Imaging of post-surgical treatment and of related complications in spinal trauma

Spinal trauma is a devastating event with a high morbidity and mortality. The rationale of imaging is to diagnose the traumatic abnormalities and characterize the type of injury, to estimate the severity of the lesions, to evaluate the potential spinal instability. In case of spinal instability, the goals of operative treatment are decompression of the spinal cord canal and stabilization of the disrupted vertebral column. Particularly, diagnostic imaging, mainly by CT and MR, has a main role in the post-treatment evaluation. The neuroradiological evaluation of the postoperative spine requires a general knowledge of the surgical approach to each spinal region and of the normal temporal evolution of expected postoperative changes. The neuroradiologist should evaluate the devices implanted, their related complications and promptly alert the surgeon of acute complications, mainly vascular and infective. During the follow-up, it is mandatory to know and search chronic complications as pseudomeningocele, accelerated degenerative disease, arachnoiditis, peridural fibrosis. Knowledge of specific complications relating to each surgical approach will assist the neuroradiologist in interpretation of postoperative images.

Imaging of post-operative spine in intervertebral disc pathology

This work is an imaging review of spine after surgery with special regard to imaging modality in intervertebral disc pathology. Advances in imaging technology can be evaluated. Depending on the clinical question is asked to the radiologist, it is possible to evaluate post-operative patients with conventional radiology (X-ray), computed tomography and magnetic resonance. Main indications for each technique are analysed. Imaging is important in the diagnosis of many forms of spine pathology and plays a fundamental role in evaluating post-surgical effects of treatments, according to the imaging method which is used, both on spine and on its surrounding tissues (intervertebral discs, spinal cord, muscles and vessels).

Fistola vertebro-giugulare

Le fistole artero-venose vertebrali sono lesioni rare, generalmente secondarie a traumi, definite dalla presenza di una comunicazione anomala tra l'arteria vertebrale, o un suo ramo, ed una vena adiacente.

L'embolizzazione trans-arteriosa con palloncini staccabili è diventata il principale trattamento di elezione delle fistole artero-venose post-traumatiche. Comunque, in qualche caso, questo approccio può risultare difficile se la fistola appare associata a formazioni pseduoaneurismatiche. In questi casi l'embolizzazione con spirali può essere una valida alternativa.

Viene qui presentato un caso di fistola vertebro-giugulare post-traumatica trattata con palloncino staccabile e spirali dopo endoprotesi della vena a protezione del sistema venoso.

Tuber Cinereum Hamartomas and Gelastic Epilepsy

We studied five patients with gelastic epilepsy sustained by hamartoma of the tuber cinereum, submitted to EEG and Video-EEG study and to MR examination. The mechanism of ictal laughter, clinical associations and prognosis for seizure control are discussed.

Hamartomas should be always suspected when gelastic seizures occur, and appropriate diagnostic tools should be employed for their diagnosis. In patients presenting with gelastic epilepsy, MR assessment of the hypothalamic region is necessary to identify a hamartoma of the tuber cinereum.

Moreover, the resolution of MR imaging provides a basis to correlate some of the clinical manifestations with the anatomical disposition of the lesion within the hypothalamus.

Gelastic epilepsy seems to correlate with large broad-based hamartomas in relationship with the mamillary bodies. In these cases, surgical treatment should be considered when symptoms are not sufficiently responsive to medical therapy.

Ectopic Suprasellar Pituitary Adenoma

The occurrence of a pituitary adenoma located entirely outside the sella turcica, so-called ectopic adenoma, is extremely rare. We report a case of a non secreting-pituitary adenoma located above the diaphragma sellae, with no invasion into the sella turcica, confirmed at surgery. The tumor was initially treated unsuccessfully by operations via the transphenoidal route. After initial negative exploration by the transphenoidal route, the patient was successfully treated by an endoscopic endonasal transphenoidal approach extended to the tuberculum sellae and the posterior planum sphenoidale to access the suprasellar supraglandular region. A brief review of ectopic adenomas and a discussion of the preoperative diagnosis are presented.

