Multimodal Imaging Modalities Research Articles

Choroidal Vasculature Changes in Age-Related Macular Degeneration: From a Molecular to a Clinical Perspective.

The contribution of choroidal vasculature to the pathogenesis of age-related macular degeneration (AMD) has been long debated. The present narrative review aims to discuss the primary molecular and choroidal structural changes occurring with aging and AMD with a brief overview of the principal multimodal imaging modalities and techniques that enable the optimal in vivo visualization of choroidal modifications. The molecular aspects that target the choroid in AMD mainly involve human leukocyte antigen (HLA) expression, complement dysregulation, leukocyte interaction at Bruch’s membrane, and mast cell infiltration of the choroid. A mechanistic link between high-risk genetic loci for AMD and mast cell recruitment has also been recently demonstrated. Recent advances in multimodal imaging allow more detailed visualization of choroidal structure, identifying alterations that may expand our comprehension of aging and AMD development.

Enhanced endoscopic ultrasound imaging for pancreatic lesions: The road to artificial intelligence.

Early detection of pancreatic cancer has long eluded clinicians because of its insidious nature and onset. Often metastatic or locally invasive when symptomatic, most patients are deemed inoperable. In those who are symptomatic, multi-modal imaging modalities evaluate and confirm pancreatic ductal adenocarcinoma. In asymptomatic patients, detected pancreatic lesions can be either solid or cystic. The clinical implications of identifying small asymptomatic solid pancreatic lesions (SPLs) of < 2 cm are tantamount to a better outcome. The accurate detection of SPLs undoubtedly promotes higher life expectancy when resected early, driving the development of existing imaging tools while promoting more comprehensive screening programs. An imaging tool that has matured in its reiterations and received many image-enhancing adjuncts is endoscopic ultrasound (EUS). It carries significant importance when risk stratifying cystic lesions and has substantial diagnostic value when combined with fine needle aspiration/biopsy (FNA/FNB). Adjuncts to EUS imaging include contrast-enhanced harmonic EUS and EUS-elastography, both having improved the specificity of FNA and FNB. This review intends to compile all existing enhancement modalities and explore ongoing research around the most promising of all adjuncts in the field of EUS imaging, artificial intelligence.

CORRELATION BETWEEN FOCAL CHOROIDAL EXCAVATION AND UNDERLYING RETINOCHOROIDAL DISEASE: A Pathological Hypothesis From Clinical Observation.

To evaluate focal choroidal excavation (FCE) in eyes with various diseases using multimodal imaging modalities and to investigate the correlation of FCE and underlying chorioretinal diseases. This retrospective observational study included 62 eyes from 56 patients who were identified by optical coherence tomography as having FCE. All included patients underwent comprehensive clinical examinations and multimodal imaging to identify and detect the characteristics of FCE and its correlation with underlying chorioretinal diseases. All included patients were of Chinese descent, and the median age at diagnosis was 43 years (range: 15-66). Seventy-three FCEs appeared in these included eyes. Most FCEs were formed at sites with anatomical changes caused by various chorioretinal diseases. Choroidal osteoma, punctate inner choroidopathy, and central serous chorioretinopathy were the most common etiologies of FCE. During follow-up, 14 eyes (22.58%) exhibited a pattern change and three eyes (4.84%) developed new-onset choroid neovascularization. Focal choroidal excavation is a common sign found in a variety of chorioretinal diseases. Processes that involve impairment or tissue loss of the outer retina and inner choroid and disrupt the balance of intraocular pressure and choroidal pressure because of mechanical disturbance may play a role in FCE formation.

THE SPECTRUM OF INTERNAL LIMITING MEMBRANE DISEASE IN ALPORT SYNDROME: A Multimodal Imaging Study.

