Differential diagnosis of leukokoria: radiologic-pathologic correlation

Congenital Malformations of the Eye: A Pictorial Review and Clinico-Radiological Correlations

Congenital malformations of the eye represent a wide and heterogeneous spectrum of abnormalities that may be part of a complex syndrome or be isolated. Ocular malformation severity depends on the timing of the causative event during eye formation, ranging from the complete absence of the eye if injury occurs during the first weeks of gestation, to subtle abnormalities if the cause occurs later on. Knowledge of ocular malformations is crucial to performing a tailored imaging protocol and correctly reporting imaging findings. Together with the ophthalmologic evaluation, imaging may help frame ocular malformations and identify underlying genetic conditions. The purpose of this pictorial review is to describe the imaging features of the main ocular malformations and the related ophthalmologic findings in order to provide a clinico-radiological overview of these abnormalities to the clinical radiologist. Sight is a crucial sense for children to explore the world and relate with their parents from birth. Vision impairment or even blindness secondary to ocular malformations deeply affects children's growth and quality of life.

Intraoperative OCT Angiography in Pediatric Patients with Persistent Fetal Vasculature

PURPOSE

To describe abnormalities of the optic nerve microvasculature in patients with persistent fetal vasculature (PFV) and their fellow eyes using OCT angiography (OCTA).

DESIGN

Cross-sectional study.

SUBJECTS

Fifty eyes of 25 patients with PFV who underwent prospective imaging using supine OCTA during examination under anesthesia at Bascom Palmer Eye Institute from March 1, 2019, to December 31, 2022.

METHODS

OCT angiography images of the optic nerve of the included patients were analyzed with a primary focus on blood flow. Demographic, clinical, and treatment factors were compared with morphologic changes in the optic disc microvasculature.

MAIN OUTCOME MEASURES

Prevalence of optic nerve microvascular abnormalities on OCTA in the affected and fellow eyes of patients with PFV.

RESULTS

A total of 50 eyes from 25 patients were reviewed, and 28% (7/25) met image quality criteria for OCTA analysis. Optic nerve OCTA showed a persistent hyaloid artery (PHA) in all (7/7) PFV eyes analyzed. Of these, flow on OCTA was detectable in 57% (4/7). A Bergmeister papilla was evident in 100% (25/25) fellow eyes, of which flow was detected in 68% (17/25). Fluorescein angiography (FA) demonstrated blood flow within the stalk in 40% (10/25) of PFV eyes and within the Bergmeister papilla in 25% (6/25) of fellow eyes. Similar findings of abnormal blood flow and presence of fibrovascular stalk were seen in both treatment-naïve and treated groups.

CONCLUSIONS

OCT angiography allows for high-resolution visualization of subtle vascular abnormalities that are not readily apparent using RetCam FA and may serve as a useful noninvasive test to confirm the patency of the PHA and Bergmeister papilla in children. The results of the present study suggest that PFV may be a bilateral and asymmetric process.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Imaging of orbital infectious and inflammatory disease in children

Most acute nontraumatic periorbital and intraorbital pathologies in pediatric patients have an underlying infectious or inflammatory etiology, and imaging frequently plays a key role in the workup and management of these children. In this paper we review the clinical presentation and imaging findings in children with some of the most common infectious and inflammatory diseases involving the orbit. Basic relevant anatomy and imaging findings on various imaging modalities are also reviewed.

Retinal imaging in infants

Digital retinal imaging is at the core of a revolution that is continually improving the screening, diagnosis, documentation, monitoring, and treatment of infant retinal diseases. Historically, imaging the retina of infants had been limited and difficult to obtain. Recent advances in photographic instrumentation have significantly improved the ability to obtain high quality multimodal images of the infant retina. These include color fundus photography with different camera angles, ultrasonography, fundus fluorescein angiography, optical coherence tomography, and optical coherence tomography angiography. We provide a summary of the current literature on retinal imaging in infants and highlight areas where further research is required.

OCT angiography of persistent hyaloid artery: a case report

Background

A persistent hyaloid artery is a rare fetal remnant. Several complications such as amblyopia, vitreous hemorrhage, and retinal detachment have been reported. Here, we present a case of vitreous hemorrhage with a persistent hyaloid artery.

Case presentation

A healthy 16-year-old male presented with blurred vision in his left eye. Vitreous hemorrhage occurred and absorbed spontaneously. Slit-lamp examination demonstrated a Mittendorf’s dot and fundus examination revealed a persistent hyaloid artery. Optical coherence tomography (OCT) showed a Bergmeister’s papilla. The blood flow of the persistent hyaloid artery via the Bergmeister’s papilla was found by OCT angiography.

