Adult neural stem cell activation in mice is regulated by the day/night cycle and intracellular calcium dynamics.

Neural stem cells (NSCs) in the adult brain transit from the quiescent state to proliferation to produce new neurons. The mechanisms regulating this transition in freely behaving animals are, however, poorly understood. We customized in vivo imaging protocols to follow NSCs for several days up to months, observing their activation kinetics in freely behaving mice. Strikingly, NSC division is more frequent during daylight and is inhibited by darkness-induced melatonin signaling. The inhibition of melatonin receptors affected intracellular Ca2+ dynamics and promoted NSC activation. We further discovered a Ca2+ signature of quiescent versus activated NSCs and showed that several microenvironmental signals converge on intracellular Ca2+ pathways to regulate NSC quiescence and activation. In vivo NSC-specific optogenetic modulation of Ca2+ fluxes to mimic quiescent-state-like Ca2+ dynamics in freely behaving mice blocked NSC activation and maintained their quiescence, pointing to the regulatory mechanisms mediating NSC activation in freely behaving animals.

In vivo live imaging of postnatal neural stem cells.

Neural stem cells (NSCs) are maintained in specific regions of the postnatal brain and contribute to its structural and functional plasticity. However, the long-term renewal potential of NSCs and their mode of division remain elusive. The use of advanced in vivo live imaging approaches may expand our knowledge of NSC physiology and provide new information for cell replacement therapies. In this Review, we discuss the in vivo imaging methods used to study NSC dynamics and recent live-imaging results with respect to specific intracellular pathways that allow NSCs to integrate and decode different micro-environmental signals. Lastly, we discuss future directions that may provide answers to unresolved questions regarding NSC physiology.

Radiomics based on MRI to predict recurrent L4-5 disc herniation after percutaneous endoscopic lumbar discectomy.

BACKGROUND: In recent years, radiomics has been shown to be an effective tool for the diagnosis and prediction of diseases. Existing evidence suggests that imaging features play a key role in predicting the recurrence of lumbar disk herniation (rLDH). Thus, this study aimed to evaluate the risk of rLDH in patients undergoing percutaneous endoscopic lumbar discectomy (PELD) using radiomics to facilitate the development of more rational surgical and perioperative management strategies. METHOD: This was a retrospective case-control study involving 487 patients who underwent PELD at the L4/5 level. The rLDH and negative groups were matched using propensity score matching (PSM). A total of 1409 radiomic features were extracted from preoperative lumbar MRI images using intraclass correlation coefficient (ICC) analysis, t-test, and LASSO analysis. Afterward, 6 predictive models were constructed and evaluated using ROC curve analysis, AUC, specificity, sensitivity, confusion matrix, and 2 repeated 3-fold cross-validations. Lastly, the Shapley Additive Explanation (SHAP) analysis provided visual explanations for the models. RESULTS: Following screening and matching, 128 patients were included in both the recurrence and control groups. Moreover, 18 of the extracted radiomic features were selected for generating six models, which achieved an AUC of 0.551-0.859 for predicting rLDH. Among these models, SVM, RF, and XG Boost exhibited superior performances. Finally, cross-validation revealed that their accuracy was 0.674-0.791, 0.647-0.729, and 0.674-0.718. CONCLUSION: Radiomics based on MRI can be used to predict the risk of rLDH, offering more comprehensive guidance for perioperative treatment by extracting imaging information that cannot be visualized with the naked eye. Meanwhile, the accuracy and generalizability of the model can be improved in the future by incorporating more data and conducting multicenter studies.

Evaluation of a novel disposable endoscope for retroflexed endoscopic rubber band ligation of internal hemorrhoids: a randomized pilot study.

