RESUMEN
OBJECTIVE: The authors sought to compare the effect of index level sagittal alignment on cephalad radiographic adjacent segment pathology (RASP) in patients undergoing cervical total disc arthroplasty (TDA) or anterior cervical discectomy and fusion (ACDF). METHODS: This was a retrospective study of prospectively collected radiographic data from 79 patients who underwent TDA or ACDF and were enrolled and followed prospectively at two centers in a multicenter FDA investigational device exemption trial of the Bryan cervical disc prosthesis used for arthroplasty. Neutral lateral radiographs were obtained pre- and postoperatively and at 1, 2, 4, and up to 7 years following surgery. The index level Cobb angle was measured both pre- and postoperatively. Cephalad disc degeneration was determined by a previously described measurement of the disc height/anteroposterior (AP) distance ratio. RESULTS: Sixty-eight patients (n = 33 ACDF; n = 35 TDA) had complete radiographs and were included for analysis. Preoperatively, there was no difference in the index level Cobb angle between the ACDF and TDA patients. Postoperatively, the ACDF patients had a larger segment lordosis compared to the TDA patients (p = 0.002). Patients who had a postoperative kyphotic Cobb angle were more likely to have undergone TDA (p = 0.01). A significant decrease in the disc height/AP distance ratio occurred over time (p = 0.035), by an average of 0.01818 at 84 months. However, this decrease was not influenced by preoperative alignment, postoperative alignment, or type of surgery. CONCLUSIONS: In this cohort of patients undergoing TDA and ACDF, the authors found that preoperative and postoperative sagittal alignment have no effect on RASP at follow-up of at least 7 years. They identified time as the only significant factor affecting RASP.
RESUMEN
PURPOSE: To evaluate the short-term reproducibility of radiomic features in liver parenchyma and liver cancers in patients who underwent consecutive contrast-enhanced CT (CECT) with intravenous iodinated contrast within 2 weeks by chance. METHODS: The Institutional Review Board approved this HIPAA-compliant retrospective study and waived the requirement for patients' informed consent. Patients were included if they had a liver malignancy (liver metastasis, n = 22, intrahepatic cholangiocarcinoma, n = 10, and hepatocellular carcinoma, n = 6), had two consecutive CECT within 14 days, and had no prior or intervening therapy. Liver tumors and liver parenchyma were segmented and radiomic features (n = 254) were extracted. The number of reproducible features (with concordance correlation coefficients > 0.9) was calculated for patient subgroups with different variations in contrast injection rate and pixel resolution. RESULTS: The number of reproducible radiomic features decreased with increasing variations in contrast injection rate and pixel resolution. When including all CECTs with injection rates differences of less than 15% vs. up to 50%, 63/254 vs. 0/254 features were reproducible for liver parenchyma and 68/254 vs. 50/254 features were reproducible for malignancies. When including all CT with pixel resolution differences of 0-5% or 0-15%, 20/254 vs. 0/254 features were reproducible for liver parenchyma; 34/254 liver malignancy features were reproducible with pixel differences up to 15%. CONCLUSION: A greater number of liver malignancy radiomic features were reproducible compared to liver parenchyma features, but the proportion of reproducible features decreased with increasing variations in contrast injection rates and pixel resolution.
