A 73-year-old woman with metastatic breast cancer and known widespread skeletal metastases was referred for bone scintigraphy. Delayed images acquired at 2 and 5 hours postinjection of 30 mCi (1089 MBq) 99mTc-HDP demonstrated markedly reduced bony uptake, markedly increased renal activity, and significantly increased soft tissue accumulation. By contrast, appropriate skeletal uptake of 99mTc-HDP was seen in prior bone scans.
View Article and Find Full Text PDFA 74-year-old man was referred for a Ga-prostate-specific membrane antigen (PSMA) PET/CT scan for newly diagnosed prostate cancer which confirmed the presence of PSMA avid cancer in the right gland with no evidence of PSMA metastasis. Incidentally, there was a markedly PSMA avid (SUVmax 7.0) lobulated periventricular mass in the region of the left basal ganglia which was T2 hyperintense and T1 hypointense with perilesional oedema and vivid Gadolinium enhancement on MRI.
View Article and Find Full Text PDFUrachal adenocarcinomas are rare cancers of the urinary bladder. Both CT and MRI are useful imaging modalities for the diagnosis and evaluation of urachal adenocarcinoma. Unlike CT or MR, there have been variable FDG PET findings with urachal tumours potentially due to considerable variation in their hypermetabolism.
View Article and Find Full Text PDFA 68-year-old gentleman was referred for F-FDG PET/CT for a pulmonary mass in the left upper lobe which demonstrated intensely FDG-avid confluent pulmonary consolidation in the left upper lobe (SUV 15.1). Histopathologic biopsy of the left upper lobe lung mass was consistent with inflammatory myofibroblastic tumor (IMT).
View Article and Find Full Text PDFA 69-year-old man with intermediate-risk prostate cancer and a mildly elevated prostate-specific antigen of 8.2 μg/L was referred for 68Ga-prostate-specific membrane antigen (68Ga-PSMA) PET/CT for primary staging. An incidental intensely 68Ga-PSMA-avid hepatic focus was seen on PSMA PET and subsequent FDG PET/CT and MRI cholangiogram.
View Article and Find Full Text PDFAlthough primary cardiac tumours are extremely uncommon, secondary tumours or cardiac metastasis are not. We present a 68-year-old gentleman with squamous cell carcinoma of the right lower lobe with bony metastasis to the right clavicle who was treated with radiotherapy to the lung and clavicle as well as combination immunotherapy (Pembrolizumab) and chemotherapy (Carboplatin/Paclitaxel). Despite completing the above treatment regime, F-FDG PET/CT scan showed progression with two new sites of metastasis including a focus in the lateral wall of the right ventricle which correlate to a soft tissue density mass on CT as well as a FDG avid mass in the left masseter.
View Article and Find Full Text PDFAn 82-year-old man with a background of non-Hodgkin lymphoma in remission, resected left lower lobe adenocarcinoma (stage IA), and resected cutaneous melanoma of the left forearm more than 5 years prior presented with cerebral metastatic disease. Excision biopsy confirmed adenocarcinoma of lung origin. Further evaluation with 18F-FDG PET/CT demonstrated FDG-avid disease in the right thorax, axilla, and lower neck and isolated cutaneous uptake in the right forearm.
View Article and Find Full Text PDFA 70-year-old gentleman with a history of Gleason score 7 (3 + 4) prostate adenocarcinoma was treated with radical prostatectomy with clear surgical margins. Postoperatively his prostate specific antigen was undetectable. However, his prostate specific antigen was slowly rising and he was referred for a Galium-Prostate Specific Membrane Antigen (PSMA) PET/CT scan.
View Article and Find Full Text PDFImportance: Intraocular lens (IOL) calculations in post-refractive cases remain a concern. Our study identifies improved options for surgeons.
Background: To evaluate and compare the prediction accuracy of IOL power calculation methods after previous laser refractive surgery using standard keratometry (SK), measured posterior corneal astigmatism (PCA) and total keratometry (TK).
We demonstrate the possibility of measuring FRET efficiency with a low-cost frequency-domain fluorescence lifetime imaging microscope (FD-FLIM). The system utilizes single-frequency-modulated excitation, which enables the use of cost-effective laser sources and electronics, simplification of data acquisition and analysis, and a dual-channel detection capability. Following calibration with coumarin 6, we measured the apparent donor lifetime in mTFP1-mVenus FRET standards expressed in living cells.
