Alessandro Meschini

Differences between Proximal versus Distal Intraorbital Optic Nerve Diffusion Tensor Magnetic Resonance Imaging Properties in Glaucoma Patients

PURPOSE To analyze in vivo the diffusion tensor magnetic resonance imaging (DT-MRI) properties of the intraorbital optic nerve at two different levels: Proximal to the optic nerve head (ONH) and distal to the ONH at the level of the orbital apex in glaucoma patients. METHODS Twenty-four patients with primary open-angle glaucoma were examined. The categorization into early and severe glaucoma was performed by Hodapps classification. Fifteen healthy individuals served as controls. DT-MRI was performed with a 3T-MR unit. RESULTS At early stage mean diffusivity (MD) values were higher at the proximal site with respect to the distal site. On the contrary, a decrease in fractional anisotropy (FA) was observed only relative to patient stage, independent of optic nerve site. Moreover, at early disease stage an increase in overall diffusivities, was evident at the proximal site, whereas at the distal site a decrease of the largest diffusivity and an increase in both the intermediate and smallest diffusivities were observed. FA and MD measured at the proximal site, had, respectively, the highest sensitivity and specificity in discriminating between healthy and glaucomatous eyes. CONCLUSIONS Our study represents the first attempt to evaluate in vivo fiber integrity changes along the optic nerve with DT-MRI. Optic nerve degeneration appears to be a process that affects differently the proximal and the distal segments of the optic nerve. The complementary high sensitivity of FA with the high specificity of MD at the proximal site may provide reliable indexes for the identification of glaucomatous patients at early stages.

Deeply infiltrating endometriosis: evaluation of retro-cervical space on MRI after vaginal opacification.

OBJECTIVES To prospectively investigate diagnostic value and tolerability of MRI after intra-vaginal gel opacification for diagnosis and preoperative assessment of deeply infiltrating endometriosis. METHODS Sixty-three women with clinical suspicion of deeply infiltrating endometriosis were previously examined with trans-vaginal ultrasonography and then with MRI pre and post administration of vaginal gel. We evaluated the tolerability of this procedure with a scoring scale from 0 to 3. We also assessed with a score from 1 to 4 the visibility of four regions: Douglas-pouch, utero-sacral-ligaments, posterior-vaginal-fornix and recto-vaginal-septum. All patients underwent laparoscopic surgery after MRI. RESULTS Five patients considered procedure intolerable. Visibility of utero-sacral-ligaments and posterior-vaginal-fornix showed to be increased with gel (p<0.001). In 57 out of 80 patients the MRI has allowed us to diagnose deeply infiltrating endometriosis. Overall, the percentages of MRI-sensitivity, specificity, positive predictive value and negative predictive value were respectively 67.8%, 95.3%, 89.4 and 83.5% without gel, and 90.8%, 94.6%, 90.8% and 94.6% with gel; trans-vaginal ultrasonography sensitivity, specificity, positive predictive value and negative predictive value were 57.5%, 96.6%, 90.9% and 79.5%. In evaluation of utero-sacral-ligaments trans-vaginal ultrasonography, MRI without gel and with gel sensitivity was respectively 61.9%, 47.6% and 81%; for recto-vaginal-septum these values were 12.5%, 68.7% and 93.7%; for pouch of Douglas 82%, 87% and 97.4%; finally for posterior-vaginal-fornix 27.3%, 36.4% and 81.8%. CONCLUSIONS MRI with gel opacification of vagina should be recommended for suspicion of deep infiltrating endometriosis, in particular for the added value in evaluation of recto-vaginal septum, utero-sacral ligaments and posterior vaginal fornix.

Diffusion tensor imaging in SPG11- and SPG4-linked hereditary spastic paraplegia

The aim of this study was to identify potential diagnostic markers of Hereditary Spastic Paraplegia (HSP). We investigated the white matter features of spastic gait (SPG)11- and SPG4-linked HSP, using diffusion tensor imaging performed with a 3-Tesla (3T) scanner. We examined four patients with SPG11 mutations, three with SPG4 mutations, and 26 healthy controls. We obtained maps of fractional anisotropy (FA) and mean diffusivity (MD), which we analyzed through both region of interest -based approach and tract-based spatial statistics (TBSS). Compared with healthy controls, SPG11 patients presented increased MD and decreased FA in the semioval centers, frontal and peritrigonal white matter, posterior limb of the internal capsule, and throughout the corpus callosum. Similar alterations were seen in the SPG4 patients at the levels of the semioval centers, the posterior limb of the internal capsule, the left cerebral pedicle, the genu and trunk of the corpus callosum, and the peritrigonal white matter on the left. No MD or FA alterations were observed in the cerebellar white matter. In a direct comparison, white matter alterations were more pronounced and widespread in HSP-SPG11 than in HSP-SPG4 patients. Joint TBSS analysis of all three groups confirmed significant widespread alterations of FA and MD values in the supratentorial white matter. This noninvasive study documented the presence of altered diffusivity in white matter in both forms of HSP, which could represent an important diagnostic marker of HSP. The association of reduced FA and increased MD in this patient population supports the interpretation of HPG as a neurodegenerative disorder.

