Distinct histologic and genetic characteristics of round cell sarcoma with CIC-DUX4 fusion and comparison with ewing sarcoma.

CIC-DUX4 fusion gene associated sarcoma is a new emerging subgroup of round cell sarcoma with Ewing sarcoma-like morphology. Distinguishing these tumors from Ewing sarcoma family tumors (ESFT) is critical because of the clinical impact but is still challenging due to the overlapped histological and immunohistochemical phenotypes of each subtype. The present study investigated small round cell sarcoma to identify CIC-DUX4 fusion positive sarcoma, examined clinical, histopathologic and immunohistochemical characteristics of CIC-DUX4 sarcoma, and evaluated parameters to differentiate Ewing sarcoma family tumors. Seventy patients with undifferentiated round cell sarcoma or Ewing-like sarcoma were retrieved. Molecular tests including EWSR1, CIC break apart FISH, and RT-PCR for CIC-DUX4 gene fusion were performed and immunohistochemistry was performed. Six cases (8.6%) of CIC-DUX4 sarcomas were detected. Histologically, CIC-DUX4 sarcomas composed of heterogeneous round, plasmacytoid, and spindle cells and more commonly showed cytologic pleomorphism with bizarre nuclei and multinucleated cells and myxoid stoma unlike ESFT. CIC-DUX4 sarcomas didn't show overall survival differences (p = 0.325) compared to ESFT but they demonstrated short disease-free survival (p = 0.034) and poor response to treatment (p = 0.007). Therefore, molecular analysis to detect the distinctive genetic alteration is mandatory in tumors with atypical histologic, immunohistochemical and/or clinical presentation for accurate diagnosis and treatment.

Diagnosis of giant cell-rich bone tumors on core needle biopsy: A practical approach.

BACKGROUND: The differential diagnosis of giant cell-rich bone tumors comprises a broad spectrum of lesions with prominent reactive osteoclast-like and/or neoplastic giant cells, with substantial differences in biologic behavior and clinical management. Evaluation of giant cell-rich bone tumors on small biopsies can be challenging especially in specimens with limited representative material. An accurate diagnosis requires a high level of skill on the part of both radiologist and pathologist as correlation with clinical and radiologic characteristics is critical. The objective of the study was to assess the utility of touch preparations (TP), immunohistochemistry (IHC) for mutation-specific markers H3G34W and H3K36M, and fluorescence in situ hybridization (FISH) for USP6 rearrangements and MDM2 amplification in the diagnostic workup of core needle biopsy specimens. METHODS: A total of 27 core needle biopsies with TPs from patients with primary giant cell-rich bone tumors (16 giant cell tumors of bone (GCTBs) (including 3 with lung metastasis), 3 chondroblastomas (CBs), 4 primary aneurysmal bone cysts (ABCs), 2 non-ossifying fibromas (NOFs), 1 low grade osteosarcoma (OS), and 1 conventional OS with tumor giant cells were analyzed with IHC for H3G34W and H3K36M and in select cases FISH for USP6 rearrangements and MDM2 amplification. RESULTS: In all cases the core biopsies were sufficient for histologic examination and diagnostic workup. 16 of 16 GCTBs were positive for H3G34W and negative for H3K36M, and 3 of 3 CBs were positive for H3K36M and negative for H3G34W. All other cases were negative for H3G34W and H3K36M. 4 of 4 primary ABCs showed rearrangement of USP6 by FISH and the low grade OS showed amplification of MDM2 by FISH. CONCLUSIONS: On-site adequacy assessment of TPs proved to be an accurate, simple, and fast method for obtaining sufficient material for complete diagnostic workup. The application of IHC for H3G34W and H3K36M and FISH for detection of rearrangements of USP6 and amplification of MDM2 can improve the diagnostic accuracy in core needle biopsy specimens.

Developing diagnostic assessment of breast lumpectomy tissues using radiomic and optical signatures.