Conclusion

The persistent hyaloid artery should be considered as a cause of spontaneous vitreous hemorrhage of young healthy patient. The OCT angiography will be a useful noninvasive approach to confirm the patency of the persistent hyaloid artery.

Evaluation of a Free Public Smartphone Application to Detect Leukocoria in High-Risk Children Aged 1 to 6 Years

PURPOSE

To determine whether a white-eye detector smartphone application (app) can be used as a screening tool to detect early signs of leukocoria in a clinical practice.

METHODS

A prospective, single-visit study of children aged 1 to 6 years presenting to the University Eye Clinic of Genova for a complete pediatric ophthalmologic examination was conducted. All children who met the enrollment criteria were screened by an orthoptist with the CRADLE (Computer Assisted Detector of Leukocoria) smartphone app for an iPhone operating system (iOS) (iPhone 7; Apple, Cupertino, CA). Cycloplegic retinoscopy and fundus examination were performed 30 minutes after one to two drops of a pediatric combination drop, comprising tropicamide 1% and phenylephrine 2.5%, were instilled. A comparison between the two methods yielded sensitivity, specificity, and negative likelihood ratio values.

RESULTS

A total of 244 eyes of 122 children were included in the study. Nine eyes of 244 (3.6%) had leukocoria evaluable by penlight caused by amblyogenic cataract, 1 (0.4%) patient had retinopathy of prematurity stage 5, and 3 (1.2%) patients had retinoblastoma. The sensitivity of the white-eye detector app was 15.38% (95% confidence interval [CI]: 1.92% to 45.45%), the specificity was 100% (95% CI: 98.48% to 100.00%), and the negative likelihood ratio was 0.85 (95% CI: 0.67 to 1.07).

CONCLUSIONS

A smartphone photoscreening app able to detect leukocoria may provide valuable support for children's parents. However, it cannot be considered an alternative to the ophthalmoscope for children. [J Pediatr Ophthalmol Strabismus. 2019;56(4):229-232.].

Prenatal Diagnosis of Persistent Hyperplastic Primary Vitreous: Report of 2 Cases and Review of the Literature

Persistent hyperplastic primary vitreous is a spectrum of congenital ocular abnormalities characterized by leukocoria, microphthalmia, cataracts, extensive intravitreal hemorrhage, persistence of the hyaloid artery, glaucoma, and retinal detachment. It might be isolated or associated with congenital syndromes such as trisomy 13, Walker-Warburg syndrome, and Norrie disease. We present 2 cases of persistent hyperplastic primary vitreous diagnosed by prenatal sonography in the early third trimester. Bilateral hyperechoic lenses and retinal nonattachment were detected in the sonographic examination of the first case, whereas irregular echogenic bands between the lenses and posterior walls of the eyes were prominent in the second case. In both of the cases, ocular findings were accompanied by intracranial findings, including severe hydrocephalus, an abnormal gyral pattern, and cerebellar hypoplasia, suggesting the diagnosis of Walker-Warburg syndrome. We also present a review of the literature regarding the prenatal diagnosis of this malformation.

Imaging of Pediatric Orbital Diseases

This article reviews a variety of congenital and developmental disorders of the pediatric orbit with particular emphasis on ocular lesions, followed by a description of developmental and neoplastic orbital and ocular masses. The relationship of these diseases to various syndromes and/or known genetic mutations is also highlighted.

Role of B-scan ocular ultrasound as an adjuvant for the clinical assessment of eyeball diseases: a pictorial essay

We report our experience in B-mode ocular ultrasonography, focusing on its contribution when the clinical examination proves to be difficult, mainly due to the existence of intraocular opacities of the ocular fundus or diagnostic doubts. We revise the ocular ultrasound technique, its indications and contraindications, comparing to the other imaging techniques. In our experience ultrasonography revealed pathological findings which confirmed the clinical suspicion in most of cases or provide additional information. With understanding of the indications for ultrasonography and proper examination technique, one can gather a vast amount of information not possible with clinical examination alone.

Persistent hyperplastic primary vitreous – The martini glass sign

No abstract.

Case 206: persistent hypertrophic primary vitreous

History This patient was a 20-month-old full-term girl who had not received any routine pediatric care. During a physical examination, left-sided leukocoria was detected. Subsequently, a left-sided cataract was diagnosed. The patient was sent for magnetic resonance (MR) imaging of the brain and orbits.