To characterize the spectrum of internal limiting membrane (ILM) disease in Alport syndrome using multimodal imaging, including widefield (WF) and ultra-widefield (UWF) modalities, and to report their relative prevalence according to the genetic pattern of inheritance. Cross-sectional clinical study of patients diagnosed with Alport syndrome. All patients underwent UWF color photography and autofluorescence, WF-optical coherence tomography angiography and spectral-domain optical coherence tomography. Demographics, past medical and ophthalmic history, and genetic mutation history were collected. Forty-two eyes of 21 patients (11 men; age 36.6 ± 12.9 years) were included. Macular spectral-domain optical coherence tomography revealed ILM granularity, more frequent in X-linked Alport syndrome and corresponding to dot maculopathy on color fundus. Mid-peripheral spectral-domain optical coherence tomography scans revealed multilamellated ILM in eight eyes (19%), presumably progressive, which corresponded to a cavitary pattern on en-face OCT. En-face OCT revealed multiple areas of retinal nerve fiber layer dehiscence in the macula, overlapping with vascular lacunae on optical coherence tomography angiography, and a coarse arrangement of retinal nerve fiber layer above and below the temporal raphe in 20 eyes (52%). Multimodal imaging allowed for the detection/characterization of retinal findings (ILM granularity, progressive ILM lamellation, retinal nerve fiber layer dehiscence, vascular lacunae, and coarse arrangement of retinal nerve fiber layer toward the disc) as multifaceted manifestations of ILM disease in Alport syndrome.

The clinical feature and outcome of groove pancreatitis in a cohort: A single center experience with review of the literature.

Groove pancreatitis (GP) is a rare form of chronic pancreatitis that is less common and is now gaining awareness with multimodal imaging modalities. Our aim is to analyze the mid-long term outcomes of patients diagnosed with GP with different treatment approaches. A computerized search from electronic patient record database between May 2013 and June 2019 with the keywords 'groove', 'paraduodenal' was applied. The clinical, radiological and pathological data of 25 patients diagnosed with GP were obtained. In the GP patient group, the median age was 55 (25-87) and 80% was male. Alcohol and tobacco abuse was 40% among GP patients. The most common symptoms were upper abdominal pain (84%) and nausea-vomiting (40%), respectively. Gastric outlet obstruction was observed in 4 (16%) patients. CT and EUS imaging were performed to majority of cases (96% and 92 %, respectively). EUS-FNA was done in 14 of 25 (56%) patients. It was reported as atypia, adenocarcinoma and benign in 2 (8%), 2 (8%) and 10 (40%) patients, respectively. EUS-FNA was helpful to diagnose two pancreatic head adenoCA whose preliminary radiological evaluation was GP. The mean follow-up period was 29 (3-71) months. Conservative approach was the predominantly preferred treatment (%56). Apart from conservative approach, treatment strategies included biliary stenting, sphincterotomy, wirsung stenting via ERCP, cholecystectomy etc. Considering all treatment modalities, symptoms improved in 12 (48%) patients and progressed with recurrent pancreatitis attacks in 7 (28%) patients. Because GP is a less well-known form of pancreatitis, it presents several challenges for clinicians in diagnosis and treatment. This form, which can mimic pancreatic malignancy in particular, must be differentiated from carcinoma. EUS(±FNA) is a useful diagnostic tool complementary to imaging. Although the conservative approach remains the first choice in most patients, the clinician should consider invasive endoscopic procedures and surgical options in special cases when necessary.

Multimodal imaging modalities in acute Vogt-Koyanagi-harada disease

Vogt-Koyanagi-Harada disease (VKH) is a severe bilateral granulomatous posterior or panuveitis. An acute case of VKH presents with gradual painful diminution of vision which may be associated with symptoms like tinnitus, hearing loss, vertigo, meningismus, poliosis, and vitiligo, although not all patients present with the complete constellation of these extra-ocular findings. Clinically these patients present with granulomatous anterior uveitis, vitritis, disc edema and serous retinal detachments.

Differences between Mycobacterium chimaera and tuberculosis Using Ocular Multimodal Imaging: A Systematic Review.

Due to their non-specific diagnostic patterns of ocular infection, differential diagnosis between Mycobacterium (M.) chimaera and tuberculosis can be challenging. In both disorders, ocular manifestation can be the first sign of a systemic infection, and a delayed diagnosis might reduce the response to treatment leading to negative outcomes. Thus, it becomes imperative to distinguish chorioretinal lesions associated with M. chimaera, from lesions due to M. tuberculosis and other infectious disorders. To date, multimodal non-invasive imaging modalities that include ultra-wide field fundus photography, fluorescein and indocyanine green angiography, optical coherence tomography and optical coherence tomography angiography, facilitate in vivo examination of retinal and choroidal tissues, enabling early diagnosis, monitoring treatment response, and relapse detection. This approach is crucial to differentiate between active and inactive ocular disease, and guides clinicians in their decisional-tree during the patients’ follow-up. In this review, we summarized and compared the available literature on multimodal imaging data of M. chimaera infection and tuberculosis, emphasizing similarities and differences in imaging patterns between these two entities and highlighting the relevance of multimodal imaging in the management of the infections.

