CEUS is significantly more accurate than US and highly comparable with MDCT in the detection of liver metastases from colorectal cancer. Therefore, in the evaluation of patients with suspected hepatic metastases from colorectal tumour, US examination must be performed after contrast administration.
The proposed method gives reliable and consistent information about 3D bone conformation. Results are obtained automatically and depend only on femur morphology, avoiding any operator-related bias. Angles in 3D space are different from those measured with standard radiographic methods, mainly due to the different definition of femoral axes.
Objective
To describe a three‐dimensional (3D) computed tomographic (CT) methodology to measure the tibial torsion angle (TTa) and to evaluate intrarater and interrater agreements and accuracy through comparison with anatomic measurements.
Study design
Ex vivo cadaveric study.
Sample population
Thirty‐six tibiae from 18 dogs.
Methods
Tibial torsion angle of each tibia was measured by using two CT techniques (axial and 3D volume rendering) by three raters who blindly measured TTa in duplicate. A semitransparent bone filter was used to enhance the visibility of the target anatomical landmarks for the 3D volume rendering CT technique. Tibial torsion angle was also quantitated in tibial specimens. Intrarater and interrater agreements were analyzed by using intraclass coefficients (ICC). Accuracy was evaluated by using adjusted R2 coefficients (R2 > 80% was considered acceptable).
Results
The 3D volume rendering CT technique had excellent intrarater and interrater agreements (ICC > 0.94) and an R2 value of 97%. The axial CT technique had good to excellent intrarater and interrater agreements (0.8 < ICC < 0.95) and an R2 of 86%. No difference was found between axial and 3D CT techniques. A mean internal TT angle of approximately −6° was found with CT and anatomic measurements.
Conclusion
The 3D volume rendering and axial CT techniques were precise and accurate for measuring TTa in dogs unaffected by patellar luxation.
Clinical relevance
Combining 3D bone manipulation with application of a semitransparent filter allows simultaneous visualization of anatomic landmarks, which may facilitate the evaluation of complex bone deformations. Internal tibial torsion may be present in nonchondrodystrophic dogs without patella luxation.
Objective: To validate a computed tomographic (CT) method to measure the femoral trochlear groove depth (FTGD). Study design: Cadaveric study. Sample population: Fifteen dogs, 26 femoral trochleae. Methods: Five points were identified from proximal to distal (proximal point [PP], P25, P50, P75, and distal point [DP]) along the trochlea via three-dimensional volume-rendering function on the sagittal plane and measured on multiplanar reconstruction images. Each rater repeated measurements in duplicate, unaware of the identity of the joint. The FTGD was quantitated on the anatomical specimens and statistically compared with CT measurements. Intrarater and interrater agreements were analyzed by using intraclass coefficients. Accuracy was evaluated by using either adjusted R2 coefficients (R2 > 80% was considered acceptable) or Student's t test. The ratio of the patellar and the trochlear width and the ratio of the patellar craniocaudal thickness inside the trochlear groove were calculated at three different patellar locations. Results: Good to excellent intrarater and interrater agreements were observed in four of five trochlear points (P25, P50, P75, and DP), and accuracy was acceptable for these points (R2 > 80%). Computed tomographic measurements differed from the mean anatomical measurements at three of five points (PP, P50, and P75; P < .01), overestimating the FTGD by an overall mean of 0.18 mm (range, 0.02-0.3). P25 and P50 were the deepest points measured. Conclusion: Computed tomography allowed precise measurements of trochlear groove depth except for the most proximal point. The deepest trochlear points were P25 and P50. P25 was the most precise and accurate point measured, while PP was the least consistent. Clinical significance: The deepest portion of the trochlea groove may be located between P25 and P50. Evaluation of this CT method in dogs with patellar luxation is recommended.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.