 (50%)
• Free fluid without solid organ injury: 9/20 (45%)

Direct signs were less frequent:

• Free intraperitoneal air: 4/20 (20%)
• Bowel wall defect: 3/20 (15%)
• Active contrast extravasation: 2/20 (10%)

The full spectrum is shown in Table 1.

Surgical correlation and final diagnosis

• Laparotomy performed: 12/20 (60%)
• Conservatively managed: 8/20 (40%)

Final classification using surgery and follow-up:

• Surgically significant bowel/mesenteric injury: 9/20 (45%)
• No surgically significant injury: 11/20 (55%)

Injury distribution (surgically significant)

• Jejunal perforation: 4
• Ileal perforation: 2
• Duodenal rent: 1
• Mesenteric tear/devascularization: 2

Diagnostic accuracy of CT

CT overall impression (Grade 3–4 positive) demonstrated:

• Sensitivity: 77.8%
• Specificity: 90.9%
• PPV: 87.5%
• NPV: 83.3%

Direct signs (free air, bowel wall defect, active extravasation) demonstrated very high specificity (100%) but lower sensitivity, consistent with published literature [1,2,6].

Figures

Figure 1

Male patient aged 35 years with history of blunt trauma to abdomen (RTA). CECT Coronal (a) reveals bowel wall thickening and hyper enhancement in proximal jejunum  with bowel wall discontinuity. Associated exoluminal interloop collection (air containing) and free fluid is seen. Axial pelvic cuts (b) reveal significant pelvic free fluid.

Figure 2

20 years male patient with history of fall. Axial CECT (a) shows mural thickening and hyper enhancement involving jejunal loops. Coronal CECT (b) reveals diffuse jejunal hyper enhancement and free fluid.

Figure 3

40 years old male patient with history of RTA. CECT reveals large pneumoperitoneum, distended stomach and free fluid. A large rent along D2 segment of duodenum with localized air containing collection in right anterior pararenal space.

Tables

Table 1. Spectrum of CT findings in blunt small-bowel and mesenteric trauma (n = 20)

Table 2. Distribution of injuries (final diagnosis) (n = 20)

Table 3. Diagnostic accuracy of CT overall impression (Grade 3–4 positive)

Reference standard: surgery + follow-up
Total injury = 9, no injury = 11

Diagnostic values

• Sensitivity = 7/9 = 77.8%
• Specificity = 10/11 = 90.9%
• PPV = 7/8 = 87.5%
• NPV = 10/12 = 83.3%

Table 4. Diagnostic performance of selected CT signs (n = 20)

Table 5. CT grading and surgical correlation

DISCUSSION

This hospital-based study describes the spectrum of CT findings in blunt small-bowel and mesenteric trauma in a South Kashmir tertiary care setting. Our findings demonstrate that indirect CT signs were more frequent than direct signs, while direct signs remained highly specific. This pattern closely matches established literature [1–6].

In our cohort, the most common CT findings were free intraperitoneal fluid (70%), mesenteric fat stranding (65%), and bowel wall thickening (50%). Prior studies and reviews have reported similar trends, with mesenteric stranding and free fluid being the most frequently encountered indirect signs [1,2,6]. Free fluid without solid organ injury is widely recognized as a red-flag finding for hollow viscus injury, especially when moderate or localized to the interloop region [2,6,8].

Direct signs such as free intraperitoneal air, bowel wall discontinuity, and active contrast extravasation were uncommon in our dataset, but when present they showed very high specificity (100%). This is consistent with the established concept that direct signs are highly specific but insensitive, because small perforations may not produce detectable pneumoperitoneum early, and bowel wall discontinuity is not always visible [1,2,6].

The diagnostic performance of CT in our study (sensitivity 77.8%, specificity 90.9%) is consistent with pooled systematic reviews reporting moderate sensitivity and high specificity for surgically significant bowel and mesenteric injury [2,5]. This supports the continued use of CT as the primary imaging tool for stable blunt trauma patients. However, false negatives remain clinically important. In our cohort, two injuries were missed on initial CT (Grade 2), highlighting the importance of repeat clinical evaluation and follow-up imaging when suspicion remains high.

Mesenteric hematoma demonstrated high specificity (90.9%) but moderate sensitivity (44.4%) in our cohort. Prior studies similarly report that focal mesenteric hematoma, particularly when adjacent to bowel loops, is a strong predictor of clinically significant injury [1,6].

Our study reinforces the value of structured reporting using a checklist and impression grading system, which reduces the chance of overlooking subtle indirect signs and helps clinicians stratify patients for observation versus surgery [6,7,9].

Limitations

1. Small sample size (n = 20) limits statistical power and generalizability.
2. Not all patients underwent surgery; follow-up was used as reference in conservatively managed cases.
3. Single-center retrospective design may introduce selection bias.
4. Oral contrast was not routinely used; thus, luminal contrast extravasation could not be assessed.

CONCLUSION

Blunt small-bowel and mesenteric trauma shows a broad spectrum of CT findings. Indirect signs such as free intraperitoneal fluid and mesenteric fat stranding are frequent but less specific, while direct signs such as free air, bowel wall defect, and active contrast extravasation are uncommon but highly specific. In our cohort, CT overall impression demonstrated sensitivity 77.8% and specificity 90.9%, consistent with published literature. Structured CT reporting and careful clinical correlation remain essential to reduce missed injuries.

REFERENCES

1. Brody JM, Leighton DB, Murphy BL, et al. CT of blunt trauma bowel and mesenteric injury: typical findings and pitfalls. Radiographics. 2000;20(6):1525-1536.
2. Abdel-Aziz H, et al. Effectiveness of computed tomography scanning to detect blunt bowel and mesenteric injuries requiring surgical intervention: a systematic literature review. Am J Surg. 2019;218(1):201-210.
3. Magu S, et al. Multi-detector computed tomography in the diagnosis of bowel and mesenteric injuries in blunt abdominal trauma. J Emerg Trauma Shock. 2012;5(2):142-148.
4. Breen DJ, et al. Blunt bowel and mesenteric injury: CT findings and clinical correlation. Clin Radiol. 1997;52(8): 571-577.
5. Hsia CC, et al. Diagnostic accuracy of computed tomography for traumatic hollow viscus injury: systematic review and meta-analysis. 2021.
6. Kaewlai R, et al. Imaging of traumatic bowel and mesenteric injuries. Radiol Clin North Am. 2023.
7. Faget C, et al. Blunt bowel and mesenteric injuries: diagnostic performance of CT and CT scoring systems. Eur Radiol. 2015.
8. The Current Diagnostic Accuracy on Free Peritoneal Fluid for Blunt Abdominal Trauma: systematic review. Diagnostics (Basel). 2021.
9. Malhotra AK, et al. Computed tomography evaluation of blunt bowel and mesenteric injury: clinical implications and pitfalls. 2014.