Imaging of cervical extradural en-plaque meningioma. A case report

Meningioma is one of the most common spinal extramedullary tumors, largely intradural. An extradural localization is possible but less frequent. There are two morphologically different types of meningioma: one is round, and the other is the "en-plaque" form, that grows along the dura mater like a sheet. The "en-plaque" form, is unusual. We report on an unusual case of epidural and extraspinal "en-plaque" meningioma, describing the MRI and CT features and discussing the possible principal differential diagnosis (neurolymphomatosis, plexiform neurofibromas/schwannomas and metastasis).

Spontaneous regression of syringomyelia in a young patient with Chiari type I malformation

Syringomyelia is a disorder in which a cyst or cavity forms within the spinal cord. This cyst, called syrinx, can expand and elongate over time, destroying the spinal cord. We describe the case of a young patient with partial spontaneous regression of syringomyelia in Chiari I malformation, confirmed by magnetic resonance imaging three years after the diagnosis. During this period the patient did not experience any clinical symptoms. Although described in literature, spontaneous regression is an unusual event and very few cases have been reported. This case report supports the belief that conservative management together with both clinical and imaging periodic controls should be preferred in stable mild-symptomatic patients.

Magnetic resonance imaging in brachial plexus injury

Brachial plexus injury represents the most severe nerve injury of the extremities. While obstetric brachial plexus injury has showed a reduction in the number of cases due to the improvements in obstetric care, brachial plexus injury in the adult is an increasingly common clinical problem. The therapeutic measures depend on the pathologic condition and the location of the injury: Preganglionic avulsions are usually not amenable to surgical repair; function of some denervated muscles can be restored with nerve transfers from intercostals or accessory nerves and contralateral C7 transfer. Postganglionic avulsions are repaired with excision of the damaged segment and nerve autograft between nerve ends or followed up conservatively. Magnetic resonance imaging is the modality of choice for depicting the anatomy and pathology of the brachial plexus: It demonstrates the location of the nerve damage (crucial for optimal treatment planning), depicts the nerve continuity (with or without neuroma formation), or may show a completely disrupted/avulsed nerve, thereby aiding in nerve-injury grading for preoperative planning. Computed tomography myelography has the advantage of a higher spatial resolution in demonstration of nerve roots compared with MR myelography; however, it is invasive and shows some difficulties in the depiction of some pseudomeningoceles with little or no communication with the dural sac.

Endovascular treatment of cerebral aneurysms using the hydrocoil embolic system

HydroCoils are platinum helical coils coated with a layer of hydrophilic acrylic polymer (hydrogel), which on contact with blood causes disentanglement of polymer chains and expansion. We retrospectively reviewed a series of 29 patients harboring 29 cerebral aneurysms treated with the Hydrocoil Embolic System in the period 2004-2005, discussing the results of endovascular procedures in terms of safety and efficacy. The immediate post-procedure angiographic control demonstrated complete aneurysm occlusion in 21 cases (72.4%), near-complete occlusion in seven cases (24.1%), whereas in one case (3.4%) there was a procedure failure with major perfusion of the sac. Five patients (17.2%) experienced thromboembolic complications, including an asymptomatic lacunar stroke of the head of the caudate nucleus, a thalamic infarct following hypotension secondary to pulmonary edema, temporal ischemia secondary to vasospasm and a small right occipital ischemic lesion. Only one patient (3.4%) suffered a major ischemic accident. No other procedure-related complication occurred. Three-month follow-up control with MR angiography and 12-month follow-up angiography demonstrated no recurrence of aneurysms. Overall, after a mean follow-up of 12 months, the clinical outcome was good recovery in 26 patients (89.6%), moderate disability in three patients (10.3%) and no vegetative status or death. Our HydroCoil series supports the safety and midterm durability of hydrogel-coated aneurysm coils in the treatment of cerebral aneurysms.

