Effect of low contrast medium-dose CTA on device sizing and access vessel assessment for TAVR.

PURPOSE: Chronic kidney disease (CKD) is prevalent in transcatheter aortic valve replacement (TAVR) candidates, leading to concerns regarding contrast medium (CM) safety. We evaluated (a) the impact of low-CM imaging on pre-TAVR measurements and (b) postcontrast acute kidney injury (PC-AKI) prevalence after dual-source computed tomography (DSCT) in TAVR candidates. METHODS: All TAVR candidates with CKD (SCr≥1.5 mg/dL) who underwent weight-based low-CM, low-pitch helical 3rd-generation DSCT in a one-year period were included, and matched to standard-CM, non-CKD controls (N = 50). Image quality (IQ) and pre-TAVR measurement interobserver variability were evaluated. Renal function change and PC-AKI were studied in the entire TAVR cohort, irrespective of scan mode (N = 153). RESULTS: Low-CM in CKD (N = 25) was performed with median 68 mL CM [52-87], 90 kV [80-90] and SCr 1.6 mg/dL [1.5-1.9], and standard-CM without CKD with median 116 mL CM [96-134], 100 kV [90-110] and SCr 1.0 mg/dL [0.9-1.1](P < 0.00). Low-CM IQ was good, though lower compared with standard-CM (P < 0.02). Interobserver measurement reliability was excellent (ICCs>0.85). Interobserver-agreement was lower in low-CM, causing prosthesis size disagreement in 5/25 (kappa-0.73) versus 0/25 with standard-CM (kappa-1.00), and transfemoral eligibility disagreement in 4/25 (kappa-0.68) versus 2/25 (kappa-0.84), respectively. Mean 1-month SCr-change in the low-CM TAVR cohort (N = 35) was -1 % [-12 to +7 %] and in standard-CM (N = 118) 0 % [-8 to +10 %](P > 0.3). PC-AKI occurred in none. CONCLUSION: Low-CM third-generation-DSCT achieves good IQ in TAVR candidates with CKD, and seems safe, with no apparent renal function deterioration or prevalence of PC-AKI. However, standard-CM protocols in non-CKD patients provide higher measurement reproducibility. Low-CM protocols should therefore be reserved for patients at high risk for PC-AKI.

Mid-ultraviolet light-emitting diode detects dipicolinic acid.

Dipicolinic acid (DPA, 2,6-pyridinedicarboxylic acid) is a substance uniquely present in bacterial spores such as that from anthrax (B. anthracis). It is known that DPA can be detected by the long-lived fluorescence of its terbium chelate; the best limit of detection (LOD) reported thus far using a large benchtop gated fluorescence instrument using a pulsed Xe lamp is 2 nM. We use a novel AlGaN light-emitting diode (LED) fabricated on a sapphire substrate that has peak emission at 291 nm. Although the overlap of the emission band of this LED with the absorption band of Tb-DPA (lambda(max) doublet: 273, 279 nm) is not ideal, we demonstrate that a compact detector based on this LED and an off-the-shelf gated photodetection module can provide an LOD of 0.4 nM, thus providing a basis for convenient early warning detectors.

The Yale-Brown Obsessive Compulsive Scale: interview versus self-report.

Several studies have demonstrated the reliability and validity of the Yale-Brown Obsessive Compulsive Scale (YBOCS) conducted by trained interviewers. The present study examined several aspects of a self-report YBOCS version relative to the usual interview format in two non-clinical samples (ns = 46 and 70) and in a clinical OCD sample (n = 36) and a clinical non-OCD group (n = 10). The self-rated instrument showed excellent internal consistency and test-retest reliability, performing somewhat better than the interview. There was good agreement between symptom checklist categories across the two versions, though clinical subjects reported more symptoms on the self-report form than on the interview. Some order effects were evident for non-clinical subjects only: those who received the self-report first scored lower on both self-report and interview than those who received the interview first. No order effects were observed in the clinical sample. The self-report version showed strong convergent validity with the interview, and discriminated well between OCD and non-OCD patients. Although more study is needed, particularly on clinical samples, these findings suggest that the self-report YBOCS may be a time-saving and less costly substitute for the interview format in assessing OCD symptoms.