Efficacy of a new delivery system based on solid lipid microparticles for the oral administration of the non-conventional antioxidant IAC on a diabetes mouse model

PURPOSE

We previously showed the positive effects of the new antioxidant molecule bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate (IAC) in reducing basal hyperglycaemia and relieving glucose intolerance in a diabetes model. However, the chemical properties of IAC did not allow an efficient oral administration, thus representing the main failing of that study. Here, we tested the effect of a new oral delivery system based on solid lipid microparticles (SLMs) in a diabetes mouse model.

METHODS

The diabetes model was induced in C57B1/6J mice using streptozotocin and nicotinamide. Only the animals that overcame the glycaemic threshold of 180 mg/dL were enrolled in the study. Diabetic animals were then randomly assigned to 4 groups (n = 9) and treated once a day for 5 consecutive weeks with IAC (50, 100, and 150 mg/kg b.w.). The control group was composed of (n = 7) healthy mice that received only the vehicle. Glucose level was weekly monitored during the treatment period and up to 3 weeks after the suspension of the treatment. Glucose tolerance and insulin-resistance test were carried out.

RESULTS

Our results showed that SLMs maintained the IAC effect in reducing basal hyperglycaemia as well as improving the insulin sensitivity and glucose tolerance.

CONCLUSION

The present study confirms that SLMs are promising drug carriers, which allow the oral administration of IAC ensuring its therapeutic efficacy. The concrete possibility to administer IAC per os represents a significant breakthrough in the putative consideration of this multi-radical scavenger in the diabetes therapeutic approach.

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.

Degenerazione dell'unità disco-somatica lombare

Gli autori, attraverso una revisione della letteratura ed uno studio retrospettivo su 125 esami RM, descrivono le alterazioni degenerative del rachide lombare in pazienti anziani, focalizzan-do l'attenzione sulla ricca semeiologia RM della patologia del complesso disco-somatico. Scopo del lavoro e quello di poter discernere le alterazioni a carattere francamente patologico da quelle che possono essere considerate segni del fisiologico invecchiamento rachideo. Viene in particolare evidenziato come la fissurazione radiale dell'anulus sia risultata, in base alla sua presenza significativamente più frequente nel gruppo dei pazienti sintomatici, il miglior segno predittivo di patologia estrusiva discale tra quelli esaminati.

Xantoastrocitoma pleomorfo

Lo xantoastrocitoma pleomorfo è una variante piuttosto rara e relativamente benigna di glioma intracranico che colpisce per lo più soggetti giovani e che mostra una eclatante disparità tra l'aspetto istologico apparentemente maligno e il comportamento clinico invece benevolo.

Dopo la prima descrizione di Kepes et al. nel 1979, 71 casi sono stati riportati nella letteratura principale. Il tumore ha una predilezione per i lobi temporale e parietale ed una localizzazione superficiale con coinvolgimento della corteccia, che rende tecnicamente più facile la sua rimozione radicale; è sempre presente un marcato pleomorfismo cellulare, con la coesistenza di più tipi cellulari, insieme con una risposta positiva alla reazione con l'immunoperossidasi (GFAP) e con l'assenza di necrosi.

La diagnosi pre-operatoria è generalmente difficile. L'iter terapeutico ottimale si fonda sul trattamento chirurgico, eventualmente reiterato in caso di recidiva, cui può associarsi il trattamento radiante.

Whole-body MRI with diffusion-weighted imaging: a valuable alternative to contrast-enhanced CT for initial staging of aggressive lymphoma

AIM

To compare the accuracy of whole-body magnetic resonance imaging (Wb-MRI) with diffusion-weighted imaging (DWI) to that of contrast-enhanced computed tomography (CE-CT) and 2-[(18)F]-fluoro-2-deoxy-d-glucose ((18)F-FDG) positron-emission tomography co-registered with low dose-CT (PET-CT) in defining lymphoma disease stage.

MATERIALS AND METHODS

From February 2010 to May 2014, 41 lymphoma patients underwent Wb-MRI-DWI, CE-CT, and (18)F-FDG PET-CT. Histological subtypes included aggressive B-cell (n=11), follicular (n=13), mantle cell (n=3), and Hodgkin's (n=14) lymphoma. To compare the procedures, the reference standard (RS) assessment was defined by combining the results from (18)F-FDG PET-CT, CE-CT, and bone marrow (BM) histology, modifications after therapy, and histological re-assessments of uncertain lesions.