Endovascular treatment of a small aneurysm of the superior cerebellar artery with a flow-diverter device. A case report

We describe the case of a 62-year-old woman who presented with a small fusiform left superior cerebellar artery (SCA) aneurysm. Aneurysms located on the SCA are uncommon and their presentation, natural history and clinical management are poorly understood. Reports on the endovascular or surgical management of SCA aneurysms are rare and usually incorporated in clinical series of basilar artery or posterior circulation aneurysms. The patient was treated by delivery of a flow-diverter Pipeline Embolization Device (PED - Chestnut Medical/ev3) at the origin of vessel. She had no procedural complications and the aneurysm volume was reduced. This paper presents additional evidence to literature reports suggesting that the new endovascular flow-diverter devices are an effective and well-tolerated treatment for complex aneurysms. Our review contributes data on the incidence of recurrence as a measure of long-term efficacy of this therapeutic approach.

Spontaneous resolution of Chiari type 1 malformation. A case report and literature review

We describe a 62-year-old woman who presented with a history of ataxia, dizziness and urinary urgency. Neurological examination disclosed a positive Romberg sign, ataxia and postural instability. A magnetic resonance imaging (MRI) scan showed Chiari type 1 malformation (CM1). Forty-eight months later, the patient was clinically improved and underwent a second MRI examination, which showed complete resolution of the Chiari 1 malformation. Spontaneous resolution of CM1 is exceptionally rare and has to be considered in the radiological and clinical management.

Endovascular treatment of vertebro-vertebral arteriovenous fistula. A report of three cases and literature review

This report describes endovascular approaches for occlusion of vertebro-vertebral arteriovenous fistula (VV-AVF) in a series of three cases and a review of the literature. Complete neuroimaging assessment, including CT, MR and DSA was performed in three patients (two female, one male) with VV-AVF. Based on DSA findings, the VV-AVF were occluded by endovascular positioning of detachable balloons (case 1), coils (case 2), or a combination of both (case 3) with parent artery patency in two out of three cases. In this small series, endovascular techniques for occlusion of VV-AVF were safe and effective methods of treatment. To date, there are no guidelines on the best treatment for VV-AVF. Detachable balloons, endovascular coiling, combined embolization procedures could all be considered well-tolerated treatments.

Paravertebral high cervical chordoma. A case report

Spinal chordomas are more often located on the midline and are associated with marked destruction of the vertebral bodies. We report a rare case of large cervical (C2-C3) right lateral paravertebral chordoma extending into the spinal canal through a very enlarged intervertebral foramen. The tumor was initially diagnosed as a mucous adenocarcinoma on a percutaneous needle biopsy. However, the neuroradiological features, including the well-defined tumor margins, the regular and sclerosing lytic bone changes with regular enlargement of the intervertebral C2-C3 foramen, were in favor of a more slowly growing lesion, such as schwannoma or neurofibroma. At surgery a well-demarcated capsulated tumor involving the nerve root was partially resected. Histology was in favor of a low-grade chordoma (Ki-67/MIB-1<1%). Postoperative proton beam therapy was also performed. The differential neuroradiological diagnosis is discussed.

