1,721,736 research outputs found
A rare case of ruptured aneurysm of the paramedian artery of Percheron
Full text linkIntroduction: The artery of Percheron is a rare anatomic variant supplying bilateral medial thalamic nuclei and a variable portion of the rostral part of midbrain. Case report: A 48-year-old female with massive subarachnoid hemorrhage due to a ruptured aneurysm of the paramedian artery of Percheron presented to the emergency room. Because of significant risk of recurrent intracranial hemorrhage, it was decided to proceed with endovascular embolization of the aneurysm. The patient was ultimately sent to a rehabilitation center and her presenting neurologic deficits showed significant improvements in the weeks following endovascular embolization treatment. Discussion: The paramedian artery of Percheron is a rare anatomic variant and subarachnoid hemorrhage due to aneurysm of this artery is exceedingly rare. This case underlines the importance of a correct evaluation of cerebral arterial anatomy in order to choose the best endovascular therapeutic approach, reduce complications, and optimize patient outcome
Prevention of post-contrast kidney injury in patients with cancer
Full text linkPost-contrast acute kidney injury is defined as a nephropathy with an increase in serum creatinine of >0.3 mg/dL (or >26.5 μmol/L) or >1.5-times the baseline within 48–72 h of intravascular administration of a contrast medium. Patients with cancer have an increased risk of post-contrast acute kidney injury not only related to the frequent use of contrast medium for computed tomography scans but also to other factors, including the type of tumour, age, oncological therapies, use of other nephrotoxic agents and dehydration. Preventive strategies were developed and may be applied to different risk profiles. Patients at risk may be detected by recently published risk scores
Gadoxetic acid-enhanced MRI of transient hepatic enhancement differences: Another cause of hypointense observation on hepatobiliary phase
No full textPurpose: To retrospectively determine the frequency, natural history and factors associated with the presence of transient hepatic enhancement difference showing hypointensity on hepatobiliary phase images of gadoxetic acid-enhanced MRI. Materials and methods: Gadoxetic acid-enhanced MRI of 125 patients (91 men; 34 women) with transient hepatic enhancement difference were retrospectively reviewed. Three readers qualitatively and quantitatively evaluated MR imaging features and evolution at follow up. The Chi-square test, Fisher's exact test and Kruskall-Wallis rank test were used for statistical analysis. Results: Transient hepatic enhancement difference were hypointense on hepatobiliary phase images in 20 of 125 cases (16%). At univariate analysis there was association with wedge-shape morphology (p < 0.001), size ≥21 mm (p < 0.001), hyperintensity on T2-weighted imaging (p < 0.001), restricted diffusion (p < 0.001) and previous treatment (p < 0.005). At multivariate analysis, the following factors were associated: previous treatment (p < 0.05), hyperintensity on T2-weighted imaging (p < 0.001) and size ≥21 mm (p < 0.001). Of 12 patients with hypointense transient hepatic enhancement difference on hepatobiliary phase images who had follow-up MRI, nine showed reduction in size. Conclusion: Transient hepatic enhancement difference observations showing hypointensity on hepatobiliary phase images of gadoxetic acid-enhanced MRI are not infrequent and may shrink at follow-up. They are more likely associated with size ≥21 mm, hyperintensity on T2-weighted images and previous treatment of adjacent tumor
Multiple sclerosis: High prevalence of the ‘central vein’ sign in white matter lesions on susceptibility-weighted images
Full text linkPurpose: The aim of this study was to determine the occurrence and distribution of the ‘central vein’ sign in white matter
lesions on susceptibility-weighted magnetic resonance images in patients with multiple sclerosis (MS) and cerebral small
vessel disease (CSVD).
Materials and methods: T2-weighted and fluid-attenuated inversion recovery magnetic resonance images of 19 MS patients
and 19 patients affected by CSVD were analysed for the presence and localisation of focal hyperintense white matter lesions.
Lesions were subdivided into periventricular or non-periventricular (juxtacortical, subcortical, deep white matter and
cerebellar) distributed. The number and localisation of lesions presenting with the central vein sign were recorded and
compared between MS and CSVD lesions.
Results: A total of 313 MS patients and 75 CSVD lesions were identified on T2-weighted and fluid-attenuated inversion
recovery magnetic resonance images. The central vein sign was found in 128 MS lesions (40.9%), and the majority of them
(71/128, 55.5%) had a periventricular distribution. The central vein sign was found in 22 out of 75 (29.3%) CSVD lesions, and
periventricular distribution was seen in six out of 22 (27.2%) CSVD lesions. The difference in the proportion of white matter
hyperintense lesions that presented with the central vein sign on susceptibility-weighted images in patients with MS and
CSVD was statistically different, and a significantly higher number of MS patients presented with lesions with the central
vein sign compared to CSVD patients.