RESULTS

Among 1025 nodal sites, 217 had disease involvement according to the RS. CE-CT yielded 23 false-negative and 11 false-positive errors. Wb-MRI-DWI failed to recognise 17 localisations and had six false-positive errors; (18)F-FDG PET-CT had no errors. Among 458 extranodal sites, 37 were positive according to the RS. (18)F-FDG PET-CT yielded four false-negative and two false-positive results. CE-CT yielded 17 false-negative errors. Wb-MRI-DWI yielded a single false-negative error. Wb-MRI-DWI was the most reliable imaging technique for BM evaluation. Considering each procedure alone, the final stage would have been missed in four cases using (18)F-FDG PET-CT, 12 cases using CE-CT, and none using Wb-MRI-DWI.

CONCLUSION

The present data support Wb-MRI-DWI as a sensitive and specific imaging technique for lymphoma evaluation, supporting its use in place of CE-CT for staging.

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.

Paget's Disease. A Case Report

Paget's disease (PD) is a common focal progressive osteometabolic disorder characterised by a disturbance in bone modelling and remodelling, because of an increase in osteoblastic and osteoclastic activity. It is a condition of unknown aetiology affecting approximately 3% of the population over 40 years of age and, approximately 10% of those over the age of 85 years. It is most common in Northern Europe and Australia and is rare in Asia and Africa. We describe the case of a 71-year-old man diagnosed with PD confined to the sacrum. After laboratory test, an imaging study with radiography, scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI) was performed disclosing findings compatible with Paget's disease in middle pathologic phase. The diagnosis was confirmed at biopsy. The structural modification of the sacrum with spongiosa rarefaction, thickening of bone and intact bone cortical, confirmed by CT, are tipical of an intermediate phase of PD. This was also supported by signal MRI changes showing substitution of the red by the fat medulla, visualized by FS sequences. Once the treatment for the bone disease was established, the patient no longer complained of pain. Special attention should be paid to male and elderly patients with pain in the lumbar spine because of the potential risk cancer development (21). The radiologist must be attentive to the possible presentations and complications of PD, even in uncommon sites, trying whenever possible to correlate the radiological features with the patient's clinical symptoms.

Giant Dilatations of Virchow-Robin Spaces in the Midbrain

Virchow-Robin spaces are lesions often seen in the brain parenchyma but their etiopathogenesis remains unsettled. Giant Virchow-Robin spaces placed in the midbrain are extremely rare. We describe three patients with a diagnosis of giant Virchow-Robin spaces in the midbrain, and their clinical and radiologic findings. We reviewed the literature in terms of the etiopathology, anatomic and radiologic appearance and differential diagnosis of the giant Virchow-Robin spaces. The diagnostic role of the high Tesla magnetic resonance devices and new sequences techniques such as three dimensional isotropic acquisition and diffusion tensor imaging were also evaluated in this case series.

Widespread microstructural white matter involvement in amyotrophic lateral sclerosis: a whole-brain DTI study

BACKGROUND AND PURPOSE

The extensive application of advanced MR imaging techniques to the study of ALS has undoubtedly improved our knowledge of disease pathophysiology, even if the actual spread of the neurodegenerative process throughout the central nervous system is not fully understood. The present study aimed to detect WM patterns of microstructural abnormalities to better investigate the pathologic process in ALS, within but also beyond CSTs, in a whole-brain analysis.

MATERIALS AND METHODS

DTI was performed in 19 patients with ALS and 20 matched healthy controls, by using whole-brain TBSS and VOI analyses.

RESULTS

We observed a significant decrease of FA in the body of CC of the ALS group (P < .05). At the VOI level, both FA decrease and RD increase in the body of CC significantly correlated with the UMN score (P = .003 and P = .02). Additionally, significant voxelwise positive correlations between FA and the ALSFRS-R were detected in the WM tracts underneath the left premotor cortex (P < .05).

CONCLUSIONS

The correlations between reduction of FA and increase of RD in the body of CC with the UMN score indicate that the WM degeneration in the CC is strictly related to the ALS pyramidal impairment, while the correlation between FA and ALSFRS-R in the associative tracts underneath the left premotor cortex might reflect the progressive spread of the disease from the motor toward the extramotor areas.