Zone-wise examination of optical coherence tomography features and their correspondence to multifocal electroretinography in eyes with nonproliferative diabetic retinopathy.

To examine (1) the retinal structure by optical coherence tomography (OCT) and function by means of multifocal electroretinography (mfERG) in eyes with and without nonproliferative diabetic retinopathy (NPDR) (2) for correspondence between local retinal function and OCT zones with retinal lesions. One hundred and thirty-two eligible participants (30 with nonproliferative DR (NPDR) and 102 with diabetes with no DR) underwent comprehensive ophthalmic examination, optical coherence tomography for retinal thickness measures, mfERG, and ultra-wide field fundus photography. OCT Early Treatment Diabetic Retinopathy Study (ETDRS) grid was overlaid on to mfERG plots. Those with NPDR had significantly thicker full retinal measures in the nine (ETDRS) zones compared to no DR. mfERG P1 latencies in rings 1-6 were significantly delayed, while the response densities in rings 4-6 were lower in the NPDR group. Significant negative correlation was noted between OCT thickness and mfERG P1 response densities in many ETDRS zones. Significant positive correlation was noted between P1 latencies and OCT thickness in a few zones. The combination of cystic spaces, microaneurysms, and hard exudates were present in all zones and were associated with a decrease in P1 response densities compared to no lesions. Reduced P1 response densities were associated with a sporadic delay in the mfERG latencies and vice versa. The number of lesions did not show correspondence to the mfERG measures. In eyes with NPDR, retinal function is differentially correlated with the DR lesions on OCT and can be assessed using multimodal imaging modalities.

OCT-Angiography for Detection of Choroidal Neovascularization: A Retrospective Real-Life Study

Purpose: The purpose of the study was to assess OCT-angiography (OCT-A) contribution for choroidal neovascularization (CNV) detection, with respect to multimodal imaging (MMI) modality (including OCT, fluorescein angiography (FFA), and indocyanine green angiography [ICG]), in a real-life consultation practice. Methods: Data of all consecutive patients undergoing OCT-A examination for CNV suspicion were collected between September 2017 and September 2019 at Strasbourg University Hospital, France. Only eyes which had anti-VEGF injection in the last 3 months were excluded. All types of neovascularization were included. For all patients, data from OCT, OCT-A, FFA, and ICG were interpreted by residents and retinal specialists, independently. Final diagnosis of CNV was based on decision to treat. Sensibility, specificity, and predictive values were computed for OCT-A alone and for MMI (OCT combined to angiography). They were computed for each group. OCT-A was also assessed as “contributory” (i.e., assessing without doubt the presence or absence of CNV) or not, with respect to MMI. Results: In total, 161 eyes of 145 patients were included. MMI sensibility was better than OCT-A sensibility (93.8 vs. 65.6%). OCT-A specificity was better than MMI specificity (96.9 vs. 89.5%). OCT-A was essential for diagnosis in 16.9% of cases. Sensibility and specificity values for all exams were better when interpreted by retinal specialists than residents. OCT-A was judged “contributory” in 57.4% of eyes. OCT-A was significantly less contributory when artefacts were present (32.9% of eyes with artefacts vs. 63.5% without, p < 0.001). Conclusion: OCT-A showed to be essential in diagnosing CNV in >16% of cases. However, it often failed to conclude for the absence of CNV, which obliged to perform more exams such as angiography. OCT-A must be part of diagnostic procedure for CNV detection but does not discard angiography in everyday life practice.

Characteristics of punctate inner choroidopathy complicated by choroidal neovascularisation on Multispectral Imaging in comparison with other imaging modalities

ABSTRACT Purpose To describe the characteristics seen on multispectral imaging (MSI) in patients with punctate inner choroidopathy (PIC) and choroidal neovascularisation (CNV) and compare the findings with current standard multimodal imaging techniques. Methods This is a retrospective observational case series of 10 patients with PIC complicated by CNV that underwent multimodal retinal imaging examinations. Results Twelve eyes of 10 patients were included. CNV was identified in 11 of the 12 eyes (91.7%) by MSI with nodular or trunk-like hyperreflectance on retinal oxy/deoxyhemoglobin map. MSI revealed choroidal vasculature around CNV in 91.7% eyes and pathological changes including retinal pigment epithelial atrophy and melanin disruption of punctate lesions in all eyes. Conclusion MSI helps in noninvasively detecting CNV in PIC patients and observing associated changes in choroidal vasculature. This imaging technique is also a promising tool for better tracking pathological changes of PIC lesions complementary to current standard multimodal imaging modalities.

