Perfusion MRI in normal and abnormal pituitary gland. A preliminary study.

Perfusion MRI (magnetic resonance imaging) of the pituitary gland was performed in 20 healthy volunteers and 63 patients with various lesions involving the pituitary gland. All patients underwent sequential contrast-enhanced MRI using spoiled gradient recalled sequences with high temporal resolution (7 seconds). Four pituitary areas (pituitary stalk, posterior lobe, postero-superior, and antero-inferior adenohypophysis) were tested with a selected region of interest. Maximal contrast percentual variation was calculated. The timing of enhancement in normal patients matched perfectly with normal pituitary vascularization. Abnormal timing in pathological condition was investigated.

Anatomia e patologia del labirinto membranoso studio con sequenze RM sensibili al flusso

Nonostante i deludenti esordi nella valutazione delle strutture labirintiche costituenti l'orecchio interno, la risonanza magnetica costituisce oggi, grazie anche al miglioramento dell'hardware e del software disponibili, una modalità diagnostica di grande efficacia non solo nell'analisi della patologia espansiva o infiammatoria coinvolgente il VII ed VIII nervo cranico, ma anche nella valutazione delle alterazioni patologiche del segnale endolabirintico in rapporto a focolai emorragici o, come recentemente dimostrato mediante uso di Gd-DTPA, nell'analisi delle alterazioni a carico della capsula oticanella fase spongiotica dell'otosclerosi. Tuttavia, lo scarso contrasto esistente tra liqui…

The Role of Magnetic Resonance Imaging in Central Hearing Deficits: Beyond the Acoustic Schwannoma

Acoustic schwannoma is assumed to be the most common cause of sensory-neural hearing loss (SNHL), and many papers have described the role of magnetic resonance imaging (MRI) in the diagnosis of cerebello-pontine angle (CPA) tumours, particularly schwannoma. We retrospectively examined 72 patients complaining of different clinical syndromes and SNHL or different kinds of acoustic impairment who underwent MRI brain study excluding the presence of acoustic schwannoma and other CPA masses. In conclusion, although acoustic schwannoma is the most common cause of acquired HD, a lesion involving the neural centers of the acoustic pathway can also determine SNHL or HD. Considering the high sensitiv…

MRI findings and evoked potentials in patients with myotonic dystrophy versus facioscapulohumeral dystrophy

Evoked potentials recordings have been applied to many neurological disorders, localizing the lesions in the central nervous system (CNS) pathways. Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive degenerative disease involving the muscles of the face and shoulders. On the contrary, myotonic distrophy (MD), the most frequent and severe myotonic disease, is caracterized by myotonia (delay of relaxation after voluntary contraction), muscular atrophy and dystrophic changes in non-muscular tissues. In the present investigation, patients with clinically and electromyographically verified FSHD and MD were examined using somatosensory evoked potentials (SEP) and brainstem aud…

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.

Familial Cavernous Angioma: MRI Study of three Generation in two Italian Families and Literature Review

According to recent magnetic resonance imaging studies, cavernous angioma (CA) seems to involve the central nervous system in 0.5%-1% of the population 1 - in a similar percentage to a large autopsy series 2.The incidence of familial CA is unknown 3: the first paper in the literature concerning familial CA was published in 1936 5: recently however, thank to the widespread use of MR, at least 13 families have been described.We report MR findings in two Italian families with familial CA.In conclusion, familial CA should be included in the differential diagnosis of patients with intracranial haemorrhage, seizures or cerebrovascular disease.

Gd-DTPA in blood-ocular barrier damage: a new diagnostic tool for future application in MRI?

The blood-brain barrier is not the only neuroepithelial blood filter in the body: the eye too is supported by a highly specialised microvascular filter, the so-called blood-ocular barrier (BOB). The BOB is actually divided into a blood-aqueous (BAB) and a blood-retinal (BRB) barrier, filtering the aqueous fluid and biological supplies, respectively, to the retina. The authors’ purpose was to study the possibility of imaging BAB or BRB damage by contrast-enhanced MRI: they examined 21 patients with a 0.5 T system and surface coil. Despite the normal findings in the damaged eyes immediately after a Gd-DTPA bolus, delayed contrast-enhanced MRI was able to show focal or diffuse barrier damage.

Calibro dei sifoni carotidei e asimmetria del poligono di Willis: Studio Angio-RM

A differenza dell'Angiografia, l'esame Angio-RM consente la simultanea visualizzazione dei vasi del poligono. Si è valutata la correlazione esistente tra calibro dei sifoni e asimmetrie di sviluppo del poligono nella popolazione normale. Sono stati esaminati 3 casi di occlusione totale di una carotide. 120 pazienti privi di patologie vascolari o neoplastiche sono stati sottoposti ad esame Angio-RM 3DTOF con Magnetization Tranfer e TONE. Sono state valutate le immagini di sorgente e 3DMIP, prima e dopo sottrazione dei pixel non vascolari. I pazienti sono stati suddivisi in 5 gruppi: I = aplasia di A1, II = ipoplasia di A1, III = lieve asimmetria di A1, IV ? arteria comunicante posteriore fe…

Ventrolateral Compression of the Brain Stem in Essential Hypertension: MR Angiography Study

Our purpose was to evaluate neurovascular compression at the level of ventrolateral medulla and NVC with the IXth and the Xth cranial nerves in patients with essential hypertension and in healthy volunteers using high resoluted Spoiled Recalled Gradient Echo (SPGR) sequences, allowing the detection of stationary tissues and moving spins. Thirty patients (19 men and 11 women) with essential hypertension were examined. Patient's ages ranged from 24 to 64 years-old (mean age was 48 y.o.). Patients older than 65 were excluded. The average of systolic blood-pressure of hypertensive patients was 183 ± 10 mmHg, while the diastolic pressure was 98 ± 10.5 mmHg. In conclusion, we consider axial sing…