High positive margin rates in oncologic breast-conserving surgery are a pressing clinical problem. Volumetric X-ray scanning is emerging as a powerful ex vivo specimen imaging technique for analyzing resection margins, but X-rays lack contrast between non-malignant and malignant fibrous tissues. In this study, combined micro-CT and wide-field optical image radiomics were developed to classify malignancy of breast cancer tissues, demonstrating that X-ray/optical radiomics improve malignancy classification. Ninety-two standardized features were extracted from co-registered micro-CT and optical spatial frequency domain imaging samples extracted from 54 breast tumors exhibiting seven tissue subtypes confirmed by microscopic histological analysis. Multimodal feature sets improved classification performance versus micro-CT alone when adipose samples were included (AUC = 0.88 vs. 0.90; p-value = 3.65e-11) and excluded, focusing the classification task on exclusively non-malignant fibrous versus malignant tissues (AUC = 0.78 vs. 0.85; p-value = 9.33e-14). Extending the radiomics approach to high-dimensional optical data-termed "optomics" in this study-offers a promising optical image analysis technique for cancer detection. Radiomic feature data and classification source code are publicly available.

Predicting Clinical Outcomes in a Diabetic Foot Ulcer Population Using Fluorescence Imaging.

OBJECTIVE: To retrospectively evaluate a cohort of patients with diabetic foot ulcers to determine if the rate of microcirculatory flow detected by fluorescence imaging within the wound and surrounding tissue is associated with healing outcomes. METHODS: Tissue perfusion parameters used for the current analysis were the ingress rate (IR) within the wound bed (R01) and in an area remote from the wound (REF), as well as time to first blush. Wounds were then categorized based on their outcome (healed, healing, chronic nonhealing, partial foot amputation, proximal amputation below the knee) and compared between patients with positive or negative wound healing outcomes. RESULTS: The final study cohort included 61 wounds and demonstrated that a higher IR within R01 and REF areas was significantly associated with positive outcomes, whereas time to first blush was not. A two-predictor logistic model found a significant relationship between IR (R01 and REF) and odds of wound healing. CONCLUSIONS: Fluorescence imaging evaluation of a diabetic foot ulcer can provide valuable information on healing outcomes that can help determine if a wound is progressing toward healing and therefore may help inform the need for advanced wound modalities, referrals, and amputation.

Imaging biological tissue with high-throughput single-pixel compressive holography.

Single-pixel holography (SPH) is capable of generating holographic images with rich spatial information by employing only a single-pixel detector. Thanks to the relatively low dark-noise production, high sensitivity, large bandwidth, and cheap price of single-pixel detectors in comparison to pixel-array detectors, SPH is becoming an attractive imaging modality at wavelengths where pixel-array detectors are not available or prohibitively expensive. In this work, we develop a high-throughput single-pixel compressive holography with a space-bandwidth-time product (SBP-T) of 41,667 pixels/s, realized by enabling phase stepping naturally in time and abandoning the need for phase-encoded illumination. This holographic system is scalable to provide either a large field of view (~83 mm2) or a high resolution (5.80 µm × 4.31 µm). In particular, high-resolution holographic images of biological tissues are presented, exhibiting rich contrast in both amplitude and phase. This work is an important step towards multi-spectrum imaging using a single-pixel detector in biophotonics.

A Computationally Virtual Histological Staining Method to Ovarian Cancer Tissue by Deep Generative Adversarial Networks.

Histological analysis to tissue samples is elemental for diagnosing the risk and severity of ovarian cancer. The commonly used Hematoxylin and Eosin (H&E) staining method involves complex steps and strict requirements, which would seriously impact the research of histological analysis of the ovarian cancer. Virtual histological staining by the Generative Adversarial Network (GAN) provides a feasible way for these problems, yet it is still a challenge of using deep learning technology since the amounts of data available are quite limited for training. Based on the idea of GAN, we propose a weakly supervised learning method to generate autofluorescence images of unstained ovarian tissue sections corresponding to H&E staining sections of ovarian tissue. Using the above method, we constructed the supervision conditions for the virtual staining process, which makes the image quality synthesized in the subsequent virtual staining stage more perfect. Through the doctors' evaluation of our results, the accuracy of ovarian cancer unstained fluorescence image generated by our method reached 93%. At the same time, we evaluated the image quality of the generated images, where the FID reached 175.969, the IS score reached 1.311, and the MS reached 0.717. Based on the image-to-image translation method, we use the data set constructed in the previous step to implement a virtual staining method that is accurate to tissue cells. The accuracy of staining through the doctor's assessment reached 97%. At the same time, the accuracy of visual evaluation based on deep learning reached 95%.

