Improved diagnostic accuracy for ulnar-sided TFCC lesions with radial reformation of 3D sequences in wrist MR arthrography

Objectives Triangular fibrocartilage complex (TFCC) injuries frequently cause ulnar-sided wrist pain and can induce distal radioulnar joint instability. With its complex three-dimensional structure, diagnosis of TFCC lesions remains a challenging task even in MR arthrograms. The aim of this study was to assess the added diagnostic value of radial reformatting of isotropic 3D MRI datasets compared to standard planes after direct arthrography of the wrist. Methods Ninety-three patients underwent wrist MRI after fluoroscopy-guided multi-compartment arthrography. Two radiologists collectively analyzed two datasets of each MR arthrogram for TFCC injuries, with one set containing standard reconstructions of a 3D thin-slice sequence in axial, coronal and sagittal orientation, while the other set comprised an additional radial plane view with the rotating center positioned at the ulnar styloid. Surgical reports (whenever available) or radiological reports combined with clinical follow-up served as a standard of reference. In addition, diagnostic confidence and assessability of the central disc and ulnar-sided insertions were subjectively evaluated. Results Injuries of the articular disc, styloid and foveal ulnar attachment were present in 20 (23.7%), 10 (10.8%) and 9 (9.7%) patients. Additional radial planes increased diagnostic accuracy for lesions of the styloid (0.83 vs. 0.90; p = 0.016) and foveal (0.86 vs. 0.94; p = 0.039) insertion, whereas no improvement was identified for alterations of the central cartilage disc. Readers’ confidence (p < 0.001) and assessability of the ulnar-sided insertions (p < 0.001) were superior with ancillary radial reformatting. Conclusions Access to the radial plane view of isotropic 3D sequences in MR arthrography improves diagnostic accuracy and confidence for ulnar-sided TFCC lesions. Key Points • In multi-compartment arthrography of the wrist, ancillary radial plane view aids assessability of the foveal and styloid ulnar-sided insertions of the triangular fibrocartilage complex. • Assessment of peripheral TFCC injuries is more accurate with access to radial multiplanar reconstructions. • Additional radial planes provide greater diagnostic confidence.

The dental pulp chamber evaluation by using cone-beam computed tomography

Background: Cone-beam computed tomographic (CBCT) imaging is a valuable tool in dental practice. It is widely used in endodontic treatment for the root canal morphology examination. Therefore, the purpose of this study was to use CBCT to calculate the volume of the pulp chamber at different tooth groups. Material and methods: This study conforms to protocols approved and in accordance with the ethics committee’s requirements, informed consent was obtained from each patient. Morphologic measurements of 120 maxillary and 120 mandibular molars (from 40 patients, aged 18–45 years) were included in this study. CBCT images were taken using a Kodak 9500 (Dental Systems, Carestream Health) operated at 90 kVp with a voxel size of 300 mm and a field of view of 90-50 mm. All scans were taken following the manufacturer’s recommendation protocol. According to the examination requirements, C-shaped roots, single-rooted molars, crowned teeth, and teeth with caries and/or restorations violating the pulp chamber were excluded. All measurements were taken on the coronal plane view. Results: In the present study, we used CBCT imaging to gather information regarding pulp chamber volume. With the scanned 3-dimensional images, we were able to clinically determine the pulp chamber parameters using a standardized and defined spatial approach. Conclusions: The data we collected here serve as a proof of principle for the analysis of dental landmarks before collecting stem cells. In this particular study, existing CBCT scans were used to provide useful information that can be used as a guide to determine the volume of the pulp chamber

Sedimentary succession and recognition marks of lacustrine gravel beach-bars, a case study from the Qinghai Lake, China

The present is the key to the past. Based on the dissection of modern beach-bars in the Qinghai Lake, Qinghai-Tibet Plateau, China, including two profiles parallelly to the shoreline, two profiles vertically to the shoreline and one plane-view profile, the sedimentary succession and recognition marks of lacustrine gravel beach-bars have been summarized. Vertically, the lacustrine gravel beach-bars develop with the “ABC” succession. The A interval, the B interval, and the C interval respectively correspond with the gravelly sand facies, the well-sorted gravel facies, and the graded sand facies. The lacustrine gravel beach-bars is composed of several combinations of the “ABC” succession, such as “ABAB”, “ABCABC”, “BCBC”. The main recognition marks of lacustrine gravel beach-bars is the following: the bottom contact is distinct and with the “ABC” succession; and the lacustrine beach-bars develop the swash bedding and sheet-like parallelly to the lakeshore. These viewpoints have significant contributions to the reconstruction of paleoenvironments and paleoshorelines and to the reservoir interpretation within lacustrine beach-bar clastic bodies.

TASK ON INDENTATION OF SMOOTH PUNCH OF AN ARBITRARY FORM IN PLANE VIEW IN HARD PLASTIC HALF-SPACE

In the work the general properties of equations of spatial problem of the theory of ideal plasticity in the condition of Treska plasticity and stressed state that correspond to the ridge of surface of fluctuation are viewed. Singular lines in hard plastic space and solutions in the neighborhood of a singular line that are similar to the expansion in beam series are viewed. On the basis of the developed theory the boundary problem appearing at indentation of punch with smooth basis in a certain plastic body which in the simplest case is a half-space is solved.