Bilateral intraocular calcification in necrotizing cytomegalovirus retinitis

We report a unique case of bilateral intraocular calcification due to necrotizing cytomegalovirus (CMV) retinitis associated with congenital CMV infection. A 7-month-old boy with a history of congenital CMV infection showed bilateral intraocular calcific plaques on computed tomography (CT) and ultrasonography. We reviewed the patient's medical files for the purpose of this report. The patient had a prior medical history of hospitalization for fever and swelling in the neck at 3 months of age. Systemic findings (anemia, neutropenia, hepatosplenomegaly, and reactive lymphadenomegaly) in association with a low CD4 count, high blood CMV viral load, and positivity for urine CMV DNA by polymerase chain reaction led to the diagnosis of bone marrow suppression and congenital CMV infection. At 7 months, he developed horizontal nystagmus and bilateral leukocoria over 20 days. Cranial CT and ultrasonography revealed bilateral intraocular calcific plaques and the patient was referred to rule out retinoblastoma. Fundoscopy was consistent with bilateral hemorrhagic, necrotizing CMV retinitis. Significant resolution of the retinal infiltrations occurred 2 weeks after initiation of systemic treatment with ganciclovir. Intraocular calcification may be a sign of active CMV retinitis. To our knowledge this is the first report of bilateral intraocular calcification serving as the presenting clinical manifestation of necrotizing CMV retinitis.

Colorimetric and longitudinal analysis of leukocoria in recreational photographs of children with retinoblastoma

Retinoblastoma is the most common primary intraocular tumor in children. The first sign that is often reported by parents is the appearance of recurrent leukocoria (i.e., "white eye") in recreational photographs. A quantitative definition or scale of leukocoria--as it appears during recreational photography--has not been established, and the amount of clinical information contained in a leukocoric image (collected by a parent) remains unknown. Moreover, the hypothesis that photographic leukocoria can be a sign of early stage retinoblastoma has not been tested for even a single patient. This study used commercially available software (Adobe Photoshop®) and standard color space conversion algorithms (operable in Microsoft Excel®) to quantify leukocoria in actual "baby pictures" of 9 children with retinoblastoma (that were collected by parents during recreational activities i.e., in nonclinical settings). One particular patient with bilateral retinoblastoma ("Patient Zero") was photographed >7, 000 times by his parents (who are authors of this study) over three years: from birth, through diagnosis, treatment, and remission. This large set of photographs allowed us to determine the longitudinal and lateral frequency of leukocoria throughout the patient's life. This study establishes: (i) that leukocoria can emerge at a low frequency in early-stage retinoblastoma and increase in frequency during disease progression, but decrease upon disease regression, (ii) that Hue, Saturation and Value (i.e., HSV color space) are suitable metrics for quantifying the intensity of retinoblastoma-linked leukocoria; (iii) that different sets of intraocular retinoblastoma tumors can produce distinct leukocoric reflections; and (iv) the Saturation-Value plane of HSV color space represents a convenient scale for quantifying and classifying pupillary reflections as they appear during recreational photography.

Current management of Coats disease

Since its original description in 1908, Coats disease has been recognized as an idiopathic cause of severe vision loss with a remarkable diversity in clinical presentation and morphology. Key clinical and imaging variables are helpful in differentiating Coats disease from life-threatening malignancies, and proper management revolves around a thorough knowledge of the differential diagnosis. Despite significant advancement in scientific understanding of the disease process and clinical spectrum, the underlying etiology remains obscure, and both primary and secondary forms are recognized. With the development of anti-VEGF therapy, vitreoretinal specialists have a new, effective adjunct to the clinical management of exudates, macular edema, and serous retinal detachment. We highlight the history, diagnostic challenges, evolving clinical spectrum, and current management of Coats disease.

Color Doppler imaging of eyes with persistent fetal vasculature

BACKGROUND

Eyes with persistent fetal vasculature (PFV) may be mistaken for retinoblastoma and provide a diagnostic challenge.

OBJECTIVE

This study aimed to evaluate the role of color Doppler imaging (CDI) in children with persistent fetal vasculature.

MATERIALS AND METHODS

Eyes with a diagnosis of PFV were evaluated by CDI.

RESULTS

Twenty eyes of 17 children were included. All had a confirmed diagnosis of PFV based on one or more of the following: clinical findings on funduscopy, characteristic findings on imaging modalities (ophthalmic gray-scale US, CT and/or MRI), typical findings observed intraoperatively, and histopathological analysis (after enucleation in one case). Blood flow within the PFV was demonstrated in 19 eyes in this series.

