k-t accelerated aortic 4D flow MRI in under two minutes: Feasibility and impact of resolution, k-space sampling patterns, and respiratory navigator gating on hemodynamic measurements.

PURPOSE: To assess the performance of highly accelerated free-breathing aortic four-dimensional (4D) flow MRI acquired in under 2 minutes compared to conventional respiratory gated 4D flow. METHODS: Eight k-t accelerated nongated 4D flow MRI (parallel MRI with extended and averaged generalized autocalibrating partially parallel acquisition kernels [PEAK GRAPPA], R = 5, TRes = 67.2 ms) using four ky -kz Cartesian sampling patterns (linear, center-out, out-center-out, random) and two spatial resolutions (SRes1 = 3.5 × 2.3 × 2.6 mm3 , SRes2 = 4.5 × 2.3 × 2.6 mm3 ) were compared in vitro (aortic coarctation flow phantom) and in 10 healthy volunteers, to conventional 4D flow (16 mm-navigator acceptance window; R = 2; TRes = 39.2 ms; SRes = 3.2 × 2.3 × 2.4 mm3 ). The best k-t accelerated approach was further assessed in 10 patients with aortic disease. RESULTS: The k-t accelerated in vitro aortic peak flow (Qmax), net flow (Qnet), and peak velocity (Vmax) were lower than conventional 4D flow indices by ≤4.7%, ≤ 11%, and ≤22%, respectively. In vivo k-t accelerated acquisitions were significantly shorter but showed a trend to lower image quality compared to conventional 4D flow. Hemodynamic indices for linear and out-center-out k-space samplings were in agreement with conventional 4D flow (Qmax ≤ 13%, Qnet ≤ 13%, Vmax ≤ 17%, P > 0.05). CONCLUSION: Aortic 4D flow MRI in under 2 minutes is feasible with moderate underestimation of flow indices. Differences in k-space sampling patterns suggest an opportunity to mitigate image artifacts by an optimal trade-off between scan time, acceleration, and k-space sampling. Magn Reson Med 79:195-207, 2018. © 2018 International Society for Magnetic Resonance in Medicine.

Cessation of hairline recession following open forehead rejuvenation.

BACKGROUND: The senior author (B.G.) observed that patients who underwent forehead rejuvenation using a pretrichial incision did not experience hairline recession. The aim of this study was to objectively measure the effects of forehead rejuvenation on hairline recession. METHODS: A 15-year retrospective review was performed in 31 forehead rejuvenation patients [17 endoscopic and 14 open (pretrichial incision) with adequate early (within 1 year) and late (≥ 8 years) postoperative photographs] and 11 age- and follow-up-matched cosmetic surgery patients who did not have forehead rejuvenation. Hair recession was measured using the Mirror program for Windows by averaging two successive perpendicular distances from bilateral medial canthi to the hairline and dividing by the intercanthal distance. In pretrichial incision patients, the distance from the incision to the anterior hairline was recorded. RESULTS: The difference in short-term postoperative hairline measurements among groups was not significant (p = 0.445). Only the pretrichial group demonstrated significant stability between short-term and long-term hairline positions (p = 0.005). The pretrichial group demonstrated a stable or improved hairline position compared with either the endoscopic (p = 0.017) or control group (p = 0.006), whereas these patients demonstrated significant recession over time. Hairline measurements between early and late postoperative photographs in the endoscopic and control groups were not significant (p = 0.621). CONCLUSIONS: The pretrichial incision results in a stable hairline position over time compared with the endoscopic technique or matched controls. Pretrichial incision patients did not demonstrate separation between the scar and hairline, indicating no hair loss in this site.

A 26-year experience with vest-over-pants technique platysmarrhaphy.

BACKGROUND: The purpose of this article is to review the efficacy of the vest-over-pants technique for elimination of the platysma bands and improvement of the cervicomental angle. METHODS: This is a retrospective chart review of 88 patients with neck aging selected randomly by a visiting fellow and a medical student. The collected information included patient demographics, cervical surgical techniques, and complications. Patient photographs obtained preoperatively and at least 8 months postoperatively were compared on front and profile views to determine the visibility of the platysmal bands and the neck contouring. Through an incision placed anterior to the submental crease, the platysma borders were identified and elevated. After completion of the other intended procedures, the platysma borders were then overlapped using the vest-over-pants technique with 4-0 Mersilene. RESULTS: The mean patient age was 57.56 years. There were 76 women (86.4 percent) and 12 men (13.6 percent). The average follow-up was 28.8 months. Of the 88 patients, 93.2 percent underwent concomitant rhytidectomy, 94.3 percent underwent submental lipectomy, 95.9 percent underwent submandibular contouring, 61.4 percent underwent removal of the anterior belly of the digastric muscle, and 5.7 percent underwent suspension or partial or total excision of the submandibular salivary gland. None of the patients had residual recurrence of the platysma bands during the follow-up period. CONCLUSION: On the basis of the detailed analysis of this group of patients and 26-year experience with this technique, the authors conclude that this procedure provides logical and enduring elimination of prominent platysma bands and suspension of neck structures.

A re-evaluation of the risk of microbial keratitis from overnight contact lens wear compared with other life risks.

PURPOSE: In 1995, Myers and Weiss published an article comparing the risk of ulcerative keratitis related to low oxygen permeability (Dk) extended contact lens wear to other life risks. This article updates the risks associated with silicone hydrogel (SH) extended wear contact lens use and some comparative life risks, to provide a current perspective within the hierarchy of life risks. METHODS: A comparative ratio was defined as the incidence of microbial keratitis in a population of SH extended wear contact lens users divided by the incidence of other disease or occurrence in a given population at risk. RESULTS: The risk of SH lens-related microbial keratitis is about 1.5 to 16 times less risky than certain nonfatal disruptive occurrences in the general population, and about the same as the risk of developing breast cancer. Compared with other ocular conditions, the risk of microbial keratitis with SH lenses is about the same as developing late-stage age-related macular degeneration or retinal detachment after cataract extraction on an annual basis; it is over 200 times greater than developing eye or orbit cancer; it is about 7, 20, or more than 30 times less than proceeding to penetrating keratoplasty in keratoconus, developing nuclear cataract, or experiencing a corneal inflammatory event during low-Dk extended wear, respectively. CONCLUSIONS: Although the risk of microbial keratitis with modern day SH contact lens extended wear has not changed since the 1980s, when put in perspective with other life risks, it is a relatively rare occurrence.