Giuseppe Como

Relevance of b‐values in evaluating liver fibrosis: A study in healthy and cirrhotic subjects using two single‐shot spin‐echo echo‐planar diffusion‐weighted sequences

To investigate the relevance of increasing b‐values in evaluating liver fibrosis through the agreement of two diffusion‐weighted (DW) sequences.

Incidental pancreatic cysts on 3D turbo spin echo magnetic resonance cholangiopancreatography: prevalence and relation with clinical and imaging features

PurposeTo estimate the prevalence of incidental pancreatic cysts (IPCs) in asymptomatic patients addressed to magnetic resonance cholangiopancreatography (MRCP), and to correlate it with clinical and imaging features.Materials and methodsMagnetic resonance cholangiopancreatography performed over 26-months on 152 patients with unsuspected/unknown pancreatic disease were reviewed to assess IPCs’ features of presentation. Multivariate analysis was performed to evaluate the correlation of IPCs with clinical information and type of pancreaticobiliary findings at MRCP.ResultsPrevalence of IPCs was 44.7%. Cysts sized 3–24 mm (mean, 6.08 mm), and were ≤4 in number in 83.8% of patients. Based on number, dimensions and relation with the main pancreatic duct, IPCs presented with intraductal-papillary-mucinous neoplasm (IPMN)-like or indeterminate patterns in 31.7% and 13.1% of patients, respectively. At follow-up on 24 patients, no evolution was found, except in one patient with proven IPMN showing increase in cysts number and dimensions (evolution rate of 4.1%). Features correlating with IPCs were age ≥60 years old, and history of autoimmune hepatobiliary disease, showing odds ratios of 5.95 (95% CI 2.77–12.79) and 0.13 (95% CI 0.04–0.44), respectively.ConclusionsIncidental pancreatic cysts represent a frequent finding at MRCP, correlating positively with increasing age, and negatively with biliary autoimmune disease. Cysts more frequently present with IPMN-like pattern.

Post-cholecystectomy syndrome: spectrum of biliary findings at magnetic resonance cholangiopancreatography

Post-cholecystectomy syndrome (PCS) is defined as a complex of heterogeneous symptoms, consisting of upper abdominal pain and dyspepsia, which recur and/or persist after cholecystectomy. Nevertheless, this term is inaccurate, as it encompasses biliary and non-biliary disorders, possibly unrelated to cholecystectomy. Biliary manifestations of PCS may occur early in the post-operative period, usually because of incomplete surgery (retained calculi in the cystic duct remnant or in the common bile duct) or operative complications, such as bile duct injury and/or bile leakage. A later onset is commonly caused by inflammatory scarring strictures involving the sphincter of Oddi or the common bile duct, recurrent calculi or biliary dyskinesia. The traditional imaging approach for PCS has involved ultrasound and/or CT followed by direct cholangiography, whereas manometry of the sphincter of Oddi and biliary scintigraphy have been reserved for cases of biliary dyskinesia. Because of its capability to provide non-invasive high-quality visualisation of the biliary tract, magnetic resonance cholangiopancreatography (MRCP) has been advocated as a reliable imaging tool for assessing patients with suspected PCS and for guiding management decisions. This paper illustrates the rationale for using MRCP, together with the main MRCP biliary findings and diagnostic pitfalls.

Post-operative imaging in liver transplantation: State-of-the-art and future perspectives

Orthotopic liver transplantation (OLT) represents a major treatment for end-stage chronic liver disease, as well as selected cases of hepatocellular carcinoma and acute liver failure. The ever-increasing development of imaging modalities significantly contributed, over the last decades, to the management of recipients both in the pre-operative and post-operative period, thus impacting on graft and patients survival. When properly used, imaging modalities such as ultrasound, multidetector computed tomography, magnetic resonance imaging (MRI) and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT. Less defined is the role for imaging in assessing primary graft dysfunction (including rejection) or chronic allograft disease after OLT, e.g., hepatitis C virus (HCV) recurrence. This paper: (1) describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice; (2) illustrates main imaging findings related to post-OLT complications in adult patients; and (3) reviews future perspectives emerging in the surveillance of recipients with HCV recurrence, with special emphasis on MRI.

