Technical Innovation: Multidimensional Computerized Software Enabled Subtraction Computed Tomographic Angiography

Fusion and subtraction post-processing in body MRI

Interpreting complex paediatric body MRI studies requires the integration of information from multiple sequences. Image processing software, some freely available, allows the radiologist to use simple and rapid post-processing techniques that may aid diagnosis. We demonstrate the use of fusion and subtraction post-processing techniques with examples from four areas of application: enterography, oncological imaging, musculoskeletal imaging and MR fistulography.

Is femoral tunnel length correlated with the intercondylar notch and femoral condyle geometry after double-bundle anterior cruciate ligament reconstruction using the transportal technique? An in vivo computed tomography analysis

PURPOSE

To analyze femoral tunnel geometry using computed tomography (CT) imaging and evaluate the anatomic factors affecting femoral tunnel length after anterior cruciate ligament (ACL) reconstruction by the transportal technique.

METHODS

Twenty-nine patients underwent an anatomic double-bundle ACL reconstruction with a femoral tunnel drill by the transportal technique. CT imaging with OsiriX software (version 3.8; Pixmeo, Geneva, Switzerland) was used to measure femoral tunnel length (anteromedial [AM], posterolateral [PL], and central), femoral tunnel divergent angle, and femoral condyle size and intercondylar notch size parameters. Correlations between femoral tunnel length and femoral condyle size and intercondylar notch size parameters were analyzed.

RESULTS

The mean AM, PL, and central femoral tunnel lengths were 33.3 ± 3.9 mm, 33.6 ± 3.6 mm, and 34.3 ± 3.2 mm, respectively. A femoral tunnel length of less than 30 mm developed in 7 cases (24.1%) in the AM aspect and 4 cases (13.8%) in the PL aspect. The mean femoral tunnel divergent angle was 14.4° ± 4.1°. A positive correlation was found between AM, not PL or central, femoral tunnel length and medial femoral condyle anteroposterior (AP) distance (P = .01, r = 0.46), lateral femoral condyle AP distance (P = .01, r = 0.43), medial-to-lateral epicondylar distance (P = .03, r = 0.39), middle notch width (P = .009, r = 0.47), notch height (P = .001, r = 0.57), and notch area (P < .001, r = 0.58).

CONCLUSIONS

After double-bundle ACL reconstruction with the transportal technique through the accessory anteromedial portal, the AM and PL femoral tunnels showed mean tunnel length greater than 30 mm and a divergent angle. However, a femoral tunnel length of less than 30 mm developed in some cases. AM femoral tunnel length was correlated with femoral condyle size (medial femoral condyle AP distance, lateral femoral condyle AP distance, and medial-to-lateral epicondylar distance) and intercondylar notch size (notch width, notch height, and notch area).

LEVEL OF EVIDENCE

Level IV, therapeutic case series.