High-resolution Ultrasound Biomicroscopy Research Articles

Generating Synthesized Ultrasound Biomicroscopy Images from Anterior Segment Optical Coherent Tomography Images by Generative Adversarial Networks for Iridociliary Assessment.

IntroductionThe aim of this study was to investigate the feasibility of generating synthesized ultrasound biomicroscopy (UBM) images from swept-source anterior segment optical coherent tomography (SS-ASOCT) images using a cycle-consistent generative adversarial network framework (CycleGAN) for iridociliary assessment on a cohort presenting for primary angle-closure screening.MethodsThe CycleGAN architecture was adopted to synthesize high-resolution UBM images trained on the SS-ASOCT dataset from the department of ophthalmology, Xinhua Hospital. The performance of the CycleGAN model was further tested in two separate datasets using synthetic UBM images from two different ASOCT modalities (in-distribution and out-of-distribution). We compared the ability of glaucoma specialists to assess the image quality of real and synthetic images. UBM measurements, including anterior chamber, iridociliary parameters, were compared between real and synthetic UBM images. Intra-class correlation coefficients, coefficients of variation, and Bland–Altman plots were used to assess the level of agreement. The Fréchet Inception Distance (FID) was measured to evaluate the quality of the synthetic images.ResultsThe whole trained dataset included anterior chamber angle images, of which 4037 were obtained by SS-ASOCT and 2206 were obtained by UBM. The image quality of real versus synthetic SS-ASOCT images was similar as assessed by two glaucoma specialists. The Bland–Altman analysis also suggested high consistency between measurements of real and synthetic UBM images. In addition, there was fair to excellent agreement between real and synthetic UBM measurements for the in-distribution dataset (ICC range 0.48–0.97) and the out-of-distribution dataset (ICC range 0.52–0.86). The FID was 21.3 and 24.1 for the synthetic UBM images from the in-distribution and out-of-distribution datasets, respectively.ConclusionWe developed a CycleGAN model to translate UBM images from non-contact SS-ASOCT images. The CycleGAN synthetic UBM images showed fair to excellent reproducibility when compared with real UBM images. Our results suggest that the CycleGAN technique is a promising tool to evaluate the iridociliary and anterior chamber in an alternative non-contact method.

3T high-resolution magnetic resonance imaging, conventional ultrasonography and ultrasound biomicroscopy of the normal canine eye

BackgroundAdvances in MRI coil technology and increased availability of high-field MRI in veterinary medicine enable the acquisition of images of increasingly high spatial resolution while preserving signal-to-noise ratio.The purpose of the present study was to compare 3T high-resolution magnetic resonance imaging (HR-MRI) with ultrasound (US) and ultrasound biomicroscopy (UBM) in the normal canine eye, to assess its potential to depict normal ocular anatomy.ResultsHR-MRI was compared with US and UBM in 10 eyes from 10 healthy beagle dogs. Ocular structures (cornea, anterior chamber, iridocorneal angle, iris, lens, ciliary body, choroid, vitreous body, posterior wall of the eye, optic nerve and optic nerve sheath, extraocular muscles) were assessed subjectively and central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AQD), anteroposterior, mediolateral and dorsoventral lens diameter (APLD, MLLD, DVLD), anteroposterior diameter of the globe including and excluding the scleroretinal rim (APDSRR, APD), vitreous chamber depth (VCD) and optic nerve sheath diameter (ONSD) were measured in HR-MRI and in US. Optic nerve diameter (OND) was measured in HR-MRI. HR-MRI and UBM appearance of the anterior segment were subjectively compared. Detailed reference high-resolution MRI images of normal eyes of Beagle dogs are provided.ConclusionsHR-MRI allowed assessment of all structures identified with US and UBM. The MRI examinations were performed under general anesthesia with the addition of a neuromuscular blocking agent, while US and UBM examinations were performed in conscious animals. Visibility of the entire ocular wall, the lens, the structures caudal to the ciliary body and the optic nerve and its sheath was superior with HR-MRI. HR-MRI allowed the distinction of retina, choroid and sclera, and the delineation of structures not previously identified in canine eyes with MRI, including Tenon’s capsule and the sub-Tenon’s space.Plane selection was more accurate with HR-MRI compared to US. In general, the range of measurements was narrower for MRI than for US. CCT, AQD, APLD, MLLD, APD, APDSRR and ONSD differed significantly between HR-MRI and US, respectively (p = 0.005-0.027).Micro-MRI may be useful for the assessment of ocular pathologies in the future.