Cervical Chordoma

Chordomas are rare and aggressive tumors derived from notochordal remnants, usually arising in the axial skeleton. The most frequently reported anatomic distribution of chordoma is 50% sacral, 35% spheno-occipital and 15% spinal. We describe the case of an elderly lady presenting with progressive dysphagia, headache and neck pain. We found an expansile mass extending from C1 to C3. While running the diagnostic plan we considered a variety of lesions possibly involving the cervical spine. Biopsy revealed the mass was a chordoma.

Spontaneous Regression of Dilated Virchow-Robin Spaces

We describe a 28-year-old woman with a dilated perivascular spaces in the right prerolandic district. The purpose of this article is to provide an in-depth overview of the MR imaging features of VR spaces and to describe magnetic resonance imaging evidence of complete regression of dilated perivascular spaces 2.

Interictal cortical reorganization in episodic migraine without aura: an event-related fMRI study during parametric trigeminal nociceptive stimulation

The aim of our study was to explore the pain processing network in patients with migraine during trigeminal nociceptive stimulation. Sixteen patients with episodic migraine without aura and 16 healthy controls performed functional magnetic resonance imaging during thermal stimuli (at 41, 51 and 53°C). Patients with migraine showed a greater activation in the perigenual part of anterior cingulate cortex at 51°C and less activation in the bilateral somatosensory cortex at 53°C compared to healthy controls. There were no differences in experimental pain perception between groups. Our findings demonstrate a functional reorganization of cerebral areas known to be involved in pain processing in patients with migraine.

DWI Reversibility after Intra-Arterial Thrombolysis. A Case Report and Literature Review

We report our case and review the literature on reversal DWI lesions, ADC thresholds and correlation between DWI lesion and outcome measured with clinical scales. A 30-years old woman was admitted to our hospital 18 hours after stroke onset. Considering the absence of alterations on CT and the worsening of symptomatology, the patient underwent MRI, which showed a slightly hyperintense signal in FLAIR images in the left portion of the pons and midbrain and a more evident bilateral DWI hyperintensity of the pons. The patient was treated with mechanical and pharmacological intra-arterial thrombolysis. The patient showed a rapid improvement of symptoms. Two weeks after the treatment her clinical conditions were characterized by a residual right hemiparesis and complete recovery of right motility, respiratory and swallowing difficulties. MR examination demonstrated a slight signal alteration of the pons left hemiportion and a disappearance of the mesencephalic signal alteration and of the right portion of the pons. DWI lesions represent irreversibly damaged tissue but new evidence suggests that DWI lesions may be reversible, especially with reperfusion, by now well demonstrated in animal models. Therefore acute DWI lesions probably contain not only irreversibly injured tissue but also parts of the penumbra. The debate on the capability of ADC maps to discriminate irreversibly from reversibly damaged tissue is a matter of controversy. ADC values in human stoke are not an independent indicator of tissue viability. The use of thresholds may improve reproducibility but not validity.

Combined first-stage hepatectomy and colorectal resection in a two-stage hepatectomy strategy for bilobar synchronous liver metastases

BACKGROUND

This study assessed the feasibility and outcomes of combined colorectal and hepatic resection as the first step of two-stage hepatectomy in patients with bilobar synchronous colorectal liver metastases.

METHODS

All patients with bilobar synchronous colorectal liver metastases who were considered for two-stage hepatectomy, combining resection of the primary tumour with the first stage of hepatectomy, between 2000 and 2008 were selected from a prospectively collected database at two institutions. Data were analysed retrospectively on an intention-to-treat basis.

RESULTS

Thirty-three patients were studied. Twenty patients received neoadjuvant chemotherapy. Combined colorectal resection and clearance of left-sided liver metastases was the first-stage procedure in all but one patient, in whom right clearance was performed. In 17 patients right portal vein ligation was undertaken at the same time. No patient died. Two patients had anastomotic leakage. Interval chemotherapy was given to 25 patients, five of whom also had percutaneous portal vein embolization. Twenty-five patients had the second-stage hepatectomy, but not eight patients with disease progression. There was one postoperative death after the second stage, and eight patients experienced morbidity. Median follow-up from the first stage was 28.7 months. Overall and disease-free survival rates for patients who completed the procedure were 80 and 44 per cent respectively at 3 years, and 48 and 22 per cent at 5 years.