CONCLUSION

CDI is a noninvasive diagnostic tool that may add useful information on the presence of blood flow within the PFV and may substantiate the diagnosis of PFV in cases of uncertainty.

Abnormalities of the globe

Although much has been published in the radiology literature on the multitudinous conditions affecting the bony orbit, there has been relatively little on diseases confined to the globe itself. As current cross-sectional imaging techniques evolve, the globes can be visualized in ever greater detail, facilitating the recognition of even fairly subtle disease entities in this region. Indeed, the fact that high-resolution detailed images of this area are achievable without significant time or radiation penalty when evaluating surrounding structures means that incidental disease is not infrequently encountered. As such, common disease entities in this region are of interest to the general radiologist and the diagnosis of globe disease need not be the remit of experienced observers in specialist centres. At our institutions we have recently encountered a number of cases covering a broad spectrum of diagnoses including traumatic, neoplastic, iatrogenic, inflammatory, and infective aetiologies. The purpose of this review is to briefly revise the pertinent anatomical and physiological properties of the globe and to familiarize the reader with the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of a number of these disease states. The collection of abnormalities included is not intended to be exhaustive, merely representative, with the emphasis towards those more commonly encountered.

MRI of retinoblastoma

We review the role of MRI in retinoblastoma and simulating lesions. Retinoblastoma is the most common paediatric intra-ocular tumour. It may be endophytic, exophytic or a diffuse infiltrating tumour. MRI can detect intra-ocular, extra-ocular and intracranial extension of the tumour. MRI is essential for monitoring patients after treatment and detection of associated second malignancies. It helps to differentiating the tumour from simulating lesions with leukocoria.

The globe: infection, inflammation, and systemic disease

Infection, inflammation, and systemic diseases affecting the globe encompass a broad range of pathologies which may ultimately lead to progressive vision loss. Clinical symptomatology varies from the inexorably silent progressive visual loss to an acute presentation of ocular pain and/or red eye. Most are diagnosed by clinical ophthalmologic examination with selective use of ultrasound, computed tomography, and magnetic resonance imaging for confirmation of the diagnosis, assessment of disease extent, and signs of associated systemic disease. Knowledge of the differential diagnoses of vision loss, ocular pain, and redness makes imaging analysis of this diverse group of processes more precise.

Is CT still useful in the study protocol of retinoblastoma?

BACKGROUND AND PURPOSE

Intralesional calcium deposition is considered a key element for differentiating retinoblastoma from simulating lesions. Our aim was to assess whether MR imaging associated with ophthalmologic investigations (ophthalmoscopy and ultrasonography) could replace CT in the detection of diagnostic intralesional calcifications in retinoblastoma.

MATERIALS AND METHODS

Ophthalmoscopic findings, MR images, CT scans, and histologic examination of 28 retinoblastomas from 23 consecutive children (11 males, 12 females; age range at admission, 1-35 months; mean age, 11 months; median age, 9 months) were retrospectively evaluated. Ultrasonography was performed in 18 patients with 21 retinoblastomas. MR imaging included T2-weighted spin-echo and gradient-echo images, fluid-attenuated inversion recovery images, and T1-weighted spin-echo images with and without contrast enhancement. Clinical data were integrated with MR imaging data to evaluate the utility of both approaches to discover calcifications; particularly, a correlation between intralesional signal-intensity void spots on MR imaging and hyperattenuating areas on CT scans was performed.

RESULTS

Ophthalmoscopy detected calcifications in 12 of 28 eyes (42.85%). Ultrasonography detected calcifications in 20 of 21 eyes (95.23%). CT showed hyperattenuating intralesional areas consistent with calcifications in 27 of 28 eyes (96.42%). MR imaging showed intralesional signal-intensity void spots in 25 of 28 eyes (89.28%). All spots detected with MR imaging matched the presence of calcifications on CT scans. Gradient-echo T2*-weighted and fast spin-echo T2-weighted images showed the highest degree of correlation with CT. When we put together ophthalmoscopy, ultrasonography, and MR imaging data, no calcifications detected on CT were missed, and the differential diagnosis was thorough.

CONCLUSIONS

A combination of clinical data and MR images may remove potentially harmful ionizing radiation from the study protocol of retinoblastoma.

Prenatal ultrasonographic diagnosis of persistent hyperplastic primary vitreous

Persistent hyperplastic primary vitreous (PHPV) is a rare developmental malformation of the eye characterized by the presence of a vascular membrane located behind the lens. We report, for the first time in the literature, the identification on ultrasound examination of bilateral cataract and thickened hyaloid artery-lens junction, leading to a diagnosis of bilateral PHPV, in a fetus at 23 weeks' gestation. Histological examination at postmortem confirmed the prenatal diagnosis of bilateral PHPV and cataract. A thorough ultrasound examination of the fetal eye in cases with cataract is recommended.