Is My Mouse Pregnant? High-Frequency Ultrasound Assessment.

The mouse is the mammalian animal model of choice for many human diseases and biological processes. Developmental biology often requires staged-pregnant mice to determine evolving processes at various timepoints. Moreover, optimal and efficient breeding of model mice requires an assessment of timed pregnancies. Most commonly, mice are mated overnight, and the presence of a vaginal plug is determined; however, the positive predictive value of this technique is suboptimal, and one needs to wait to know if the mouse is truly pregnant. High-resolution ultrasound biomicroscopy is an effective and efficient tool for imaging: 1) Whether a mouse is pregnant; 2) What gestational stage the mouse has reached; and 3) Whether there are intrauterine losses. In addition to the embryos and fetuses, the investigator must also recognize common artifacts in the abdominal cavity so as not to mistake these for a gravid uterus. This article provides a protocol for imaging along with illustrative examples.

Metabolomic differences in blastocoel and uterine fluids collected in vivo by ultrasound biomicroscopy on rabbit embryos†.

The success of embryo development and implantation depends in part on the environment in which the embryo evolves. However, the composition of the uterine fluid surrounding the embryo in the peri-implantation period remains poorly studied. In this work, we aimed to develop a new strategy to visualize, collect, and analyze both blastocoelic liquid and juxta-embryonic uterine fluid from in vivo peri-implantation rabbit embryos. Using high-resolution ultrasound biomicroscopy, embryos were observed as fluid-filled anechoic vesicles, some of which were surrounded by a thin layer of uterine fluid. Ultrasound-guided puncture and aspiration of both the blastocoelic fluid contained in the embryo and the uterine fluid in the vicinity of the embryo were performed. Using nuclear magnetic resonance spectroscopy, altogether 24 metabolites were identified and quantified, of which 21 were detected in both fluids with a higher concentration in the uterus compared to the blastocoel. In contrast, pyruvate was detected at a higher concentration in blastocoelic compared to uterine fluid. Two acidic amino acids, glutamate and aspartate, were not detected in uterine fluid in contrast to blastocoelic fluid, suggesting a local regulation of uterine fluid composition. To our knowledge, this is the first report of simultaneous analysis of blastocoelic and uterine fluids collected in vivo at the time of implantation in mammals, shedding new insight for understanding the relationship between the embryo and its local environment at this critical period of development.

Long-term Follow-up of 14 Eyes With Bilateral and Multiple Ciliary Body Cysts: Prognosis of this Rare Entity.

To describe the long-term outcomes of eyes with bilateral and multiple ciliary body cysts (CBC). This retrospective study included patients with multiple and bilateral CBC diagnosed by high-resolution ultrasound biomicroscopy and followed by a single glaucoma specialist from 2000 to 2020. All patients underwent complete ophthalmic examination including dynamic indentation gonioscopy, retinal nerve fiber layer (RNFL) measurement by optic coherence tomography and automated perimetry. Seven patients (14 eyes) with bilateral and multiple CBC were included with a mean follow-up of 98±39 months. Four eyes of 2 patients had complete angle closure at first examination and 3 of them underwent trabeculectomy with good visual outcomes. Four eyes of 2 patients had a reversible angle-closure at first examination and underwent a ultrasound biomicroscopy-guided laser peripheral iridotomy (LPI) which reopened the irido-corneal angles. Two of these eyes needed intensification of hypotensive drops during the follow-up. Among the 6 eyes (3 patients) with open angle at first examination, all had had LPI at last follow-up visit, 5 had normal RNFL and visual field and 1 received an additional hypotensive drop because of RNFL progression. Our long-term cohort of bilateral and multiple CBC demonstrates that this rare entity may have a good prognosis if LPI is performed before extension of peripheral anterior synechiae. Irreversible angle closure required trabeculectomy in 75% of cases in our cohort with however good visual outcomes.

The independent and add-on values of radial intima thickness measured by ultrasound biomicroscopy for diagnosis of coronary artery disease.