Fast Spin Echo e Spin-Echo

Uno dei maggiori problemi connessi alio studio del SNC di pazienti in età pediatrica con RM è indubbiamente costituito dalla durata dell'esame stesso, che impone sovente la necessità di una sedazione farmacologica del paziente e limita allo stretto indispensabile il numero delle acquisizioni effettuate. Appare pertanto facilmente intuibile l'entusiasmo rivolto verso nuovi tipi di sequenze che presentino quale caratteristica principale una drastica riduzione dei tempi di acquisizione pur mantenendo un'affidabile qualità diagnostica. Le sequenze di tipo Fast-Spin-Echo (FSE) costituiscono il successivo sviluppo delle sequenze denominate RARE (Rapid Acquisition Relaxation Enhanced) descritte d…

MR imaging of the brain: findings in asymptomatic patients with thalassemia intermedia and sickle cell-thalassemia disease.

The purpose of this study was to evaluate the spectrum of MR findings of the brain in asymptomatic patients affected with thalassemia intermedia or sickle cell-thalassemia disease to prevent brain damage by identifying patients at risk for stroke so that transfusional or pharmacologic treatment could be implemented.Forty-one asymptomatic patients who were younger than 50 years and were affected by minor hemoglobinopathies underwent MR imaging of the brain. Ischemic lesions were classified as small, medium, or large and as single or multifocal. Atrophic changes were graded subjectively as mild, moderate, or severe. A grade of brain damage was assigned to every patient. The frequency and seve…

Sequential contrast-enhanced magnetic resonance imaging in the diagnosis of growth hormone deficiencies

The purpose of the present study was to assess the presence and the time-course of contrast-enhancement in the pituitary gland and pituitary stalk of 24 patients with isolated growth hormone (GH) deficiency and multiple pituitary hormone deficiency. The patients were evaluated clinically (auxological measurements), endocrinologically (spontaneous GH secretion and GH stimulation tests) and with conventional MRI scans. In addition, fast-framing dynamic magnetic resonance imaging (MRI) with Gd-DTPA enhancement was used to quantitate the time course of contrast enhancement within the neurohypophysis, pituitary stalk, postero-superior adenohypophysis and antero-inferior adenohypophysis. In 3 pat…

MRI of inner ear fluids using modified GRASS sequences: a useful tool in the assessment of the normal and pathological labyrinth

MRI is acquiring a progressively more important role in the investigation of petrous bone disease. Nevertheless, despite the extensive use of MRI in the detection of inflammatory or neoplastic involvement of the seventh and eighth cranial nerves, conventional spinecho images cannot be considered the modality of choice in inner ear imaging “Steady-state sequences” are known to be motion sensitive. By setting a very short repetition time, a large flip angle and a long echo time, one can obtain a sequence sufficiently sensitive to the slow movement of endo- and perilymph. We report our experience in MRI of normal and pathological inner ear with modified GRASS sequences.

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 …

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.

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 intr…

Intravenous gammaglobulin treatment in chronic progressive multiple sclerosis

Su di un caso di Schwannoma primitivo intraorbitario

Gli Schwannomi costituiscono il 6,8% dei tumori intracranici ed originano solitamente dai nervi sensitivi, con particolare predilezione per il V e VIII nervo cranico. Uno schwannoma a partenza da un nervo oculomotore costituisce invece una evenienza piuttosto rara, e solo 17 casi di s. del III n.c. sono stati documentati in letteratura. Sono da considerare ancora più rari gli schwannomi ad esclusiva localizzazione intraorbitaria (1–5, 7% dei tumori orbitari). Solitamente tipico dell'uomo adulto, con l'eccezione dei soggetti affetti da Neurofibromatosi di tipo 2, lo schwannoma orbitario esordisce solitamente come un processo espansivo a lento accrescimento, determinante diplopia, esoftalmo …

Accumulo di ferro a livello ipofisario in pazienti affetti da beta-talassemia major: Aspetti RM

Gli autori si propongono di valutare le modificazioni del segnale RM a livello ipofisario nella emosiderosi secondaria in pazienti affetti da beta-talassemia major. Lo studio è stato condotto prospetticamente su un gruppo di 20 pazienti in regime alto-trasfusionale e trattamento ferro-chelante e su 10 volontari sani come gruppo di controllo. Gli esami RM sono stati condotti con apparecchiatura a magnete superconduttivo a 0,5T con sequenze SE TI-dipendenti e GRE TE*-dipendenti. Il sovraccarico di ferro è stato valutato mediante il dosaggio della ferritina sierica. è stata effettuata una valutazione quantitativa delle immagini RM SE T1- e GRE T2*-dipendenti attraverso la misurazione, mediant…

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.

Brain Morphometry and Psychobehavioural Measures in Autistic Low-Functioning Subjects

In the last two decades neurological research has significantly increased knowledge on the neuroanatomic bases of autism. Several autopsy and quantitative magnetic resonance imaging (MRI) studies have reported central nervous system (CNS) abnormalities which may underlie the social, language and cognitive dysfunction typical of the autistic disorder.Despite the wealth of evidence that the “autistic brain” is different from normal in a number of structures, the relationship between the severity of the developmental impairment in autism and the degree of the brain abnormality remains unknown.The aim of the present study is to correlate the areas of some brain regions, as calculated on the bas…

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.

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

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.