CONCLUSION

In patients with bilobar synchronous colorectal liver metastases who are candidates for two-stage hepatectomy, combined resection of the primary tumour and first-stage hepatectomy reduces the number of procedures, optimizes chemotherapy administration and may improve outcome.

Hippocampal Asymmetry with Hippocampal Sulcus Remnants in a Patient with Mild Cognitive Impairment

A 65-year-old woman underwent MRI for a mild cognitive impairment (MCI) at Mini-Mental State Examination (MMSE). MRI showed hippocampal sulcus remnants bilaterally, although they were larger on the right, and left hippocampal atrophy with increased left fimbrio-subicular distance (right side: 1.2 mm; left side: 2.0 mm). The meaning of these findings in relation to clinical aspects is discussed and reviewed according to data from the literature.

Spontaneous Resolution of Eosinophilic Granuloma in a Patient with a Psychotic Disorder

A 16-year-old female who manifested psychotic symptoms underwent CT and MRI for the evaluation of an incidentally discovered asymptomatic palpable mass of the right occipital region of the skull. The correlation between clinical and radiological data and biopsy data led to the diagnosis of eosinophilic granuloma. The radiological finding is discussed and reviewed in relation to clinical aspects and literature data.

Non-Alcoholic Wernicke Encephalopathy: MR Imaging and Review of the Literature

We describe a patient with non-alcoholic Wernicke's encephalopathy caused by long-term parenteral nutrition. The diagnosis is based on clinical and magnetic resonance findings. We also reviewed the literature review in typical and atypical findings at MR examination.

Lung cancer single intramedullary metastasis vs delayed radionecrosis. A case report

Intramedullary metastases are rare, accounting for 0.9-5% of spinal metastases. Radiation myelopathy is considered one of the most distressing complications of radiotherapy. In both cases symptoms are aspecific, and there are no characteristic neuroradiologic findings. We describe a case of single intramedullary metastasis from lung microcytoma in a 55-year-old man with a history of malignancy, treated by radiotherapy five years previously. The patient returned to our observation complaining of pain and paraesthesia in the left C7 area. Spinal MRI and rachicentesis findings were aspecific. Ten days later a new MRI showed that the lesion size had increased, and neoplastic cells were found in CSF. Intramedullary metastases are extremely rare, accounting for 0.1-0.4% of all CNS tumors. The risk of developing delayed radionecrosis varies with the total dose administered. In both cases diagnosis is histological, while contrast-enhanced MRI is highly sensitive and specific in identifying and characterizing the lesion. In case of metastatic lesions the prognosis is unfavorable. Differential diagnosis is important because it has a strong effect on patient management.

Does the default-mode functional connectivity of the brain correlate with working-memory performances?

The "default-mode" network is an ensemble of cortical regions that are typically deactivated during demanding cognitive tasks in functional magnetic resonance imaging (fMRI) studies. Using functional connectivity analysis, this network can be studied as a "stand-alone" brain system whose functional role is supposed to consist in the dynamic control of intrinsic processing activities like attention focusing and task-unrelated thought generation and suppression. Independent component analysis (ICA) is the method of choice for generating a statistical image of the "default-mode" network (DMN) using a task- and seed-independent distributed model of fMRI functional connectivity without prior specification of node region extent and timing of neural activation. We used a standard graded working-memory task (n-back) to induce fMRI changes in the default-mode regions and ICA to evaluate to DMN functional connectivity in nineteen healthy volunteers. Based on the known spatial variability of the ICA-DMN maps with the task difficulty levels, we hypothesized the ICA-DMN may also correlate with the subject performances. We confirmed that the relative extent of the anterior and posterior midline spots within the DMN were oppositely (resp. positively in the anterior and negatively in the posterior cingulate cortex) correlated with the level of task difficulty and found out that the spatial distribution of DMN also correlates with the individual task performances. We conclude that the working-memory function is related to a spatial re-configuration of the DMN functional connectivity, and that the relative involvement of the cingulate regions within the DMN might function as a novel predictor of the working-memory efficiency.

Re-Biopsies of the Prostate after Endo-Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) in Patients with ASAP: Preliminary Results

Introduction e Objectives

There are some evidences that the combination of EndoMRI and MRS might be able to limit the number of iterative biopsies in patients with negative biopsies of the prostate and a still rising PSA. The aim of this study is to evaluate the possible role of EndoMRI/MRS in patients with ASAP.

