Diclofenac Sodium 3% in Hyaluronic Acid 2.5% Gel Significantly Diminishes the Actinic Keratosis Area and Severity Index.

BACKGROUND/AIMS: Actinic keratosis area and severity index (AKASI) is a new assessment tool to quantify the severity of actinic damage on the head. Thus far, it has not been evaluated in monitoring the efficacy of field-directed topical treatments in actinic keratosis (AK) in routine clinical practice. Thus, the aim of this study was to determine treatment outcomes by using AKASI 3 months after the initiation of topical application of diclofenac sodium 3% in hyaluronic acid 2.5% gel (DFS) in patients with AKs on the head. METHODS: We performed a retrospective analysis of patients with AKs who had AKASI scores prior to and after treatment with DFS. RESULTS: Of the 24 patients included, 20 (83.3%) showed an improvement in AKASI, 2 (8.3%) a stable AKASI, and 2 (8.3%) a worsening of AKASI after a median (interquartile range) follow-up period of 91.5 days (89.8-104.3). The median AKASI reduction was 31.4% (16.7-59.1). The Wilcoxon test showed significant differences (p = 0.0008) between baseline and posttreatment AKASI values. CONCLUSIONS: AKASI is an easy-to-use quantitative tool for assessing the treatment outcome of field-directed therapies. Field-directed therapies of AK should no longer be monitored by assessments based on lesion counts alone.

Improved nerve conspicuity with water-weighting and denoising in two-point Dixon magnetic resonance neurography.

BACKGROUND: T2-weighted, two-point Dixon fast-spin-echo (FSE) is an effective technique for magnetic resonance neurography (MRN) that can provide quantitative assessment of muscle denervation. Low signal-to-noise ratio and inadequate fat suppression, however, can impede accurate interpretation. PURPOSE: To quantify effects of principal component analysis (PCA) denoising on tissue signal intensities and fat fraction (FF) and to determine qualitative image quality improvements from both denoising and water-weighting (WW) algorithms to improve nerve conspicuity and fat suppression. STUDY TYPE: Prospective. SUBJECTS: Twenty-one subjects undergoing MR neurography evaluation (11/10 male/female, mean age = 46.3±13.7 years) with 60 image volumes. Twelve subjects (23 image volumes) were determined to have muscle denervation based on diffusely elevated T2 signal intensity. FIELD STRENGTH/SEQUENCE: 3 T, 2D, two-point Dixon FSE. ASSESSMENT: Qualitative assessment included overall image quality, nerve conspicuity, fat suppression, pulsation and ringing artifacts by 3 radiologists separately on a three-point scale (1 = poor, 2 = average, 3 = excellent). Quantitative measurements for FF and signal intensity relative to normal muscle were made for nerve, abnormal muscle and subcutaneous fat. STATISTICAL TESTS: Linear and ordinal regression models were used for quantitative and qualitative comparisons, respectively; 95% confidence intervals (CIs) and p-values for pairwise comparisons were adjusted using the Holm-Bonferroni method. Inter-rater agreement was assessed using Gwet's agreement coefficient (AC2). RESULTS: Simulations showed PCA-denoising reduced FF error from 2.0% to 1.0%, and from 7.6% to 3.1% at noise levels of 10% and 30%, respectively. In human subjects, PCA-denoising did not change signal levels and FF quantitatively. WW decreased fat signal significantly (-83.6%, p < 0.001). Nerve conspicuity was improved by WW (odds ratio, OR = 5.8, p < 0.001). Fat suppression was improved by both PCA (OR = 3.6, p < 0.001) and WW (OR = 2.2, p < 0.001). Overall image quality was improved by PCA + WW (OR = 1.7, p = 0.04). CONCLUSIONS: WW and PCA-denoising improved nerve conspicuity and fat suppression in MR neurography. Denoising can potentially provide improved accuracy of FF maps for assessing fat-infiltrated muscle.