Dark-field hyperspectral imaging for label free detection of nano-bio-materials.

Nanomaterials are playing an increasingly important role in cancer diagnosis and treatment. Nanoparticle (NP)-based technologies have been utilized for targeted drug delivery during chemotherapies, photodynamic therapy, and immunotherapy. Another active area of research is the toxicity studies of these nanomaterials to understand the cellular uptake and transport of these materials in cells, tissues, and environment. Traditional techniques such as transmission electron microscopy, and mass spectrometry to analyze NP-based cellular transport or toxicity effect are expensive, require extensive sample preparation, and are low-throughput. Dark-field hyperspectral imaging (DF-HSI), an integration of spectroscopy and microscopy/imaging, provides the ability to investigate cellular transport of these NPs and to quantify the distribution of them within bio-materials. DF-HSI also offers versatility in non-invasively monitoring microorganisms, single cell, and proteins. DF-HSI is a low-cost, label-free technique that is minimally invasive and is a viable choice for obtaining high-throughput quantitative molecular analyses. Multimodal imaging modalities such as Fourier transform infrared and Raman spectroscopy are also being integrated with HSI systems to enable chemical imaging of the samples. HSI technology is being applied in surgeries to obtain molecular information about the tissues in real-time. This article provides brief overview of fundamental principles of DF-HSI and its application for nanomaterials, protein-detection, single-cell analysis, microbiology, surgical procedures along with technical challenges and future integrative approach with other imaging and measurement modalities. This article is categorized under: Diagnostic Tools > in vitro Nanoparticle-Based Sensing Diagnostic Tools > in vivo Nanodiagnostics and Imaging Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery.

Development and validation of a risk scoring model for postoperative adult moyamoya disease.

The current grading system for moyamoya disease (MMD) is focused on angiographic studies with limited clinical application. The authors aimed to determine relevant factors that may impact postoperative outcome and establish a scoring system to predict the functional outcome. Adult patients with MMD who underwent treatment between 1998 and 2016 were included. Factors such as age, sex, comorbidity, smoking, MMD family history, initial presentation, multimodal imaging modalities, and types of surgical revascularization were thoroughly reviewed. These factors were analyzed to determine possible risk factors related to unfavorable 6-month postoperative outcomes using the modified Rankin Scale (mRS) (unfavorable: mRS score ≥ 3). A scoring system was developed using these independent risk factors to predict the outcome and validated using prospectively collected data from multiple centers between 2017 and 2018. Of 302 patients for whom applications were submitted, 260 patients (321 hemispheres) met the diagnostic criteria. In multivariate analysis, hyperlipidemia, smoking, cerebral infarction on preoperative CT or MRI, and moderately to severely reduced regional cerebrovascular reserve results from Diamox SPECT were significantly related to unfavorable outcome. The authors developed a scoring system and stratified patients into risk groups according to their scores: low-risk (score 0-3), intermediate-risk (score 4-6), and high-risk (score 7-9) groups. This model demonstrated both good discrimination and calibration using C-statistics and the Hosmer-Lemeshow goodness-of-fit test showing 0.812 (95% CI 0.743-0.881) (p = 0.568) for the development and 0.954 (95% CI 0.896-1) (p = 0.097) for the temporal and external validation cohort. The authors' scoring system is readily adoptable to predict the postoperative outcome for MMD. Their data revealed the importance of smoking and hyperlipidemia, which were the only modifiable factors included in the scoring system. The authors validated their scoring system both internally and externally and maintained good performance, highlighting the system's generalizability and reliability.

Microvascular Changes Associated with Optic Disc Drusen: Case Report

Optic disc drusen (ODD) is an important clinical entity that is sometimes misdiagnosed as papilledema because of elevated and blurred disc margins. A 17-year-old male who presented with headaches underwent detailed ophthalmological examination as well as colored fundus photography, B-scan ultrasonography (USG), fundus autofluorescence (FAF), optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), and visual field testing. His visual acuity was 10/10 in both eyes. Fundus examination revealed bilateral blurred and elevated optic disc margins. Diagnosis of bilateral ODD was confirmed with B-scan USG. FAF imaging revealed hyperautofluorescent areas on both optic discs. Optic nerve head OCT scans showed elevated irregular disc borders and thinning of the retinal nerve fiber layer in both eyes. On visual field testing, loss of the nasal visual field was detected in the left eye. OCTA imaging showed focal capillary dropout, especially in the nasal peripapillary area, in both eyes and reduced peripapillary and macular vessel density. In this case report, we evaluated the clinical findings and the structural features of bilateral ODD with multimodal imaging modalities including OCTA.