Safety of early carotid artery stenting after systemic thrombolysis: a single center experience.

Background. Patients with acute ischemic stroke due to internal carotid artery (ICA) disease are at high risk of early stroke recurrence. A combination of IV thrombolysis and early carotid artery stenting (CAS) may result in more effective secondary stroke prevention. Objective. We tested safety and durability of early CAS following IV thrombolysis in stroke patients with residual stenosis in the symptomatic ICA. Methods. Of consecutive patients treated with IV rtPA, those with residual ICA stenosis ≥70% or <70% with an ulcerated plaque underwent early CAS (>24 hours). The protocol included pre-rtPA MRI and MR angiography, and post-rtPA carotid ultrasound and CT angiography. Stroke severity was assessed by the NIH Stroke Scale (NIHSS). Three- and twelve-month stent patency was assessed by ultrasound. Twelve-month functional outcome was assessed by the modified Rankin Scale (mRS). Results. Of 145 consecutive IV rtPA-treated patients, 6 (4%) underwent early CAS. Median age was 76 (range 67–78) years, median NIHSS at stroke onset was 12 (range 9–16) and 7 (range 7-8) before CAS. Median onset-to-CAS time was 48 (range 30–94) hours. A single self-expandable stent was implanted to cover the entire lesion in all patients. The procedure was uneventful in all patients. After 12 months, all patients had stent patency, and the functional outcome was favourable (mRS ≤ 2) in all but 1 patient experiencing a recurrent stroke for new-onset atrial fibrillation. Conclusion. This small case series of a single centre suggests that early CAS may be considered a safe alternative to CEA after IV rtPA administration in selected patients at high risk of stroke recurrence.

MR-PET fusion imaging in evaluating adnexal lesions: a preliminary study

PurposeThe objective of this preliminary study was to examine the effects of combined magnetic resonance/positron emission tomography (MR-PET) evaluation in the morphofunctional characterisation of ovarian lesions.Materials and methodsFrom June 2008 to September 2010, we evaluated 24 patients (mean age 44±10 years; range 24–74) with ovarian lesions incidentally detected on ultrasonography (US) and/or multislice computed tomography (CT). All patients underwent MR imaging of the pelvis and total-body CT-PET. PET and MR images were subsequently fused at postprocessing using specific anatomical criteria. Results were compared with the histological examination.ResultsOf the 24 examined lesions, 19 were malignant and five were benign on histological examination. MR, CT-PET and MR-PET sensitivity was 84%, 74% and 94%, respectively and specificity 60%, 80% and 100%, respectively. Positive (PPV) and negative predictive (NPV) values were 93% and 44% for CT-PET, 89% and 50% for MR and 100% and 83% for MR-PET, respectively.ConclusionsPelvic MR-PET fusion imaging provides advantages in terms of sensitivity and especially specificity compared with MR imaging or CT-PET alone. The added value of this fusion imaging modality lies in combining the benefits of the morphological evaluation provided by MR imaging and the metabolic assessment provided by PET.RiassuntoObiettivoScopo di questo studio preliminare è stato esaminare gli effetti della valutazione combinata risonanza magnetica (RM)/tomografia ad emissione di positroni (PET) nella caratterizzazione morfo-funzionale delle lesioni ovariche.Materiali e metodiDa giugno 2008 a settembre 2010 sono state valutate 24 pazienti (età media di 44±10 anni; range 24–74 anni) con riscontro casuale di lesione annessiale mediante esame ecotomografico e/o tramite tomografia computerizzata (TC) multistrato. Ogni paziente è stata sottoposta ad esame RM della pelvi e a valutazione TC/PET whole-body. Successivamente la PET e le immagini RM sono state fuse con post-processing attraverso specifici criteri anatomici. I risultati ottenuti sono stati confrontati con l’esito dell’esame istologico.RisultatiDelle 24 lesioni esaminate 19 sono risultate maligne all’esame istologico e 5 sono risultate benigne. I valori di sensibilità della RM, TC/PET e RM/PET sono stati rispettivamente 84%, 74% e 94%. I valori di specificità sono risultati rispettivamente 60%, 80% e 100%. Il valore predittivo positivo e il valore predittivo negativo sono stati rispettivamente del 93% e 44% per la TC/PET, 89% e 50% per la RM e 100% ed 83% per la RM/PET.ConclusioniLa fusione delle immagini PET con l’acquisizione RM della pelvi comporta vantaggi in termini di sensibilità e soprattutto di specificità rispetto alla sola RM o alla TC/PET. Il valore aggiunto di questa metodica di fusione di immagini consiste nello associare i vantaggi della valutazione morfologica RM allo studio metabolico PET.

