What is the difference between a CT scan and an X-ray?

Numbers match the citations in the article. A working link isn't proof that a page supports a claim; check the quoted passage and date.

1. 1

   CT scan (Wikipedia)

   WikipediaPublished Oct 10, 2026Checked Oct 11, 2026

   “A computed tomography scan (CT scan), formerly known in a more rudimentary state as computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists. CT scanners use a rotating X-ray tube and a row of detectors placed in a gantry to measure X-ray attenuations by different tissues inside the body. The multiple X-ray measurements taken from different angles are then processed on a computer using tomographic reconstruction algorithms to produce tomographic (cross-sectional) images (virtual "slices") of a body. CT scans can be used in patients with metallic implants or pacemakers, for whom magnetic resonance imaging (MRI) is contraindicated. Since its development in the 1970s, CT scanning has proven to be a versatile imaging technique. While CT is most prominently used in medical diagnosis, it can also be used to form images of non-living objects.”

2. 2

   Additional Fracture Detection by Computed Tomography After Plain Radiography in Adults with Isolated Foot and Ankle Trauma: A Retrospective Selected-Cohort Study.

   Journal of clinical medicine (Arslan et al.)Published Aug 11, 2026Checked Oct 11, 2026

   “Plain radiographs were categorized as normal in 628 patients, suspicious in 283, and definite fracture in 89. CT detected acute fractures in 386 patients (38.6%). The CT-confirmed fracture proportions were 14.8% in the normal radiograph group, 72.1% in the suspicious radiograph group, and 100.0% in the definite fracture group. The proportion of patients without a definite fracture on plain radiography but with an acute fracture on CT was 29.7%. Fracture-pattern classification was unavailable in 85 of 386 cases with CT-confirmed fractures (22.0%); therefore, fracture-pattern analyses were considered exploratory. In this selected CT cohort, CT identified additional acute fractures in a subset of adult isolated foot and ankle trauma cases that could not be definitively classified as fractures on plain radiography. Because CT was not systematically performed in all trauma patients, the findings represent selected-cohort CT yield rather than true population-level diagnostic accuracy.”

3. 3

   Radiation exposure for planning deformity corrections with hexapods: comparison of conventional X-ray, standard CT, and ultra-low-dose CT.

   Archives of orthopaedic and trauma surgery (Schüll et al.)Published Sep 23, 2026Checked Oct 11, 2026

   “The values were compared using descriptive statistics and inferential analysis (repeated-measures ANOVA; p ResultsThe mean effective dose was 1.41 µSv (min 0.66 µSv, max 2.53 µSv, SD ± 0.6 µSv) for conventional X-rays, 4.61 µSv (min 2.97 µSv, max 6.68 µSv, SD ± 1.00 µSv) for ULD-CT, and 150.8 µSv (min 94.85 µSv, max 224.6 µSv, SD ± 35.81 µSv) for standard CT. ULD-CT showed significantly lower radiation exposure than standard CT while offering sufficient image quality for treatment planning. Although the radiation dose of ULD-CT was higher than that of X-rays, but in relation to the measurement precision achieved, there was a clear reduction in dose compared to standard CT.ConclusionULD-CT provides image quality suitable for treatment planning comparable to standard CT with significantly reduced radiation exposure. Given the significantly improved planning quality and acceptable dose, ULD-CT can be recommended as a favorable balance between precision and radiation protection. In conclusion, ULD-CT represents a valuable imaging option for obtaining the most accurate determination of the distance between two points, particularly when defining mounting parameters.”

4. 4

   Next-gen paediatric imaging: ultra-low dose chest photon-counting CT approaching chest radiograph doses.

   European radiology experimental (Limantoro et al.)Published Sep 8, 2026Checked Oct 11, 2026

   “The optimal settings were identified as Sn100 kVp, 2 mAs and pitch 1.5, yielding an ED of 14 µSv. All paediatric scans were assessed as acceptable, but a preference for an increased dose protocol was given to rule out interstitial lung disease or bronchiectasis. The mean total ED from the localiser and ULDCT of the chest was 11.6 [IQR: 10.9-12.8] µSv compared to 8.2 [IQR: 6.2-13.6] µSv for standard chest radiography.ConclusionOur PCD ULDCT chest protocol, approaching chest radiograph doses, is promising for (follow-up of) focal abnormalities and follow-up imaging of known chest pathology in children.Key pointsQuestion Can the technique of photon-counting detector CT result in radiation dose reduction, while achieving adequate image quality? Findings An ultra-low dose CT chest protocol was developed with a comparable dose to a single chest radiograph. Relevance statement The ultra-low dose CT chest protocol is promising in the setting of (follow-up of known) focal chest abnormalities, long-term follow-up after congenital diaphragmatic hernia repair and follow-up of interstitial lung disease in children.”

5. 5

   Emergency Department Imaging of Pediatric Patients with Blunt Thoracic Trauma: A Systematic Review, Meta-Analysis, and Practice Management Guideline.

   Journal of the American College of Emergency Physicians open (Lam et al.)Published Jul 28, 2026Checked Oct 11, 2026

   “Four relevant questions related to imaging after blunt thoracic trauma in pediatric patients were developed using clearly defined Population (P), Intervention (I), Comparison (C), and appropriately selected Outcomes (O) (PICO). A systematic review and meta-analysis were conducted using the Grading of Recommendations Assessment, Development and Evaluation methodology. The multispecialty working group reached consensus on the final evidence-based recommendation. A total of 10,447 articles were screened, and data from 3 studies were included in the final meta-analysis. All the studies were retrospective in design, and the quality of the available evidence was determined to be very low. Based on the limited data, we were only able to make a recommendation on one of the 4 drafted PICO questions. In pediatric (<18 years) patients with blunt trauma presenting to the emergency department who have no or minor traumatic findings on initial screening chest imaging, we conditionally recommend that chest CT not be routinely used to identify thoracic injuries requiring procedural or operative intervention, or to identify thoracic injuries leading to mortality.”