Conference Contribution Details
Mandatory Fields
McWilliams S, Murphy KM, O'Regan K, Arellano R, Maher MM, O'Connor oj
European Society of Gastrointestinal Radiology
Oral Presentation
Salzbur, Austria
Oral Presentation
Optional Fields
CT-guided core needle biopsy(CNB) can be impaired due to streak artefact obscuring needle tip visualization. Eight biopsy needles in two sizes from two manufacturers with and without stylets were imaged in a CT phantom using 64-slice CT reconstructed with ASIR and FBP(n=16). CNB-related streak artefact was quantified with profile analysis using ImageJ and Microsoft Excel. Hounsfield unit(HU) differences between the maximum HU at the needle tip and the minimum HU in the streak artefact beyond were compared for each variable. Image acceptability and streak artefact were qualitatively assessed on each phantom image after randomization and on 40 CT CNB procedures with and without the central stylet by three blinded reviewers. Statistical analysis (Mann-Whitney U-test, Kappa and T-test) was performed using SPSS (p-value <0.05 considered statistically significant). Artefact was significantly less without the stylet than with the stylet in-situ (median 1145HU versus 3390HU, p<0.001) for all needles and for 19G needles versus 17G needles (median 1334HU vs 2780HU, respectively; p=0.006). There was no difference based on manufacturer (p=0.906), or reconstruction algorithm (p=0.524). Qualitative analysis of 40 cases demonstrated moderate(0.44) and substantial(0.65) agreement regarding needle tip visualisation and streak artefact, respectively, confirming significantly improved needle visibility and reduced streak artifact after stylet removal. Streak artefact and needle tip visualisation can be improved on CT by confirming needle position after stylet removal.