N. Maggialetti

Multiparametric 3T MR approach to the assessment of cerebral gliomas: tumor extent and malignancy.

IntroductionContrast-enhanced MR imaging is the method of choice for routine assessment of brain tumors, but it has limited sensitivity and specificity. We verified if the addition of metabolic, diffusion and hemodynamic information improved the definition of glioma extent and grade.MethodsThirty-one patients with cerebral gliomas (21 high- and 10 low-grade) underwent conventional MR imaging, proton MR spectroscopic imaging (1H-MRSI), diffusion weighted imaging (DWI) and perfusion weighted imaging (PWI) at 3 Tesla, before undergoing surgery and histological confirmation. Normalized metabolite signals, including choline (Cho), N-acetylaspartate (NAA), creatine and lactate/lipids, were obtained by 1H-MRSI; apparent diffusion coefficient (ADC) by DWI; and relative cerebral blood volume (rCBV) by PWI.ResultsPerienhancing areas with abnormal MR signal showed 3 multiparametric patterns: “tumor”, with abnormal Cho/NAA ratio, lower ADC and higher rCBV; “edema”, with normal Cho/NAA ratio, higher ADC and lower rCBV; and “tumor/edema”, with abnormal Cho/NAA ratio and intermediate ADC and rCBV. Perienhancing areas with normal MR signal showed 2 multiparametric patterns: “infiltrated”, with high Cho and/or abnormal Cho/NAA ratio; and “normal”, with normal spectra. Stepwise discriminant analysis showed that the better classification accuracy of perienhancing areas was achieved when regarding all MR variables, while 1H-MRSI variables and rCBV better differentiated high- from low-grade gliomas.ConclusionMultiparametric MR assessment of gliomas, based on 1H-MRSI, PWI and DWI, discriminates infiltrating tumor from surrounding vasogenic edema or normal tissues, and high- from low-grade gliomas. This approach may provide useful information for guiding stereotactic biopsies, surgical resection and radiation treatment.

Phenylketonuria: white-matter changes assessed by 3.0-T magnetic resonance (MR) imaging, MR spectroscopy and MR diffusion