PURPOSE: Retroflexed endoscopic rubber band ligation (ERBL) for treating Grade II and III internal hemorrhoids using disposable endoscopes has not been previously assessed. We therefore compared the safety and effectiveness of ERBL for internal hemorrhoids using novel disposable endoscopes versus traditional reusable endoscopes. METHODS: This prospective randomized controlled trial involved 42 patients who underwent ERBL for Grade II and III internal hemorrhoids using either a disposable endoscope (n = 21) or a reusable endoscope (n = 21). Safety was assessed by the incidence of equipment failure, device-related adverse events, and in-procedure stability of vital signs. Effectiveness was assessed by the postoperative therapeutic effect, feasibility of retroflexed ERBL, and incidence of complications. RESULTS: In terms of safety, no life-threatening events, equipment failure, or device-related adverse effects occurred during the procedures in either group. The rate of diastolic blood pressure stability was significantly different between the two groups (P = .049), but the rates of systolic blood pressure and heart rate stability were similar. In terms of effectiveness, the therapeutic effects on postoperative Day 30 were similar in both groups. Image clarity and endoscopic flexibility in the disposable endoscope group were mildly inferior to those in the reusable endoscope group, but without statistical significance. Matching between the endoscope and ligating device was 100% in both groups. The incidence of complications on postoperative Days 1 and 10 was not significantly different between the two groups. CONCLUSION: Compared with reusable endoscopes, disposable endoscopes are equally safe, feasible, and reliable in ERBL for internal hemorrhoids.

Unilateral biportal endoscopic discectomy via translaminar approach for highly upward-migrated lumbar disc herniation: a technical note and preliminary treatment outcomes.

STUDY DESIGN: A technical note and retrospective case series. OBJECTIVE: Highly upward-migrated lumbar disc herniation (LDH) is challenging due to its problematic access and incomplete removal. The most used interlaminar approach may cause extensive bony destruction. We developed a novel translaminar approach using the unilateral portal endoscopic (UBE) technique, emphasizing effective neural decompression, and preserving the facet joint's integrity. METHODS: This retrospective study included six patients receiving UBE translaminar discectomy for highly upward-migrated LDHs from May 2019 to June 2021. The migrated disc was removed through a small keyhole on the lamina of the cranial vertebra. The treatment results were evaluated by operation time, hospital stays, complications, visual analog scale (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) score, and modified MacNab criteria. RESULTS: The mean pre-operative VAS for back pain (5.0 ± 4.9), VAS for leg pain (9.2 ± 1.0), JOA score (10.7 ± 6.6), and ODI (75.7 ± 25.3) were significantly improved to 0.3 ± 0.5, 1.2 ± 1.5, 27.3 ± 1.8, 5.0 ± 11.3 respectively at the final follow-up. Five patients had excellent, and one patient had good outcomes according to the Modified MacNab criteria. The hospital stay was 2.7 ± 0.5 days. No complication was recorded. The MRI follow-up showed complete disc removal, except for one patient with an asymptomatic residual disc. CONCLUSIONS: UBE translaminar discectomy is a safe and effective minimally invasive procedure for highly upward-migrated LDH with satisfactory treatment outcomes and nearly 100% facet joint preservation.

Extended endoscopic endonasal approach to the chiasmatic cistern: An anatomical study of the arachnoid.

This paper studied the arachnoid of the chiasmatic cistern (CC) and the methods for increasing the exposure of the CC from an endoscopic perspective. Eight anatomical specimens with vascular injection were used for endoscopic endonasal dissection. The anatomical characteristics of the CC were studied and documented, and anatomical measurements were collected. The CC is an unpaired five-walled arachnoid cistern located between the optic nerve, optic chiasm, and the diaphragma sellae. The average exposed area of the CC before the anterior intercavernous sinus (AICS) was transected was 66.67 ± 33.76 mm2 . After the AICS was transected and the pituitary gland (PG) was mobilized, the average exposed area of the CC was 95.90 ± 45.48 mm2 . The CC has five walls and a complex neurovascular structure. It is located in a critical anatomical position. The transection of the AICS and mobilization of the PG or the selective sacrifice of the descending branch of the superior hypophyseal artery can improve the operative field.

Is ultraviolet light disinfection fit to be the future standard for the disinfection of flexible endoscopes without a working channel?

OBJECTIVE: To investigate colony-forming unit (CFU) reduction on contaminated flexible endoscopes (FEs) without a working channel after UV-C light disinfection, compared to the current disinfection method with the endoscope washer disinfector (EWD). DESIGN, SETTING AND PARTICIPANTS: After pharyngolaryngoscopy, a manual pre-cleaning with tap water was performed. A culture was then collected by rolling the distal 8-10 cm of the FE over an Agar plate. The FE was disinfected using the D60 (60-s disinfection process with UV-C light) or the EWD (gold standard reprocessing process with water and chemicals). Another culture was then taken. After incubation, a CFU count was performed. RESULTS: A total of 200 FEs without a working channel were divided equally between the two disinfection groups. After clinical use and manual pre-cleaning, 84 of the 100 (84.0%) (UV-C light group) and 79 of the 100 (79.0%) (EWD) FEs were contaminated with at least 1 CFU. FEs that showed no contamination after use were excluded from further analysis. After disinfection with UV-C light, 72 (85.7%) FEs showed no contamination (i.e., 0 CFUs) versus 66 (83.5%) FEs after reprocessing with the EWD. CONCLUSION: There is no difference in CFUs reduction on contaminated FEs without a working channel between UV-C light disinfection and the current gold standard, the EWD.

