Comparing different analysis methods for quantifying the MRI amide proton transfer (APT) effect in hyperacute stroke patients

Amide proton transfer (APT) imaging is a pH mapping method based on the chemical exchange saturation transfer phenomenon that has potential for penumbra identification following stroke. The majority of the literature thus far has focused on generating pH‐weighted contrast using magnetization transfer ratio asymmetry analysis instead of quantitative pH mapping. In this study, the widely used asymmetry analysis and a model‐based analysis were both assessed on APT data collected from healthy subjects (n = 2) and hyperacute stroke patients (n = 6, median imaging time after onset = 2 hours 59 minutes). It was found that the model‐based approach was able to quantify the APT effect with the lowest variation in grey and white matter (≤ 13.8 %) and the smallest average contrast between these two tissue types (3.48 %) in the healthy volunteers. The model‐based approach also performed quantitatively better than the other measures in the hyperacute stroke patient APT data, where the quantified APT effect in the infarct core was consistently lower than in the contralateral normal appearing tissue for all the patients recruited, with the group average of the quantified APT effect being 1.5 ± 0.3 % (infarct core) and 1.9 ± 0.4 % (contralateral). Based on the fitted parameters from the model‐based analysis and a previously published pH and amide proton exchange rate relationship, quantitative pH maps for hyperacute stroke patients were generated, for the first time, using APT imaging

Ultrasonography and color Doppler in juvenile idiopathic arthritis: diagnosis and follow-up of ultrasound-guided steroid injection in the wrist region. A descriptive interventional study

<p>Abstract</p> <p>Background</p> <p>The wrist region is one of the most complex joints of the human body. It is prone to deformity and functional impairment in juvenile idiopathic arthritis (JIA), and is difficult to examine clinically. The aim of this study was to evaluate the role of ultrasonography (US) with Doppler in diagnosis of synovitis, guidance of steroid injections, and follow-up examinations of the wrist in JIA.</p> <p>Methods</p> <p>In 11 patients (median age 12.5 years, range 2-16), 15 wrists with clinically active arthritis were assessed clinically by US and color Doppler (Logiq 9, GE, 16-4 MHz linear transducer) prior to and 1 and 4 weeks after US-guided steroid injection.</p> <p>Results</p> <p>US detected synovitis in the radio-carpal joints, the midcarpal joints, and the tendon sheaths in 87%, 53% and 33% of the wrists, respectively. Multiple compartments were involved in 67%. US-guidance allowed accurate placement of steroid in all 21 injected compartments, with a low rate of subcutaneous atrophy. Synovial hypertrophy was normalized in 86% of the wrists, hyperemia in 91%, and clinically active arthritis in 80%.</p> <p>Conclusions</p> <p>US enabled detection of synovial inflammation in compartments that are difficult to evaluate clinically and exact guidance of injections, and it was valuable for follow-up examinations. Normalization of synovitis was achieved in most cases, which supports the notion that US is an important tool in management of wrist involvement in JIA.</p

Ultrasonography and color Doppler in juvenile idiopathic arthritis: diagnosis and follow-up of ultrasound-guided steroid injection in the ankle region. A descriptive interventional study