Proposal for a Vascular Computed Tomography-Based Grading System in Posterior Circulation Stroke: A Single-Center Experience

OBJECTIVE The aim of this study is to investigate the role of a computed tomography angiography (CTA)-based approach in patients undergoing mechanical thrombectomy for vertebrobasilar stroke treatment. METHODS A CTA and digital subtraction angiography (DSA) retrospective analysis of patients with acute vertebrobasilar stroke treated with thrombectomy was performed. A modified Rankin Scale score of 3 or lower at 3 months was considered as favorable outcome. The posterior circulation ASPECTS (pc-ASPECTS) was evaluated on CTA and vertebrobasilar segments involved in the occlusion were assessed using a 6-point posterior circulation computed tomography angiography (pc-CTA) vascular score aimed at evaluating the posterior circulation vascular pattern including collaterals. The primary end point was the correlation between pc-CTA and outcome; secondary end points included the concordance between CTA-DSA images and the correlation between pc-ASPECTS and outcome. RESULTS Fifteen patients with vertebrobasilar stroke were retrospectively analyzed. All patients in coma showed a bad outcome (P = .01) and all patients with an alert state showed a good outcome (P = .004). An excellent interobserver agreement for pc-CTA (P = .001) was observed with poor interobserver agreement for pc-ASPECTS (P = .21). No significant correlations between pc-ASPECTS and clinical outcome were observed. Patients with good outcome had a lower pc-CTA (P = .02). The patency of the distal third of the basilar artery and both posterior cerebral arteries was related with good outcome. CONCLUSION The pc-CTA seems to have prognostic value in patients with vertebrobasilar stroke undergoing mechanical thrombectomy. It may be used as an additional prognostic triage technique in this subgroup of stroke patients.

Brain MR diffusion tensor imaging in Kennedy's disease

Introduction Kennedy’s disease (KD) is a progressive degenerative disorder affecting lower motor neurons. We investigated the correlation between disease severity and whole brain white matter microstructure, including upper motor neuron tracts, by using diffusion-tensor imaging (DTI) in eight patients with KD in whom disease severity was evaluated using the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS). Methods From DTI acquisitions we obtained maps of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (L1) and radial diffusivities (L2, L3). We then employed tract-based spatial statistics (TBSS) to investigate within-patient correlations of DTI invariants with ALSFRS and disease duration (DD). Results We found a significant correlation between low ALSFRS and 1) low FA values in association commissural and projection fibers, and 2) high L3 values in commissural tracts and fronto-parietal white matter. Additionally, we found a significant association between longer DD and 1) low FA in the genu and body of corpus callosum, association fibers and midbrain and 2) high L1 in projection and association tracts. Conclusions The associations between clinical variables and white matter microstructural changes in areas thought to be spared by the disease process support the hypothesis of a multisystem involvement in the complex pathogenic mechanisms responsible for the clinical disability of these patients.

MR-PET fusion imaging in evaluating adnexal lesions: a preliminary study Fusione RM/PET nelle lesioni annessiali: studio preliminare