Eye size in retinoblastoma: MR imaging measurements in normal and affected eyes

PURPOSE

To evaluate eye size retrospectively by using magnetic resonance (MR) imaging to measure axial length (AL), equatorial diameter (ED), and eye volume (EV) in patients with retinoblastoma and to evaluate the possible effect of retinoblastoma on eye size.

MATERIALS AND METHODS

Local ethics committee approval was obtained with waiver of informed consent. MR images of 100 patients with retinoblastoma (50 girls, 50 boys; mean age, 19 months; age range, 9 days to 68 months) were scored by one observer (AL, ED, EV, and tumor volume measurements), with a second observer reviewing all measurements. Normal eyes of patients with unilateral retinoblastoma served as controls. Interobserver measurement agreement was evaluated in a random subset of 50 eyes with use of intraclass correlation coefficients. Linear mixed model analysis was used with adjustments for age, laterality, and sex.

RESULTS

Interobserver agreement was good (intraclass correlation coefficients >or= 0.89). Eyes with retinoblastoma had significantly shorter ALs (95% confidence interval [CI]: -0.57 mm, -0.16 mm; P=.001) and EDs (95% CI: -1.01 mm, -0.66 mm; P<.001) and significantly smaller EVs (95% CI: -336 mm(3), -151 mm(3); P<.001) than normal eyes. Within patients, a significant negative relationship was found between tumor volume and EV (P<.001).

CONCLUSION

MR imaging measurements of AL, ED, and EV were significantly smaller in eyes with retinoblastoma than in normal eyes. In addition, in patients with retinoblastoma, the larger the tumor volume, the smaller the eye.

From the archives of the AFIP: Pediatric orbit tumors and tumorlike lesions: neuroepithelial lesions of the ocular globe and optic nerve

Tumors and tumorlike lesions of the globe and optic nerve in children represent a different histologic spectrum than in adults; the imaging appearances of these lesions reflect their pathologic features. Retinoblastoma is a tumor of infancy and the most common intraocular tumor in children. There are heritable and nonheritable forms. The most common clinical finding is leukocoria. The differential diagnoses of this sign include several nonneoplastic lesions: Persistent hyperplastic primary vitreous is a congenital persistence of an embryonic structure causing a retrolental mass. The primitive vasculature may produce a septum in the posterior chamber. Coats disease is a vascular malformation of the retina that produces a lipoproteinaceous subretinal exudate. The vascular malformation enhances with intravenous contrast material, and the fat-containing subretinal exudate does not. Larval endophthalmitis is a granulomatous reaction to the dead or dying larvae of Toxocara canis or T. cati. The most important feature that allows differentiation of retinoblastoma from these so-called pseudoretinoblastomas is the presence of calcification in the former. Medulloepithelioma has two histologic forms; the teratoid type may contain calcifications, but it usually arises anteriorly from the ciliary body rather than posteriorly from the retina. Optic nerve glioma is the most common tumor of the optic nerve in children and is frequently associated with neurofibromatosis type 1. These gliomas are usually pilocytic astrocytomas and cause fusiform enlargement of the nerve.

Relevance of CT and MRI in retinoblastoma for the diagnosis of postlaminar invasion with normal-size optic nerve: a retrospective study of 150 patients with histological comparison

BACKGROUND

Detection of optic nerve invasion is mandatory in children primarily enucleated for retinoblastoma to ensure a free resection margin.

OBJECTIVE

To assess the accuracy of CT and MRI for the detection of postlaminar invasion in normal-size nerves.

MATERIALS AND METHODS

A total of 150 patients enucleated for retinoblastoma were included. Imaging data (119 CT and 46 MRI) were retrospectively reviewed and compared with histological findings. Abnormal contrast enhancement of the optic nerve was used as diagnostic criterion for invasion. The associations between postlaminar invasion and several indirect signs were also assessed. Statistical analysis was performed with the Kruskal-Wallis and Fisher exact tests.

RESULTS

Postlaminar invasion on histology was observed in 8% (12/150). The sensitivity, specificity, accuracy and negative and positive predictive values were 60%, 95%, 91%, 95% and 60% for MRI, and 0%, 100%, 94% and 94% (PPV not assessable) for CT, respectively. Tumour diameter was the only indirect radiological sign significantly associated with postlaminar optic nerve invasion (P=0.002).