BACKGROUND: The ankle region is frequently involved in juvenile idiopathic arthritis (JIA) but difficult to examine clinically due to its anatomical complexity. The aim of the study was to evaluate the role of ultrasonography (US) of the ankle and midfoot (ankle region) in JIA. Doppler-US detected synovial hypertrophy, effusion and hyperemia and US was used for guidance of steroid injection and to assess treatment efficacy. METHODS: Forty swollen ankles regions were studied in 30 patients (median age 6.5 years, range 1-16 years) with JIA. All patients were assessed clinically, by US (synovial hypertrophy, effusion) and by color Doppler (synovial hyperemia) before and 4 weeks after US-guided steroid injection. RESULTS: US detected 121 compartments with active disease (joints, tendon sheaths and 1 ganglion cyst). Multiple compartments were involved in 80% of the ankle regions. The talo-crural joint, posterior subtalar joint, midfoot joints and tendon sheaths were affected in 78%, 65%, 30% and 55% respectively. Fifty active tendon sheaths were detected, and multiple tendons were involved in 12 of the ankles. US-guidance allowed accurate placement of the corticosteroid in all 85 injected compartments, with a low rate of subcutaneous atrophy (4,7%). Normalization or regression of synovial hypertrophy was obtained in 89%, and normalization of synovial hyperemia in 89%. Clinical resolution of active arthritis was noted in 72% of the ankles. CONCLUSIONS: US enabled exact anatomical location of synovial inflammation in the ankle region of JIA patients. The talo-crural joint was not always involved. Disease was frequently found in compartments difficult to evaluate clinically. US enabled exact guidance of steroid injections, gave a low rate of subcutaneous atrophy and was proved valuable for follow-up examinations. Normalization or regression of synovial hypertrophy and hyperemia was achieved in most cases, which supports the notion that US is an important tool in the management of ankle involvement in JIA

Autoimmune Neuromuscular Disorders in Childhood

Autoimmune neuromuscular disorders in childhood include Guillain-Barré syndrome and its variants, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), juvenile myasthenia gravis (JMG), and juvenile dermatomyositis (JDM), along with other disorders rarely seen in childhood. In general, these diseases have not been studied as extensively as they have been in adults. Thus, treatment protocols for these diseases in pediatrics are often based on adult practice, but despite the similarities in disease processes, the most widely used treatments have different effects in children. For example, some of the side effects of chronic steroid use, including linear growth deceleration, bone demineralization, and chronic weight issues, are more consequential in children than in adults. Although steroids remain a cornerstone of therapy in JDM and are useful in many cases of CIDP and JMG, other immunomodulatory therapies with similar efficacy may be used more frequently in some children to avoid these long-term sequelae. Steroids are less expensive than most other therapies, but chronic steroid therapy in childhood may lead to significant and costly medical complications. Another example is plasma exchange. This treatment modality presents challenges in pediatrics, as younger children require central venous access for this therapy. However, in older children and adolescents, plasma exchange is often feasible via peripheral venous access, making this treatment more accessible than might be expected in this age group. Intravenous immunoglobulin also is beneficial in several of these disorders, but its high cost may present barriers to its use in the future. Newer steroid-sparing immunomodulatory agents, such as azathioprine, tacrolimus, mycophenolate mofetil, and rituximab, have not been studied extensively in children. They show promising results from case reports and retrospective cohort studies, but there is a need for comparative studies looking at their relative efficacy, tolerability, and long-term adverse effects (including secondary malignancy) in children

Volume changes of extremely large and giant intracranial aneurysms after treatment with flow diverter stents.

INTRODUCTION: This study assessed volume changes of unruptured large and giant aneurysms (greatest diameter &gt;20 mm) after treatment with flow diverter (FD) stents. METHODS: Clinical audit of the cases treated in a single institution, over a 5-year period. Demographic and clinical data were retrospectively collected from the hospital records. Aneurysm volumes were measured by manual outlining at sequential slices using computerised tomography (CT) or magnetic resonance (MR) angiography data. RESULTS: The audit included eight patients (seven females) with eight aneurysms. Four aneurysms involved the cavernous segment of the internal carotid artery (ICA), three the supraclinoid ICA and one the basilar artery. Seven patients presented with signs and symptoms of mass effect and one with seizures. All but one aneurysm was treated with a single FD stent; six aneurysms were also coiled (either before or simultaneously with FD placement). Minimum follow-up time was 6 months (mean 20 months). At follow-up, three aneurysms decreased in size, three were unchanged and two increased. Both aneurysms that increased in size showed persistent endosaccular flow at follow-up MR; in one case, failure was attributed to suboptimal position of the stent; in the other case, it was attributed to persistence of a side branch originating from the aneurysm (similar to the endoleak phenomenon of aortic aneurysms). At follow-up, five aneurysms were completely occluded; none of these increased in volume. CONCLUSION: Complete occlusion of the aneurysms leads, in most cases, to its shrinkage. In cases of late aneurysm growth or regrowth, consideration should be given to possible endoleak as the cause

