Axons from the median and ulnar nerves can pass to each other through aberrant connections between them. Multiple interconnections between the nerves may provide a detour route for nerve fibres going to the hand. We investigated the incidence of variations and the associations between them in 90 cadaveric upper limbs. In 91% of upper limbs, one to five variations were found, with several statistically significant associations. The contribution of the C8 nerve to the lateral cord was positively associated with an accessory contribution of the lateral cord to the ulnar nerve. The latter variation showed positive association with the occurrence of any of the variations in the hand itself. Ulnar innervation of the superficial head of the flexor pollicis brevis was positively associated with the Riche-Cannieu communication. The co-existence of the variations and their associations may be the explanation for unusual clinical findings related to median and ulnar conduction, which appear contrary to anatomical knowledge.

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Background:In intensity modulated radiation therapy, cone beam computed tomography (CT) has been used to evaluate patients prior to treatment. This study conducted a comparative evaluation of the image reconstruction ability of the clinically used half-fan bowtie filter and the full-fan bowtie filter. Materals and Methods: A CT simulation marker was inserted inside a human phantom, and the pelvic region, a large field-of-view region, was scanned by moving the isocenter along the x-axis ±1-5 cm with the full-fan mode. Furthermore, image verification was conducted based on the planning CT image and bone to confirm the setup correction value. The obtained value was then compared with that from the clinically used half-fan scan. Results:The evaluation of the reconstructed image (from the isocenter to the marker) after setting the median line did not show a significant difference with respect to the image obtained using the half-fan scan. Planning CT images and setup errors were compared in three directions, and the results showed that each mean value was within the margin of error (±3 mm). The 3D vector value was determined to be within 0-2.45 mm, and the comparison of the value obtained from the half-fan scan showed no statistically significant result. Conclusion:The application of a phantom study to actual patients in the future will reduce the error caused by movement during the treatment due to the short scan time and will reduce the imaging dose for patients during setup error confirmation and correction.