Poisson noisy image restoration via overlapping group sparse and nonconvex second-order total variation priors.

The restoration of the Poisson noisy images is an essential task in many imaging applications due to the uncertainty of the number of discrete particles incident on the image sensor. In this paper, we consider utilizing a hybrid regularizer for Poisson noisy image restoration. The proposed regularizer, which combines the overlapping group sparse (OGS) total variation with the high-order nonconvex total variation, can alleviate the staircase artifacts while preserving the original sharp edges. We use the framework of the alternating direction method of multipliers to design an efficient minimization algorithm for the proposed model. Since the objective function is the sum of the non-quadratic log-likelihood and nonconvex nondifferentiable regularizer, we propose to solve the intractable subproblems by the majorization-minimization (MM) method and the iteratively reweighted least squares (IRLS) algorithm, respectively. Numerical experiments show the efficiency of the proposed method for Poissonian image restoration including denoising and deblurring.

Evaluating Laryngopharyngeal Tumor Extension Using Narrow Band Imaging Versus Conventional White Light Imaging.

OBJECTIVE/HYPOTHESIS: Comparing detection and extension of malignant tumors by flexible laryngoscopy in the outpatient setting with laryngoscopy under general anesthesia using both White Light Imaging (WLI) and Narrow Band Imaging (NBI). STUDY DESIGN: Prospective study. METHODS: Two hundred and thirty-three patients with laryngeal and pharyngeal lesions underwent flexible and rigid laryngoscopy, with both WLI and NBI. Extension of malignant lesions (n = 132) was compared between both techniques in detail. RESULTS: Sensitivity of NBI during flexible endoscopy (92%), was comparable with that of WLI during rigid endoscopy (91%). The correlation of tumor extension between flexible and rigid laryngoscopy was high (rs  = 0.852-0.893). The observed tumor extension was significantly larger when using NBI in both settings. The use of NBI during flexible laryngoscopy leads to upstaging (12%) and downstaging (2%) of the T classification. CONCLUSIONS: NBI during flexible laryngoscopy could be an alternative to WLI rigid endoscopy. NBI improves visualization of tumor extension and accuracy of T staging. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:E2222-E2231, 2021.

Intraoperative imaging technology to maximise extent of resection for glioma: a network meta-analysis.

