L. Manfrè

Plain film, CT and MRI sensibility in the evaluation of intraorbital foreign bodies in an in vitro model of the orbit and in pig eyes.

Abstract. Detection and characterization of intraorbital foreign bodies (IFB) is fundamental in acute trauma setting, preventing inflammatory sequelae or complications related to IFB movements when a MRI study is planned. Papers concerning plain film and CT sensibility in IFB detection show controversial results. For this reason we investigated plain film, CT and MRI sensibility in the evaluation of IFB. For an in vitro model, specimens of dry and fresh wood, glass, iron, plastic and graphite were immersed in animal lard and in a 0.9 % sodium chloride plus 3.5 g/dl human serum albumin solution. Specimens of different size and nature where also implanted into enucleated pig eyes. Air bubbles were introduced also. Plain film, CT and MRI investigation were performed. Plain films underestimated intraocular IFB as plastic, fresh or dry wooden IFB were not demonstrated. The CT study was always able to depict and differentiate IFB according to the attenuation values. Severe artefacts prevented demonstration of iron, glass and graphite IFB on MRI, whereas plastic or wooden IFB were always detected. Despite radiographs have been suggested as a prerequisite for MR imaging, because our results showed plain film to underestimate radiolucent IFB, we suggest CT as the modality of choice when IFB has to be ruled out.

Idiopathic intracranial hypertension: orbital MRI

The case is reported of a patient with idiopathic intracranial hypertension examined with magnetic resonance imaging. Marked enhancement of the optic nerve heads was found, which might be related to blood-retinal barrier breakdown related to a sudden rise in intracranial cerebrospinal fluid pressure.

Blood-ocular barrier damage: use of contrast-enhanced MRI

Abstract. The blood-ocular barrier (BOB) shares similar neuroepithelial origin, microanatomy and functions with the blood-brain barrier. There are many natural (e. g. diabetes, hypertension) or iatrogenic (chemotherapy, retinal photocoagulation) conditions which can cause a BOB breakdown, resulting in visual acuity impairment or loss. The authors examined 42 patients affected by BOB damage in different pathological conditions. All patients previously underwent a conventional fluoroangiographic (FA) study. Nine patients with normal FA exam were evaluated also. Despite normal MRI findings immediately after Gd-DTPA injection, contrast leakage into the vitreous body or into the aqueous fluid was demonstrated in delayed scans (40–50 min after contrast administration), proving the existence of a BOB damage (sensitively 94 %). Although FA exam remains the choice modality in BOB breakdown demonstration, we propose MRI as a useful diagnostic tool when optic media opacity (cataract, haemovitreous, intraocular silicon oil) occurs, preventing direct retinal fundus imaging and/or an early screening tool.

Trigeminal neuralgia and cerebellopontine-angle lipoma in a child.

Trigeminal neuralgia and cerebellopontine‐angle lipomas are very rare in children. We describe the history and findings of an 8‐year‐old boy with right trigeminal neuralgia and a lipoma detected by magnetic resonance imaging at the level of the root‐entry zone of the right seventh cranial nerve. We propose a possible mechanism of infiltration of the trigeminal rootlets by the lipoma.

MRI of the inner ear: use of modified GRASS and fast spin-echo sequences

Abstract We report our experience with MRI of the normal and pathological inner ear with fast spin-echo and modified gradient recalled at steady state sequences. Although earlier studies on temporal bone MRI were discouraging, improvements in MR technology combined with the use of paramagnetic contrast media can make MRI a useful diagnostic tool for the assessment of inner ear pathology. Conventional spin-echo imaging seems not to be the modality of choice because of the relatively thick slices and the long acquisition times.

Imaging of “Malignant” External Otitis

“Malignant” external otitis or necrotizing external otitis (NEO) is a rare and severe infection of the external auditory meatus, causing destructive changes of the petrous bone, infiltrating inframastoid and intracranial tissues, with potentially lethal consequences. Five male diabetic patients, aged 61 to 85 years-old (mean age was 74 y.o), referred with biopsy-proven NEO, underwent CT and MRI studies for the assessment of the extension of the disease. Clinical data concerning the examined patients are summarized in table 1. Contrast-enhanced MRI does not seem to help in differentiating granulation from neoplastic tissues, as both demonstrate inhomogeneous enhancement. In conclusion, NEO remains a life-threatening disease and early diagnosis is necessary for adequate pharmacological and hyperbaric therapy. Although non-specific, MRI appears to be the choice modality in demonstration of the extension and follow-up of NEO and related complications. CT, however, still maintains a complementary role in the assessment of bony erosion secondary to the disease.

Rheumatoid Arthritis: Evaluation of Temporomandibular Joint Abnormalities with MR Imaging

It is well known that the temporomandibular joint (TMJ), as well as other joints, may be affected in patients with rheumatoid arthritis (RA). Conventional radiographic methods can be used in the assessment of bone damage but its usefulness is limited as the soft tissue involvement cannot be demonstrated. Many reports have shown the potential of magnetic resonance imaging in the evaluation of different TMJ components, all of which are often compromised in rheumatic disease; moreover MR imaging is superior for depicting advanced stages of rheumatic disease with various degrees of disc destruction. The purpose of this study was to evaluate the role of MR imaging in the assessment of RA. MR imaging of the TMJ was performed on 14 patients (11 women and 3 men, aged 36–79 years, mean 57.5) with diagnosed RA in stages 2 and 3 according to Steinbroker criteria. Both TMJs were evaluated in ten patients. A total of 24 TMJs were studied in this group of patients. Informed consent was obtained in each case. The goal of MR is not only to facilitate a diagnosis of rheumatoid arthritis, which may be done using laboratory and clinical parameters, but to assess the extent of the early soft-tissue and bone manifestations of the inflammatory process and to identify the stage of the disease.

Orbital varices: a tricky diagnosis in MRI

Orbital varix (OV) is a rare condition causing intermittent positional exophthalmos. Because of low venous pressure, OVs tend to collapse, being frequently undetectable in routine CT or MRI examinations. We describe one case of giant intraorbital varix studied with CT and MRI techniques.

MR Imaging in Intrinsic Tectal Tumours

This article presents some anatomic and neuroradiologic clues in the identification of intrinsic tectal tumours and the main related problems of differential diagnosis. The majority of intrinsic tectal lesions are low-grade gliomas that have been recognized as a potential cause of late-onset aqueductal stenosis. The superb sensitivity of magnetic resonance (MR) imaging and its multiplanar imaging capability allow an optimal diagnostic accuracy in the tectal region. For this reason, MR imaging should be included in the work-up of all patients with neurological findings of brain stem dysfunction and late-onset aqueductal stenosis. Tectal gliomas particularly merit an accurate MR long-term follow-up monitoring, since they may ultimately show evidence of progressive growth and require therapeutic intervention to maintain disease control.

Transcranial Colour Doppler Ultrasound of Cerebral Arteriovenous Malformations in Patients with Persistent Migraine

The use of transcranial color Doppler ultrasound (TCCD) in the evaluation of children with arterio-venous intracranial malformations (AVM) has been previously described, but only recently has the use of TCCD been extended to adults. Our Department, with the contribution of the University centre for migraine treatment, has used TCCD experimentally used in 100 patients with persistent migraine resistant to therapy, for the evaluation of TCCD sensitivity in detecting flow hemodynamic abnormalities. Correlating with the normal flow measurement findings of the cerebral vessels 2/100 (2%) patients, who underwent TCCD examination, showed direct and indirect signs suggesting cerebral vessels anomalies, that were correlated with AVM.