Carotid intima-media thickness (CIMT) has been widely used to risk stratify and predict coronary artery disease (CAD) despite its significant limitations. To test whether radial artery intima thickness (RIT) is closely associated with atherosclerotic risk factors, and whether RIT has an independent and additive value for diagnosis of CAD. One hundred and sixteen consecutive CAD patients and 79 age and gender-matched healthy controls were enrolled in this study. RIT, radial media thickness, radial intima-media thickness, and CIMT were measured with a high-resolution ultrasound biomicroscopy. Binary logistic regression was used to assess association between CAD and ultrasonic parameters, biochemical biomarkers or traditional risk factors. Receiver-operating characteristic curves were plotted to compare performances of several diagnostic models. RIT was positively associated with age, systolic blood pressure, statin administration, and hypertension. The independent value of RIT for differentiating CAD was similar to that of CIMT, but the add-on value of RIT to traditional risk factors for detecting CAD was superior to that of CIMT. Moreover, addition of RIT and CIMT to traditional risk factors increased AUC for detecting CAD from 0.724 to 0.867 significantly (P = 0.003). RIT could detect CAD independently similarly to CIMT. The add-on value of RIT to traditional risk factors for detecting CAD was superior to CIMT and addition of RIT and CIMT to traditional risk factors markedly increased the power to diagnose CAD. Thus, RIT measured by ultrasound biomicroscopy provided a novel approach to non-invasive diagnosis of CAD.

Canine central corneal thickness measurements via Pentacam-HR® , optical coherence tomography (Optovue iVue® ), and high-resolution ultrasound biomicroscopy.

To compare central corneal thickness (CCT) values in canine eyes using Pentacam-HR® Scheimpflug imaging (Pentacam), Optovue® iVue spectral-domain optical coherence tomography (SD-OCT), and high-resolution ultrasound biomicroscopy (UBM) and generate normative canine Pentacam CCT values. Twenty-four client-owned dogs (37 eyes) with nondiseased cornea(s) presenting to the Colorado State University Veterinary Teaching Hospital. Corneal images were acquired via Pentacam, SD-OCT, and UBM in the listed order. Machine-calculated values of CCT from Pentacam and SD-OCT were compared to operator-measured values from UBM. Bland-Altman analysis was performed to evaluate agreement between instruments. Mean CCT ± SD measured by Pentacam was 629.73 ± 64.57 μm, by SD-OCT was 610.56 ± 57.48 μm, and by UBM was 689.77 ± 55.93 μm. On average, Pentacam CCT was 19.17 ± 32.90 μm (3%) thicker than SD-OCT and 65.12 ± 44.52 μm (10.3%) thinner than UBM. SD-OCT was on average 82.47 μm (13.5% ) thinner than UBM. The 95% limits of agreement were (-45.31, 83.65), (-152.38, 22.13), and (-126.674, -38.270) for Pentacam vs. SD-OCT, Pentacam vs. UBM, and SD-OCT vs. UBM respectively. All differences were statistically significant (P < 0.01). Considering there is an average of 7.5% normal diurnal variation in canine CCT, a 3.0% difference between Pentacam and SD-OCT values is likely not clinically relevant. However, Pentacam measurements were both statistically and clinically significantly different from UBM and SD-OCT measurements.

Effects of Shenlian extract on experimental atherosclerosis in ApoE-deficient mice based on ultrasound biomicroscopy.

BackgroundThis study directly and dynamically investigated the effects of SL extract (i.e., a combination of Radix Salviae miltiorrhizae and Andrographis paniculata extract) on plaque progression in vivo by high resolution ultrasound biomicroscopy (UBM).MethodsAn atherosclerosis model was established by placing a perivascular collar on the right common carotid artery in apolipoprotein E-deficient (ApoE-/-) mice. Thickness, plaque area and local blood flow were observed by UBM, pathological changes were observed by histochemical staining, and lipid levels were measured by respective commercially available kits.ResultsCompared with the model group, the SL extract groups showed reduced wall thickness of the aortic arch (GC: P = 0.001, P = 0.002, and P < 0.001; LC: P < 0.001, P < 0.001, and P < 0.001; BC: P = 0.027, P = 0.017, and P = 0.003; respectively), which presented with retarded plaque progression of the cartoid artery with concordantly increased blood flow (P = 0.002 and P < 0.001) as visualized in vivo by UBM. Histological analysis confirmed the reduction of carotid atherosclerosis.ConclusionsThe SL extract inhibited the formation of atherosclerotic plaques in an ApoE-/- mice model by UBM analysis, and did so by effects that ameliorated local blood flow and improved blood lipid levels.

