Three-dimensional (3D) area and volume measurements for rhinoplasty.

BACKGROUND: Morphometric changes achieved in rhinoplasty are mostly analyzed on two-dimensional (2D) images. However, most of these alterations are amenable to three-dimensional (3D) analysis. OBJECTIVES: Objective measurements for rhinoplasty are currently done on 2D photographic analyses. We believe that newer techniques will develop. This is a study to help define new parameters. METHODS: Landmarks that are widely used in the literature were used to define the boundaries of these measurements. They comprised certain parts of the nose (tip, dorsum, radix, etc.). Measurements were done on a generic face (GF) 3D model. The model's nose was then morphed using the free, open-source 3D modeling software (Blender) to generate seven different deformed noses and to perform the area and volume measurements. RESULTS: Each nose with a different type of deformity demonstrated significant area and volume differences. For example, comparing area measurements to GF-Pleasant nose, GF-Snub nose showed a significant difference at the tip (43.3% reduction). Volume measurements were found to be mostly parallel to the area measurements; however, some incongruences were noted. CONCLUSIONS: We show that new area and volume measurements can be reliably developed for 3D-scanned images. These measurements can be utilized and will enrich the facial analysis and evaluation of the outcomes of rhinoplasty.

Evaluation of 13,466 Fecal Immunochemical Tests in Patients Attending Primary Care for High- and Low-Risk Gastrointestinal Symptoms of Colorectal Cancer.

AIM/OBJECTIVE: Quantitative fecal immunochemical tests (FIT) were recommended by NICE for patients in primary care presenting with low-risk symptoms of colorectal cancer (CRC). FIT is more accurate in the detection of CRC than symptom criteria. Despite this, CRC still occurs with a negative FIT and the importance of safety netting for patients with severe or persistent symptoms is paramount. We aimed to evaluate the utilization and accuracy of FIT for CRC in low and high-risk symptom groups presenting to primary care, the effectiveness of safety netting in primary care, referral practices with FIT utilization for symptomatic patients and the clinical features of FIT negative patients with CRC. MATERIALS AND METHODS: Medical records and databases of all patients undertaking a FIT sample in the Herts Valleys CCG between June 2019 and November 2021 were reviewed. 13,466 consecutive FIT samples were requested for 12,231 patients between June 2019 and November 2021. RESULTS: Analysis of diagnostic accuracy was undertaken for the first 5341 patients with a minimum of 12 months follow up. Sensitivity for CRC, in FIT ≥ 4 µg Hb/g, ≥ 10 µg Hb/g and ≥ 100 µg Hb/g was 93% (95% CI 85-98%), 91% (95% CI 82-96%) and 72% (95% CI 60-81%) with a number needed to investigate of 36, 19 and 6, respectively. CONCLUSION: A FIT ≥ 10 µg Hb/g in conjunction with ongoing GP clinical concern within 8 weeks had a sensitivity for CRC of 97% (95% CI 90-100%), a PPV of 3.6% (95% CI 3.4-3.7%) and a number needed to investigate to detect one CRC of 28.