Epidemiology and genetics of intracranial aneurysms

Intracranial aneurysms are acquired lesions (5-10% of the population), a fraction of which rupture leading to subarachnoid hemorrhage with devastating consequences. Until now, the exact etiology of intracranial aneurysms formation remains unclear. The low incidence of subarachnoid hemorrhage in comparison with the prevalence of unruptured IAs suggests that the vast majority of intracranial aneurysms do not rupture and that identifying those at highest risk is important in defining the optimal management. The most important factors predicting rupture are aneurysm size and site. In addition to ambiental factors (smoking, excessive alcohol consumption and hypertension), epidemiological studies have demonstrated a familiar influence contributing to the pathogenesis of intracranial aneurysms, with increased frequency in first- and second-degree relatives of people with subarachnoid hemorrhage. In comparison to sporadic aneurysms, familial aneurysms tend to be larger, more often located at the middle cerebral artery, and more likely to be multiple. Other than familiar occurrence, there are several heritable conditions associated with intracranial aneurysm formation, including autosomal dominant polycystic kidney disease, neurofibromatosis type I, Marfan syndrome, multiple endocrine neoplasia type I, pseudoxanthoma elasticum, hereditary hemorrhagic telangiectasia, and Ehlers-Danlos syndrome type II and IV. The familial occurrence and the association with heritable conditions indicate that genetic factors may play a role in the development of intracranial aneurysms. Genome-wide linkage studies in families and sib pairs with intracranial aneurysms have identified several loci on chromosomes showing suggestive evidence of linkage, particularly on chromosomes 1p34.3-p36.13, 7q11, 19q13.3, and Xp22. For the loci on 1p34.3-p36.13 and 7q11, a moderate positive association with positional candidate genes has been demonstrated (perlecan gene, elastin gene, collagen type 1 A2 gene). Moreover, 3 of the polymorphisms analyzed in 2 genes (endothelial nitric oxide synthase T786C, interleukin-6 G572C, and interleukin-6 G174C) were found to be significantly associated with ruptured/unruptured aneurysms: the endothelial nitric oxide synthase gene single-nucleotide polymorphisms increased the risk, while IL-6 G174C seemed protective. More recently, two genomic loci (endothelin receptor A and cyclin-dependent kinase inhibitor 2BAS) have been found to be significantly associated with intracranial aneurysms in the Japanese population; endothelin-1 is a potent vasoconstrictor produced by the endothelial cells. Until now, there are no diagnostic tests for specific genetic risk factors to identify patients who are at a high risk of developing intracranial aneurysms. Knowledge of the genetic determinants may be useful in order to allow clues on stopping aneurysm formation and obtain diagnostic tools for identifying individuals at increased risk. Further multicenter studies have to be carried out.

A rare case of intraosseous lipoma involving the sphenoclival region

We describe the case of a 23-year-old man whose CT scan revealed a hypodense lesion reshaping the superior and middle third of the clivus and partially invading the sphenoidal sinus. MRI showed an irregular-shaped lesion occupying the body of the sphenoid bone, involving the superior and middle third of the clivus and sprouting into the sphenoid sinus. The lesion was hyperintense on T1- and T2-weighted sequences with a thin peripheral rim of hypointensity, without enhancement after i.v. gadolinium injection. The pathology report confirmed an intraosseus lipoma. Intraosseous lipomas involving the spheno-clival region are extremely rare. CT and MRI scan interpretation can be troublesome but this rare pathology has to be considered in the differential diagnosis.

Basilar artery hypoplasia

A rare case of segmental hypoplasia of the basilar artery is described in a 49-year-old man with transient vertebrobasilar ischemia, explored by magnetic resonance imaging (MRI) and digital angiography (DA). The embryology, clinical relevance and magnetic resonance findings of this arterial anomaly are discussed, with a review of six previously reported cases. Segmental aplasia was suggested in our case by magnetic resonance, and subsequently confirmed not only by time-of-flight magnetic resonance, but also by DA. Only ultrathin-slice T2-weighted images revealed the real finding of basilar artery hypoplasia. This sequence, not employed in previously reported cases, is mandatory to allow a clear differential diagnosis between basilar artery aplasia and hypoplasia.

Type a Niemann-Pick Disease

We describe three patients with type A Niemann-Pick disease (NPD-A). NPD-A is an autosomal recessive neuronal storage disease classified among the sphingolipidoses, characterized by accumulation of sphingomyelin in various tissues and in the brain. Magnetic Resonance imaging (MRI) of our three patients showed a marked delay of myelination with frontal atrophy. Few descriptions of this MRI pattern of delayed myelination have been published to date.