The multimodal imaging characteristics of multiple evanescent white dot syndrom

Objective To observe the multimodal imaging characteristics of multiple evanescent white dot syndrom (MEWDS). Methods This was a retrospective series case study. Eighteen patients (18 eyes) diagnosed with MEWDS in Eye Center of The Second People’s Hospital of Foshan from September 2015 to April 2017 were enrolled in this study. There were 12 females and 6 males, with the mean age of 35.9 years. The disease course ranged from 3 to 90 days, with the mean of 14 days. All the patients underwent BCVA, slit-lamp microscope with +90D preset lens, fundus photography, spectral domain OCT (SD-OCT) and FAF examinations. FFA was simultaneously performed in 6 eyes, FFA and ICGA were simultaneously performed in 12 eyes. Ten patients received the treatment of glucocorticoids and vasodilator substance, and other 8 patients without any treatment. The follow-up duration was 4.5 months. The multimodal imaging characteristics were reviewed and analyzed. Results Fundus color photography showed a variable number of small dots and large spots lesions (14 eyes), and/or fovea granularity (7 eyes) and disk swelling (5 eyes). A variable number of little dots and larger spots lesions showed respectively in FFA, FAF and ICGA were needle-like dots distributed in a wreathlike pattern and a large plaque occasionally confluent of early highly fluorescent, highly autofluorescence and hypofluoresence. Combined hypofluorescent spots with overlying dots were observed in 10 eyes of the late stages of the ICGA. Black lesions in the gray background show in ICGA were the most obvious and the most extensive, gray-white lesions in the gray-black show in FAF were the second, light gray-black lesions in the gray show in FFA were the least. Gray-white lesions in an orange background show in fundus photography were not obvious and transient. SD-OCT showed disruption of the ellipsoid zone and/or accumulations of hyperreflective material from the ellipsoid layer toward the outer plexiform layer and vitreous cells. During the period of following-up, some patients were prescribed low-dose glucocorticoid and some not, almost all the patients except one patient experienced recovery in BCVA and the lesions in fundus imaging. Conclusions The lesions in MEWDS eyes in modern multimodal imaging modalities among fundus photography (fovea granularity), FFA (needle-like dots distributed in a wreathlike pattern and a large plaque occasionally confluent of early highly fluorescent), ICGA (flake hypofluorescent) and SD-OCT (disruption of the ellipsoid zone) showed good consistency. Almost eyes were recovery. Key words: Retinal diseases/diagnosis; Multimodal imaging characteristics

Data Curation for Preclinical and Clinical Multimodal Imaging Studies

PurposeIn biomedical research, imaging modalities help discover pathological mechanisms to develop and evaluate novel diagnostic and theranostic approaches. However, while standards for data storage in the clinical medical imaging field exist, data curation standards for biomedical research are yet to be established. This work aimed at developing a free secure file format for multimodal imaging studies, supporting common in vivo imaging modalities up to five dimensions as a step towards establishing data curation standards for biomedical research.ProceduresImages are compressed using lossless compression algorithm. Cryptographic hashes are computed on the compressed image slices. The hashes and compressions are computed in parallel, speeding up computations depending on the number of available cores. Then, the hashed images with digitally signed timestamps are cryptographically written to file. Fields in the structure, compressed slices, hashes, and timestamps are serialized for writing and reading from files. The C++ implementation is tested on multimodal data from six imaging sites, well-documented, and integrated into a preclinical image analysis software.ResultsThe format has been tested with several imaging modalities including fluorescence molecular tomography/x-ray computed tomography (CT), positron emission tomography (PET)/CT, single-photon emission computed tomography/CT, and PET/magnetic resonance imaging. To assess performance, we measured the compression rate, ratio, and time spent in compression. Additionally, the time and rate of writing and reading on a network drive were measured. Our findings demonstrate that we achieve close to 50 % reduction in storage space for μCT data. The parallelization speeds up the hash computations by a factor of 4. We achieve a compression rate of 137 MB/s for file of size 354 MB.ConclusionsThe development of this file format is a step to abstract and curate common processes involved in preclinical and clinical multimodal imaging studies in a standardized way. This work also defines better interface between multimodal imaging modalities and analysis software.