BACKGROUND: Multiple studies have identified the prognostic relevance of extent of resection in the management of glioma. Different intraoperative technologies have emerged in recent years with unknown comparative efficacy in optimising extent of resection. One previous Cochrane Review provided low- to very low-certainty evidence in single trial analyses and synthesis of results was not possible. The role of intraoperative technology in maximising extent of resection remains uncertain. Due to the multiple complementary technologies available, this research question is amenable to a network meta-analysis methodological approach. OBJECTIVES: To establish the comparative effectiveness and risk profile of specific intraoperative imaging technologies using a network meta-analysis and to identify cost analyses and economic evaluations as part of a brief economic commentary. SEARCH METHODS: We searched CENTRAL (2020, Issue 5), MEDLINE via Ovid to May week 2 2020, and Embase via Ovid to 2020 week 20. We performed backward searching of all identified studies. We handsearched two journals, Neuro-oncology and the Journal of Neuro-oncology from 1990 to 2019 including all conference abstracts. Finally, we contacted recognised experts in neuro-oncology to identify any additional eligible studies and acquire information on ongoing randomised controlled trials (RCTs). SELECTION CRITERIA: RCTs evaluating people of all ages with presumed new or recurrent glial tumours (of any location or histology) from clinical examination and imaging (computed tomography (CT) or magnetic resonance imaging (MRI), or both). Additional imaging modalities (e.g. positron emission tomography, magnetic resonance spectroscopy) were not mandatory. Interventions included fluorescence-guided surgery, intraoperative ultrasound, neuronavigation (with or without additional image processing, e.g. tractography), and intraoperative MRI. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the search results for relevance, undertook critical appraisal according to known guidelines, and extracted data using a prespecified pro forma. MAIN RESULTS: We identified four RCTs, using different intraoperative imaging technologies: intraoperative magnetic resonance imaging (iMRI) (2 trials, with 58 and 14 participants); fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) (1 trial, 322 participants); and neuronavigation (1 trial, 45 participants). We identified one ongoing trial assessing iMRI with a planned sample size of 304 participants for which results are expected to be published around winter 2020. We identified no published trials for intraoperative ultrasound. Network meta-analyses or traditional meta-analyses were not appropriate due to absence of homogeneous trials across imaging technologies. Of the included trials, there was notable heterogeneity in tumour location and imaging technologies utilised in control arms. There were significant concerns regarding risk of bias in all the included studies. One trial of iMRI found increased extent of resection (risk ratio (RR) for incomplete resection was 0.13, 95% confidence interval (CI) 0.02 to 0.96; 49 participants; very low-certainty evidence) and one trial of 5-ALA (RR for incomplete resection was 0.55, 95% CI 0.42 to 0.71; 270 participants; low-certainty evidence). The other trial assessing iMRI was stopped early after an unplanned interim analysis including 14 participants; therefore, the trial provided very low-quality evidence. The trial of neuronavigation provided insufficient data to evaluate the effects on extent of resection. Reporting of adverse events was incomplete and suggestive of significant reporting bias (very low-certainty evidence). Overall, the proportion of reported events was low in most trials and, therefore, issues with power to detect differences in outcomes that may or may not have been present. Survival outcomes were not adequately reported, although one trial reported no evidence of improvement in overall survival with 5-ALA (hazard ratio (HR) 0.82, 95% CI 0.62 to 1.07; 270 participants; low-certainty evidence). Data for quality of life were only available for one study and there was significant attrition bias (very low-certainty evidence). AUTHORS' CONCLUSIONS: Intraoperative imaging technologies, specifically 5-ALA and iMRI, may be of benefit in maximising extent of resection in participants with high-grade glioma. However, this is based on low- to very low-certainty evidence. Therefore, the short- and long-term neurological effects are uncertain. Effects of image-guided surgery on overall survival, progression-free survival, and quality of life are unclear. Network and traditional meta-analyses were not possible due to the identified high risk of bias, heterogeneity, and small trials included in this review. A brief economic commentary found limited economic evidence for the equivocal use of iMRI compared with conventional surgery. In terms of costs, one non-systematic review of economic studies suggested that, compared with standard surgery, use of image-guided surgery has an uncertain effect on costs and that 5-ALA was more costly. Further research, including completion of ongoing trials of ultrasound-guided surgery, is needed.