PurposeThis study evaluated the sensitivity of a 3.0-Tesla (T) magnetic resonance imaging (MRI) in measuring cerebral phenylalanine using proton magnetic resonance spectroscopy and in assessing MR-documented white-matter changes by means of diffusion studies (diffusion-weighted imaging, apparent diffusion coefficient map; diffusion tensor imaging) in patients with phenylketonuria.Materials and methodsThirty-two patients with the classical clinical and biochemical deficits of phenylketonuria underwent biochemical (blood phenylalanine), genotypic (phenylalanine hydroxylase gene) and radiological investigation by means of MRI, proton magnetic resonance spectroscopy and diffusion magnetic resonance imaging with a 3.0-T scanner.ResultsPeriventricular and subcortical white-matter changes were detected on all MR scans. In 29/32 patients, proton magnetic resonance spectroscopy easily documented abnormal signal elevation at 7.36 ppm, corresponding to phenylalanine, despite its low concentration. Phenylalanine signal amplitude relative to the creatine/phosphocreatine signal increased linearly with blood phenylalanine values (r 0.7067; p<0.001). Diffusion MRI demonstrated hyperintensity in the areas exhibiting MRI changes as well as decreased apparent diffusion coefficient values, but fractional anisotropy indices were normal.ConclusionsThe high signal, together with better spectral, spatial, contrast and temporal resolution, makes the 3.0-T MR the most suitable technique in the study of the phenylketonuria. In particular, the multimodal approach with MRI, proton magnetic resonance spectroscopy and diffusion magnetic resonance imaging can provide more information than previous studies performed with low-field systems.RiassuntoObiettivoValutare in pazienti con fenilchetonuria la sensibilità di un sistema di risonanza magnetica (RM) a 3,0 Tesla (T) nel misurare la fenilalanina cerebrale con la spettroscopia protonica e nel documentare le alterazioni della sostanza bianca rilevate con lo studio RM di base utilizzando gli studi di diffusione (imaging pesato in diffusione, mappa del coefficiente di diffusione apparente, imaging del tensore).Materiali e metodiTrentadue pazienti con il deficit clinico e biochimico classico di fenilchetonuria sono stati sottoposti ad uno studio biochimico (livelli della fenilalanina cerebrale), genotipico (gene fenilalanina idrossilasi) e radiologico mediante uno studio RM di base, di spettroscopia e di diffusione con apparecchiatura a 3,0 T.RisultatiIn tutte le immagini RM morfologiche sono state rilevate alterazioni della sostanza bianca periventricolari e sottocorticali. In 29 pazienti su 32 la spettroscopia protonica ha rilevato facilmente un picco anomalo a 7,36 ppm corrispondente alla fenilalanina nonostante la sua bassa concentrazione. Ls’ampiezza del segnale della fenilalanina relativo al rapporto creatina/fosfocreatina incrementa linearmente con la fenilalanina ematica (r=0,7067; p<0,001). Lo studio di diffusione ha evidenziato iperintensità focali nelle aree di alterato segnale documentate con lo studio RM di base, valori di coefficiente di diffusione apparente ridotto e indici di anisotropia frazionata normale.ConclusioniLs’alto segnale assieme alla maggiore risoluzione spettrale, spaziale, di contrasto e temporale rende il sistema 3,0 T ideale per lo studio della fenilchetonuria. In particolare ls’approccio multimodale con imaging RM di base, di spettroscopia e di diffusione può fornire maggiori informazioni rispetto ai precedenti studi acquisiti con sistemi a più basso campo.Purpose. This study evaluated the sensitivity of a 3.0-Tesla (T) magnetic resonance imaging (MRI) in measuring cerebral phenylalanine using proton magnetic resonance spectroscopy and in assessing MR-documented whitematter changes by means of diffusion studies (diffusionweighted imaging, apparent diffusion coefficient map; diffusion tensor imaging) in patients with phenylketonuria. Materials and methods. Thirty-two patients with the

Whole-body MR-DWIBS vs. [18F]-FDG-PET/CT in the study of malignant tumors: a retrospective study