View Article and Find Full Text PDFAsia Pac J Ophthalmol (Phila)
August 2019
Purpose: The aim of this study was to compare the intraobserver repeatability and agreement of central corneal thickness (CCT) measurements by 2 commonly available instruments, Zeiss IOL Master 700 (SS-OCT-based optical biometry device) and Tomey corneal specular microscope EM-3000 (Noncontact specular microscopy).
Design: Retrospective study.
Methods: This is a retrospective analysis of data from routine clinical practice in which preoperative CCT measurements of 105 patients scheduled for cataract surgery were analyzed.
We present a novel optical coherence tomography (OCT)-based technique for rapid volumetric imaging of red blood cell (RBC) flux in capillary networks. Previously we reported that OCT can capture individual RBC passage within a capillary, where the OCT intensity signal at a voxel fluctuates when an RBC passes the voxel. Based on this finding, we defined a metric of statistical intensity variation (SIV) and validated that the mean SIV is proportional to the RBC flux [RBC/s] through simulations and measurements.
View Article and Find Full Text PDFWe introduce an integration of dynamic light scattering (DLS) and optical coherence tomography (OCT) for high-resolution 3D imaging of heterogeneous diffusion and flow. DLS analyzes fluctuations in light scattered by particles to measure diffusion or flow of the particles, and OCT uses coherence gating to collect light only scattered from a small volume for high-resolution structural imaging. Therefore, the integration of DLS and OCT enables high-resolution 3D imaging of diffusion and flow.
View Article and Find Full Text PDFTO DATE, TWO MAIN CATEGORIES OF OCT TECHNIQUES HAVE BEEN DESCRIBED FOR IMAGING HEMODYNAMICS: Doppler OCT and OCT angiography. Doppler OCT can measure axial velocity profiles and flow in arteries and veins, while OCT angiography can determine vascular morphology, tone, and presence or absence of red blood cell (RBC) perfusion. However, neither method can quantify RBC velocity in capillaries, where RBC flow is typically transverse to the probe beam and single-file.
View Article and Find Full Text PDFIn vivo optical microscopic imaging techniques have recently emerged as important tools for the study of neurobiological development and pathophysiology. In particular, two-photon microscopy has proved to be a robust and highly flexible method for in vivo imaging in highly scattering tissue. However, two-photon imaging typically requires extrinsic dyes or contrast agents, and imaging depths are limited to a few hundred microns.
View Article and Find Full Text PDFDoppler optical coherence tomography (DOCT) and OCT angiography are novel methods to investigate cerebrovascular physiology. In the rodent cortex, DOCT flow displays features characteristic of cerebral blood flow, including conservation along nonbranching vascular segments and at branch points. Moreover, DOCT flow values correlate with hydrogen clearance flow values when both are measured simultaneously.
View Article and Find Full Text PDFWe describe methods and algorithms for rapid volumetric imaging of cortical vasculature with optical coherence tomography (OCT). By optimizing system design, scanning protocols, and algorithms for visualization of capillary flow, comprehensive imaging of the surface pial vasculature and capillary bed is performed in approximately 12 s. By imaging during hypercapnia and comparing with simultaneous CCD imaging, the sources of contrast of OCT angiography are investigated.
View Article and Find Full Text PDFGold punchwork and underdrawing in Renaissance panel paintings are analyzed using both three-dimensional swept source / Fourier domain optical coherence tomography (3D-OCT) and high resolution digital photography. 3D-OCT can generate en face images with micrometer-scale resolutions at arbitrary sectioning depths, rejecting out-of-plane light by coherence gating. Therefore 3D-OCT is well suited for analyzing artwork where a surface layer obscures details of interest.
View Article and Find Full Text PDFWe report a Doppler optical cardiogram gating technique for increasing the effective frame rate of Doppler optical coherence tomography (DOCT) when imaging periodic motion as found in the cardiovascular system of embryos. This was accomplished with a Thorlabs swept-source DOCT system that simultaneously acquired and displayed structural and Doppler images at 12 frames per second (fps). The gating technique allowed for ultra-high speed visualization of the blood flow pattern in the developing hearts of African clawed frog embryos (Xenopus laevis) at up to 1000 fps.
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