The utilisation of high frequency mini probe colonoscopic ultrasound in the assessment of colorectal disease

Student thesis: Doctoral ThesisDoctor of Medicine

Abstract

This research looks at the feasibility of colonoscopic high frequency ultrasound in the colon using mini probe technology. The objectives are across four different areas with assessment of colonic cancer, malignant colorectal polyps, rectal polyps and diverticular disease
High frequency 12 and 20 MHz ultrasound were used to locally stage colonic cancer and compare this to conventional CT in patients undergoing elective colonic resection. In addition, depth of infiltration of rectal polyps was determined by 20 MHz ultrasound and these findings compared with MRI in patients undergoing TEMS procedure. Malignant colorectal polyps were assessed after endoscopic removal to assess for the presence of residual or recurrent disease in the colonic wall and also to stage the local lymph nodes. Finally, the thickness of colonic wall in patients with diverticular disease was measured using 20 MHz ultrasound and this was compared with normal controls.
The research has clearly shown that colonoscopic high frequency mini probe ultrasound is feasible in the colon with reproducible results. Overall, 12 and 20 MHz colonoscopic ultrasound are superior to CT for local staging of colonic cancer. 20 MHz ultrasound offers greater accuracy for assessment of depth of infiltration of rectal polyps compared with MRI. This probe may also be utilised to assess the colonic wall for residual disease in the polypectomy scar of malignant polyps but larger numbers are needed with longer follow up in order to draw firm conclusions. Finally, it was feasible to measure the thickness of colonic wall in patients with diverticular disease and this was greater than that seen in normal patients.
In conclusion, this research has been promising in that colonoscopic high frequency mini probe ultrasound is feasible in the colon and can be used to assess colorectal polyps and cancer and diverticular disease. In order to draw firm conclusions, this pilot research needs to be taken further with larger scale studies.
Date of Award17 Aug 2012
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorS Papagrigoriadis (Supervisor) & Ingvar Bjarnason (Supervisor)

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