Methods

From November 2005 to September 2008 we enrolled 28 consecutive patients diagnosed with ASAP at a TRUS-guided needle prostate biopsy. All patients underwent prostatic EndoMRI and MRS. A prostatic zone was classified as: suspicious for prostate cancer if low intensity signal was present on T2-weighted images and/or if the choline + creatine / citrate ratio was >0.86; equivocal or negative otherwise. A subsequent 12-core needle prostate biopsy was performed and supplementary biopsies were added in the suspicious zones. The results of MRI/MRS were then compared with histological findings.

Results

The combination of EndoMRI and MRS was suspicious for cancer in 70% of patients, equivocal in 23% and negative in 7%. Histological findings at re-biopsy included: prostate cancer in 35%, ASAP in 23%, BPH or prostatitis in 42%. In 78% of patients diagnosed with prostate cancer the combination MRI/MRS was suspicious and in 22% equivocal. In all patients the cancer was found in suspicious zones at MRI/MRS where targeted biopsies were performed.

Conclusions

The combination of EndoMRI and MRS proved to have a good sensitivity but a poor specificity in identifying a concurrent prostate cancer among patients with ASAP. The location of positive cores for prostate cancer was consistent with the suspicious zones at MRI/MRS.

Value of endorectal MRI and MRS in patients with elevated prostate-specific antigen levels and previous negative biopsies to localize peripheral zone tumours

AIM

To evaluate prospectively the role of endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) in detecting peripheral zone tumour in patients with total prostate-specific antigen (PSA) values>or=4 ng/ml and one or more negative transrectal ultrasound (TRUS) biopsy rounds.

MATERIAL AND METHODS

Fifty-four consecutive men (mean age 65.4+/-5.2 years, mean total PSA 10.8+/-7.5 ng/ml), underwent a combined MRI-MRS examination with endorectal coil. MRI included transverse, coronal, and sagittal T2-weighted and transverse T1-weighted fast spin-echo sequences. MRS data were acquired using a double spin-echo point resolved spectroscopy (PRESS) sequence. A 10-site scheme was adopted to evaluate the prostate peripheral zone. A peripheral prostatic site was classified as suspicious if low intensity signal was present on T2-weighted images and/or if the choline+creatine/citrate ratio was >0.86. Following MRI-MRS all patients were submitted to a standard 10-core biopsy scheme to which from one to three supplementary samples were added from suspicious MRI and/or MRS sites. In per-patient analysis findings were considered true-positive if biopsy positive patients were classified as suspicious, irrespectively of lesion site indication.

RESULTS

Prostate cancer (PC) was detected in 17 of 54 patients (31.5%); median Gleason score was 6 (range 4-8). On a per-patient basis sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were respectively 100, 64.9, 56.7, 100, and 75.9% for MRI; 82.2, 70.3, 57.7, 92.9, and 75.9% for MRS; and 100, 51.4, 48.6, 100, and 66.7% for combined MRI-MRS. In all the 17 PC patients, combined MRI-MRS correctly indicated the sites harbouring cancer, whereas both MRI and MRS gave erroneous indications in two patients.

CONCLUSION

The results of the present study show that MRI alone might be able to select negative patients in whom further biopsies are unnecessary. The combination of MRI and MRS might be able to drive biopsies in suspicious sites and increase the cancer detection rate. Further studies are required to confirm these data.

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.

Correlation of 11C-choline PET and PSA values in patients with prostate cancer and biochemical relapse after primary treatments