PurposeThe objective of this preliminary study was to examine the effects of combined magnetic resonance/positron emission tomography (MR-PET) evaluation in the morphofunctional characterisation of ovarian lesions.Materials and methodsFrom June 2008 to September 2010, we evaluated 24 patients (mean age 44±10 years; range 24–74) with ovarian lesions incidentally detected on ultrasonography (US) and/or multislice computed tomography (CT). All patients underwent MR imaging of the pelvis and total-body CT-PET. PET and MR images were subsequently fused at postprocessing using specific anatomical criteria. Results were compared with the histological examination.ResultsOf the 24 examined lesions, 19 were malignant and five were benign on histological examination. MR, CT-PET and MR-PET sensitivity was 84%, 74% and 94%, respectively and specificity 60%, 80% and 100%, respectively. Positive (PPV) and negative predictive (NPV) values were 93% and 44% for CT-PET, 89% and 50% for MR and 100% and 83% for MR-PET, respectively.ConclusionsPelvic MR-PET fusion imaging provides advantages in terms of sensitivity and especially specificity compared with MR imaging or CT-PET alone. The added value of this fusion imaging modality lies in combining the benefits of the morphological evaluation provided by MR imaging and the metabolic assessment provided by PET.RiassuntoObiettivoScopo di questo studio preliminare è stato esaminare gli effetti della valutazione combinata risonanza magnetica (RM)/tomografia ad emissione di positroni (PET) nella caratterizzazione morfo-funzionale delle lesioni ovariche.Materiali e metodiDa giugno 2008 a settembre 2010 sono state valutate 24 pazienti (età media di 44±10 anni; range 24–74 anni) con riscontro casuale di lesione annessiale mediante esame ecotomografico e/o tramite tomografia computerizzata (TC) multistrato. Ogni paziente è stata sottoposta ad esame RM della pelvi e a valutazione TC/PET whole-body. Successivamente la PET e le immagini RM sono state fuse con post-processing attraverso specifici criteri anatomici. I risultati ottenuti sono stati confrontati con l’esito dell’esame istologico.RisultatiDelle 24 lesioni esaminate 19 sono risultate maligne all’esame istologico e 5 sono risultate benigne. I valori di sensibilità della RM, TC/PET e RM/PET sono stati rispettivamente 84%, 74% e 94%. I valori di specificità sono risultati rispettivamente 60%, 80% e 100%. Il valore predittivo positivo e il valore predittivo negativo sono stati rispettivamente del 93% e 44% per la TC/PET, 89% e 50% per la RM e 100% ed 83% per la RM/PET.ConclusioniLa fusione delle immagini PET con l’acquisizione RM della pelvi comporta vantaggi in termini di sensibilità e soprattutto di specificità rispetto alla sola RM o alla TC/PET. Il valore aggiunto di questa metodica di fusione di immagini consiste nello associare i vantaggi della valutazione morfologica RM allo studio metabolico PET.

Fusione RM/PET nelle lesioni annessiali: Studio preliminare

PurposeThe objective of this preliminary study was to examine the effects of combined magnetic resonance/positron emission tomography (MR-PET) evaluation in the morphofunctional characterisation of ovarian lesions.Materials and methodsFrom June 2008 to September 2010, we evaluated 24 patients (mean age 44±10 years; range 24–74) with ovarian lesions incidentally detected on ultrasonography (US) and/or multislice computed tomography (CT). All patients underwent MR imaging of the pelvis and total-body CT-PET. PET and MR images were subsequently fused at postprocessing using specific anatomical criteria. Results were compared with the histological examination.ResultsOf the 24 examined lesions, 19 were malignant and five were benign on histological examination. MR, CT-PET and MR-PET sensitivity was 84%, 74% and 94%, respectively and specificity 60%, 80% and 100%, respectively. Positive (PPV) and negative predictive (NPV) values were 93% and 44% for CT-PET, 89% and 50% for MR and 100% and 83% for MR-PET, respectively.ConclusionsPelvic MR-PET fusion imaging provides advantages in terms of sensitivity and especially specificity compared with MR imaging or CT-PET alone. The added value of this fusion imaging modality lies in combining the benefits of the morphological evaluation provided by MR imaging and the metabolic assessment provided by PET.RiassuntoObiettivoScopo di questo studio preliminare è stato esaminare gli effetti della valutazione combinata risonanza magnetica (RM)/tomografia ad emissione di positroni (PET) nella caratterizzazione morfo-funzionale delle lesioni ovariche.Materiali e metodiDa giugno 2008 a settembre 2010 sono state valutate 24 pazienti (età media di 44±10 anni; range 24–74 anni) con riscontro casuale di lesione annessiale mediante esame ecotomografico e/o tramite tomografia computerizzata (TC) multistrato. Ogni paziente è stata sottoposta ad esame RM della pelvi e a valutazione TC/PET whole-body. Successivamente la PET e le immagini RM sono state fuse con post-processing attraverso specifici criteri anatomici. I risultati ottenuti sono stati confrontati con l’esito dell’esame istologico.RisultatiDelle 24 lesioni esaminate 19 sono risultate maligne all’esame istologico e 5 sono risultate benigne. I valori di sensibilità della RM, TC/PET e RM/PET sono stati rispettivamente 84%, 74% e 94%. I valori di specificità sono risultati rispettivamente 60%, 80% e 100%. Il valore predittivo positivo e il valore predittivo negativo sono stati rispettivamente del 93% e 44% per la TC/PET, 89% e 50% per la RM e 100% ed 83% per la RM/PET.ConclusioniLa fusione delle immagini PET con l’acquisizione RM della pelvi comporta vantaggi in termini di sensibilità e soprattutto di specificità rispetto alla sola RM o alla TC/PET. Il valore aggiunto di questa metodica di fusione di immagini consiste nello associare i vantaggi della valutazione morfologica RM allo studio metabolico PET.