ANTECEDENTES: En múltiples estudios se ha identificado la importancia pronóstica del alcance de la resección en el tratamiento del glioma. En los últimos años han surgido diferentes tecnologías intraoperatorias con una eficacia comparativa desconocida para optimizar el alcance de la resección. Una revisión Cochrane anterior proporcionó evidencia de certeza baja a muy baja en los análisis de un solo ensayo y no fue posible la síntesis de los resultados. La función de la tecnología intraoperatoria para maximizar el alcance de la resección aún no está clara. Debido a las múltiples tecnologías complementarias disponibles, esta pregunta de investigación se presta a un enfoque metodológico de metanálisis en red. OBJETIVOS: Establecer el perfil comparativo de efectividad y riesgo de determinadas tecnologías de imagenología intraoperatorias mediante un metanálisis en red e identificar análisis de costos y evaluaciones económicas como parte de un breve comentario económico. MÉTODOS DE BÚSQUEDA: Se hicieron búsquedas en CENTRAL (2020, número 5), MEDLINE vía Ovid hasta la semana 2 de mayo de 2020, y Embase vía Ovid hasta la semana 20 de 2020. Se realizó una búsqueda retrospectiva de todos los estudios identificados. Se hicieron búsquedas manuales en dos revistas, Neuro­oncology y Journal of Neuro­oncology, desde 1990 hasta 2019, y se incluyeron todos los resúmenes de congresos. Finalmente, se estableció contacto con expertos reconocidos en neurooncología para identificar cualquier estudio elegible adicional y obtener información sobre los ensayos controlados aleatorizados (ECA) en curso. CRITERIOS DE SELECCIÓN: ECA que evaluaron a personas de todas las edades con presuntos tumores gliales nuevos o recidivantes (de cualquier ubicación o histología) a partir del examen clínico y la imagenología (tomografía computarizada [TC] o imagenología de resonancia magnética [IRM], o ambas). Las modalidades adicionales de imagenología (p.ej., tomografía de emisión de positrones, espectroscopia de resonancia magnética) no fueron obligatorias. Las intervenciones incluyeron cirugía guiada por fluorescencia, ecografía intraoperatoria, neuronavegación (con o sin procesamiento adicional de las imágenes, p.ej., tractografía) e IRM intraoperatoria. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Dos autores de la revisión, de forma independiente, evaluaron los resultados de la búsqueda en cuanto a su relevancia, realizaron la evaluación crítica según las guías conocidas y extrajeron los datos mediante un formulario predeterminado. RESULTADOS PRINCIPALES: Se identificaron cuatro ECA, que utilizaron diferentes tecnologías de imagenología intraoperatorias: la resonancia magnética (IRM) intraoperatoria (dos ensayos, con 58 y 14 participantes); la cirugía guiada por fluorescencia con ácido 5­aminolevulínico (5­ALA) (un ensayo, 322 participantes); y la neuronavegación (un ensayo, 45 participantes). Se identificó un ensayo en curso que evaluó la IRM con un tamaño de la muestra planificado de 304 participantes, del que se espera la publicación de los resultados alrededor del invierno de 2020. No se han identificado ensayos publicados sobre la ecografía intraoperatoria. Los metanálisis en red o los metanálisis tradicionales no fueron apropiados debido a la falta de ensayos homogéneos en tecnologías de imagenología. De los ensayos incluidos, hubo una notable heterogeneidad en la localización de los tumores y en las tecnologías de imagenología utilizadas en los brazos control. Hubo inquietudes significativas con respecto al riesgo de sesgo en todos los estudios incluidos. Un ensayo de IRM encontró un aumento en la extensión de la resección (razón de riesgos [RR] para la resección incompleta 0,13; intervalo de confianza [IC] del 95%: 0,02 a 0,96; 49 participantes; evidencia de certeza muy baja) y un ensayo de 5­ALA (RR para la resección incompleta 0,55; IC del 95%: 0,42 a 0,71; 270 participantes; evidencia de certeza baja). El otro ensayo que evaluó la IRM se interrumpió de forma temprana después de un análisis intermedio no planificado que incluyó 14 participantes; por lo tanto, el ensayo proporciona evidencia de calidad muy baja. El ensayo de neuronavegación no proporcionó datos suficientes para evaluar los efectos sobre el grado de resección. El informe de los eventos adversos fue incompleto e indicó la presencia de sesgo de informe significativo (evidencia de certeza muy baja). En general, la proporción de eventos informados fue baja en la mayoría de los ensayos y, por lo tanto, pueden haber estado presentes o no problemas relacionados con el poder estadístico suficiente para detectar diferencias en los desenlaces. No se informó adecuadamente sobre los desenlaces de supervivencia, aunque un ensayo no informó evidencia de mejora en la supervivencia general con 5­ALA (cociente de riesgos instantáneos [CRI] 0,82; IC del 95%: 0,62 a 1,07; 270 participantes; evidencia de certeza baja). Solo hubo datos disponibles sobre la calidad de vida de un estudio, con un sesgo de desgaste significativo (evidencia de certeza muy baja). CONCLUSIONES DE LOS AUTORES: Las tecnologías de imagenología intraoperatoria, específicamente la IRM y el 5­ALA, pueden ser beneficiosas para maximizar el grado de resección en los participantes con glioma de grado alto. Sin embargo, lo anterior se basa en evidencia de certeza baja a muy baja. Por lo tanto, los efectos neurológicos a corto y a largo plazo no están claros. No están claros los efectos de la cirugía guiada por imágenes sobre la supervivencia general, la supervivencia sin progresión ni la calidad de vida. No fue posible realizar metanálisis en red ni tradicionales debido al alto riesgo de sesgo identificado, a la heterogeneidad y a los ensayos pequeños incluidos en esta revisión. Un comentario económico breve encontró evidencia económica limitada sobre el uso equívoco de la IRM en comparación con la cirugía convencional. En cuanto a los costos, una revisión no sistemática de estudios económicos indicó que, en comparación con la cirugía estándar, el uso de la cirugía guiada por imágenes no tiene un efecto claro sobre los costos y que el ácido 5­aminolevulínico fue más costoso. Se necesitan estudios de investigación adicionales, incluida la finalización de los ensayos en curso sobre la cirugía guiada por ecografía.