CONCLUSION

Our results suggest that MRI is more relevant than CT for preoperative detection of optic nerve invasion in patients with retinoblastoma. Tumour diameter is the only indirect sign significantly associated with postlaminar invasion.

Retinoblastoma: MR imaging parameters in detection of tumor extent

PURPOSE

To assess diagnostic accuracy of preoperatively performed magnetic resonance (MR) imaging for detection of tumor extent in a large patient population with histopathologically proved retinoblastoma.

MATERIALS AND METHODS

Local ethics committee approval and informed consent were not required for retrospective review of patients' images and records. Fifty-eight eyes in 28 girls (mean age, 21 months; range, 2-59 months) and 28 boys (mean age, 24 months; range, 2-76 months) with retinoblastoma were retrospectively reviewed by one radiologist on unenhanced T1-weighted, dual-echo T2-weighted, and gadolinium-enhanced T1-weighted MR images. MR imaging parameters such as growth pattern, anterior chamber hyperintensity, and involvement of choroid, ciliary body, optic nerve, sclera, orbital fat, and pineal gland were determined. Tumor volume was measured and correlated to metastatic risk factors. Imaging and pathologic findings were compared. Statistical analysis was performed by using logistic regression with log likelihood ratio chi(2) test or Fisher exact test.

RESULTS

Choroidal invasion was suspected with MR imaging in 21 eyes; findings were false-positive in 13 eyes and false-negative in three (73% sensitivity, 72% specificity, 72% accuracy). Anterior chamber hyperintensity on T1-weighted MR images obtained after contrast agent administration correlated well with clinical presence of reactive neovascular processes. MR imaging findings were true-positive in 21 of 32 eyes with proved prelaminar optic nerve invasion (66% sensitivity) and false-positive in one (96% specificity, 79% accuracy). Postlaminar optic nerve invasion was correctly detected in two eyes; in two other eyes, this metastatic risk factor was missed (50% sensitivity, 100% specificity, 97% accuracy). Scleral and extrascleral tumor invasion were correctly excluded in all eyes. Tumor volume was statistically associated with prelaminar optic nerve invasion (P = .001) and choroidal invasion (P = .031).

CONCLUSION

MR imaging is accurate for tumor staging and detection of metastatic risk factors; detection of intraocular tumor infiltration remains difficult. Tumor volume, measured with MR imaging, was associated with prelaminar optic nerve and choroidal involvement.

MR imaging of the globe and optic nerve

The superb contrast resolution of MR imaging has significantly improved radiologists' ability to evaluate the anterior visual pathways and globe. Optimal imaging of the orbit requires the radiologist to have a working understanding of the clinical questions the ophthalmologist needs answered. In this article, basic orbit anatomy, MR imaging protocols for the orbit, and common clinical scenarios encountered when imaging the orbit are reviewed, with a focus on the optic nerve and globe.

Leucocoria na infância: diagnóstico diferencial por ultra-sonografia, tomografia computadorizada e ressonância magnética

Leucocoria é um reflexo pupilar anormal à luz incidente, em geral relacionado a uma anormalidade intra-ocular, ocorrendo freqüentemente em crianças. A avaliação da criança com leucocoria deve ser feita principalmente para excluir o diagnóstico de retinoblastoma (causa da metade dos casos). Os autores apresentam os aspectos clínicos e de imagem essenciais ao diagnóstico das causas mais comuns de leucocoria.

Retinoblastoma: Abnormal gadolinium enhancement of anterior segment of eyes at MR imaging with clinical and histopathologic correlation

PURPOSE

To evaluate abnormal gadolinium enhancement of the anterior segment of eyes harboring retinoblastoma at magnetic resonance (MR) imaging and correlate this finding with clinical and histopathologic information.

MATERIALS AND METHODS

Three neuroradiologists examined 46 eyes with 34 retinoblastomas in 25 children on gadolinium-enhanced T1-weighted orbital MR images obtained shortly after contrast material injection for evidence of abnormally high signal intensity in the anterior segment. Twenty-two of the 34 affected eyes were enucleated, and six of these 22 eyes were treated with preenucleation adjuvant therapy. Thus, correlation of the clinical, MR imaging, and histopathologic findings in 16 eyes was performed. Statistical analysis was performed with nonparametric methods (Fisher exact test). P <.05 indicated a statistically significant difference.