Conclusion: The presence of the central vein sign on susceptibility-weighted images for MS lesions improves the understanding of the periventricular distribution of MS lesions and could contribute as adjunctive diagnostic criteria for MS
disease
Studio di segmentazione morfovolumetrica in pazienti con declino cognitivo lieve amnestico (aMCI) e demenza di Alzheimer (AD) rispetto ad un gruppo di controllo (Normal Aging Brain, NAB)
Full text linkSCOPO: Presentare i risultati preliminari di un’analisi di segmentazione morfovolumetrica (VBM) eseguita in pazienti con aMCI ed AD rispetto ad una popolazione di controllo (NAB). Tali dati saranno in futuro correlati ad altri parametri clinico-psicologici raccolti (età, sesso, scolarità, MMSE, ADL, IADL).
MATERIALI E METODI: Sono stati sottoposti ad esame RM encefalo 103 soggetti, utilizzando uno scanner RM GE Signa HDxt da 1,5T ed acquisendo, tra le altre, una sequenza Sag 3D T1 FSPGR IR preped ASSET che è stata utilizzata per l’analisi VBM eseguita con il tool sienax (FSL). I risultati sono stati valutati in termini di valori medi e deviazioni standard mediante applicazione del t-test tra gruppi (α=0.05). Sono stati esclusi pz. con dataset RM incompleti o inficiati, con severa leucoaraiosi o altri insulti parenichimali o reperti accessori che potessero inficiare i risultati delle analisi; a seguito di tale selezione la popolazione di studio è risultata pari a 58 soggetti (27♂ e 31♀; età media 72,95 / range 61-85 / dev. stand. 6,66; naMCI=21, nAD=19, nNAB=18).
RISULTATI: Differenze statisticamente significative: tra i vol. di st. grigia (p=0.002) e vol. cerebrali globali (p=0.004) tra AD e NAB; tra i vol. di st. grigia (p=0.005) e vol. cerebrali globali (p=0.004) tra aMCI e AD. Non evidenziate differenze statisticamente significative nei dati di segmentazione tra aMCI e NAB o tra i vol. della st. bianca dei tre gruppi.
CONCLUSIONI: I risultati ottenuti, in linea con la letteratura, evidenziano certamente l’importanza di questo tipo di analisi ma al tempo stesso confermano come sia necessario utilizzare altre tecniche di studio per differenziare quadri clinici oggi non discriminabili con tecniche di imaging convenzionali o tecniche di analisi che fanno riferimento alla sola morfovolumetria cerebrale
LA DIAGNOSI DI DOLICOECTASIA DELLA CAROTIDE INTERNA E LE SUE IMPLICAZIONI CLINICO-PATOLOGICHE
Full text linkRISONANZA MAGNETICA (RM) MORFOLOGICA E FUNZIONALE NELLO STUDIO DELL'ADENOCARCINOMA PROSTATICO (CAP)
No full textObiettivi didattici. Illustrare i reperti morfologici e funzionali del CaP, all'imaging RM. Introduzione. La RM è una metodica fondamentale nello studio del CaP; oltre all'imaging morfologico, permette importanti acquisizioni funzionali che aumentano la sua performance diagnostica. Tecnica d'esame. Lo studio RM della prostata prevede sequenze assiali t1, assiali, coronali e sagittali T2, DWI, sequenze spettroscopiche e sequenze perfusioni (GE T1w 3d fat-sat). In T1 la prostata ha intensità di segnale medio-bassa omogenea, senza possibilità di distinzione dell'anatomia zona e ghiandolare o d'identificazione di eventuali CaP. Queste sequenze permettono la visualizzazione di eventuali residui ematici post-bioptici e dell'interfaccia ghiandola/tessuto adiposo periprostatico. Le sequenze T2 pesate permettono una valutazione dell'anatomia zonale prostatica con la zona periferica iperintensa (ZP) rispetto alla zona centrale (GC). Il CaP si presente come un'area ipointensa nel contesto della normale ZP. Nelle sequenze perfusioni il CaP mostra un'intensa captazione (wash-in) con successiva rapida dismissione (wash-out) del mezzo di contrasto, comportamento meglio visibile grazie all'elaborazione di curve intensità/tempo che mostrano una morfologia differente rispetto al tessuto sano. Nelle sequenze DWI la minore diffusività delle molecole di acqua nel CaP si manifesta come iperintensitànelle immagini DWI ed ipointensità nelle mappe ADC con valore di ADC <1.24. La spettroscopia permete una valutazione metabolica della prostata: il CaP mostra incremento di Colina (Cho) e Creatina (Cr) con riduzione del Citrato (Ci) che si riflette in un incremento nel valore del rapporto Cho+Cr/Ci. Conclusioni. La RM ha un ruolo di primaria importanza nella identificazione, localizzazione , stadiazione loco-regionale e follow up del paziente con CaP
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