High-resolution ultrasound biomicroscopy as an adjunctive diagnostic tool for anterior scleral inflammatory disease.

To study high-resolution ultrasound biomicroscopy (UBM) findings in anterior scleral inflammatory disease and evaluate the efficacy of high-resolution UBM as an adjunctive diagnostic tool. A cross-sectional study. The medical records of 30 patients (33 eyes) with episcleritis or anterior scleritis were reviewed for clinical features and high-resolution UBM findings. Ultrasound biomicroscopy (UBM) examination was performed using 50MHz Aviso S (Quantel Medical, Clermont-Ferrand, France). Seventeen eyes had episcleritis [nodular (12), simple (five)], and 16 eyes had anterior scleritis [nodular (14), diffuse (two)] as classified by UBM. The use of high-resolution UBM allowed high-resolution imaging of the sclera and episclera and showed characteristic patterns of episcleritis and anterior scleritis. The clinical classification matched UBM findings in 25 (76%) eyes. In the other eight eyes (24%), UBM analysis led to a change in the final classification: four eyes with suspected episcleritis were classified with scleritis, and four eyes with suspected scleritis were classified with episcleritis. Eleven patients (36.7%) had an associated systemic disease. High-resolution UBM enabled visualization of distinct imaging findings of episcleritis and anterior scleritis, indicating its usefulness in the classification of challenging cases of anterior scleral inflammatory disease.

Ultrasound Biomicroscopic Imaging for Interleukin-1 Receptor Antagonist-Inhibiting Atherosclerosis and Markers of Inflammation in Atherosclerotic Development in Apolipoprotein-E Knockout Mice.

We sought to validate the hypothesis that the development of atherosclerosis can be suppressed by the interleukin-1 receptor antagonist (IL-1Ra) in murine models of atherosclerosis in vivo, noninvasively seen by means of high-resolution ultrasound biomicroscopy, and we studied changes in inflammatory markers such as IL-1 and C-reactive protein (CRP) plasma levels in these models of atherosclerosis. We divided IL-1Ra(+/-)/apolipoprotein-E (apoE)(-/-) and IL-1Ra(+/+)/apoE(-/-) mice into 2 age groups, used as atherosclerotic models. The control groups were age-matched IL-1Ra(+/+)/apoE(+/+) mice. Plaque thickness was measured in the ascending aorta in short-axis images by means of ultrasound and histology. Plasma levels of IL-1 and CRP were quantified in the 3 murine groups. At 16 weeks, plaque thickness in the ascending aortas of the IL-1Ra(+/-)/apoE(-/-) mice was significantly greater than that in the IL-1Ra(+/+)/apoE(-/-) mice, on ultrasound and histology (P <0.01). In contrast, at 32 weeks, the differences between these 2 genotypes were not statistically significant. Serum IL-1 levels were lower in the IL-1Ra(+/-)/apoE(-/-) mice than in the IL-1Ra(+/+)/apoE(-/-) mice at 16 and 32 weeks (P <0.05). At 16 weeks, serum CRP levels in the IL-1Ra(+/-)/apoE(-/-) mice were higher than in the IL-1Ra(+/+)/apoE(-/-) mice (P <0.01). Our results suggest that ultrasound biomicroscopy enables evaluation of atherosclerotic lesions in vivo, noninvasively and in real-time, in apoE(-/-) mice. Partial IL-1Ra deficiencies might promote early plaque development in 16-week-old apoE(-/-) mice. The balance of IL-1 and IL-1Ra might influence atherosclerotic development. Finally, CRP might affect the initiation of atherosclerosis, rather than its progression.

GW24-e2259 Evaluation of atherosclerosis in low density lipoprotein receptor defect mice by ultrasound biomicroscopy

ObjectivesLow density lipoprotein receptor defect mice model by transgenetic technology was used to detect atherosclerosis by Ultrasound Biology (UBM). And evaluate the value of low density lipoprotein receptor defect in...