5073

Background: 11C-choline PET has demonstrated promising results in the evaluation of suspected recurrence after a primary treatment in prostate cancer (PC) patients (pts). However in pts with asymptomatic biochemical relapse (BR), the timing of PET scan is a subject of controversy. Most authors argue against performing PET scan for rising PSA values <5 ng/ml. Aim of our study was to evaluate if there is a PSA cut-off that significatively correlates to 11C-choline PET positivity. Methods: 68 pts with rising PSA after primary treatment underwent 11C-choline PET. Median age was 68 yrs (range 43–84). Median PSA at the time of PET scan was 2.91 ng/ml (range 0.12- 71.60). Primary treatments were: 27 (40%) radical prostatectomy (RP), 22 (32%) external-beam radiation therapy (EBRT), 13 (19%) RP + adjuvant EBRT, 6 (9%) hormonal therapy. Results: 11C-choline PET was positive in 39/68 pts (57%) and negative in 29/68 (43%). Median PSA values were 1.18 ng/ml (range 0.12–6.47) and 5.14 ng/ml (range 1.33–71.60) in pts with negative and positive PET scan respectively. Median PSA values were statistically different in positive and negative 11C-choline PET (Mann-Whitney U Test. p< 0.001). No positive uptake was seen in pts with PSA <1 ng/ml (12/68); all pts with PSA >6.5 ng/ml had a positive finding; for PSA values between 1 and 6.5 ng/ml (33/68), 11C- choline PET showed a pathological uptake in 18 pts. The Receiver Operative Characteristic (ROC) analysis found that a PSA cut-off of 2.31 ng/ml has a sensitivity of 87% and a specificity of 83% in respect of 11C-choline PET positivity. Conclusions: For PSA values > 2.3 ng/ml the probability to have a positive 11C-choline PET is high in order to recommend to perform the exam in clinical practice, even if further data are needed. On the contrary, we can’t suggest to perform PET scan in pts with PSA <1 ng/ml.

No significant financial relationships to disclose.

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.

Giant Intracranial Chordoma: Neuroradiological and Radiotherapeutic Aspects

We describe a rare case of giant intracranial chordoma, emphasizing the patient's long survival and his excellent response to radiotherapy that led to a progressive regression of neurological symptomatology up to disappearance, in the absence of cerebral white matter damages.

Diagnostic accuracy of portal-phase CT and MRI with mangafodipir trisodium in detecting liver metastases from colorectal carcinoma

AIM

To compare the diagnostic accuracy of single section spiral computed tomography (CT) and magnetic resonance imaging (MRI) with tissue-specific contrast agent mangafodipir trisodium (MnDPDP) in the detection of colorectal liver metastases.

MATERIAL AND METHODS

One hundred and twenty-five consecutive patients undergoing surgery for primary and/or metastatic disease were evaluated using CT (5 mm collimation and reconstruction interval, pitch 2), two-dimensional fast spoiled gradient echo (2D FSPGR) T1 and single shot fast-spin echo (SSFSE) T2 weighted breath-hold MRI sequences, performed before and after intravenous administration of MnDPDP. The reference standards were intraoperative ultrasound and histology.

RESULTS

The per-patient accuracy of CT was 72.8 versus 78.4% for unenhanced MRI (p = 0.071) and 82.4% for MnDPDP-enhanced MRI (p = 0.005). MnDPDP-enhanced MRI appeared to be more accurate than unenhanced MRI but this was not significant (p = 0.059). The sensitivity of CT was 48.4% versus 58.1% for unenhanced MRI (p = 0.083) and 66.1% for MnDPDP-enhanced MRI (p = 0.004). The difference in specificity between procedures was not significant. The per-lesion sensitivity was 71.7, 74.9 and 82.7% for CT, unenhanced MRI, and MnDPDP-enhanced MRI, respectively; the positive predictive value of the procedures was respectively 84.0, 96.0 and 95.8%. MnDPDP-enhanced MRI provided a high level diagnostic confidence in 92.5% of the cases versus 82.5% for both unenhanced MRI and CT. The kappa value for inter-observer variability was >0.75 for all procedures.

CONCLUSIONS

The diagnostic accuracy and sensitivity of MnDPDP-enhanced MRI is significantly higher than single section spiral CT in the detection of colorectal cancer liver metastases; no significant difference in diagnostic accuracy was observed between unenhanced MRI and MnDPDP-enhanced MRI.

Magnetic Resonance angiography of the pulmonary veins before and after radiofrequency ablation for atrial fibrillation

PURPOSE

To study the usefulness of magnetic resonance angiography (MRA) in imaging of the pulmonary veins (PV) before and after radiofrequency ablation procedures in patients with atrial fibrillation.

MATERIALS AND METHODS

Between July 2002 and April 2003, 50 patients with atrial fibrillation underwent MRA prior to ablation; 18 patients also underwent post-procedure MRA. Images were acquired with 3D-spoiled gradient echo sequences after intravenous administration of the paramagnetic contrast medium gadopentetate dimeglumine; an automatic triggering device was used to start the angiographic sequence (Smartprep, General Electric Medical Systems). Postprocessing was performed with maximum intensity projection (MIP) and virtual endoscopy (VE) software (Navigator, GEMS).

