No abstract

Tethered capsule endomicroscopy (TCE) is an emerging screening technology that comprehensively obtains microstructural OCT images of the gastrointestinal (GI) tract in unsedated patients. To advance clinical adoption of this imaging technique, it will be important to validate TCE images with co-localized histology, the current diagnostic gold standard. One method for co-localizing OCT images with histology is image-targeted laser marking, which has previously been implemented using a driveshaft-based, balloon OCT catheter, deployed during endoscopy. In this paper, we present a TCE device that scans and targets the imaging beam using a low-cost stepper motor that is integrated inside the capsule. In combination with a 4-laser-diode, high power 1430/1450 nm marking laser system (800 mW on the sample and 1s pulse duration), this technology generated clearly visible marks, with a spatial targeting accuracy of better than 0.5 mm. A laser safety study was done on swine esophagus ex vivo, showing that these exposure parameters did not alter the submucosa, with a large, 4-5x safety margin. The technology was demonstrated in living human subjects and shown to be effective for co-localizing OCT TCE images to biopsies obtained during subsequent endoscopy.

Aims Plaque burden (PB) measurement using intravascular optical coherence tomography (IVOCT) is currently thought to be inferior to intravascular ultrasound (IVUS). We developed an automated IVOCT image processing algorithm to enhance the external elastic lamina (EEL) contour. Thus, we investigated the accuracies of standard IVOCT and an IVOCT enhancement algorithm for measuring PB using IVUS as the reference standard. Methods and results The EEL-enhancement algorithm combined adaptive attenuation compensation, exponentiation, angular registration, and image averaging using three sequential frames. In two different laboratories with intravascular imaging expertise, PB was quantified on 200 randomized, matched IVOCT and IVUS images by four independent observers. Fibroatheroma, fibrocalcific plaque, fibrous plaque, pathological intimal thickening (PIT), and mixed plaque were included in each set. Pearson’s correlation coefficients between IVUS and standard IVOCT measurements of PB were 0.61, 0.67, 0.76, 0.78, and 0.87 for fibroatheromas, mixed plaques, fibrocalcific plaques, fibrous plaques, and PIT plaques, respectively. Pearson’s correlation coefficients increased to 0.81, 0.83, 0.83, 0.84, and 0.90 when using the EEL-enhanced images (P = 0.003, P = 0.004, P = 0.08, P = 0.12, and P = 0.23, respectively). EEL-enhanced IVOCT analysis was associated with a lower EEL-area measurement absolute error for fibroatheromas, mixed plaques, and all pooled plaques (P = 0.006, P = 0.02, and P < 0.001, respectively). Compared with standard IVOCT, the EEL-enhanced IVOCT images had a higher sensitivity (79% vs. 28%, P < 0.001) and specificity (98% vs. 85%, P = 0.03) for plaques with an IVUS PB ≥70%. Conclusion EEL-enhanced IVOCT can be used to reliably measure PB in all types of coronary atherosclerotic lesions, including fibroatheromas and mixed plaques.

Purpose: To evaluate the safety, efficacy, and efficiency of the Ngenuity 3-dimensional (3D) heads-up display (HUD) visualization system for primary rhegmatogenous retinal detachment (RRD) repair at a large academic medical center in the United States. Methods: This retrospective review comprised consecutive patients aged 18 years or older who had primary RRD repair (pars plana vitrectomy [PPV] alone or combined PPV and scleral buckle) performed by the same fellowship-trained vitreoretinal surgeon using the 3D visualization system and a traditional standard operating microscope (SOM) at Massachusetts Eye and Ear from June 2017 to December 2021. The minimum follow-up was 90 days. Results: The 3D HUD group comprised 50 eyes of 47 patients and the SOM group, 138 eyes of 136 patients. There were no between-group differences in single surgery anatomic success rates at 3 months (98% HUD vs 99% SOM; P = 1.00) or at the last follow-up (94% HUD vs 98% SOM; P = .40). The rate of postoperative proliferative vitreoretinopathy was similar between the 2 groups (3 months: 3% HUD vs 5% SOM, P = .94; last follow-up, 2% HUD vs 3% SOM, P = .93). There was no difference in the mean duration of surgery (57.4 ± 28.9 minutes HUD vs 59.4 ± 29.9 minutes SOM; P = .68). Conclusions: Anatomic and functional outcomes, in addition to surgical efficiency, of noncomplex primary RRD repair with a 3D HUD system were similar to those of surgery performed with an SOM.