174 ULTRASOUND BIOMICROSCOPIC IMAGE ATTRIBUTES OF OVARIAN FOLLICLES IN HEIFERS

High-resolution ultrasound biomicroscopy (UBM) with high-frequency transducers (20 to 50 MHz) has enabled imaging of small antral follicles (&lt;1 mm) and acoustic characterisation of the follicular antrum and wall. Quantitative echotextural analysis of the images generated by UBM provides detailed functional information about the granulosa and theca layers of follicle walls. The objectives of our study were to compare biomicroscope image echotextures between dominant and largest subordinate follicles during the first follicular wave and to characterise UBM attributes of the ovulatory follicle. Hereford crossbred heifers (14 to 16 months old, n = 12) were used. Ovarian examinations were performed transvaginally from Day –4 or –3 (Day 0 = ovulation) to Day 10 using a UBM imaging instrument (Vevo 660; Visual Sonics Inc., Toronto, Canada) equipped with a 25-MHz end-fire transducer. Echotextural assessment was performed by spot metrics of the follicle antrum and follicle wall by using a series of custom-developed computer algorithms optimized for ultrasonography (Synergyne©, Version 2.8, WHIRL, Saskatoon, SK, Canada). Although subordinate and dominant follicles development were tracked from Day –2 (around 1 mm in diameter) to Day 10, the ovulatory follicle was tracked only from Day –4 to ovulation. All data were analysed by analysis of variance for repeated measures using the Mixed procedure (Littell et al. 1998) in the Statistical Analysis System software package (SAS version 8.2 for MS Windows; SAS Institute Inc., Cary, NC, USA). No differences were detected between dominant and largest subordinate follicle in the mean pixel value (MPV) or pixel heterogeneity (PH) of the antrum. However, the MPV of the wall of dominant follicles was greater and PH tended to be greater than that of the largest subordinate follicles (P = 0.05 and P = 0.1, respectively). This result could be evidence that the dominant follicle would be healthier. The PH of the wall the ovulatory follicle decreased (P = 0.03) from Day –4 to Day –1; however, no changes in MPV were observed. Similarly, no changes were detected in MPV or PH of the follicular antrum. The loss of granulosa cells from the follicular wall can explain, at least in part, the decrease in mean pixel value and pixel heterogeneity of the follicular wall detected in ovulatory follicles. Moreover, morphologic changes indicative of atresia are typically represented by high values of number of pixel values. In conclusion, although no differences in antral characteristics of dominant v. subordinate follicles were detected, mean pixel value and pixel heterogeneity of the follicular wall were higher in dominant follicles, and pixel heterogeneity of follicular wall of ovulatory follicles decreased over days. Quantitative pixel analysis from follicular wall images using UBM could be applied to evaluate follicles in live animals. However, more studies using this technique are necessary. Research was supported by NSERC and CIHR. Luiz Pfeifer was supported by CAPES from Ministry of Education, Brazil.

TCT-396 Assessment of early radial injury after transradial coronary intervention by high-resolution ultrasound biomicroscopy: Innovative technology application

The radial artery has become an alternative vascular access site for percutaneous coronary procedures. Transradial coronary intervention (TRI) introduces injury to the radial artery (RA) which will affect repeat transradial coronary procedure and the quality as a bypass conduit. We sought to compare

ASSESSMENT OF EARLY RADIAL INJURY AFTER TRANSRADIAL CORONARY INTERVENTION BY HIGH-RESOLUTION ULTRASOUND BIOMICROSCOPY

ObjectivesThe radial artery has become an alternative vascular access site for percutaneous coronary procedures. Transradial coronary intervention (TRI) introduces injury to the radial artery (RA) which will affect repeat transradial...

The success of treating keratoconus: visual acuity and follow-up with ultrasound biomicroscopy

Background Keratoconus is a progressive, noninflammatory corneal ectasia that is usually treated successfully with contact lenses. Age younger than 30 years was indentified as a risk for penetrating keratoplasty. The high resolution ultrasound biomicroscopy is an ‘in vivo’ examination method and is suitable for diagnostic and morphometrical examinations. We used this device to diagnose keratoconus and follow its course.