PurposeOur aim was to assess the overall diagnostic accuracy of magnetic resonance diffusion-weighted whole-body imaging with background signal suppression (MR-DWIBS) compared with ([18F]-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT), considered the reference standard of whole-body tumour imaging modalities, in a series of consecutive patients with malignant tumour.Materials and methodsThirty-eight patients diagnosed with a malignant tumour over a 4-month period were enrolled in this retrospective, observational study. PET/CT and MR-DWIBS images were reviewed in double-blind manner by a nuclear medicine physician and radiologists with 4 years experience. Lesion size, standard uptake value (SUV) and apparent diffusion coefficient (ADC) were measured and calculated for each lesion.ResultsThe qualitative analysis of MR-DWIBS and [18F]-FDG-PET/CT showed that two patients were negative at both techniques. MR-DWIBS was positive in 36 patients, 34 of whom were positive and two negative at [18F]-FDG-PET/CT, respectively. Two hundred and fifty-five lesions were identified by MR-DWIBS and 184 by [18F]-FDG-PET/CT, which was a significative discordance. Correlation between SUV and ADC of lesions positive at both techniques was not statistically significant. The mean difference between lesion size in [18F]-FDG-PET/CT and MR-DWIBS was not statistically significant. No correlation was found between glucose metabolism and water motion.ConclusionsMR-DWIBS may be used to evaluate localisation of parenchymal neoplasms but is less efficacious in characterising lymph-node and skeletal lesions. [18F]-FDG-PET/CT remains the best whole-body technique to identify lymph-node and skeletal lesions, but its limitation is identifying tumours with low glucose metabolism as in mucinous neoplasms. MR-DWIBS evaluation must be integrated with morphological images to increase MR diagnostic accuracy.RiassuntoObiettivoL’obiettivo del nostro lavoro è stato stabilire il valore di accuratezza diagnostica della whole-body risonanza magnetica (RM)-diffusion weighted whole body imaging with background signal suppression (DWIBS) rispetto alla 18F-fluor-deossiglucosio (FDG)-tomografia a emissione di positroni (PET)/tomografia computerizzata (TC), considerata il gold standard nell’ambito della diagnostica whole body nell’imaging dei tumori, in un gruppo di pazienti con diagnosi di neoplasia maligna.Materiali e metodiSono stati inclusi 38 pazienti con diagnosi di neoplasia maligna in un periodo di 4 mesi. Le immagini PET/TC e RM-DWIBS sono state rivalutate in doppio cieco da un medico nucleare e da un radiologo con 4 anni di esperienza. Per ciascuna lesione sono state valutate dimensioni, standardized uptake value (SUV) e coefficiente di diffusione apparente (ADC).RisultatiLa valutazione qualitativa sia della MR-DWIBS che della 18F-FDG-PET/TC ha riscontrato due soli pazienti negativi per entrambe le tecniche. La RM-DWIBS è risultata positiva in 36 pazienti, di cui 34 erano positivi e 2 risultavano negativi alla 18F-FDG-PET/TC. Duecentocinquantacinque lesioni sono state identificate con la MR-DWIBS e 184 con 18F-FDG-PET/TC. È stata dimostrata una discordanza significativa. La correlazione tra SUV e ADC nelle lesioni positive ad entrambe le tecniche non è risultata statisticamente significativa. La differenza media tra la dimensione delle lesioni alla 18F-FDG-PET/TC e alla RM-DWIBS non è risultata statisticamente significativa. Non è stata dimostrata alcuna correlazione tra il metabolismo glucidico e i movimenti di diffusione.ConclusioniI risultati di questo studio retrospettivo dimostrano che la RM-DWIBS può essere utilizzata per studiare le localizzazioni parenchimali e scheletriche di neoplasia, ma che essa risulta meno efficacie nella caratterizzazione delle lesioni linfonodali. La 18F-FDG-PET/TC resta la tecnica migliore per valutare le lesioni linfonodali. Il limite della 18F-FDG-PET/TC è identificare tumori con basso metabolismo glucidico come le neoplasie mucinose. Lo studio RM-DWIBS deve essere integrato con immagini morfologiche per aumentarne l’ accuratezza diagnostica.