Significant increased bacterial contamination with endoscope overnight and weekend storage times.

BACKGROUND AND AIM: Forced-air drying (FAD) cabinets are recommended for storage of reprocessed endoscopes, but financial constraints prevent their universal application. The study aimed to determine bacterial contamination in flexible gastroscopes (FG) channels after storage, in a cabinet with filtered air and UV lights, but without FAD. METHODS: Eight FG in clinical use in an endoscopy service of a large Brazilian hospital were sampled: immediately "Time zero" (N = 50), 12 h "Time 1" (N = 25), and 60 h "Time 2" (N = 25) after reprocessing. Following a flush-brush-flush of channels, 40-mL sterile water and 3 cm of the brush were collected. Each sample was divided, filtered onto two 0.22-µm membranes, and incubated in media without or with disinfectant neutralizer. Automated method was used for identification and antibiotic resistance test of isolated bacteria. RESULTS: Bacterial contamination in times "1" and "2" was 5.9 and 16.1 times greater than that of "Time zero," respectively. Number of positive cultures in media with and without neutralizer was similar at times "1" and "2," while media with neutralizer produced more positive cultures at "Time zero." Most bacteria isolated at "Time 2" were Gram-negative rods (52.3%) and showed resistance to one or more antibiotics (65%). CONCLUSION: Bacterial contamination was detected on reprocessed FG stored in non-FAD cabinets overnight (12 h) and increased with longer storage time (60 h). The contamination source is likely to be bacteria in biofilm which multiply in the absence of FAD. Evidence-based criteria should be available for storage time according to the cabinet available.

Feasibility of Cholangioscopy Using Multibending Ultra-Slim Endoscope Through a Lumen-Apposing Metal Stent for Choledochoduodenostomy.

BACKGROUND AND AIMS: Endoscopic ultrasound (EUS) guided choledochoduodenostomy using a lumen-apposing metal stent (LAMS) allows access to the biliary system with a sufficiently large diameter stent. However, an appropriate endoscope for this purpose is required. We evaluated the feasibility of per-oral cholangioscopy (POC) using a multibending ultra-slim endoscope through a LAMS for EUS-guided choledochoduodenostomy. METHODS: Twelve patients who underwent EUS-guided choledochoduodenostomy, followed by POC via a LAMS, were enrolled. POC was performed with an multibending ultra-slim endoscope. The primary outcome was technical success, defined as examination of both hepatic ducts and either the distal common bile duct or stricture site within 10 min. The types of intervention and adverse events were also assessed. RESULTS: Technical success was achieved in all cases with the multibending ultra-slim endoscope. Narrow-band imaging endoscopy was performed in five cases (41.7%) and POC-guided targeted biopsy was performed in three cases (25.0%). Stone extraction during POC was performed in two patients (16.7%) and foreign body removal from the intrahepatic duct was performed in one patient. One patient underwent additional metal stent insertion under direct visualization. After POC, no stent migration or severe adverse events were seen in any case. CONCLUSIONS: POC using a multibending ultra-slim endoscope for diagnostic or therapeutic purposes can be performed effectively and safely through a LAMS after EUS-guided choledochoduodenostomy.

Neuroendoscopy: history, endoscopes, and instrumentation.