Ultrasound biomicroscopy assessment of atherosclerosis in apolipoprotein-E knockout mice

ObjectivesThe purpose of this study was to validate the hypothesis high-resolution ultrasound biomicroscopy (UBM) can observe that atherosclerotic (AS) progression of invivo mice can be suppressed by IL-1Ra.MethodsTwo different age...

Response to Day and Foster

Sir, We value the interest Day and Foster1 have expressed in our case.2 The reported cases of seclusio pupillae in pseudophakia are accompanied by clear, clinical descriptions of an immobile iris that is tethered to the anterior capsule where the rhexis edge lies, typically in the mid periphery.3, 4, 5 In the largest case series, Gaton et al describe ‘iris bombe and a shallow anterior chamber with a fixed, non-reacting pupil and increased IOP (40 and 60 mm Hg)'. In our case, the pupil was mobile, and ∼2–3 mm smaller than the adequately sized anterior rhexis. The iris did not have the typical bombe appearance and pupil dilated uniformly without any signs of pigmentation on the anterior capsule suggestive of prior iridocapsular adhesion. Choroidal effusions are increasingly being implicated in primary angle closure. It remains unclear if they are a causative factor or consequence. We could find no reports where choroidal effusions were seen in the context of seclusio pupillae, and the findings in phakic primary angle closure may not be directly transferrable to our case. In the paper by Sakai et al,6 inclusion into the acute primary angle closure (APAC) group required bilateral narrow angles, IOP >40 mm Hg, nausea/vomiting, and corneal oedema in phakic patients. This is quite different from the case we present. Of their APAC patients, only 2 of 70 had grade 3 effusions and they make no mention of these extending beyond the equator. Our patient had large choroidal detachments, with folds visible at the posterior pole through an undilated pupil. Utilizing the facilities available to us, we performed dynamic ultrasonography and were happy that the iris was fully mobile. High-resolution ultrasound biomicroscopy would have been helpful in confirming the pathology, however, this modality was unavailable at our institution. Peripheral iridotomy is not without risk. It is only of value in cases of pupil block and as such would be ineffective in this case. We were fortunate enough to be able to document what we recognized as an unusual case and have included a video highlighting some of the salient features that we believe support our interpretation (Supplementary Video).

Noninvasive Assessment of Atherosclerosis in Apolipoprotein-E Knockout Mice by Ultrasound Biomicroscopy

Intima media thickness is a marker for human atherosclerosis. This study aimed to validate the hypothesis that atherosclerosis progression in vivo in mice can be visualized noninvasively using high-resolution ultrasound biomicroscopy (UBM), and to study the association between UBM characteristics and plasma lipids in the apolipoprotein-E knockout (ApoE-/-) mouse model. Four age groups of male ApoE-/- mice were used as atherosclerotic models, with age-matched male C57BL/6 mice used as controls. Plaque thickness and area measured by UBM correlated with histologic measurements (r = 0.81, r = 0.70, respectively; p < 0.001). Serum total cholesterol, low density lipoprotein cholesterol and triglycerides were higher in the ApoE-/- groups compared with controls ( p < 0.01). Plaque thickness was correlated with total cholesterol (r = 0.505, p < 0.001). High-resolution UBM provides a noninvasive, accurate means of detecting atherosclerosis progression in vivo in mice and can detect changes in the early stage of atherosclerosis.