Role of advanced MR imaging modalities in diagnosing cerebral gliomas

The objective of this study was to evaluate the potential role of newly developed, advanced magnetic resonance (MR) imaging techniques (spectroscopy, diffusion and perfusion imaging) in diagnosing brain gliomas, with special reference to histological typing and grading, treatment planning and posttreatment follow-up. Conventional MR imaging enables the detection and localisation of neoplastic lesions, as well as providing, in typical cases, some indication about their nature. However, it has limited sensitivity and specificity in evaluating histological type and grade, delineating margins and differentiating oedema, tumour and treatment side-effects. These limitations can be overcome by supplementing the morphological data obtained with conventional MR imaging with the metabolic, structural and perfusional information provided by new MR techniques that are increasingly becoming an integral part of routine MR studies. Incorporation of such new MR techniques can lead to more comprehensive and precise diagnoses that can better assist surgeons in determining prognosis and planning treatment strategies. In addition, the recent development of new, more effective, treatments for cerebral glioma strongly relies on morphofunctional MR imaging with its ability to provide a biological interpretation of these characteristically heterogeneous tumours.RiassuntoLo scopo del lavoro è di illustrare le potenzialità delle nuove e più avanzate modalità di studio RM (spettroscopia, diffusione, perfusione) nella diagnostica dei gliomi cerebrali, con particolare riferimento alla definizione dell’istotipo e del grading, alla pianificazione del trattamento e al follow-up post-trattamento. Con la RM di base è possibile nei casi tipici identificare la lesione neoplastica, stabilirne la sede e la topografia e proporre un’ipotesi di natura. Vi è però una limitata sensibilità e specificità nella definizione dell’istotipo e del grading, nell’individuazione dei margini neoplastici e nella differenziazione tra tumore ed edema o effetti del trattamento. È necessario pertanto integrare le informazioni fornite dalla RM di base con le informazioni di carattere metabolico, strutturale ed emodinamico fornite dalle più recenti tecniche RM, oramai parte integrante di uno studio di routine. In tal modo sono possibili diagnosi sempre più precise ed esaustive per il chirurgo, necessarie per definire la prognosi e l’impostazione delle diverse strategie terapeutiche. Inoltre, il recente sviluppo di nuovi e più efficaci trattamenti ha reso sempre più necessario uno studio RM morfofunzionale con cui ottenere in maniera non invasiva una “neuropatologia in vivo” e quindi un’interpretazione biologica della eterogeneità tipica di tali tumori.Abstract The objective of this study was to evaluate the potential roleof newly developed, advanced magnetic resonance (MR)imaging techniques (spectroscopy, diffusion and perfusionimaging) in diagnosing brain gliomas, with specialreference to histological typing and grading, treatmentplanning and posttreatment follow-up. Conventional MRimaging enables the detection and localisation of neoplasticlesions, as well as providing, in typical cases, someindication about their nature. However, it has limitedsensitivity and specificity in evaluating histological typeand grade, delineating margins and differentiating oedema,tumour and treatment side-effects. These limitations can beovercome by supplementing the morphological dataobtained with conventional MR imaging with themetabolic, structural and perfusional information providedby new MR techniques that are increasingly becoming anintegral part of routine MR studies. Incorporation of suchnew MR techniques can lead to more comprehensive andprecise diagnoses that can better assist surgeons indetermining prognosis and planning treatment strategies. Inaddition, the recent development of new, more effective,treatments for cerebral glioma strongly relies onmorphofunctional MR imaging with its ability to provide abiological interpretation of these characteristicallyheterogeneous tumours.

3.0 T MR Angiography

Magnetic resonance angiography (MRA) is a well-established non-invasive technique for the evaluation of intracranial arterial and venous vasculature. It can be performed without and with administration of contrast agent. The use of high field scanners offer important advantages such as increase of the spatial and temporal resolution. Additional gains are obtained with parallel imaging, which significantly reduces examination times and increases anatomical coverage providing the same image quality.

3.0 T MRI Diagnostic Features: Comparison with Lower Magnetic Fields

3.0 T magnetic resonance (MR) scanner, compared to low-field systems, offer several advantages as higher signal/noise ratio (SNR), greater spatial and temporal resolution. Some disadvantages are: the increase of specific absorption rates (SAR) and of acoustic noise, the dielectric resonance, although in the more recent equipment, these problems have largely been resolved by improvements in hardware and software. High filed MR find their best applications in the evaluation of the central nervous system especially with functional studies thanks to raise of magnetic susceptibility and chemical shift effects.

MRI of popliteo-meniscal fasciculi of the knee: a pictorial review

The popliteomeniscal fascicules (PMFs) provide the attachment of the lateral meniscus to the popliteus musculotendinous region, forming the floor and the roof the popliteal hiatus. In the second half of 1900’s, some anatomic studies claim the important function of the PMF as stabilizers of the lateral meniscus; these anatomical structures work in conjunction with the popliteus musculotendinous unit to prevent excessive lateral meniscal movement and possible meniscus subluxation. A correct diagnosis of the PMFs pathology is crucial to establish the suitable surgical treatment for each patient. MRI is a well-established imaging technique in the musculoskeletal system and the frequency of recognition of normal PMF in the normal knees is high in almost all MRI studies. At day, the gold standard for diagnosis is the arthroscopic evaluation that allows the direct visualization of the popliteo-meniscal ligaments at popliteal hiatus and evaluation of lateral meniscal movements. For this reason if unstable condition of meniscus was suspected, arthroscopic observation with probing into the popliteo-meniscal fascicle area is essential for the identification of the fascicle tears. Despite many treatments have being proposed in literature since now there is high recurrence of knee locking after repair and it is fundamental to develop new surgical techniques in order to achieve better outcome. (www.actabiomedica.it)

