MR imaging findings of endophthalmitis

Magnetic resonance imaging in paediatric ocular and orbital lesions: A pictorial review

Paediatric orbital lesions encompass a wide spectrum of benign and malignant entities that can arise from different components of the orbit. Clinical symptoms and signs are often nonspecific, and imaging plays a crucial role in the diagnosis and management. Ultrasonography has a limited role and radiation is a major concern with CT especially in the paediatric population. MRI is the modality of choice that avoids the radiation hazard and provides superior soft tissue contrast. The lesions can be localized using the 'compartment' approach which helps to narrow the list of differentials. MRI also provides critical information for management such as presence of perineural spread and intracranial extension. This article depicts the spectrum of Magnetic Resonance imaging findings encountered in paediatric ocular and orbital lesions.

Diffusion-weighted imaging of the orbit

Orbital lesions compose a heterogeneous group of pathologies that often present with non-specific imaging findings on conventional magnetic resonance imaging (MRI) sequences (T1-and T2-weighted). Accordingly, the application of diffusion MRI offers an opportunity to further distinguish between lesions along this spectrum. Diffusion-weighted imaging (DWI) represents the simplest and most frequent clinically utilised diffusion imaging technique. Recent advances in DWI techniques have extended its application to the evaluation of a wider spectrum of neurological pathology, including orbital lesions. This review details the manifestations of select orbital pathology on DWI and underscores specific situations where diffusion imaging allows for increased diagnostic sensitivity compared to more conventional MRI techniques. These examples also describe preferred management for orbital lesions identified by DWI.

ENDOGENOUS ENDOPHTHALMITIS CAUSED BY GROUP B STREPTOCOCCUS IN A HEALTHY, TERM NEONATE

PURPOSE

The purpose of this study was to describe an unusual case of unilateral, endogenous endophthalmitis in an otherwise healthy, term neonate.

METHODS

A 3-week-old otherwise healthy, term male infant was referred to St. Louis Children's Hospital for a second opinion of presumed panuveitis of the right eye.

RESULTS

Diffusion-weighted magnetic resonance imaging demonstrating purulent intraocular contents facilitated the diagnosis of endophthalmitis. Examination of surgical vitreous samples by staining and cytology demonstrated gram-positive bacterial cocci in short chains, thereby confirming endophthalmitis. Polymerase chain reaction testing of vitreous fluid identified Streptococcus agalactiae , despite an unremarkable systemic workup and a negative prepartum maternal Group B streptococcal screen.

CONCLUSION

Endogenous endophthalmitis is a rare but devastating cause of vision loss in otherwise healthy, term neonates. Prompt diagnosis may be facilitated by magnetic resonance imaging and diagnostic vitreous biopsy.

Clinical and CT comparative study of invasive and non-invasive Klebsiella pneumoniae liver abscesses

AIM

To investigate the clinical and CT features of invasive and non-invasive Klebsiella pneumoniae liver abscesses (KPLA).

MATERIALS AND METHODS

Fifty-one patients with KPLA diagnosis including 26 invasive and 25 non-invasive KPLA cases were analysed retrospectively. All patients underwent routine abdominal unenhanced and three-phase enhanced CT examinations. The CT images were assessed by two experienced radiologists by examining location, number, size, septa, texture, gas in the pus cavity, portal phlebitis, thrombophlebitis, and abnormal perfusion during the arterial phase. Statistical differences for continuous characteristics were analysed with independent samples t-test or Wilcoxon's test, while the chi-square test or Fisher's exact test was used for categorical variables. A logistic regression analysis was performed to determine the independent related factors of invasive KPLA and receiver operating characteristic (ROC) curves were used for assessment.

RESULTS

Age and type 2 diabetes were significantly different between the patients with invasive and non-invasive KPLA. In addition, patients with invasive KPLA had lower levels of platelet and total protein (p<0.05) and higher total bilirubin compared to patients with non-invasive KPLA. Throughout the regression analysis, total bilirubin, platelets, and total protein demonstrated an area under the ROC curves of 0.717, 0.745, and 0.728, respectively.

