Barium swallow X-ray in bowel obstruction
Author:
Mikael Häggström [notes 1]
Projectional radiography ("X-ray") with peroral intake of barium can determine whether a bowel obstruction is partial or incomplete, and may give clues to the cause.[1]
Contents
Planning
- Indication
After a CT in abdominal pain indicates bowel obstruction, but otherwise inconclusive.[1]
- Endpoint and chronology
Imaging is generally made until the contrast reaches the large colon (if small bowel obstruction is suspected). The first image may be taken at 2 hours after peroral contrast intake.[notes 2]
Evaluation
- Distension
On abdominal X-rays, the small intestine is considered to be abnormally dilated when the diameter exceeds 3 cm.[2][3] This number accounts for an expected geometric magnification in radiography, where the projection on the detector becomes larger than the actual organ, with a factor that may be between 1.05 and 1.40.[4]
| Mild | 2.5–2.9 cm |
| Moderate | 3-4 cm |
| Severe | >4 cm |
The exact geometric magnification of X-rays is generally not known, however, leaving the options:
- If a previous CT has been made, adjust the sizes by fixed reference point such as the width of a lumbar vertebra:
Actual width ≈ Width in X-ray / (Width of vertebra on X-ray) x (Width of same vertebra on CT)
- Yet, this fully corrects the magnification only if the target structure and the reference point are at the same depth.
- Reporting a "roughly estimated" diameter by dividing the measured intestinal diameter in the image and dividing it by a rather arbitrary factor of 1.2. However, this confers a false impression of certainty.
- Reporting a qualitative diameter of the intestine, which may be on a mild-moderate-severe scale. However, the measured diameter still needs to be adjusted for geometric magnification in order to be compared to numbers in the table at right.
- Transit time
Small intestinal transit time can generally be described as delayed if exceeding 6 hours from oral contrast intake to presence in the colon.[7]
Report
Should include:
- Time since intake of contrast.
- Any distension of the intestines (see section above)
- The most distal part reached by the contrast.
If contrast hasn't reached the large intestine already, a Swedish practice[8] is to also state when the next image will be taken unless otherwise decided by the referring clinician. The frequency of further imaging depends on the progress. It is often 4-8 hours and then 6-12 hours, possibly later if overnight.[8]
- See also: General notes on reporting
Notes
- ↑ For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Radlines:Authorship for details.
- ↑ In patients having undergone gastric bypass surgery, the first image may be taken 1 hour after peroral contrast intake.
References
- ↑ 1.0 1.1 Thompson JS (2002). "Contrast radiography and intestinal obstruction. ". Ann Surg 236 (1): 7-8. PMID 12131079. PMC: 1422542. Archived from the original. .
- ↑ Ali Nawaz Khan (2016-09-22). Small-Bowel Obstruction Imaging. Medscape. Retrieved on 2017-02-07.
- ↑ . Abdominal X-ray - Abnormal bowel gas pattern. radiologymasterclass.co.uk. Retrieved on 2017-02-07.
- ↑ Estimated from radiographs of the chest and lumbar vertebral colon: M Sandborg, D R Dance, and G Alm Carlsson. Implementation of unsharpness and noise into the model of the imaging system: Applications to chest and lumbar spine screen-film radiography. Faculty of Health Sciences, Linköping University. Report 90. Jan. 1999. ISRN: LIU-RAD-R-090
- ↑ Kuang, Lian-qin; Zhao, Da-wei; Cheng, Cheng; Wang, Yi (2016). "Prediction of Small Bowel Obstruction Caused by Bezoars Using Risk Factor Categories on Multidetector Computed Tomographic Findings ". BioMed Research International 2016: 1–9. doi:. ISSN 2314-6133.
- ↑ Jacobs, S.L.; Rozenblit, A.; Ricci, Z.; Roberts, J.; Milikow, D.; Chernyak, V.; Wolf, E. (2007). "Small bowel faeces sign in patients without small bowel obstruction ". Clinical Radiology 62 (4): 353–357. doi:. ISSN 00099260.
- ↑ Szarka, Lawrence A.; Camilleri, Michael (2012). "Methods for the Assessment of Small-Bowel and Colonic Transit ". Seminars in Nuclear Medicine 42 (2): 113–123. doi:. ISSN 00012998.
- ↑ 8.0 8.1 NU Hospital Group, Sweden