Ruolo delle nuove ed avanzate modalità di studio RM nella diagnostica neuroradiologica dei gliomi cerebrali

The objective of this study was to evaluate the potential role of newly developed, advanced magnetic resonance (MR) imaging techniques (spectroscopy, diffusion and perfusion imaging) in diagnosing brain gliomas, with special reference to histological typing and grading, treatment planning and posttreatment follow-up. Conventional MR imaging enables the detection and localisation of neoplastic lesions, as well as providing, in typical cases, some indication about their nature. However, it has limited sensitivity and specificity in evaluating histological type and grade, delineating margins and differentiating oedema, tumour and treatment side-effects. These limitations can be overcome by supplementing the morphological data obtained with conventional MR imaging with the metabolic, structural and perfusional information provided by new MR techniques that are increasingly becoming an integral part of routine MR studies. Incorporation of such new MR techniques can lead to more comprehensive and precise diagnoses that can better assist surgeons in determining prognosis and planning treatment strategies. In addition, the recent development of new, more effective, treatments for cerebral glioma strongly relies on morphofunctional MR imaging with its ability to provide a biological interpretation of these characteristically heterogeneous tumours.RiassuntoLo scopo del lavoro è di illustrare le potenzialità delle nuove e più avanzate modalità di studio RM (spettroscopia, diffusione, perfusione) nella diagnostica dei gliomi cerebrali, con particolare riferimento alla definizione dell’istotipo e del grading, alla pianificazione del trattamento e al follow-up post-trattamento. Con la RM di base è possibile nei casi tipici identificare la lesione neoplastica, stabilirne la sede e la topografia e proporre un’ipotesi di natura. Vi è però una limitata sensibilità e specificità nella definizione dell’istotipo e del grading, nell’individuazione dei margini neoplastici e nella differenziazione tra tumore ed edema o effetti del trattamento. È necessario pertanto integrare le informazioni fornite dalla RM di base con le informazioni di carattere metabolico, strutturale ed emodinamico fornite dalle più recenti tecniche RM, oramai parte integrante di uno studio di routine. In tal modo sono possibili diagnosi sempre più precise ed esaustive per il chirurgo, necessarie per definire la prognosi e l’impostazione delle diverse strategie terapeutiche. Inoltre, il recente sviluppo di nuovi e più efficaci trattamenti ha reso sempre più necessario uno studio RM morfofunzionale con cui ottenere in maniera non invasiva una “neuropatologia in vivo” e quindi un’interpretazione biologica della eterogeneità tipica di tali tumori.Abstract The objective of this study was to evaluate the potential roleof newly developed, advanced magnetic resonance (MR)imaging techniques (spectroscopy, diffusion and perfusionimaging) in diagnosing brain gliomas, with specialreference to histological typing and grading, treatmentplanning and posttreatment follow-up. Conventional MRimaging enables the detection and localisation of neoplasticlesions, as well as providing, in typical cases, someindication about their nature. However, it has limitedsensitivity and specificity in evaluating histological typeand grade, delineating margins and differentiating oedema,tumour and treatment side-effects. These limitations can beovercome by supplementing the morphological dataobtained with conventional MR imaging with themetabolic, structural and perfusional information providedby new MR techniques that are increasingly becoming anintegral part of routine MR studies. Incorporation of suchnew MR techniques can lead to more comprehensive andprecise diagnoses that can better assist surgeons indetermining prognosis and planning treatment strategies. Inaddition, the recent development of new, more effective,treatments for cerebral glioma strongly relies onmorphofunctional MR imaging with its ability to provide abiological interpretation of these characteristicallyheterogeneous tumours.