RESULTS

Fourteen of the 34 affected eyes showed abnormal gadolinium enhancement of the anterior segment. Regarding the 16 eyes evaluated for statistical analysis, a significant correlation (P =.011) between abnormal gadolinium enhancement of the anterior segment and histopathologically documented optic nerve infiltration was noted. A trend toward an association between abnormal enhancement and elevated intraocular pressure (P =.215), tumor growth beyond the equator at MR imaging (P =.125), and histopathologically proved iris neoangiogenesis (P =.182) also was noted. Histopathologic evidence of optic nerve and/or choroid infiltration correlated significantly (P =.001; sensitivity, 100% [nine of nine eyes]; specificity, 86% [six of seven eyes]) with abnormal enhancement.

CONCLUSION

Abnormal gadolinium enhancement of the anterior segments of eyes harboring retinoblastoma seems to indicate more aggressive tumor behavior.

Persistência hiperplástica do vítreo primitivo: avaliação por métodos de imagem

Persistência hiperplásica do vítreo primitivo (PHVP) é um desenvolvimento anormal, afetando crianças, resultante da falha de regressão do vítreo primitivo e dos vasos hialóides, com proliferação de tecido conectivo. A PHVP pode ter três variações: uma anterior, outra posterior e uma terceira com a combinação das duas. Clinicamente manifesta-se como leucocoria (reflexo branco pupilar) em um olho de dimensões reduzidas. Esta anomalia é usualmente unilateral e não associada com outros achados sistêmicos. Leucocoria, descolamento de retina, pregas retinianas e catarata podem confundir PHVP com outras afecções oculares que têm achados semelhantes. Retinoblastoma, catarata congênita, retinopatia da prematuridade e pseudogliomas são doenças com achados semelhantes aos da PHVP. A visualização direta dos remanescentes do sistema vascular hialóide fetal é a melhor evidência da lesão presente, se não fosse, muitas vezes impossivel, à fundoscopia, devido à opacidade do tecido. Nestes casos, a visualização indireta, por meio de ultra-sonografia, tomografia computadorizada e ressonância magnética, fornece o diagnóstico. As imagens obtidas por estes métodos proporcionam, ainda, informações e diagnóstico diferencial com outras doenças, particularmente com o retinoblastoma. Os autores fazem uma revisão na literatura e apresentam um estudo iconográfico das imagens e achados da PHVP.

MR imaging of the globe and optic nerve

MR imaging is an important tool for the evaluation of the optic nerve and globe. A working knowledge of the clinical questions an ophthalmologist faces helps radiologists optimize MR imaging protocols and focus their attention on the important clinical issues.

Coats disease: smaller volume of the affected globe

PURPOSE

To determine whether a significant smaller volume of the affected globe, compared with that of the normal globe, is an additional feature of Coats disease.

MATERIALS AND METHODS

Ocular globe volume was assessed in 13 children (11 boys, two girls; age range, 0.6-14 years; mean age, 4.1 years) with Coats disease and in 18 (eight boys, 10 girls; age range, 0.5-12 years; mean age, 3.6 years) with unilateral retinoblastoma. Orbital computed tomographic scans were available for all children; magnetic resonance images were available for 11 children-seven with Coats disease and four with retinoblastoma. For volume estimation, anteroposterior and equatorial diameters of ocular globes were measured. Statistical analysis was conducted with univariate and multivariate methods.

RESULTS

In children with Coats disease, the mean volume of the affected globe was 4,877.03 mm(3) (range, 2,951.47-6,284.70 mm(3)) and that of the normal globe, 6,018.00 mm(3) (range, 4,062.32-7,509.26 mm(3)). In children with retinoblastoma, the mean volume of the affected globe was 4,557.06 mm(3) (range, 1,612.01-7,463.00 mm(3)) and that of the normal globe, 4,402.11 mm(3) (range, 1,360.46- 7,463.00 mm(3)). The Coats disease population had a significantly smaller volume of the affected globe (z = -3.1009; P =.002); the retinoblastoma population did not have a statistically significant trend toward a bigger affected globe volume (z = -1.7064; P =.088). The difference between the affected globe volume and the normal globe volume in children with Coats disease was the only significant independent variable (P =.005).

CONCLUSION

A significantly smaller volume of the affected globe is an additional feature of Coats disease.