INTRODUCTION: Endoscopy was first employed in the surgical treatment of neurosurgical diseases early in the twentieth century, but did not become an established practice for a long time, mainly because of poor technology and clinical results. After a slow re-appearance in the 1980s, the 1990s saw an explosion of techniques and instrumentation. Continuing technological improvement has led to further expansion of surgical techniques and indications for use of neuroendoscopy. DISCUSSION: The expansion of ventricular endoscopy has led to significant understanding of CSF disorders. Aqueduct stenosis as cause of hydrocephalus and arachnoid cysts are an example of pathologies, the concept and understanding of which now is considerably enhanced, due to the application of neuroendoscopy in their treatment. Management of loculated hydrocephalus has been facilitated considerably with the use of the endoscope. The concepts of aqueductoplasty, septostomy, and foraminoplasty of the foramina of Monro and Magendie emerged, which were previously unknown. Skull base surgery, especially surgery for craniopharyngioma, has seen dramatic improvement in results with the use of the endoscope. Coupling of the endoscope with neuronavigation has expanded technical capabilities even further. Overall, we can do a lot more with the endoscope now in comparison to 30 years ago. CONCLUSION: We should always remember that the endoscope is only a tool. Its use has indications and limitations related to its design and our ability to extract the maximum, in the context of its shortcomings. Further technological advances will push surgical frontiers even more in years to come.

Imaging-Navigated Surgery.

It is vitally important to guide or navigate therapeutic proceedings with a direct and visual approach in order to carefully undertake precision medical manipulations and efficiently evaluate the treatments. Imaging-navigated surgery is one of the common and prevailing technologies to realize this target, and more importantly it merges visualized medicine into next-generation theranostic paradigms in modern medicine. Endoscopes, surgical robots, and nanorobots are three major domains in terms of imaging-navigated surgery. The history of endoscopy has seen upgraded developments since the early 1800s. In contrast, surgical robots have been widely used and investigated in recent years, and they came into clinical uses only in the past decades. Nanorobots which closely depend on innovated and multifunctional biomaterials are still in their infancy. All these imaging-navigated technologies show similar and apparent advantages such as minimal invasiveness, minimized pain, positive prognosis, and relatively expected recovery, which have greatly improved surgery efficiency and patients' life quality. Therefore, the imaging-navigated surgery will be discussed in this chapter, and advanced clinical and preclinical medical applications will also be demonstrated for a diverse readers and comprehensive understanding.

Clinical analysis of delayed epistaxis following endoscopic sinus surgery.

OBJECTIVE: To investigate the clinical characteristics and treatment methods associated with delayed epistaxis following endoscopic sinus surgery. METHODS: The clinical data of 46 patients with delayed epistaxis following endoscopic sinus surgery were retrospectively analyzed. To explore the clinical features, pathogenesis, and treatment plan for delayed epistaxis, the postoperative bleeding time, bleeding inducements, systemic complications, surgical approach, the hemorrhage locations and responsible vessels, and treatment methods were analyzed. RESULTS: The average bleeding time was 16.34 ± 9.05 days after the operation, and 76.6% of the cases occurred 6-20 days after the operation. Sphenopalatal artery hemorrhage accounted for 69.6% (32/46), the most common of which was a posterior nasal septal artery hemorrhage (17/32). A total of 45 patients received endoscopic low-temperature plasma hemostasis following ineffective nasal packing, and no rebleeding in the ipsilateral nasal cavity was observed during the postoperative follow-up for 3 to 6 months. CONCLUSIONS: The peak of hemorrhaging in delayed epistaxis following endoscopic sinus surgery occurred at 6-20 days post-operatively. Bleeding of the posterior nasal septal artery from the sphenopalatine artery was the most common. Surgical methods were closely related to delayed postoperative hemorrhage. Treatment with low temperature plasma hemostasis under nasal endoscope was found to be effective.

MiWEndo: Evaluation of a Microwave Colonoscopy Algorithm for Early Colorectal Cancer Detection in Ex Vivo Human Colon Models.

This study assesses the efficacy of detecting colorectal cancer precursors or polyps in an ex vivo human colon model with a microwave colonoscopy algorithm. Nowadays, 22% of polyps go undetected with conventional colonoscopy, and the risk of cancer after a negative colonoscopy can be up to 7.9%. We developed a microwave colonoscopy device that consists of a cylindrical ring-shaped switchable microwave antenna array that can be attached to the tip of a conventional colonoscope as an accessory. The accessory is connected to an external unit that allows successive measurements of the colon and processes the measurements with a microwave imaging algorithm. An acoustic signal is generated when a polyp is detected. Fifteen ex vivo freshly excised human colons with cancer (n = 12) or polyps (n = 3) were examined with the microwave-assisted colonoscopy system simulating a real colonoscopy exploration. After the experiment, the dielectric properties of the specimens were measured with a coaxial probe and the samples underwent a pathology analysis. The results show that all the neoplasms were detected with a sensitivity of 100% and specificity of 87.4%.