Microscopic Analysis of Viral Infection.

Viruses engineered to express fluorescent proteins can be used with live-cell imaging techniques to monitor the progression of infection in real time. Here we describe a set of methods to track infection spreading from one cell population to another as well as to visualize transfer of virions between cells. This approach is extended to multiplexing with physiological readouts of cell death, which can be correlated with single-cell resolution to viral infection.

Optical imaging guided- 'precision' biopsy of skin tumors: a novel approach for targeted sampling and histopathologic correlation.

Dermoscopy and reflectance confocal microscopy (RCM) are two noninvasive, optical imaging tools used to facilitate clinical diagnosis. A biopsy technique that produces exact correlation with optical imaging features is not previously reported. To evaluate the applications of a novel feature-focused 'precision biopsy' technique that correlates clinical-dermoscopy-RCM findings with histopathology. This was a prospective case-series performed during August 2017 and June 2019 at a tertiary care cancer. We included consecutive patients requiring a precise dermoscopy-RCM-histopathologic correlation. We performed prebiopsy dermoscopy and both wide probe and handheld RCM of suspicious lesions. Features of interest were isolated with the aid of paper rings and a 2 mm punch biopsy was performed in the dermoscopy- or RCM-highlighted area. Tissue was processed either en face or with vertical sections. One-to-one correlation with histopathology was obtained. Twenty-three patients with 24 lesions were included in the study. The mean age was 64.6 years (range 22-91 years); there were 16 (69.6%) males, 14 (58.3%) lesions biopsied were on head and neck region. We achieved tissue-conservation diagnosis in 100% (24/24), 13 (54.2%) were clinically equivocal lesions, six (25%) were selected for 'feature correlation' of structures on dermoscopy or RCM, and five (20.8%) for 'correlation of new/unknown' RCM features seen on follow-up. The precision biopsy technique described herein is a novel method that facilitates direct histopathological correlation of dermoscopy and RCM features. With the aids of optical imaging devices, accurate diagnosis may be achieved by minimally invasive tissue extraction.

Usefulness of sentinel lymph node mapping using indocyanine green and fluorescent imaging in the diagnosis of lymph node metastasis in endometrial cancer.

The lymph node status is the most important prognostic factor for endometrial cancer. This study aimed to assess whether sentinel lymph node mapping (SLNM) is applicable in endometrial cancer. A retrospective review of patients with endometrial cancer who were diagnosed and treated in Asan Medical Centre from September 2015 to December 2017 was conducted. One hundred patients underwent robotic (da Vinci®) or laparoscopic surgical treatment, including SLNM with indocyanine green (ICG) fluorescence detection using the Firefly® and NIR/ICG systems. At least one lymph node area was observed in 100% of SLNM cases. Sentinel node detection and frozen biopsy were performed in all cases, and all patients with metastasis were found on SLNM. The sensitivity and negative predictive value were both 100% in the patient-by-patient and station-by-station analyses. SLNM appears to be a feasible method to reduce the morbidity and increase the detection rate in early-stage endometrial carcinoma.What is already known on this subject? There are studies that it is safe to diagnose the possibility of lymph node metastasis through sentinel lymph node mapping in endometrial cancer.What do the results of this study add? In this study, it is shown that the accuracy of sentinel lymph node mapping is 100% accurate.What are the implications of these findings for clinical practise and/or further research? Therefore, total lymphadenectomy will not be necessary for the future.

Five-component model validation of reference, laboratory and field methods of body composition assessment.