Comparison of Portal Venous and Delayed Phases of Gadolinium-Enhanced Magnetic Resonance Imaging Study of Cirrhotic Liver for the Detection of Contrast Washout of Hypervascular Hepatocellular Carcinoma

Objective: To retrospectively compare portal venous phase (PVP) and delayed phase (DP) for the detection of tumor washout at gadobenate dimeglumine-enhanced liver magnetic resonance imaging (MRI) in cirrhotic patients with hypervascular hepatocellular carcinoma (HCC). Methods: Thirty-three patients with 55 HCCs underwent 1.5-T MRI by means of fat-suppressed T1-weighted sequence obtained before and after gadobenate dimeglumine administration, during early and late arterial phases, PVP (70 seconds), and DP (180 seconds). Detection rates of contrast washout of hypervascular HCCs and tumor-to-liver contrast on PVP and DP were measured and compared. Results: Among 54 hypervascular HCCs, washout was present in 24 (44%) of 54 tumors on PVP and in 44 (82%) of 54 on DP (P < 0.001). In 20 (37%) of 54 tumors, washout was deemed present only on DP. Delayed phase images yielded significantly higher mean tumor-to-liver contrast absolute values compared with PVP images (−24.5 [56.1] vs −9.3 [52.6], P = 0.001). Conclusions: Delayed phase is superior to PVP for the washout detection of hypervascular HCC at gadobenate dimeglumine-enhanced MRI of cirrhotic liver.

White matter abnormalities in the right posterior hemisphere in generalized anxiety disorder: a diffusion imaging study

BACKGROUND Prior imaging studies have shown structural, functional and biochemical impairments in patients with generalized anxiety disorder (GAD), particularly in the right hemisphere. In this study we investigated, for the first time to the best of our knowledge, the white-matter microstructure organization in GAD. METHOD A total of 12 patients with DSM-IV GAD and 15 matched healthy controls underwent a magnetic resonance imaging session of diffusion weighted imaging, exploring white-matter water molecules by the means of apparent diffusion coefficients (ADCs). Regions of interests were placed in the frontal, parietal, temporal and occipital lobes and in the splenium and genu of the corpus callosum, bilaterally. RESULTS ADC measures were significantly greater in patients with GAD in the right splenium and right parietal cortex compared with healthy controls (p⩽0.002). No significant correlations between ADCs and age or clinical variables were found. CONCLUSIONS We provide evidence that GAD is associated with disrupted white-matter coherence of posterior right hemisphere regions, which may partly sustain the impaired cognitive regulation of anxiety. Future diffusion imaging investigations are expected to better elucidate the communication between the parietal cortex and other right hemisphere regions in sustaining the cognitive processing of social and emotional stimuli in patients with GAD.

Will Multi-Parametric Magnetic Resonance Imaging be the Future Tool to Detect Clinically Significant Prostate Cancer?

Multi-parametric magnetic resonance imaging is an emerging imaging modality for diagnosis, staging, characterization, and treatment planning of prostate cancer. In this report, we reviewed the literature for studies assessing the accuracy of multi-parametric magnetic resonance imaging in detecting clinically significant prostate cancer, and we critically examined the future role of this imaging tool in various clinical diagnostic settings. There is accumulating evidence suggesting a high accuracy of multi-parametric magnetic resonance imaging in ruling out clinically significant disease. Although definition for clinically significant disease widely varies, the negative predictive value is very high at up to 98%. Multi-parametric magnetic resonance imaging should, thus, be further evaluated for application in different clinical scenarios in which it is desirable to reduce the proportion of unnecessary prostate biopsies and to limit the detection of indolent disease, such as opportunistic screening, persistent prostate cancer suspicion in men with previous negative prostate biopsies, and eligibility for active surveillance. Continued improvement in standardization of technical parameters, functional sequences, and image reporting systems is a pre-requisite for a rapid and successful dissemination of this imaging modality.

Negative predictive value for cancer in patients with “Gray‐Zone” PSA level and prior negative biopsy: Preliminary results with multiparametric 3.0 tesla MR

To investigate the negative predictive value (NPV) for malignancy of 3.0 Tesla (T) MRI in patients with “gray zone” PSA level and prior negative biopsies.

Impact of clinical data on chest radiography sensitivity in detecting pulmonary abnormalities in immunocompromised patients with suspected pneumonia