CONCLUSION

Invasive KPLA occurs predominantly in younger patients with type 2 diabetes. Laboratory tests revealed low platelet and total protein levels and high total bilirubin levels. If the patient with KPLA exhibits hepatic venous thrombophlebitis with no abnormal enhancement around the abscess in the arterial phase of enhanced CT, it indicates that the abscess has invaded.

Autoimmune disease of head and neck, imaging, and clinical review

Autoimmune disease of the head and neck (H&N) could be primary or secondary to systemic diseases, medications, or malignancies. Immune-mediated diseases of the H&N are not common in daily practice of radiologists; the diagnosis is frequently delayed because of the non-specific initial presentation and lack of familiarity with some of the specific imaging and clinical features. In this review, we aim to provide a practical diagnostic approach based on the specific radiological findings for each disease. We hope that our review will help radiologists expand their understanding of the spectrum of the discussed disease entities, help them narrow the differential diagnosis, and avoid unnecessary tissue biopsy when appropriate based on the specific clinical scenarios.

Imaging of Painful Ophthalmologic Disorders

Cross-sectional imaging with computed tomography (CT) and MRI are diagnostic examinations useful in the diagnosis of painful ophthalmologic disorders and their potential complications. CT is a first-line imaging study for suspected orbital infections, particularly useful in differentiating preseptal cellulitis and orbital cellulitis and detecting complications such as orbital abscess. When compared with CT, MRI is better for orbital soft tissue evaluation, particularly useful for optic neuritis, ocular diseases such as endophthalmitis, and invasive fungal rhinosinusitis with orbital involvement. CT angiography is the preferred noninvasive imaging modality for the detection and classification of carotid cavernous fistula.

Clinical features and MRI characteristics of retinal detachment in dogs and cats

The aim of this retrospective observational study was to characterize the MRI appearance of retinal detachment (RD) in a sample of dogs and cats. Study inclusion was based on the following medical record criteria: (a) had a diagnosis of RD in at least one eye by either funduscopic examination or ocular ultrasound and had an MRI evaluation including the eyes, or (b) had a diagnosis of RD documented in an MRI report for at least one eye and also had a clinical eye examination. Eighteen patients (12 dogs, 6 cats) and 35 eyes met the inclusion criteria, although four eyes that were clinically examined could not be visualized funduscopically and did not have ocular ultrasound performed (criterion 2). The MRI and clinical diagnosis (via either funduscopy or ultrasound) of RD/no RD was concordant in 27 of 31 eyes (87%). Qualitatively, RD appeared as a variable intensity curvilinear structure located internal and adjacent to the sclera on all sequences and was best delineated on T2W sequences. RDs inconsistently contrast enhanced and, although there was no statistical difference, subjectively appeared more clearly delineated on dorsal and parasagittal images. In conclusion, findings from the current study support using MRI as an ancillary diagnostic test for confirmation or further characterization of RD in dogs and cats.

CT and MR imaging of orbital inflammation

PURPOSE

Orbital inflammation can be idiopathic or in the context of a specific disease and it can involve different anatomical orbital structures. On imaging, inflammatory disease is frequently mistaken for infection and malignant tumors, and its underlying cause is often not determined. Through this article we aim to improve orbital inflammation diagnosis and underlying inflammatory diseases recognition.

METHODS

The imaging protocols and characteristics of orbital inflammation were reviewed.

RESULTS

A decision tree for the evaluation of these patients is provided. First, a combination of clinical and radiological clues is used to recognize inflammation, in particular to differentiate it both from orbital infection and tumor. Subsequently, different radiological patterns are recognized, often allowing the differentiation of the several orbital inflammatory diseases.

CONCLUSION

The use of adequate imaging protocols and subsequent evaluation allow the recognition of an orbital lesion as inflammatory and the diagnosis of the underlying inflammatory disease. All in all, a proper treatment can be established, and at times, a biopsy can be avoided.