Iron oxide-gold core-shell nano-theranostic for magnetically targeted photothermal therapy under magnetic resonance imaging guidance.

Recent efforts in the area of photothermal therapy (PTT) follow two important aims: (i) selective targeting of plasmonic nanoparticles to the tumor and (ii) real-time guidance of PTT operation through employing multimodal imaging modalities. In the present study, we utilized a multifunctional theranostic nanoplatform constructed from iron (III) oxide-gold (Fe2O3@Au) core-shell nanoparticles to fulfill these aims. The Au shell exhibits surface plasmon resonance, a property that is exploited to realize PTT. The magnetic core enables Fe2O3@Au to be employed as a magnetic resonance imaging (MRI) contrast agent. Furthermore, the magnetic core has the potential to establish a magnetic drug targeting strategy through which Fe2O3@Au can be directed to the tumor site by means of magnetic field. To test these potentials, Balb/c mice bearing CT26 colorectal tumor model were intravenously injected with Fe2O3@Au. Immediately after injection, a magnet was placed on the tumor site for 3h to concentrate nanoparticles, followed by the near infrared (NIR) laser irradiation. MRI study confirmed the accumulation of nanoparticles within the tumor due to T2 enhancement capability of Fe2O3@Au. The in vivo thermometry results demonstrated that the tumors in magnetic targeting group had a significantly higher temperature elevation rate upon NIR irradiation than non-targeted group (~ 12°C vs. 8.5°C). The in vivo antitumor assessment revealed that systemic injection of Fe2O3@Au in combination with magnetic targeting and NIR irradiation resulted in complete remission of tumor growth. Therefore, Fe2O3@Au can establish a targeted PTT strategy for efficient eradication of tumor cells under the guidance of MRI.

Iron-gold (Fe2O3@Au) core-shell nano-theranostic for magnetically targeted photothermal therapy under magnetic resonance imaging guidance

Introduction: Photothermal therapy (PTT) is a nanotechnology-assisted cancer hyperthermia approach in which the interaction between laser light and plasmonic nanoparticles generates a localized heating for thermoablation of the tumor. Recent efforts in the area of PTT follow two important aims: (i) exploitation of targeting strategies for preferential accumulation of plasmonic nanoparticles within the tumor and (ii) enabling real-time guidance of PTT operation through employing multimodal imaging modalities. Materials and Methods: In the present study, we utilized a multifunctional theranostic nanoplatform constructed from a magnetic core and Au shell (Fe2O3@Au) in order to fulfill these aims. The Au shell exhibits surface plasmon resonance, a property that is exploited to realize PTT. The magnetic core enables Fe2O3@Au to be used as magnetic resonance imaging (MRI) contrast agent. Furthermore, the magnetic core can also be used to achieve a magnetic drug targeting strategy through which Fe2O3@Au would be concentrated in the tumor site by means of magnetic field. Balb/c mice bearing CT26 colorectal tumor model were intraperitoneally injected with Fe2O3@Au. Immediately after injection, a magnet (magnetic field strength of 0.4 Tesla) was placed on the tumor site for 6 hours in order to concentrate Fe2O3@Au, and thereafter the tumors were irradiated with the near infrared (NIR) laser source (808 nm; 2 W/cm2; 3 min). This experiment was conducted for three sessions. Results: MRI confirmed the accumulation of nanoparticles within the tumor due to T2 enhancement capability of Fe2O3@Au. The temperature of the tumors without magnetic targeting was increased by ~7°C after NIR irradiation, whereas the tumors in magnetic targeting group showed a temperature rise of ~12°C. Conclusion: The in vivo antitumor assessment revealed that intraperitoneal injection of Fe2O3@Au nanoparticles and their targeting via magnetic field toward the tumor followed by NIR irradiation remarkably inhibited tumor growth and induced extensive necrosis. Therefore, Fe2O3@Au can establish a targeted MRI-guided PTT strategy.

Brain Quantitative MRI Metrics in Astronauts as a Unique Professional Group.

