A Case with the Abscess in the Sigmoid Colon/Mesocolon by Three-Dimensional Computed Tomography (3D-CT) and Reconstruction Method

Bando H, Kato Y, Yamashita H and Ogura K

Published on: 2025-12-15

Abstract

Recently, three-dimensional computed tomography (3D-CT) and reconstruction by Synapse Vincent has been applied. The case was 73-year-old male with lower abdominal pain and fever. The images of 3D-CT with reconstruction suggested the presence of a sigmoid diverticulum penetrating the mesenterium and an abscess (60x50x40mm in large) in the sigmoid colon and mesocolon. Treatment consisted of laparoscopic drainage of the abscess and administration of ampicillin/sulbactam (ABPC/SBT). One month later, CT showed the shrink of the abscess. Laboratory tests over a 3-week period showed normalization of CRP (13.4 to 0.4 mg/dL) and white blood cell (WBC) counts (8000 to 5100 /μL).

Keywords

Three-dimensional computed tomography (3D-CT); Reconstruction; Synapse Vincent; Artificial Intelligence (AI); Sigmoid diverticulum

Introduction

In recent years, three-dimensional computed tomography (3D-CT) has been developed in European and North American countries [1,2]. With the technique of Artificial Intelligence (AI) application, detail images would be synthesized and produced [3,4]. In actual clinical practice, some types of 3D-CT are used [5]. Among various reports, the course of blood vessels can be expressed with minute level [6].

Authors and co-researchers have continued radiological reports concerning many patients with various diseases and impaired functions. In order to exam the morphological condition, 3D-CT associated with reconstruction technique was used by the application of Synapse Vincent that was produced in Japan [7,8]. We reported so far beneficial aspects of Synapse Vincent, and several interesting cases [9,10]. We have recently experienced a meaningful case who was an elderly male who developed fever and lower abdominal pain. He received the evaluation of 3D-CT reconstruction, and general clinical progress will be described with some perspectives.

Case Presentation

Medical History and Symptoms

The patient was a 73-year-old man with hypertension since his 60s. At age 71, he was diagnosed with atrophic gastritis through upper gastrointestinal endoscopy and was receiving medication. In early January 2025, he developed a fever of 38°C (100°F). He took antipyretics and his symptoms improved. Around that time, he gradually developed lower abdominal pain. One week later, he presented to the clinic with fatigue and a fever of 38°C (100°F). No known influenza or COVID-19 infections were reported in his immediate surroundings, and influenza and COVID-19 antigen tests were negative. The lower abdominal pain persisted. Abdominal plain CT and contrast-enhanced CT on Jan 17, 2025 revealed a suspected abscess involving a diverticulum and penetrating from a sigmoid diverticulum (Figure 1a and 1b).

Treatment was initiated with ampicillin/sulbactam (ABPC/SBT) 1.5g twice daily. A consultation was made regarding transfer to a secondary emergency hospital, and the patient was transferred to Tokushima Prefectural Hospital the following day. The diagnosis was a sigmoid diverticulum penetrating the mesenterium and an abscess (60x50x40mm) in the sigmoid colon and mesocolon. Treatment consisted of laparoscopic drainage of the abscess. Treatment was clinically effective, and abdominal CT scans showed a reduction in the size of the abscess (Figure 1c). Laboratory tests over a 3-week period showed normalization of CRP (13.4 to 0.4 mg/dL) and white blood cell (WBC) counts (8000 to 5100 /μL) (Table 1).

Figure 1: Abdominal CT scan.

Table 1: Progress of Biochemistry data.

			2025
		Units	Jan 16	Jan 20	Jan 23	Feb 02	Feb 25
Inflam.
	CRP	(mg/dL)	13.4	4.9	1.2	0.4
CBC
	WBC	(x10^2/μL)	80	47	46	48	51
	RBC	(x10^4/μL)	396	376	385	433	450
	Hb	(g/dL)	12.5	11.5	11.7	13.6	13.7
	PLT	(x10^4/μL)	41.5	38.9	36.9	24.4	24.0
Liver
	AST	(U/L)	14	38	29	29
	ALT	(U/L)	23	26	36	30
	ALP	(U/L)	73	59	59	78
Renal
	BUN	(mg/dL)	11	8	8	14
	Cre	(mg/dL)	0.77	0.65	0.74	0.77
	eGFR	(mL/min/1.73m²)	75.4	90.7	78.7	75.4
Nutrition
	TP	(g/dL)	6.4
	Alb	(g/dL)	2.9	2.5	2.9

Reconstruction of CT scan

By the use of the AI application of Synapse Vincent, the image of the reconstruction of 3D-CT was conducted. The abscess in the mesenterium was observed with the Turkoid blue color in the square frontal views (Figure 2). By the addition of the bone image onto Figure 2, the frontal view of the abdominal organs, abscess and costal bones is found (Figure 3). When the CT reconstruction was performed in the oblique view, the abscess can be detected more apparently, which was surrounded by the sigmoid colon (Figure 4).

Figure 2:?CT reconstruction in frontal view.

Figure 3:?CT reconstruction with costal bones.

Figure 4:?CT Reconstruction in oblique view.

Discussion

3D-CT has been highly evaluated for diagnosis and pre-operative investigation. Detail study of the inferior mesenteric artery (IMA) and the inferior mesenteric vein (IMV), and the sigmoid arteries (SAs) was performed by 3D-CT exam [11]. As a result, 3D-CT with reconstruction would contribute the analysis of detail anatomical situation. In the case of abscess in the abdomen, CT-guided percutaneous punctures have been underwent. In such exam, 3D-CT image created by combining 170 two-dimensional CT images has contributed to provide clear puncture route and to decrease the necessary time for the procedure [12].

In the current case, it was rather difficult to detect the cause and anatomical positioning of abdominal discomfort. Several images of these 3D-CT images with reconstruction were synthesized. They are clearly produced for the satisfactory quality. From these reconstructed images, the abscess as well as the course of blood vessels was proved to be clearly visible [13]. Therefore, pathophysiological detail situations in the relationships among abscess, sigmoid colon, possible penetrating focus could be detected. For reference, statistical data for sigmoid diverticular perforation were observed. Concerning the prevalence study, 133 cases for sigmoid diverticular perforation during 15 years were identified and investigated [14]. As a result, its annual prevalence has been increasing. It was 2.4 per 100,000 in 1986 and 3.8 per 100,000 in 2000.

This case was treated by the drainage of the pus of the abscess and the administration of antibiotics. The clinical progress seemed to be satisfactory, where abdominal CT scan 1 month later showed the shrink of the abscess. The cause of the abscess may be i) originally existing the diverticulum in the sigmoid colon, ii) developing sigmoid diverticulitis by certain geneses [15], iii) penetrating from the diverticulum to the mesenterium, and iv) the formation of the abscess in the sigmoid colon and also mesocolon.

Certain limitation may be present for this case. He was diagnosed as the abscess in the sigmoid colon and mesocolon, and treated successfully. The pathophysiology seems to include some stages for the exacerbation of the clinical progress. He will be required to be followed up carefully, in particular for the any changes in the gastro-intestinal (GI) tract.

In conclusion, 73-year-old male developed abdominal discomfort and fever, and was diagnosed as abscess of the colon. For the diagnosis and treatment, 3D-CT with reconstruction has shown clinical efficacy. This technique will be expected to evolve more in the future.

Conflict of interest: The authors declare no conflict of interest.

Funding: There was no funding received for this paper.

International Journal of Case Reports and Clinical Images