This study reports the validity of body fat percentage (BF%) estimates from several commonly employed techniques as compared with a five-component (5C) model criterion. Healthy adults (n 170) were assessed by dual-energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), multiple bioimpedance techniques and optical scanning. Output was also used to produce a criterion 5C model, multiple variants of three- and four-component models (3C; 4C) and anthropometry-based BF% estimates. Linear regression, Bland-Altman analysis and equivalence testing were performed alongside evaluation of the constant error (CE), total error (TE), se of the estimate (SEE) and coefficient of determination (R2). The major findings were (1) differences between 5C, 4C and 3C models utilising the same body volume (BV) and total body water (TBW) estimates are negligible (CE ≤ 0·2 %; SEE < 0·5 %; TE ≤ 0·5 %; R2 1·00; 95 % limits of agreement (LOA) ≤ 0·9 %); (2) moderate errors from alternate TBW or BV estimates in multi-component models were observed (CE ≤ 1·3 %; SEE ≤ 2·1 %; TE ≤ 2·2 %; R2 ≥ 0·95; 95 % LOA ≤ 4·2 %); (3) small differences between alternate DXA (i.e. tissue v. region) and ADP (i.e. Siri v. Brozek equations) estimates were observed, and both techniques generally performed well (CE < 3·0 %; SEE ≤ 2·3 %; TE ≤ 3·6 %; R2 ≥ 0·88; 95 % LOA ≤ 4·8 %); (4) bioimpedance technologies performed well but exhibited larger individual-level errors (CE < 1·0 %; SEE ≤ 3·1 %; TE ≤ 3·3 %; R2 ≥ 0·94; 95 % LOA ≤ 6·2 %) and (5) anthropometric equations generally performed poorly (CE 0·6- 5·7 %; SEE ≤ 5·1 %; TE ≤ 7·4 %; R2 ≥ 0·67; 95 % LOA ≤ 10·6 %). Collectively, the data presented in this manuscript can aid researchers and clinicians in selecting an appropriate body composition assessment method and understanding the associated errors when compared with a reference multi-component model.

Real-time Lissajous imaging with a low-voltage 2-axis MEMS scanner based on electrothermal actuation.

Laser scanning based on Micro-Electro-Mechanical Systems (MEMS) scanners has become very attractive for biomedical endoscopic imaging, such as confocal microscopy or Optical Coherence Tomography (OCT). These scanners are required to be fast to achieve real-time image reconstruction while working at low actuation voltage to comply with medical standards. In this context, we report a 2-axis Micro-Electro-Mechanical Systems (MEMS) electrothermal micro-scannercapable of imaging large fields of view at high frame rates, e.g. from 10 to 80 frames per second. For this purpose, Lissajous scan parameters are chosen to provide the optimal image quality within the scanner capabilities and the sampling rate limit, resulting from the limited A-scan rate of typical swept-sources used for OCT. Images of 233 px × 203 px and 53 px × 53 px at 10 fps and 61 fps, respectively, are experimentally obtained and demonstrate the potential of this micro-scannerfor high definition and high frame rate endoscopic Lissajous imaging.

Evaluation of visible NIR-I and NIR-II light penetration for photoacoustic imaging in rat organs.

In this study, we evaluate the penetration capability of light in visible, near-infrared-I (NIR-I) and near-infrared-II (NIR-II) optical windows for photoacoustic macroscale imaging inside 9 biological tissues with three typical penetration depths. An acoustic resolution photoacoustic microscopy is designed to guarantee the consistent experiment conditions except excitation wavelength. Experimental results show that short NIR-II (1000-1150 nm) shows the best performance inside kidney, spleen and liver tissues at all depths, while NIR-I (700-1000 nm) works better for muscle, stomach, heart and brain tissues, especially in deep imaging. This study proposes the optimal selection of illumination wavelengths for photoacoustic macroscale imaging in rat organs, which enables the best signal-to-noise ratio (SNR) of the observed target.

Linked Color Imaging and the Kyoto Classification of Gastritis: Evaluation of Visibility and Inter-Rater Reliability.