RESULTS

The venoatrial junction was visualised with MRA VE in 49 of 50 patients (98.0%). Twenty-seven patients out of 49 (55.1%) had two PV ostia on both sides, 13 (26.5%) had two right ostia and a single common left ostium, 5 (10.2%) had supernumerary PV and 4 (8.2%) had both a supernumerary right PV and a single common left ostium. Flythrough navigation showed the number and spatial arrangement of second-order PV branches in 48 out of 49 patients (98.0%). In postablation examinations, mild stenosis was detected with MIP and VE in 17 out of 83 PV examined (20.5%).

CONCLUSIONS

This study confirms the clinical value of magnetic resonance imaging for visualising PV ostia in patients undergoing radiofrequency ablation for atrial fibrillation. Before the ablation procedure, MRA allows an accurate evaluation of PV number, shape and size; after the procedure, MRA is useful in screening for post-ablation stenosis and describing the location and severity of stenosis when present.

Magnetic resonance angiography virtual endoscopy in the assessment of pulmonary veins before radiofrequency ablation procedures for atrial fibrillation

Magnetic resonance angiography (MRA) is a safe and non-invasive imaging method that can readily depict the pulmonary veins (PV), whose imaging has acquired momentum with the advent of new techniques for radiofrequency ablation of atrial fibrillation (AF). We evaluated whether virtual endoscopy from 3D MRA images (MRA-VE) is feasible in studying the morphology of PV. Fifty patients with AF underwent pre-ablative MRA (1.5 T). Images were acquired with axial T-2 weighted and 3D-SPGR sequences after intravenous administration of Gd-DTPA and automatic triggering. Postprocessing was performed by an experienced radiologist with maximum intensity projection (MIP) and virtual endoscopy software (Navigator, GEMS). The venoatrial junction was visualized with MRA-VE in 49 of 50 patients (98.0%). Twenty-seven patients (55.1%) had two ostia on both sides, 13 patients (26.5%) had two ostia on the right and a single common ostium on the left, 5 patients (10.2%) had accessory PV and 4 patients (8.2%) had both an accessory right PV and a single common ostium on the left. Flythrough navigation showed the number and spatial disposition of second-order PV branches in 48 out of 49 patients (98.0%). MRA-VE is an excellent tool for at-a-glance visualization of ostia morphology, navigation of second-generation PV branches and easy endoluminal assessment of left atrial structures in pre-ablative imaging.

Perfusion- and BOLD-based fMRI in the study of a human pathological model for task-related flow reductions

In the present work, an arteriovenous malformation was taken as a pathological model for studying task-related flow decreases during a motor task. Combined Blood Oxygen Level Dependent (BOLD)-perfusion experiments were applied in order to evaluate the relative sensitivity of these techniques to task-related reductions in cerebral blood flow (CBF). Results shows that, by matching the sensitivity of the methods (which exhibit a different contrast-to-noise ratio) in the primary motor cortex, the spatial extent of the regions of decreased perfusion signal is larger than those of the BOLD signal reduction. The above finding suggests that perfusion imaging, that already represents a gold standard method in the detection of vascular phenomena, may estimate task-related flow decreases in a functional time-series better than BOLD.

Dynamic contrast enhanced magnetic resonance imaging in monitoring bone metastases in breast cancer patients receiving bisphosphonates and endocrine therapy

PURPOSE

To study the role of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in monitoring the response of bone metastases to endocrine therapy combined with bisphosphonates in patients with breast cancer.

MATERIAL AND METHODS

Ten breast cancer patients with bone metastases who were to receive endocrine therapy and bisphosphonates were investigated prospectively by DCE-MRI. We chose a reference lesion for each patient who was studied at baseline, within 3 weeks from the second administration of bisphosphonates, and after 4 and 8 months from the initiation of medical treatment. Time/intensity curves, representing temporal changes of signal intensity in areas of interest in the context of the target lesions (ROI), were obtained for each DCE-MRI.

RESULTS

Changes in the shape of the T/I curves suggesting tumor regression were seen shortly after the initiation of medical treatment in the three patients who had the most durable responses.

CONCLUSION

DCE-MRI has the potential to detect early changes related to medical treatment in bone metastases from breast cancer. If confirmed in larger series, these data identify DCE-MRI as a diagnostic tool for evaluating new bone targeting antineoplastic agents.

