Development of a cost-effective system for digital off-line analysis of transrectal ultrasound

Remote sonographic interpretation: comparison of standardized video clips to still images

OBJECTIVE

The aim of our study was to evaluate the role of standardized video clips compared with still images in the diagnostic accuracy of remote sonographic interpretation.

METHODS

We compared the remote interpretation of sonographic examinations acquired with a standardized video clip approach to examinations performed with still images alone in 60 patients with various hepatic and extrahepatic pathologies.

RESULTS

The use of video clips improved the diagnostic accuracy of sonographic studies interpreted remotely compared with the use of still images (p < 0.0001). The sensitivity, specificity, and positive and negative predictive values increased from 47.3% to 68.3%, 81.8% to 87.8%, 71.5% to 81%, and 63.8% to 74.5%, respectively.

CONCLUSIONS

Standardized video clips are easy to obtain, less operator-dependent than still images, and can be transferred to remote sites without loss of important data. We recommend this method in remote interpretation (teleradiology and distant consultation) of sonographic examinations.

Transrectal ultrasonography and magnetic resonance imaging in the staging of rectal cancer. Effect of experience

OBJECTIVE

To evaluate the effect of experience on preoperative staging of rectal cancer using magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS).

MATERIAL AND METHODS

From January 2002 to May 2006, 134 consecutive patients with biopsy-proven rectal cancer were examined with a 1.5-Tesla MRI unit and TRUS using a 6.5-MHz transducer. An experienced gastrointestinal radiologist (R1) or a general radiologist (R2) performed the evaluations. All patients (78 M, 56 F, mean age 69.1 years, range 38-89) were treated with surgery alone. The mean size of the tumour was 4.0 cm (range 1.1-7.5). A complete postoperative histopathological examination was used as the gold standard.

RESULTS

At pathology, 42 of 134 (31%) tumours were classified as T1-T2 and 92 (69%) were classified as T3-T4. The TRUS sensitivity in rectal tumour T-staging was 93% for R1 and 75% for R2 (p<0. 01); specificity was 83% for R1 and 46% for R2 (p<0.05). The MRI sensitivity in rectal tumour T-staging was 96% for R1 and 77% for R2 (p<0. 05); the specificity was 74% for R1 and 40% for R2 (p<0.05). There was no difference in the results of N-staging between R1 and R2 for either TRUS or MRI.

CONCLUSION

Reader experience had a statistically significant positive effect on the preoperative prediction of tumour involvement of the rectal wall. To obtain high-quality preoperative prediction of rectal cancer T-stage, it is suggested that preoperative TRUS and MRI staging should be supervised by an expert in the colorectal cancer team. In addition to this supervision, the person responsible for staging should be trained through a defined training programme.