162 OVARIAN ULTRASOUND BIOMICROSCOPY IN RABBITS

Invasive methods (e.g. histology) limit serial assessment of ovarian structures in rabbits and impede progress in our understanding of factors responsible for inducing ovulation. Serial transrectal or transvaginal ultrasonography of ovarian structures has revolutionized our understanding of reproductive patterns in domestic animals, but the approach is limited in smaller species by the small physical size of the animal and the ovary. The advent of high-resolution ultrasound biomicroscopy (UBM), however, has permitted recent characterisation of ovarian dynamics in species as small as mice. As part of a larger study on factors influencing ovulation in rabbits, the objective of the present study was to validate UBM as a method of assessing ovarian structures in rabbits by comparing ultrasound image attributes with histological attributes. Female New Zealand White rabbits (n = 4; 5 to 5.5 months of age) were given ovulation-inducing treatments and examined daily by conventional transabdominal ultrasonography with a 12-MHz linear-array probe (MyLabTM5). Rabbits were killed with sodium pentobarbital 8 days after treatment. Ovarian UBM was performed ex situ in a water bath. A 25-MHz oscillating sector-array transducer (Visualsonics) was moved mechanically at a constant speed along the long axis of each ovary, and images were recorded (300 frames per 10-s cine-loop). After UBM, ovaries (n = 8) were fixed in 10% formaldehyde, embedded in paraffin, serial-sectioned at 10-μm thickness, and stained with Masson’s trichrome. Digital photomicrographs were taken of every third section of each ovary. For each ovary, follicles ≥0.6 mm and corpora lutea (CL) were counted and measured by scrolling through the UBM cine-loops and the serial micrographs. Ovarian follicles ≥1.5 mm were readily detected by conventional ultrasonography, and such follicles were present in the ovaries of all rabbits on the day of treatment, but CL structures were not clearly discernable during the 8 days after treatment. In vivo transabdominal UBM failed to yield satisfactory images of the ovaries probably because of high acoustic impedance of the body wall. The number (mean ± SEM) of CL detected by UBM ex situ in each pair of ovaries was highly correlated (r = 0.99; P &lt; 0.05) with the number detected by histology (8.5 ± 2.9 v. 8.8 ± 3.0). The diameter of CL was also highly correlated (2.1 ± 0.7 v. 1.8 ± 0.6 mm; r = 0.99; P &lt; 0.05). Similarly, a high correlation was detected between UBM and histology in the number of follicles ≥0.6 mm (17.3 ± 2.3 v. 19.0 ± 1.6; r = 0.96 P &lt; 0.05), and follicle diameter (1.1 ± 0.05 v. 1.1 ± 0.03 mm; r = 0.96; P &lt; 0.05). Interestingly, UBM of each ovary required on average 2 h compared with 30 h for histology. The results validate the accuracy of UBM for assessing rabbit ovaries ex situ, but identify limitations of present ultrasound approaches for examining rabbit ovaries in situ. Supported by the Natural Sciences and Engineering Research Council of Canada. The authors thank D. Nesbitt for assistance with histological procedures.

Abstract A229: Novel in vivo imaging of chemotherapy-induced gonadotoxicity

Abstract Introduction: Advances in cancer therapy have improved the long-term survival of cancer patients who may then face infertility and premature gonadal failure due to chemotherapy. It has been demonstrated that the chemotherapeutic agent doxorubicin (DXR) induces apoptosis in germ cells, though its role in inflicting potential gonadal failure remains obscure. We had previously shown ovarian damage in mice following DXR treatment, manifested by reduced ovarian size and weight and by apoptosis. We aimed at establishing a real-time in vivo molecular imaging platform in mice designated to evaluate chemotherapy-induced toxicity and to assess potential vascular insult in both ovaries and testes. Methods: The volume of both ovaries and testes was measured in vivo by ultrasound biomicroscopy (Vevo2100) and by high resolution MRI, over a period of one month after adminstration of 10mg/kg intraperitoneal DXR. Ovaries were imaged by ultrasound using microbubbles as a contrast agent for evaluating the effect of DXR on ovarian blood flow. Results: We have established a platform of visualizing the gonads by innovative high resolution ultrasound biomicroscopy and MRI that enabled in vivo detection of chemotherapy-induced effects in the same individuals over time. We observed a constant, significant reduction in gonadal volume, evident by both MRI and ultrasound. The ovary volume was reduced to 52% (N=10, p&amp;lt;0.05) of baseline values over one month. A similar trend was observed in the testes (reduced to 38% of baseline values over one month; N=6 p&amp;lt;0.05)). The use of bubbles as contrast media depicted a 30% reduction in ovarian blood flow already 15 min after DXR administration. Conclusions: Using high resolution, state of the art imaging modules enabled us to trace chemotherapy-induce gonadotoxicity by in vivo imaging of the same individuals throughout an extended period of time. The acute reduction of ovarian blood flow following chemotherapy treatment may suggest a role for vascular injury in inflicting ovarian damage. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A229.