Wireless Capsule Endoscope Localization with Phase Detection Algorithm and Adaptive Body Model.

Wireless capsule endoscopes take and send photos of the human digestive tract, which are used for medical diagnosis. The capsule's location enables exact identification of the regions with lesions. This can be carried out by analyzing the parameters of the electromagnetic wave received from the capsule. Because the human body is a complex heterogeneous environment that impacts the propagation of wireless signals, determining the distance between the transmitter and the receiver based on the received power level is challenging. An enhanced approach of identifying the location of endoscope capsules using a wireless signal phase detection algorithm is presented in this paper. For each capsule position, this technique uses adaptive estimation of human body model permittivity. This approach was tested using computer simulations in Remcom XFdtd software using a numerical, heterogeneous human body model, as well as measurements with physical phantom. The type of transmitting antenna employed in the capsule also has a significant impact on the suggested localization method's accuracy. As a result, the helical antenna, which is smaller than the dipole, was chosen as the signal's source. For both the numerical and physical phantom studies, the proposed technique with adaptive body model enhances localization accuracy by roughly 30%.

Gastric Schwannoma, a benign neoplasm hiding as gastrointestinal stromal tumour.

Gastric Schwannomas are rare, submucosal mesenchymal tumours arising from the nerve plexus of the Gut wall. They have an incidence rate of 0.2% of all Gastric tumours. They are mostly asymptomatic, but can present with vague gastrointestinal symptoms and the fact that histopathologically, they are similar to Gastrointestinal stromal tumours, so they are most often misinterpreted as Gastrointestinal stromal tumours. We present a case, which was also hiding as GIST (Gastrointestinal stromal tumours) preoperatively, on the basis of Endoscopic and Radiological investigations. The diagnosis was then confirmed as Gastric Schwannoma, postoperatively by immunohistochemical analysis. Hence, it is important to diagnose correctly to make appropriate treatment decisions. The findings presented here can may be helpful for a clinician for diagnosing a Gastric Schwannoma.

Consultation on kidney stones, Copenhagen 2019: aspects of intracorporeal lithotripsy in flexible ureterorenoscopy.

PURPOSE: To summarize current knowledge on intracorporeal laser lithotripsy in flexible ureterorenoscopy (fURS), regarding basics of laser lithotripsy, technical aspects, stone clearance, lithotripsy strategies, laser technologies, endoscopes, and safety. METHODS: A scoping review approach was applied to search literature in PubMed, EMBASE, and Web of Science. Consensus was reached through discussions at the Consultation on Kidney Stones held in September 2019 in Copenhagen, Denmark. RESULTS AND CONCLUSIONS: Lasers are widely used for lithotripsy during fURS. The Holmium laser is still the predominant technology, and specific settings for dusting and fragmenting have evolved, which has expanded the role of fURS in stone management. Pulse modulation can increase stone ablation efficacy, possibly by minimizing stone retropulsion. Thulium fibre laser was recently introduced, and this technology may improve laser lithotripsy efficiency. Small fibres give better irrigation, accessibility, and efficiency. To achieve optimal results, laser settings should be adjusted for the individual stone. There is no consensus whether the fragmentation and basketing strategy is preferable to the dusting strategy for increasing stone-free rate. On the contrary, different stone scenarios call for different lithotripsy approaches. Furthermore, for large stone burdens, all laser settings and lithotripsy strategies must be applied to achieve optimal results. Technology for removing dust from the kidney should be in focus in future research and development. Safety concerns about fURS laser lithotripsy include high intrarenal pressures and temperatures, and measures to reduce both those aspects must be taken to avoid complications. Technology to control these parameters should be targeted in further studies.

Colorectal stent placement assisted by a slim gastroscope: technique and outcomes.

BACKGROUND: The distorted anatomy in patients with obstruction renders colon stent placement difficult. Here, we propose two novel techniques for stent implantation. METHODS: Patients in whom there was difficulty placing the guidewire with the normal method were retrospectively included in our study. All of the patients underwent the technique of combining a slim gastroscope with a normal colonoscope. We assessed the technical success, clinical success, and adverse events associated with self-expanding metal stent placement. RESULTS: From June 2018 to June 2020, 30.5% of patients with difficult catheterization were included in this study. Finally, stents in 17 of 18 patients (3 rectum, 13 sigmoid colon, 1 descending colon, and 1 hepatic flexure) (94.4%) were placed successfully, assisted by a slim gastroscope with or without radiography, and the obstruction was relieved. Only one remaining patient experienced failure. No intraoperative or 30-day postoperative morbidity or mortality was observed. CONCLUSION: The present study showed that the stent implantation technique assisted by a slim gastroscope combined with a normal colonoscope was a relatively safe and effective method for abolishing difficult intestinal stenosis. More studies are needed to compare the advantages and disadvantages of this technique with normal endoscopic implantation.