Role of advanced MR imaging modalities in diagnosing cerebral gliomas Ruolo delle nuove ed avanzate modalità di studio RM nella diagnostica neuroradiologica dei gliomi cerebrali

The objective of this study was to evaluate the potential role of newly developed, advanced magnetic resonance (MR) imaging techniques (spectroscopy, diffusion and perfusion imaging) in diagnosing brain gliomas, with special reference to histological typing and grading, treatment planning and posttreatment follow-up. Conventional MR imaging enables the detection and localisation of neoplastic lesions, as well as providing, in typical cases, some indication about their nature. However, it has limited sensitivity and specificity in evaluating histological type and grade, delineating margins and differentiating oedema, tumour and treatment side-effects. These limitations can be overcome by supplementing the morphological data obtained with conventional MR imaging with the metabolic, structural and perfusional information provided by new MR techniques that are increasingly becoming an integral part of routine MR studies. Incorporation of such new MR techniques can lead to more comprehensive and precise diagnoses that can better assist surgeons in determining prognosis and planning treatment strategies. In addition, the recent development of new, more effective, treatments for cerebral glioma strongly relies on morphofunctional MR imaging with its ability to provide a biological interpretation of these characteristically heterogeneous tumours.RiassuntoLo scopo del lavoro è di illustrare le potenzialità delle nuove e più avanzate modalità di studio RM (spettroscopia, diffusione, perfusione) nella diagnostica dei gliomi cerebrali, con particolare riferimento alla definizione dell’istotipo e del grading, alla pianificazione del trattamento e al follow-up post-trattamento. Con la RM di base è possibile nei casi tipici identificare la lesione neoplastica, stabilirne la sede e la topografia e proporre un’ipotesi di natura. Vi è però una limitata sensibilità e specificità nella definizione dell’istotipo e del grading, nell’individuazione dei margini neoplastici e nella differenziazione tra tumore ed edema o effetti del trattamento. È necessario pertanto integrare le informazioni fornite dalla RM di base con le informazioni di carattere metabolico, strutturale ed emodinamico fornite dalle più recenti tecniche RM, oramai parte integrante di uno studio di routine. In tal modo sono possibili diagnosi sempre più precise ed esaustive per il chirurgo, necessarie per definire la prognosi e l’impostazione delle diverse strategie terapeutiche. Inoltre, il recente sviluppo di nuovi e più efficaci trattamenti ha reso sempre più necessario uno studio RM morfofunzionale con cui ottenere in maniera non invasiva una “neuropatologia in vivo” e quindi un’interpretazione biologica della eterogeneità tipica di tali tumori.Abstract The objective of this study was to evaluate the potential roleof newly developed, advanced magnetic resonance (MR)imaging techniques (spectroscopy, diffusion and perfusionimaging) in diagnosing brain gliomas, with specialreference to histological typing and grading, treatmentplanning and posttreatment follow-up. Conventional MRimaging enables the detection and localisation of neoplasticlesions, as well as providing, in typical cases, someindication about their nature. However, it has limitedsensitivity and specificity in evaluating histological typeand grade, delineating margins and differentiating oedema,tumour and treatment side-effects. These limitations can beovercome by supplementing the morphological dataobtained with conventional MR imaging with themetabolic, structural and perfusional information providedby new MR techniques that are increasingly becoming anintegral part of routine MR studies. Incorporation of suchnew MR techniques can lead to more comprehensive andprecise diagnoses that can better assist surgeons indetermining prognosis and planning treatment strategies. Inaddition, the recent development of new, more effective,treatments for cerebral glioma strongly relies onmorphofunctional MR imaging with its ability to provide abiological interpretation of these characteristicallyheterogeneous tumours.