Thalamic changes in mesial temporal sclerosis: a limbic system pathology. A case report

Hippocampal abnormalities correlated with mesial temporal sclerosis (MTS) are well documented. MTS may be associated with extrahippocampal anomalies involving limbic structures along a known neuroanatomic pathway (Papez circuit). We report a patient with MTS and thalamic changes. Seizure-related thalamic damage could have been caused by abnormal electric discharges from the mamillary body to the anterior thalamus through the mamillothalamic tract. This suggests that MTS is not limited to the temporal lobe but could represent a limbic system pathology.

Trigeminal Perineural Spread of Head and Neck Tumors

Perineural tumor spread (PNS) of head and neck malignancies is a well-known form of metastatic disease in which a lesion can migrate away from the primary site along the endoneurium or perineurium. MR imaging is considered the primary method for evaluating patients with symptoms related to the trigeminal nerve in most clinical settings. Both CT and MR imaging can detect perineural spread, but MRI is the modality of choice because of its capability to detect direct signs (nerve enlargement and enhancement) and indirect signs (neuropathic muscular atrophy, obliteration of fat planes). In addition, MRI is more sensitive because of its superior soft-tissue contrast, its multiplanar capability and decreased artifacts from dental hardware. Fat suppression images after contrast injection are mandatory to better detect nerve enhancement. CT is useful in detecting foraminal enlargement or more destructive bone patterns. Nerve function can be perserved until later in the course of the disease: patients with perineural spread demonstrated at radiologic or pathologic examination may have normal or nonspecific nerve function at clinical examination (patients are misdiagnosed with Bell's palsy or trigeminal neuralgia). Hence MRI assessment of perineural tumor location and extension is important.

Non-Inferential Multi-Subject Study of Functional Connectivity during Visual Stimulation

Independent component analysis (ICA) is a powerful technique for the multivariate, non-inferential, data-driven analysis of functional magnetic resonance imaging (fMRI) data-sets. The non-inferential nature of ICA makes this a suitable technique for the study of complex mental states whose temporal evolution would be difficult to describe analytically in terms of classical statistical regressors. Taking advantage of this feature, ICA can extract a number of functional connectivity patterns regardless of the task executed by the subject. The technique is so powerful that functional connectivity patterns can be derived even when the subject is just resting in the scanner, opening the opportunity for functional investigation of the human mind at its basal "default" state, which has been proposed to be altered in several brain disorders. However, one major drawback of ICA consists in the difficulty of managing its results, which are not represented by a single functional image as in inferential studies. This produces the need for a classification of ICA results and exacerbates the difficulty of obtaining group "averaged" functional connectivity patterns, while preserving the interpretation of individual differences. Addressing the subject-level variability in the very same framework of "grouping" appears to be a favourable approach towards the clinical evaluation and application of ICA-based methodologies. Here we present a novel strategy for group-level ICA analyses, namely the self-organizing group-level ICA (sog-ICA), which is used on visual activation fMRI data from a block-design experiment repeated on six subjects. We propose the sog-ICA as a multi-subject analysis tool for grouping ICA data while assessing the similarity and variability of the fMRI results of individual subject decompositions.

Assessment of right ventricular function by strain rate imaging in chronic obstructive pulmonary disease

The purpose of the current study was to compare right ventricular (RV) myocardial wall velocities (tissue Doppler imaging) and strain rate imaging (SRI) parameters with conventional echocardiographic indices evaluating RV function in chronic obstructive pulmonary disease (COPD) patients. In total, 39 patients with COPD and 22 healthy subjects were included in the current study. Seventeen patients had pulmonary artery pressure <35 mmHg (group I) and 22 patients had pulmonary artery pressure >35 mmHg (group II). Tissue Doppler imaging, strain and strain rate (SR) values were obtained from RV free wall (FW) and interventricular septum. Respiratory function tests were performed (forced expiratory volume in one second/vital capacity (FEV(1)/VC) and carbon monoxide diffusion lung capacity per unit of alveolar volume (D(L,CO)/V(A))). Strain/SR values were reduced in all segments of group II patients compared with group I patients and controls with lowest values at basal FW site. A significant relationship was shown between peak systolic SR at basal FW site and radionuclide RV ejection fraction. A significant relationship was shown between peak systolic SR at basal FW site and D(L,CO)/V(A) and FEV(1)/VC. In conclusion, in chronic obstructive pulmonary disease patients, strain rate imaging parameters can determine right ventricular dysfunction that is complementary to conventional echocardiographic indices and is correlated with pulmonary hypertension and respiratory function tests.