BACKGROUND/AIMS: To compare white light imaging (WLI) with linked color imaging (LCI) and blue LASER imaging (BLI) in endoscopic findings of Helicobacter pylori presently infected, previously infected, and uninfected gastric mucosae for visibility and inter-rater reliability. METHODS: WLI, LCI and BLI bright mode (BLI-bright) were used to obtain 1,092 endoscopic images from 261 patients according to the Kyoto Classification of Gastritis. Images were evaluated retrospectively by 10 experts and 10 trainee endoscopists and included diffuse redness, spotty redness, map-like redness, patchy redness, red streaks, intestinal metaplasia, and an atrophic border (52 cases for each finding, respectively). Physicians assessed visibility as follows: 5 (improved), 4 (somewhat improved), 3 (equivalent), 2 (somewhat decreased), and 1 (decreased). Visibility was assessed from totaled scores. The inter-rater reliability (intraclass correlation coefficient) was also evaluated. RESULTS: Compared with WLI, all endoscopists reported improved visibility with LCI: 55.8% for diffuse redness; LCI: 38.5% for spotty redness; LCI: 57.7% for map-like redness; LCI: 40.4% for patchy redness; LCI: 53.8% for red streaks; LCI: 42.3% and BLI-bright: 80.8% for intestinal metaplasia; LCI: 46.2% for an atrophic border. For all endoscopists, the inter-rater reliabilities of LCI compared to WLI were 0.73-0.87. CONCLUSION: The visibility of each endoscopic finding was improved by LCI while that of intestinal metaplasia was improved by BLI-bright.

Optical fiber-based dispersion for spectral discrimination in fluorescence lifetime imaging systems.

The excited state lifetime of a fluorophore together with its fluorescence emission spectrum provide information that can yield valuable insights into the nature of a fluorophore and its microenvironment. However, it is difficult to obtain both channels of information in a conventional scheme as detectors are typically configured either for spectral or lifetime detection. We present a fiber-based method to obtain spectral information from a multiphoton fluorescence lifetime imaging (FLIM) system. This is made possible using the time delay introduced in the fluorescence emission path by a dispersive optical fiber coupled to a detector operating in time-correlated single-photon counting mode. This add-on spectral implementation requires only a few simple modifications to any existing FLIM system and is considerably more cost-efficient compared to currently available spectral detectors.

Demonstration of flat-top beam illumination in widefield multiphoton microscopy.

Multiphoton microscopy provides a suitable technique for imaging biological tissues with submicrometer resolution. Usually a Gaussian beam (GB) is used for illumination, leading to a reduced power efficiency in the multiphoton response and vignetting for a square-shaped imaging area. A flat-top beam (FTB) provides a uniform spatial intensity distribution that equalizes the probability of a multiphoton effect across the imaging area. We employ a customized widefield multiphoton microscope to compare the performance of a square-shaped FTB illumination with that based on using a GB, for both two-photon fluorescence (TPF) and second-harmonic generation (SHG) imaging. The variation in signal-to-noise ratio across TPF images of fluorescent dyes spans ∼5.6 dB for the GB and ∼1.2 dB for the FTB illumination, respectively. For the GB modality, TPF images of mouse colon and Convallaria root, and SHG images of chicken tendon and human breast biopsy tissue showcase ∼20 % area that are not imaged due to either insufficient or lack of illumination. For quantitative analysis that depends on the illuminated area, this effect can potentially lead to inaccuracies. This work emphasizes the applicability of FTB illumination to multiphoton applications.

Temperature imaging using a cationic linear fluorescent polymeric thermometer and fluorescence lifetime imaging microscopy.

Temperature is one of the most important of the physiological parameters that determine the biological status of living organisms. However, intracellular temperature was not imaged at the single-cell level until recently because of the lack of a molecular thermometer that can be applied to living cells. We have recently developed a method for imaging intracellular temperature using a cationic linear fluorescent polymeric thermometer (FPT) and fluorescence lifetime imaging microscopy (FLIM). The cationic linear FPT exhibits cell permeability in various mammalian cell lines and yeast cells, entering live cells within 10 min of incubation. Intracellular thermometry using the cationic linear FPT and FLIM can be used to image temperature with high temperature resolution (0.3-1.29 °C within a temperature range of 25-35 °C). The diffuse intracellular localization of the cationic linear FPT allows a high spatial resolution (i.e., the light microscope's diffraction limit, 200 nm), enabling the detection of temperature distributions at the subcellular level. This protocol, including the construction of a calibration curve and intracellular temperature imaging, requires ~14 h. Experience in handling cultured mammalian cells and use of a confocal laser-scanning microscope (CLSM) is required.