Axial growth of the fetal eye and evaluation of the hyaloid artery: in utero ultrasonographic study

The aims of this prospective, cross-sectional study were to report axial ocular growth during human gestation, to determine the presence of the hyaloid artery (HA) and its blood flow, and to provide a timetable for HA regression. The study group comprised 231 low-risk singleton pregnancies between 14 and 38 weeks' gestation. Ocular axial length (OAL), anterior chamber depth (ACD) and posterior chamber depth (PCD) were measured using high-resolution ultrasound. The growth of these eye segments in correlation with gestational age (GA) was established. The presence of the HA and its regression were determined. By using power Doppler, ultrasound blood flow within the HA was estimated. HA regression is a gradual process that is not evident before 18 weeks' gestation. In all fetuses beyond 29 weeks' gestation, no HA could be detected (P<0.001). Blood flow within the HA was documented only until the 16th week of gestation. The correlation coefficients, r=0.924, 0.784 and 0.929, for OAL, ACD and PCD, respectively, were found to be highly statistically significant (P<0.0001). The present data offer normative measurements of the fetal axial eye lengths, timetable for HA regression and flow cessation.

Ultrasonographic diagnosis of persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous in two dogs

Ultrasonography was performed on a Basset hound and a Doberman clinically suspected of persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous. In both dogs, hyperechoic lenses with a triangular-shaped echodense structure retrolentally were visible, and a very thin hyperechoic strand was seen penetrating the anechoic vitreous from this retrolental tissue to the area of the optic nerve. Using color Doppler imaging, blood flow was evident in parts of the retina in both dogs. With power Doppler imaging there was blood flow in the lens and hyperechoic strand of the Basset hound on the first examination; whereas, on re-examination 5 months later, this was not found. Other abnormalities, such as retinal detachment, endophthalmitis, vitreous hemorrhage, microphthalmia, and posterior neoplasia could be excluded.

B mode ultrasonography--spectrum of paediatric ocular disease

BACKGROUND

Despite having appropriate sonographic equipment available many radiologists remain unfamiliar with B mode sonography of the eye.

OBJECTIVE

This article reviews the advantages and disadvantages of B mode sonography of the paediatric eye. We illustrate the spectrum of eye abnormalities occurring in paediatric practice and the sonographic appearance of clinical entities for which sonography is appropriate.

MATERIALS AND METHOD

We reviewed our experience of eye sonography within a paediatric radiology department over 8 years. A total of 212 sonographic examinations were performed on 206 eyes in 103 children, aged from 3 days to 16 years (mean 4.6 years).

RESULTS

Sonography was well tolerated by the children, was a very useful imaging modality and was the only diagnostic imaging modality required in 94%. Supplementary computed tomography (CT) was performed in ten of 206 eyes (5%) and magnetic resonance imaging (MR) was performed in two of 206 eyes (1%).

CONCLUSIONS

B mode sonography is a very useful imaging modality for suspected ocular or orbital pathology in children and is often the appropriate first line investigation following clinical evaluation. Radiologists familiar with sonography of the eye can provide valuable support to their ophthalmology colleagues.

The pathological globe: clinical and imaging analysis

Categorizing globe lesions based on clinical presentation can suggest a short list of diagnostic possibilities. Imaging of the globe with ultrasound, CT and MRI is presented with a focus on key differential points. The radiologist can then efficiently tailor the examination in order to differentiate among the diagnostic possibilities.

MR imaging in retinoblastoma

We studied the appearance of retinoblastoma on unenhanced and gadolinium-enhanced images and the accuracy of tumour staging with MR imaging. The MR images were obtained in 18 children with retinoblastoma and compared with histopathological findings after enucleation. The MR imaging included T1-weighted and dual-echo T2-weighted images before, and T1-weighted images after, gadopentetate dimeglumine injection. The contrast between tumour and ipsilateral vitreous strongly increased (57 %) after gadolinium on T1-weighted images (p = 0.004). Tumour was strongly hypointense as compared with ipsilateral vitreous in all patients using heavily T2-weighted (TE = 120 ms) images (p = 0.001). The estimated T2 of tumour (mean 96 + 14 ms) did not correlate with histological grading or degree of calcification. Unenhanced T1-weighted MR images rightfully excluded extrascleral growth in 16 of 16 cases, but its presence was confirmed after enucleation in only one of 2 abnormal MR scans. Invasion of the optic nerve behind the cribriform plate was confirmed in 2 of 3 abnormal gadolinium-enhanced MR scans, but also in 1 of the 15 cases in which MR images were normal. The T2-weighted images were useful in assessing retinal detachment. We conclude that heavily T2-weighted images, unenhanced T1-weighted images and gadolinium-enhanced T1-weighted MR images are complementary in characterizing and staging retinoblastoma.

Orbital sonography in children

Orbital sonography with color-flow Doppler imaging is a relatively new technology with significant application in the pediatric patient. This review stresses the primary indications for pediatric ophthalmic ultrasound and also discusses those instances where the use of ultrasound supplements other imaging studies.