Fenilchetonuria: Studio RM a 3,0 T delle alterazioni della sostanza bianca con imaging di base, di spettroscopia e di diffusione

PurposeThis study evaluated the sensitivity of a 3.0-Tesla (T) magnetic resonance imaging (MRI) in measuring cerebral phenylalanine using proton magnetic resonance spectroscopy and in assessing MR-documented white-matter changes by means of diffusion studies (diffusion-weighted imaging, apparent diffusion coefficient map; diffusion tensor imaging) in patients with phenylketonuria.Materials and methodsThirty-two patients with the classical clinical and biochemical deficits of phenylketonuria underwent biochemical (blood phenylalanine), genotypic (phenylalanine hydroxylase gene) and radiological investigation by means of MRI, proton magnetic resonance spectroscopy and diffusion magnetic resonance imaging with a 3.0-T scanner.ResultsPeriventricular and subcortical white-matter changes were detected on all MR scans. In 29/32 patients, proton magnetic resonance spectroscopy easily documented abnormal signal elevation at 7.36 ppm, corresponding to phenylalanine, despite its low concentration. Phenylalanine signal amplitude relative to the creatine/phosphocreatine signal increased linearly with blood phenylalanine values (r 0.7067; p<0.001). Diffusion MRI demonstrated hyperintensity in the areas exhibiting MRI changes as well as decreased apparent diffusion coefficient values, but fractional anisotropy indices were normal.ConclusionsThe high signal, together with better spectral, spatial, contrast and temporal resolution, makes the 3.0-T MR the most suitable technique in the study of the phenylketonuria. In particular, the multimodal approach with MRI, proton magnetic resonance spectroscopy and diffusion magnetic resonance imaging can provide more information than previous studies performed with low-field systems.RiassuntoObiettivoValutare in pazienti con fenilchetonuria la sensibilità di un sistema di risonanza magnetica (RM) a 3,0 Tesla (T) nel misurare la fenilalanina cerebrale con la spettroscopia protonica e nel documentare le alterazioni della sostanza bianca rilevate con lo studio RM di base utilizzando gli studi di diffusione (imaging pesato in diffusione, mappa del coefficiente di diffusione apparente, imaging del tensore).Materiali e metodiTrentadue pazienti con il deficit clinico e biochimico classico di fenilchetonuria sono stati sottoposti ad uno studio biochimico (livelli della fenilalanina cerebrale), genotipico (gene fenilalanina idrossilasi) e radiologico mediante uno studio RM di base, di spettroscopia e di diffusione con apparecchiatura a 3,0 T.RisultatiIn tutte le immagini RM morfologiche sono state rilevate alterazioni della sostanza bianca periventricolari e sottocorticali. In 29 pazienti su 32 la spettroscopia protonica ha rilevato facilmente un picco anomalo a 7,36 ppm corrispondente alla fenilalanina nonostante la sua bassa concentrazione. Ls’ampiezza del segnale della fenilalanina relativo al rapporto creatina/fosfocreatina incrementa linearmente con la fenilalanina ematica (r=0,7067; p<0,001). Lo studio di diffusione ha evidenziato iperintensità focali nelle aree di alterato segnale documentate con lo studio RM di base, valori di coefficiente di diffusione apparente ridotto e indici di anisotropia frazionata normale.ConclusioniLs’alto segnale assieme alla maggiore risoluzione spettrale, spaziale, di contrasto e temporale rende il sistema 3,0 T ideale per lo studio della fenilchetonuria. In particolare ls’approccio multimodale con imaging RM di base, di spettroscopia e di diffusione può fornire maggiori informazioni rispetto ai precedenti studi acquisiti con sistemi a più basso campo.Purpose. This study evaluated the sensitivity of a 3.0-Tesla (T) magnetic resonance imaging (MRI) in measuring cerebral phenylalanine using proton magnetic resonance spectroscopy and in assessing MR-documented whitematter changes by means of diffusion studies (diffusionweighted imaging, apparent diffusion coefficient map; diffusion tensor imaging) in patients with phenylketonuria. Materials and methods. Thirty-two patients with the