Photon-counting CT in the diagnosis of esophageal diverticulum: a case description
Introduction
An esophageal diverticulum refers to an abnormal pouch-like outpouching formed by the protrusion of one or more layers of the esophageal wall, which can occur at any location along the esophagus. This disease has a relatively low clinical incidence, and most patients present with no specific symptoms in the early stage of the disease course. As the diverticulum gradually increases in volume, clinical manifestations such as dysphagia, halitosis, vomiting and chest pain may occur successively. Existing studies have suggested that long-term chronic irritation of an esophageal diverticulum may be associated with a potential risk of malignant transformation, and a small number of cases may progress to esophageal squamous cell carcinoma (1). At present, the diagnosis of esophageal diverticula mainly relies on digital X-ray barium esophagography, yet this examination has certain limitations: it fails to clearly visualize the fine anatomical structures in the deep part of the lesion, and the examination results are also susceptible to the subjective factors of the operator. Based on this, the present study adopted photon-counting computed tomography (PCCT) to perform low-dose chest CT examinations, aiming to achieve accurate detection of esophageal diverticula and systematically analyze their morphological characteristics as well as the adjacent anatomical relationship between the diverticulum and the esophageal wall.
Case presentation
A 60-year-old female patient underwent chest imaging as part of an annual routine physical examination. An esophageal diverticulum was incidentally detected on the left wall of the middle-upper esophagus (approximately at the level of the 5th to 6th thoracic vertebrae) via PCCT scan (Figure 1). During subsequent follow-up, the patient reported occasional reflux-related discomfort. A digital X-ray barium esophagography was then performed, which confirmed the presence of the diverticulum with an orifice width of approximately 1.8 cm (Figure 2). In this case, ultra-thin-section chest imaging was performed using PCCT with the following scanning parameters: tube voltage 120 kV, effective tube current 40 mAs, section thickness 0.2 mm, and convolution kernel Br40, which contributed to ultra-high-resolution and low radiation dose (volume CT dose index, CTDIvol: 3.2 mGy) (2). Subsequently, using a dedicated workstation (syngo.via VB60A, Siemens, Erlangen, Germany), cine rendering and curved planar reconstruction techniques were employed to visualize the adjacent relationship between the esophagus and the esophageal diverticulum from multiple angles, which significantly enhanced the visualization of the esophageal diverticulum (Figure 1). All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.
Discussion
In this case, an esophageal diverticulum was initially identified during routine chest imaging with low-dose PCCT, and the diagnosis was subsequently validated via barium meal radiography. This observation suggests the potential value of incorporating the visualization and assessment of esophageal diverticula in routine chest CT interpretations—particularly with attention to the anatomical relationship between esophageal diverticula and the airway—within the context of this single case. While such an approach may help improve the detection of potential asymptomatic lesions, broader recommendations for routine esophageal diverticulum assessment in chest CT protocols would require validation in larger cohorts (3). The PCCT system utilized in this study is equipped with an advanced photon-counting detector, a key technical distinction from conventional CT. Unlike conventional CT detectors that measure integrated X-ray energy, PCCT’s photon-counting technology enables precise identification and quantification of individual incident X-ray photon energy. This unique capability confers three advantages that are difficult to replicate with conventional low-dose CT: (I) substantially reduced radiation exposure without compromising image quality; (II) minimized image noise through energy-resolved detection; (III) ultra-high spatial resolution maintained under low-dose conditions. While multiplanar reconstruction (MPR) and volume rendering (VR) are common post-processing techniques in conventional CT, the superior raw image quality of PCCT—facilitated by its photon-counting detector—ensures clearer delineation of the diverticular orifice morphology and anatomical course even at a low radiation dose (CTDIvol: 3.2 mGy). This technical advantage also mitigates the risk of image artifact-induced deformation (4,5), a limitation that may affect conventional low-dose CT when imaging fine anatomical structures such as small diverticular orifices. For the present case, the PCCT scan was conducted using a customized protocol integrating low radiation dose (CTDIvol: 3.2 mGy) and ultra-high spatial resolution (slice thickness: 0.2 mm)—a combination rarely achievable with conventional CT, which typically requires a trade-off between dose reduction and spatial resolution. Under the combined effect of these parameters, clear visualization of the edge contours and orifice structure of the esophageal diverticulum was achieved. Notably, the detailed depiction of the diverticulum’s anatomical course and orifice location—facilitated by MPR and VR—was enhanced by PCCT’s inherent high signal-to-noise ratio and spatial resolution, rather than relying solely on post-processing. Conventional low-dose CT, by contrast, often struggles to resolve such fine anatomical features due to increased noise and limited resolution under similar dose constraints. Collectively, these findings from a single case indicate that low-dose PCCT may offer a promising imaging approach for the detection of esophageal diverticula, particularly for identifying fine anatomical details that may be poorly delineated on conventional low-dose CT. While the utility of this technique warrants further investigation in larger patient populations, the present case highlights PCCT’s unique potential to balance low radiation exposure with superior visualization of esophageal diverticular morphology.
Conclusions
The PCCT can opportunistically detect early esophageal diverticula at a low radiation dose, which may facilitate the early identification of related pathological changes linked to esophageal cancer.
Acknowledgments
None.
Footnote
Funding: None.
Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-aw-2198/coif). The authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
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