Development of "de novo" aneurysms following endovascular procedures

Two personal cases of "de novo" aneurysms of the anterior communicating artery (ACoA) occurring 9 and 4 years, respectively, after endovascular carotid occlusion are described. A review of the 30 reported cases (including our own two) of "de novo" aneurysms after occlusion of the major cerebral vessels has shown some features, including a rather long time interval after the endovascular procedure of up to 20-25 years (average 9.6 years), a preferential ACoA (36.3%) and internal carotid artery-posterior communicating artery (ICA-PCoA) (33.3%) location of the "de novo" aneurysms, and a 10% rate of multiple aneurysms. These data are compared with those of the group of reported spontaneous "de novo" aneurysms after SAH or previous aneurysm clipping. We agree that the frequency of "de novo" aneurysms after major-vessel occlusion (two among ten procedures in our series, or 20%) is higher than commonly reported (0 to 11%). For this reason, we suggest that patients who have been submitted to endovascular major-vessel occlusion be followed up for up to 20-25 years after the procedure, using non-invasive imaging studies such as MR angiography and high-resolution CT angiography. On the other hand, periodic digital angiography has a questionable risk-benefit ratio; it may be used when a "de novo" aneurysm is detected or suspected on non-invasive studies. The progressive enlargement of the ACoA after carotid occlusion, as described in our case 1, must be considered a radiological finding of risk for "de novo" aneurysm formation.

Pituitary macroadenoma and diaphragma sellae meningioma: differential diagnosis on MRI

Diaphragma sellae meningiomas are unusual tumours often not distinguished from pituitary macroadenomas. Preoperative differentiation is essential, because the trans-sphenoidal approach is used for surgical removal of adenomas, while meningiomas are approached via a craniotomy. We reviewed five patients in whom a diaphragma sellae meningioma was initially diagnosed as a nonsecreting pituitary macroadenoma. MRI criteria for differential diagnosis are discussed. The main findings considered are visibility of the pituitary gland, contrast enhancement, the centre of the lesion and sellar enlargement. These criteria, applied to a blind review, allow correct identification of the tumours.

[The echographic anatomy of the larynx and the perilaryngeal structures]

The normal laryngeal and perilaryngeal structures (neither nodal nor vascular) of 120 healthy and informed volunteers and of 46 patients with extralaryngeal neck conditions were studied with ultrasonography (US). The study was performed with a high-frequency linear probe on the transverse and sagittal planes; the patients were examined supine, with neck hyperextension, during quiet breathing, in inspiratory and expiratory breath-holding, during Valsalva maneuver or phonation. Axial scans clearly depict, in cranio-caudal direction, the base of the tongue, the hyoid and adjacent muscular structures. At the laryngeal vestibule epiglottis is always clearly demonstrated as a thin hypoechoic curvilinear rim and the pre-epiglottic space as a fat-filled and markedly echogenic structure. Pyriform sinuses are more difficult to study with US and should therefore be always distended by air during Valsalva because no suitable US contrast agent is available for their exploration yet. The ossification of thyroid laminae prevents or hinders the exploration of endolaryngeal structures because of consequent posterior acoustic shadow. In case of partial ossification or cartilaginous thyroid laminae, paraglottic spaces are easily demonstrated with US, as well as the false cords and, partially, arytenoids and posterior laryngeal wall muscles. The muscular structure of the true cords, their mobility in the M-mode and, in half of the cases, the thin vocal plicae joining anteriorly in the anterior commissure, are easily depicted with US. To conclude, US permits to demonstrate normal laryngeal anatomy by a quick and harmless examination in several breathing and phonation phases, which is an essential premise to the correct interpretation of abnormal US findings.