High field functional MRI

Functional magnetic resonance imaging (fMRI) has become the most widely used approach for studying brain functions in humans. The rapid and widespread diffusion of fMRI has been favoured by the properties this technique presents, and particularly by its sensitivity in analysing brain functional phenomena and by the lack of biological invasiveness, resulting in an unprecedented and unparalleled flexibility of use. These properties of fMRI brought the functional examination of the brain within the reach of the whole neuroscience community and have appreciably stimulated the research on the functional processes of the living brain. Among the main features of fMRI, its spatial and temporal resolution represents clear advantages compared with the other methods of functional neuroimaging. In fact, the high spatial resolution of fMRI permits to produce more precise and better localised information, and its temporal resolution provides the potential of a better understanding of neural dynamics at the level of single functional areas and of the neural constituents of functional patterns. A fundamental possibility of improving spatial and temporal resolution without excessively degrading signal-to-noise ratio consists in the use of high magnetic field intensity fMRI units. Besides, high field units make the use of more demanding fMRI paradigms, like single trial event related studies, much more compatible with the need of a solid statistical evaluation. This has notably promoted the diffusion of high field MRI units for human studies throughout the world, with very high field MRI units, up to 8 T, working in a few research centres, and a larger number of MRI units with field intensity ranging between 3 and 5 T.

Endoscopic endonasal transsphenoidal approach: outcome analysis of 100 consecutive procedures

The endoscopic endonasal transsphenoidal approach has been proposed in the past decade as a minimally invasive surgical technique for the removal of pituitary tumors. From January 1997 to November 1999, 100 consecutive patients with pituitary tumors underwent endoscopic endonasal surgery, according to Jho's technique. We employed 0 degrees, 30 degrees, 45 degrees, and 70 degrees rigid endoscopes, 18 - 30 cm in length, 4 mm in diameter with an outer sleeve for irrigation and secured to a holder. Among the 87 pituitary adenomas, tumor removal was total in 51, subtotal (> 80 %) in 20 and partial in 16 cases. Four craniopharyngiomas were totally removed and an intra-suprasellar arachnoid cyst was emptied; a biopsy was performed in the two patients with a clivus chordoma. The two cases of sphenoid sinusitis were cured by surgery, the three patients with spontaneous CSF rhinorrhea were successfully treated and the residual nasal meningocele was removed. The endoscopic endonasal transsphenoidal approach appeared to be less traumatic than the traditional microsurgical approach, was very effective, and was characterized by a reduced number of complications. However, the relatively small series together with the short follow-up do not allow us to draw definitive conclusions. The post-operative reduction in hospital stay (two days in 40 of 100), significantly reduced the cost of patient's management.

The Italian multi-centre project on evaluation of MRI and other imaging modalities in early detection of breast cancer in subjects at high genetic risk

This report presents the preliminary results of the first phase (21 months) of a multi-centre, non-randomised, prospective study, aimed at evaluating the effectiveness of contrast-enhanced magnetic resonance imaging (MRI), X-ray mammography (XM) and ultrasound (US) in early diagnosis of breast cancer (BC) in subjects at high genetic risk. This Italian national trial (coordinated by the Istituto Superiore di Sanità, Rome) so far recruited 105 women (mean age 46.0 years; median age 51.0; age range 25-77 years), who were either proven BRCA1 or BRCA2 mutation carriers or had a 1 in 2 probability of being carriers (40/105 with a previous personal history of BC). Eight cases of breast carcinomas were detected in the trial (mean age 55.3 years, median age 52.5; age range 35-70 years; five with previous personal history of BC). All trial-detected BC cases (8/8) were identified by MRI, while XM and US correctly classified only one. MRI had one false positive case, XM and US none. Seven "MRI-only" detected cancers (4 invasive, 3 in situ) occurred in both pre- (n = 2) and post-menopausal (n = 5) women. With respect to the current XM screening programmes addressed to women in the age range 50-69 years, the global incidence of BC in the trial (7.6%) was over ten-fold higher. The cost per "MRI-only" detected cancer in this particular category of subjects at high genetic risk was substantially lower than that of an XM-detected cancer in the general women population. These preliminary results confirmed that MRI is a very useful tool to screen subjects at high genetic risk for breast carcinoma, not only in pre-, but also in post-menopausal age, with a low probability of false positive cases.

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.