As part of its technological sophistication, the International Space Station (ISS) Program operates a robust medical surveillance schedule for its rotating 6-person crew to control the known health risks and to address knowledge gaps related to human health in space flight environment. Recent evidence on visual impairment in a subset of ISS crew has renewed the interest in the effects of long-duration space flight on the central nervous system (CNS). Through retrospective analysis in a sample of 10 healthy astronauts, we demonstrate the utility of multimodal quantitative magnetic resonance imaging (qMRI) with diffusion tensor imaging (DTI)-based customized brain templates to examine the structural attributes of various CNS compartments in this occupational group. The study included 10 healthy astronauts (45-55 years). All subjects had previous space flights with the median duration of 110 days. Multimodal quantitative structural imaging modalities performed and used in analyses. A host of CNS features are presented, which are largely commensurate with the available normative data. Remarkably, some of our findings demonstrate statistically significant positive features suggestive of structural neuroplasticity conceivably associated with the professional activities of astronauts, and compensatory neurogenesis that counterweighs the expected normative volume loss with age. The novelty of this exploratory report is in the demonstration of a qMRI toolset as a potential capability for characterization and surveillance of unique professional groups, and for future prospective examinations of the effects of various long-term exposures on CNS.

MULTIMODAL FUNDUS IMAGING OF OUTER RETINAL TUBULATIONS IN CHOROIDAL OSTEOMA PATIENTS.

To evaluate the morphological findings of outer retinal tubulations (ORTs) shown on multimodal imaging modalities in patients with choroidal osteoma. Nineteen eyes of 17 patients with choroidal osteoma underwent full clinical and imaging assessments. Color fundus photography, spectral-domain optical coherence tomography (OCT), and en face OCT were used to identify and detect the characteristics of ORT structures, including the shape, configuration, location, and distribution in the fundus. Optical coherence tomography angiography was implemented as an assist to differentiate tumor's feeder vessels from choroidal neovascularization. The correlations between age, gender, tumor features, best-corrected visual acuity at baseline, OCT characteristics, and the presence of ORTs were analyzed. Outer retinal tubulations were identified in five eyes (26.3%). All were located at the decalcified region of the tumor where the choroidal vessels, retinal pigment epithelium, and overlying outer retinal structures were considerably disrupted to varying degrees. With spectral-domain OCT, the ORTs appeared as one or multiple, round or ovoid, hyporeflective lumens with hyperreflective borders confined to the outer nuclear layer, sometimes with hyperreflective luminal content (four eyes, 80%). In one eye, ORTs were found at the focal choroidal excavation. On en face OCT, these tubulations exhibited different shapes, including a dendritic pattern in two eyes, a tube-like pattern in one eye, a circular pattern in one eye, and a hairpin pattern in one eye. Simultaneous OCT angiography imaging demonstrated that the area of choroidal neovascularization was underneath ORT in one eye and very close to ORT in two eyes. The ORTs of three eyes were above or adjacent to tumor's rich feeder vessels. Statistically, age (P = 0.007), greatest tumor linear dimension (P = 0.003), total tumor area (P = 0.002), decalcification area (P = 0.000), and the presence of intraretinal fluid (P = 0.01) and retinal pigment epithelium alterations (P = 0.038) within the foveola and central 1-mm region of patients with ORT were significantly different from those of patients without ORTs. The results of this study suggest that age, the greatest tumor linear dimension, total tumor area, decalcification area, and the presence of intraretinal fluid and retinal pigment epithelium alterations within the foveola and central 1-mm region might be risk factors for ORT formation. Spectral-domain OCT combined with en face OCT provides comprehensive imaging information for ORTs in choroidal osteoma.

Diverse application of MRI for mouse phenotyping.

Small animal models, particularly mouse models, of human diseases are becoming an indispensable tool for biomedical research. Studies in animal models have provided important insights into the etiology of diseases and accelerated the development of therapeutic strategies. Detailed phenotypic characterization is essential, both for the development of such animal models and mechanistic studies into disease pathogenesis and testing the efficacy of experimental therapeutics. MRI is a versatile and noninvasive imaging modality with excellent penetration depth, tissue coverage, and soft tissue contrast. MRI, being a multi-modal imaging modality, together with proven imaging protocols and availability of good contrast agents, is ideally suited for phenotyping mutant mouse models. Here we describe the applications of MRI for phenotyping structural birth defects involving the brain, heart, and kidney in mice. The versatility of MRI and its ease of use are well suited to meet the rapidly increasing demands for mouse phenotyping in the coming age of functional genomics. Birth Defects Research 109:758-770, 2017. © 2017 Wiley Periodicals, Inc.