PRINCIPI FISICI E TECNICI E PROPEDEUTICA SEMEIOLOGICA IN RISONANZA MAGNETICA

Dalla Prefazione: La Diagnostica per Immagini è oggi al primo posto fra le indagini strumentali indispensabili a supporto della prima diagnosi clinica ed è il filo conduttore del monitoraggio del decorso clinico di diverse patologie. Nei dieci anni intercorsi dalla prima edizione, l’imaging ha subito tumultuose evoluzioni tecnologiche in termini di digitalizzazione delle immagini, con straordinari risultati applicativi, tanto da introdurre nuove metodiche e ridurne l’indicazione o farne scomparire altre. L’acquisizione delle immagini in TC ed RM è divenuta più veloce e i pixel delle immagini digitali più piccoli. Ciò ha consentito nuove applicazioni cliniche quali la cardio-TC, l’entero-TC e la colonscopia virtuale, l’angio-TC di tutti gli apparati fino a livello dei piccoli vasi: quest’ultima ha completamente sostituito l’angiografia convenzionale. I sistemi CAD (Computed Aided Detection) stanno sempre più affiancando la diagnosi radiologica come strumento di seconda lettura in settori quale il torace, la mammografia e la colonscopia virtuale, specie negli esami di screening. Inoltre, la digitalizzazione delle immagini insieme alla diffusione dei sistemi RIS-PACS ha radicalmente mutato l’attività del radiologo, che oggi si svolge su workstation capaci di visualizzare velocemente migliaia di immagini, facilitandone così la lettura, e di eseguire su queste ricostruzioni tridimensionali in tempo reale; per di più essa può essere svolta in sedi distanti. Contemporaneamente, negli ultimi anni si è osservato in tutto il mondo uno smisurato incremento di richieste delle indagini radiologiche, che ha indotto la necessità di strumenti per promuovere l’appropriatezza e l’efficacia degli interventi ed un uso più razionale delle risorse: da qui la nascita di numerose linee guida per le indicazioni alle varie metodiche di imaging e di algoritmi decisionali condivisi dalle varie società scientifiche per le diverse patologie, che devono essere conosciuti. I radiologi in formazione, come anche gli specialisti di altre discipline, debbono dunque rendersi edotti delle numerose problematiche di ordine tecnico- metodologico e interpretativo che emergono nelle applicazioni cliniche delle tante e complesse apparecchiature, con l’imperativo del più razionale e accurato utilizzo di esse. Essi sentono profondamente questo loro dovere ed è infatti molto frequente da parte loro la richiesta di testi che forniscano chiare e complete informazioni sull’ottimale impiego delle varie tecniche d’indagine, specie se trattano nel loro insieme e con criterio d’integrazione tutte le tecniche di diagnostica per immagini. Con questo nostro lavoro abbiamo dunque inteso concorrere a soddisfare tale domanda, proponendoci di fornire ai radiologi un testo di approfondimento ed una guida ragionata nella scelta della tecnica di elezione e di quelle complementari nello studio morfologico e funzionale delle patologie dei diversi apparati e di illustrarne i principali reperti morfologici. Abbiamo cercato di redigere questo testo con modalità e terminologia tali da poterlo rendere anche un manuale di facile consultazione per tutti i medici operanti nel campo della medicina generale e nelle branche specialistiche, che vogliano orientarsi nel complesso settore della diagnostica per immagini, vogliano acquisire le informazioni necessarie per valutare in ciascuna patologia l’utilità delle varie tecniche, desiderino conoscerne le potenzialità e anche i limiti e vogliano rendersi edotti dei risultati che si possono ottenere mediante l’integrazione delle diverse tecniche. Negli ultimi dieci anni si sono inoltre sviluppate la genomica e la proteomica e, per lo studio di questi fenomeni, si sono sviluppate le nanotecnologie (quali i sistemi meccanici di microelettronica, o MEMS), in grado di identificare a livello molecolare le variazioni della composizione dei costituenti del corpo umano e l’imaging molecolare (la micro-PET o tomografia ad emissione di positroni, la micro-SPECT o tomografia ad emissione di un singolo fotone, la micro-TC, la micro-RM, la micro-ecografia e l’optical imaging), alcune delle quali vengono applicate solamente in campo pre-clinico su modelli animali da laboratorio (come l’optical imaging), altre già trovano analoga e routinaria applicazione sia preclinica che clinica. Tali argomenti, che probabilmente troveranno applicazione umana negli anni a venire, sono anch’essi stati oggetto di trattazione. L’opera si compone di due volumi ed è organizzata in cinque parti. La Parte Prima (capitoli 1-3) tratta dei principi fisici delle metodiche computerizzate (TC ed RM) e dei relativi mezzi di contrasto. La Parte Seconda (capitoli 4-26) è dedicata a tutti i settori di applicazione delle metodiche TC ed RM nei diversi distretti anatomici, passando in rassegna tutte le principali patologie d’organo; è la più ampia in quanto in essa è contenuta la maggior parte delle informazioni (dati epidemiologici e anatomopatologici, classificazioni nosologiche, algoritmi diagnostici, classificazioni in stadi della patologia neoplastica, ecc.) che servono anche come riferimento nell’esporre le applicazioni cliniche delle altre tecniche. La Parte Terza (capitoli 27-29) presenta tre metodiche innovative (spettroscopia RM, RM funzionale, ed imaging molecolare). La Parte Quarta (II volume) esamina le applicazioni dell’US nei diversi distretti anatomici. La Parte Quinta (II volume) è dedicata alle applicazioni della Medicina Nucleare. ANTONINO LENTINI, RITA GOLFIER

