Image Quality Assessment of Deep Learning Image Reconstruction in Torso Computed Tomography Using Tube Current Modulation.

Novel deep learning image reconstruction (DLIR) reportedly changes the image quality characteristics based on object contrast and image noise. In clinical practice, computed tomography image noise is usually controlled by tube current modulation (TCM) to accommodate changes in object size. This study aimed to evaluate the image quality characteristics of DLIR for different object sizes when the in-plane noise was controlled by TCM. Images acquisition was performed on a GE Revolution CT system to investigate the impact of the DLIR algorithm compared to the standard reconstructions of filtered-back projection (FBP) and hybrid iterative reconstruction (hybrid-IR). The image quality assessment was performed using phantom images, and an observer study was conducted using clinical cases. The image quality assessment confirmed the excellent noise- reduction performance of DLIR, despite variations due to phantom size. Similarly, in the observer study, DLIR received high evaluations regardless of the body parts imaged. We evaluated a novel DLIR algorithm by replicating clinical behaviors. Consequently, DLIR exhibited higher image quality than those of FBP and hybrid-IR in both phantom and observer studies, albeit the value depended on the reconstruction strength, and proved itself capable of providing stable image quality in clinical use.

Charlson comorbidity index is predictive of postoperative clinical outcome after single-level posterior lumbar interbody fusion surgery.

BACKGROUND: In several previous studies, Charlson comorbidity index (CCI) score was associated with postoperative complications, mortality, and re-admission. There are few reports about the influence of CCI score on postoperative clinical outcome. The purpose of this study was to investigate the influence of comorbidities as calculated with CCI on postoperative clinical outcomes after PLIF. METHODS: Three hundred sixty-six patients who underwent an elective primary single-level PLIF were included. Postoperative clinical outcome was evaluated with the Japanese Orthopaedic Association lumbar score (JOA score). The correlation coefficient between the CCI score and postoperative improvement in JOA score was investigated. Patients were divided into three groups according to their CCI score (0, 1, and 2+). JOA improvement rate, length of stay (LOS), and direct cost were compared between each group. Postoperative complications were also investigated. RESULTS: There was a weak negative relationship between CCI score and JOA improvement rate (r = - 0.20). LOS and direct cost had almost no correlation with CCI score. The JOA improvement rate of group 0 and group 1 was significantly higher than group 2+. LOS and direct cost were also significantly different between group 0 and group 2+. There were 14 postoperative complications. Adverse postoperative complications were equivalently distributed in each group, and not associated with the number of comorbidities. CONCLUSIONS: A higher CCI score leads to a poor postoperative outcome. The recovery rate of patients with two or more comorbidities was significantly higher than in patients without comorbidities. However, the CCI score did not influence LOS and increased direct costs. The surgeon must take into consideration the patient's comorbidities when planning a surgical intervention in order to achieve a good clinical outcome.

The effectiveness of preoperative assessment using a patient-specific three-dimensional pseudoarticulation model for minimally invasive posterior resection in a patient with Bertolotti's syndrome: a case report.

BACKGROUND: Bertolotti's syndrome is widely known to cause low back pain in young patients and must be considered as a differential diagnosis. Its treatment such as conservative therapy or surgery remains controversial. Surgical procedure is recommended for intractable low back pain. The three-dimensional (3D) lumbosacral transitional vertebrae anatomy should be completely understood for a successful surgery. Using an intraoperative 3D navigation and preoperative preliminary surgical planning with a patient-specific 3D plaster model contribute for safe surgery and good outcome. CASE PRESENTATION: A case of a 22-year-old Japanese male patient with intractable left low back pain due to lumbosacral transitional vertebrae with Bertolotti's syndrome. The symptom resisted the conservative treatment, and anesthetic injection at pseudoarticulation only provided a short-term pain relief. Posterior resection using intraoperative three-dimensional (3D) navigation has been performed through microendoscopic view. Pseudoarticulation was totally and successfully resected in a safe manner. CONCLUSIONS: Preoperative surgical planning and rehearsal using a patient-specific 3D plaster model was greatly useful and effective for surgeons in performing accurate and safe pseudoarticulation resection.

[Effectiveness of Intraoperative Histologic Assessment of Surgical Margins for Breast-Conserving Surgery].

BACKGROUND: The effectiveness of intraoperative histologic assessment of surgical margins for breast-conserving surgery is unclear. In this study, we investigated the effectiveness of intraoperative histologic assessment of surgical margins for breast-conserving surgery. METHODS: Sixty-six patients who underwent breast-conserving surgery for breast cancer at our hospital between January 2007 and December 2013 were retrospectively examined for an association between the surgical margin status and locoregional recurrence. The surgical margins were then evaluated by intraoperative histologic assessment. RESULTS: The median observation period was 52 months. Positive margins were found in 14 patients (21%). A total mastectomy was performed in 9 patients, and additional resection in 5 patients. In the permanent tissue sample, the intraoperative assessment was found to be false negative in 2 patients (3.8%), who received boost irradiation postoperatively. No locoregional recurrence was observed in all patients who underwent additional resection or total mastectomy due to positive margins. The rate of margin positivity was significantly higher in invasive lobular carcinomas and in cancers with intraductal extension. CONCLUSIONS: Intraoperative histologic assessment of the surgical margin was useful for reducing the rate of local recurrence.