Is the lateral neck radiograph still a viable investigation for an impacted fish bone in the aero-digestive tract: going back to basics.

Transcription

1 Is the lateral neck radiograph still a viable investigation for an impacted fish bone in the aero-digestive tract: going back to basics. Poster No.: C-0353 Congress: ECR 2011 Type: Scientific Exhibit Authors: D. Shetty 1, D. A. T. gay 2 ; 1 Plymouth/UK, 2 plymouth/uk Keywords: Digital radiography, Esophagus, Ear / Nose / Throat DOI: /ecr2011/C-0353 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 8

2 Purpose To evaluate the radio-opacity of fish bones from a number of species using digital radiography in order to establish whether the lateral neck radiograph remains a valid investigation for an impacted fish bone in the aero-digestive tract. Methods and Materials The bones from six popular fish consumed in the United Kingdom (namely Bream, Plaice, Mackerel, Pollock, Bass and Trout) were sourced locally. The bones were removed from fillets of fish and cleaned in water. Bones from each species were measured and placed within a standardised soft tissue neck phantom. Radiographs were then taken using the General Electric (GE) Definium 8000 digital radiographic x-ray tube with an exposure of 4.0mAs at KV 80, which are the standard exposure factors used for lateral neck soft tissue radiography. The images were reviewed by 15 Radiology Consultants and Registrars from Plymouth Hospital's NHS Trust on a GE PACS workstation. The bones were either visible or not on the lateral neck radiograph and documented as such. Results Fish bones from six different species of fish were imaged to assess their radio-opacity. The average length of the bones was 24.8mm with a range of 20mm to 31mm. The results are summarised below. Species of Fish Size (mm) Visible on radiograph (/15) Bream Mackerel Pollock Bass Trout Plaice Not visible on radiograph (/15) Page 2 of 8

3 All twelve radiographs containing fish-bones were visible and indicated as such by the 15 Radiology Consultant and Registrars. There were 6 (40%) radiology consultants and 9 (60%) radiology registrars. There was one control film containing no bones and this was correctly identified by all 15 radiologists. Images for this section: Fig. 1: Digital radiography of fish bones in a standard soft tissue neck phantom: Control film. Page 3 of 8

4 Fig. 2: Digital radiography of fish bones in a standard soft tissue neck phantom: Pollock. Page 4 of 8

5 Fig. 3: Digital radiography of fish bones in a standard soft tissue neck phantom: Bream. Page 5 of 8

6 Fig. 4: Digital radiography of fish bones in a standard soft tissue neck phantom: Bass. Page 6 of 8

7 Conclusion There is ongoing debate as to the potential role of plain film radiography in the initial assessment of patients presenting with an impacted foreign body. With fish bones remaining a significant culprit (1), the importance of early detection in order to avoid the potential complications, such as oesophageal perforation, retropharyngeal abscess formation, peri-oesophagitis, mediastinitis or vascular fistula formation is paramount (2). The differing radio-opacities of fish bones have been documented previously (3,4). The radio-density of a fish bone is thought to be inferred from the intrinsic functionality of the fish in question. Ell and Sprigg (3) concluded that trout and mackerel were poorly visualized by soft tissue radiographic techniques and thus knowledge of both the fish ingested and the relative radio-opacities of various fish would be useful in film interpretation. The use of digital media however, as demonstrated here, has revealed that all six fish species including those of trout and mackerel were visible using modern acquisition and visualization techniques. Foreign bodies within the neck, particularly bones have been documented as potentially awkward due to the ossification of the cricoid, thyroid or hyoid cartilages (4,5). As stated by Palme et al (2) CT is far superior to plain film radiography in both the detection and accurate localization of a fish bone as well as the recognition of any complications. If there was any doubt on the lateral neck radiograph due to cartilage ossification or cervical vertebrae osteophyte formation, a convincing history with or indeed without ancillary radiographic signs such as soft tissue swelling would merit a CT scan for reassurance. The authors believe that the lateral neck radiograph remains a viable first line investigation for an impacted fish bone in the aero-digestive tract. It is a relatively low dose examination that has, with the advances in radiography, the ability to detect fish bones that were previously thought to be of insufficient radio-density to be accurately visualised. This is ofcourse with the proviso that the option to proceed to CT is always available if there is any diagnostic uncertainty on the radiograph or more importantly if the patient is compromised. References 1. Singh B, Kanto M, Har-El G, Lucente FE. Complications associated with 327 foreign bodies of the pharynx, larynx and oesophagus. Ann Otol Rhinol Laryngol 1997;106: Page 7 of 8

8 2. Palme CE, Lowinger D, Peterson AJ. Fish bones at the cricopharyngeus: A comparison of plain-film radiography and computed tomography. The Laryngoscope 1999;109(12): Ell SR, Sprigg A. The radio-opacity of fish bones- species variation. Clinical Radiology 1991;44: Ell SR. Radio-opacity of fishbones. Journal of Laryngology and Otology 1989;103: Richardson GS. Unusual calcification of cricoid cartilage masquerading as a foreign body in the oesophagus. Archives of Otolaryngology 1955;62: Zoller H, Bowie ER. Foreign body in the air and food passages versus calcifications of laryngeal cartilages. Archives of Otolaryngology 1957;65: Personal Information Page 8 of 8