Introduction: Advances in Optical Coherence Tomography, Photoacoustic Imaging, and Microscopy

The editors introduce the Biomedical Optics Express feature issue, “Advances in Optical Coherence Tomography, Photoacoustic Imaging, and Microscopy,” which combines three technical areas from the 2010 Optical Society of America (OSA), Biomedical Optics (BIOMED) Topical Meeting held on 11–14 April in Miami, Florida, and includes contributions from conference attendees

Wavelength-swept Tm-doped fiber laser operating in the two-micron wavelength band

A wavelength-swept thulium-doped silica fiber laser using an intracavity rotating slotted-disk wavelength scanning filter in combination with an intracavity solid etalon for passive control of temporal and spectral profiles is reported. The laser yielded a wavelength swept output in a step-wise fashion with each laser pulse separated from the previous pulse by a frequency interval equal to the free-spectral-range of the etalon and with an instantaneous linewidth of <0.05 nm. Scanning ranges from 1905 nm to 2049 nm for a cladding-pumping laser configuration, and from 1768 nm to 1956 nm for a core-pumping laser configuration were achieved at average output powers up to ~1 W

Risk of second primary malignancies among patients with carcinoid of the lung

Objectives: Little is known about the etiology of pulmonary carcinoids (PC). Associations with other types of cancer may identify shared risk factors but results from earlier studies were inconclusive. The aim of the present study was to explore the association between PC and other primary malignancies for identifying risk factors.Methods: A query of the nationwide Netherlands Cancer Registry generated data about patients diagnosed with PC from 1989 to 2018. The occurrence of second primary malignancies was evaluated separately for year 1 and years 2-30. The expected numbers of second primary malignancies were calculated using incidence reference tables, controlling for age, gender and period. Confidence intervals (95 % CI) for the ratio between observed and expected numbers (SIR: standardized incidence ratio) were calculated using Poisson distributions.Results: In a total of 2933 patients with PC, 425 consecutive primary malignancies were observed in 376 patients. Concomitant diagnoses in the first year mainly comprised lung (n = 59) and renal cancer (n =14). Metachronous malignancies beyond the first year were most common for breast (n = 50), colorectal (n = 41), prostate (n = 32), and lung cancer (n = 29). Beyond year 1, the overall risk of second primary cancer in patients with PC was similar to the risk within the general population (n = 256, SIR =1.12, 95 % CI 0.99-1.27). Increased risks were observed for soft tissue sarcoma (n = 5, SIR = 3.52, 95 % CI 1.14-8.22) and GEPNET (n = 4, SIR = 4.30, 95 % CI 1.17-11.01).Conclusions: Concomitant diagnosis of PC with other cancers is common, reflecting surveillance diagnostics. Apart from MEN-1 family history, no shared risk factors could be identified.Pathogenesis and treatment of chronic pulmonary disease

Optimum spectral window for imaging of art with optical coherence tomography

Optical Coherence Tomography (OCT) has been shown to have potential for important applications in the field of art conservation and archaeology due to its ability to image subsurface microstructures non-invasively. However, its depth of penetration in painted objects is limited due to the strong scattering properties of artists’ paints. VIS-NIR (400 nm – 2400 nm) reflectance spectra of a wide variety of paints made with historic artists’ pigments have been measured. The best spectral window with which to use optical coherence tomography (OCT) for the imaging of subsurface structure of paintings was found to be around 2.2 μm. The same spectral window would also be most suitable for direct infrared imaging of preparatory sketches under the paint layers. The reflectance spectra from a large sample of chemically verified pigments provide information on the spectral transparency of historic artists’ pigments/paints as well as a reference set of spectra for pigment identification. The results of the paper suggest that broadband sources at ~2 microns are highly desirable for OCT applications in art and potentially material science in general

Optical coherence tomography for the identification of musculoskeletal structures of the spine: a pilot study

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine requiring in severe cases invasive surgery. Here, we explore the potential of optical coherence tomography (OCT) as a guiding tool for novel fusionless minimally invasive spinal surgeries on an ex vivo porcine model. We show that OCT, despite its limited penetration depth, may be used to precisely locate structures such as growth plate, bone and intervertebral disk using relative attenuation coefficients. We further demonstrate a segmentation algorithm that locates growth plates automatically on en-face OCT reconstructions