PurposeChest radiography (CXR) of immunocompromised patients has low sensitivity in the early evaluation of pulmonary abnormalities suspected to be infectious. The purpose of the study was to evaluate whether the knowledge of clinical data improves the diagnostic sensitivity of CXR in the particular setting of immunocompromised patients after hematopoietic stem cell transplantation (HSCT).Materials and methodsSixty-four CXRs of immunocompromised patients with clinically suspected pneumonia were retrospectively and independently evaluated by two radiologists to assess the presence of radiological signs of pneumonia, before (first reading) and after (second reading) the knowledge of clinical data. A chest computed tomography (CT) performed within 3 days was assumed as the standard of reference. For each reading, sensitivity of both radiologists was calculated.ResultsReaders showed a sensitivity of 39% and 58.5% for the first reading, and 43.9% and 41.5% for the second reading, respectively. For both readers, these values were not significantly different from those obtained at first reading (McNemar’s test, p>0.05). Interobserver agreement at second reading was fair (Cohen test, k=0.33).ConclusionsThe sensitivity of CXR is too low to consider it a stand-alone technique for the evaluation of immunocompromised patients after HSCT with suspected pneumonia, even if the radiologist knows detailed clinical data. For these patients, an early chest CT evaluation is therefore recommended.RiassuntoObiettivoLa radiografia (Rx) del torace ha bassa sensibilità nell’individuazione precoce di infiltrati polmonari di sospetta natura infettiva nei pazienti immunocompromessi. Scopo dello studio è stato valutare se la conoscenza della clinica del paziente possa migliorarne la sensibilità diagnostica nel particolare contesto dei pazienti immunodepressi per trapianto di cellule staminali.Materiali e metodiDue medici radiologi hanno valutato retrospettivamente 64 radiografie del torace di pazienti immunocompromessi con sospetto clinico di polmonite per l’eventuale presenza di reperti compatibili con polmonite, senza conoscere (prima lettura) e conoscendone (seconda lettura) la storia clinica. Il gold standard utilizzato è stato una tomografia computerizzata (TC) del torace eseguita entro tre giorni dall’Rx. Per ciascuna lettura, è stata calcolata la sensibilità dei due lettori.RisultatiLa sensibilità dei due radiologi è stata rispettivamente del 39% e del 58,5% nella prima lettura e del 43,9% e del 41,5% nella seconda lettura. Confrontando i dati ottenuti nella prima e nella seconda lettura è emerso come, per entrambi i lettori, la differenza non fosse statisticamente significativa (test di McNemar, p>0,05). Nella seconda lettura, la correlazione inter-osservatore è stata discreta (k di Cohen 0,33).ConclusioniAnche alla luce di dettagliate informazioni cliniche, la sensibilità della radiografia del torace rimane troppo bassa per considerare tale indagine sufficiente nella valutazione dei pazienti immunocompromessi, in seguito a trapianto di cellule staminali emopoietiche, con sospetta polmonite. In tali pazienti, è dunque consigliabile un precoce utilizzo della TC torace.

Accuracy of visual analysis vs. apparent diffusion coefficient quantification in differentiating solid benign and malignant focal liver lesions with diffusion-weighted imaging.

PurposeThe authors compared the accuracy of diffusion-weighted imaging (DWI) visual analysis (VA) vs. apparent diffusion coefficient quantification (ADC-Q) in assessing malignancy of solid focal liver lesions (FLLs).Materials and methodsUsing a 1.5-T system, two radiologists retrospectively assessed as benign or malignant 50 solid FLLs: (a) by VA of signal intensity on DWI images at b=800 s/mm2 and ADC map; (b) by quantifying lesion ADC. Reference standard included histology or follow-up confirmation of diagnosis by a consensus panel. Receiver operating characteristic (ROC) curve analysis was performed.Results Because of 20 false-negative hepatocellular carcinomas, VA showed lower accuracy than ADC-Q (52.0% vs. 68.0%). However, stratified accuracy for metastases was higher with VA (75.0 vs. 66%). ADC and signal features of malignant and benign FLLs were found to largely overlapConclusionsVA performed worse than ADC-Q for hepatocellular carcinoma and better for metastases. Overall, the accuracy of both methods was limited because of the overlap in visual appearance and ADC values between solid benign and malignant FLLs.RiassuntoObiettivoUsando l’imaging pesato in diffusione (DWI), abbiamo confrontato l’accuratezza di analisi visiva (AV) e quantificazione del coefficiente di diffusione apparente (Q-ADC) nella diagnosi di malignità delle lesioni focali epatiche (LFE).Materiali e metodi Su un sistema ad 1,5 T, due radiologi hanno retrospettivamente caratterizzato come benigne o maligne 50 LFE solide: (a) attraverso la AV dell’intensità di segnale nelle immagini DWI acquisite a b=800 s/mm 2 e nella mappa ADC; (b) quantificando l’ADC delle lesioni. La diagnosi finale si è basata sui risultati dell’istologia o sulla conferma al follow-up della diagnosi ottenuta in consenso da due radiologi esperti. La analisi statistica è stata incentrata su una analisi receiver operating characteristic (ROC)Risultati A causa di 20 epatocarcinomi risultati falsinegativi, la AV ha dimostrato minore accuratezza rispetto alla Q-ADC (52,0% vs. 68,0%). Tuttavia, la stratificazione dell’analisi ha evidenziato che l’accuratezza nel caso delle metastasi era maggiore per la AV (75,0% vs. 66,7%). Gli ADC e le caratteristiche di segnale delle LFE maligne e benigne si sono dimostrati ampiamente sovrapponibiliConclusioniRispetto alla Q-ADC, la AV è risultata meno accurata nella diagnosi di malignità nel caso dell’epatocarcinoma, e più accurata nel caso delle metastasi. Complessivamente, l’accuratezza di entrambi i metodi è risultata limitata a causa della sovrapposizione delle caratteristiche di segnale e di ADC fra lesioni solide benigne e maligne.