Results of surgical and endovascular treatment of intracranial micro-arteriovenous malformations with emphasis on superselective angiography

Background. The authors retrospectively reviewed the results of two different treatment modalities (surgery and endovascular approach) in patients with intracranial micro-arteriovenous malformations (micro-AVMs). The goal of this study is to evaluate the respective role of surgical treatment and superselective acrylic embolization in the management of micro-AVMs. Method. Fourteen patients with micro-AVMs who had been treated by surgical resection or endovascular acrylic embolization during a 6-year period were analyzed. The average age at presentation was 44.6 years (range, 24-65 yr) with no sex dominance. All patients presented with an intracranial haemorrhage, which was superficial in twelve patients and in eloquent brain areas in seven patients. Severe neurological deficits were observed in eleven patients. Findings. Digital subtraction angiography (DSA) demonstrated micro-AVMs in eleven patients (78.5%) while in three patients (21.5%) the micro-AVM was detected only by superselective angiography (SA). Eight patients underwent surgical intervention which led to definitive resection in seven with no peri-operative morbidity. SA was performed in nine patients and followed by successful acrylic embolization of the micro-AVM in seven with haemorrhagic complications in two patients. All fourteen lesions were completely obliterated as demonstrated angiographically. Outcomes were classified according to the Modified Rankin Scale. With a mean long term clinical follow-up of 33 months (range, 8-75 mo), seven patients were Grade 0, six patients were Grade I and one patient was Grade IV. Conclusions. SA is deemed necessary to visualize micro-AVMs in case of questionable or negative findings also at delayed DSA in young healthy patients with otherwise unexplained intracranial haemorrhage. Obliteration of micro-AVM can be accomplished either surgically or endovascularly; however, the endovascular approach is associated with a defined procedural risk for haemorrhagic complications and long term angiographic follow-up is necessary