Comparative evaluation of posterior percutaneous endoscopy cervical discectomy using a 3.7 mm endoscope and a 6.9 mm endoscope for cervical disc herniation: a retrospective comparative cohort study.

BACKGROUND: Posterior percutaneous endoscopy cervical discectomy (p-PECD) is an effective strategy for the treatment of cervical diseases, with a working cannula ranging from 3.7 mm to 6.9 mm in diameter. However, to date, no studies have been performed to compare the clinical outcomes of the use of endoscopes with different diameters in cervical disc herniation (CDH) patients. The purpose of this study was to compare the clinical outcomes of patients with unilateral CDH treated with p-PECD using a 3.7 mm endoscope and a 6.9 mm endoscope. METHODS: From January 2016 to June 2018, a total of 28 consecutive patients with single-level CDH who received p-PECD using either the 3.7 mm or the 6.9 mm endoscope were enrolled. The clinical results, including the surgical duration, hospitalization, visual analog scale (VAS) score and modified MacNab criteria, were evaluated. Cervical fluoroscopy, CT, and MRI were also performed during follow-up. RESULTS: Tthere was a significant difference in regard to the average identification time of the "V" point (18.608 ± 3.7607 min vs. 11.256 ± 2.7161 min, p < 0.001) and the mean removal time of the overlying tissue (16.650 ± 4.1730 min vs. 12.712 ± 3.3079 min, p < 0.05) for the use of the 3.7 mm endoscope and the 6.9 mm endoscope, respectively. The postoperative VAS and MacNab scores of the two endoscopes were significantly improved compared with those the preoperative scores (p < 0.05). CONCLUSION: The application of both the 3.7 mm endoscope and 6.9 mm endoscope represent an effective method for the treatment of CDH in selected patients, and no significant difference can be observed in the clinical outcomes of the endoscopes. The 6.9 mm endoscope shows superiority to the 3.7 mm endoscope in terms of the efficiency of "V" point identification, the removal of overlying soft tissue and the prevention of spinal cord injury. However, the 6.9 mm endoscope may be inferior to the 3.7 mm endoscope in regards to anterior foraminal decompression due to its large diameter; this result needs to be further evaluated with the support of a large number of randomized controlled trials.

Scanning and Actuation Techniques for Cantilever-Based Fiber Optic Endoscopic Scanners-A Review.

Endoscopes are used routinely in modern medicine for in-vivo imaging of luminal organs. Technical advances in the micro-electro-mechanical system (MEMS) and optical fields have enabled the further miniaturization of endoscopes, resulting in the ability to image previously inaccessible small-caliber luminal organs, enabling the early detection of lesions and other abnormalities in these tissues. The development of scanning fiber endoscopes supports the fabrication of small cantilever-based imaging devices without compromising the image resolution. The size of an endoscope is highly dependent on the actuation and scanning method used to illuminate the target image area. Different actuation methods used in the design of small-sized cantilever-based endoscopes are reviewed in this paper along with their working principles, advantages and disadvantages, generated scanning patterns, and applications.

Image processing metrics for phase identification of a multiaxis MEMS scanner used in single pixel imaging.

This paper applies image processing metrics to tracking of perturbations in mechanical phase delay in a multi-axis microelectromechanical system (MEMS) scanner. The compact mirror is designed to scan a laser beam in a Lissajous pattern during the collection of endoscopic confocal fluorescence images, but environmental perturbations to the mirror dynamics can lead to image registration errors and blurry images. A binarized, threshold-based blur metric and variance-based sharpness metric are introduced for detecting scanner phase delay. Accuracy of local optima of the metric for identification of phase delay is examined, and relative advantages for processing accuracy and computational complexity are assessed. Image reconstruction is demonstrated using both generic images and sample tissue images, with significant improvement in image quality for tissue imaging. Implications of non-ideal Lissajous scan effects on phase detection and image reconstruction are discussed.