Simone Maurea

Sonographic hepatic-renal ratio as indicator of hepatic steatosis: comparison with 1H magnetic resonance spectroscopy

The aim of this study was to determine the diagnostic performance of ultrasound (US) in the quantitative assessment of steatosis by comparison with proton magnetic resonance spectroscopy ((1)H-MRS) as a reference standard. Three liver echo-intensity indices were derived: US hepatic mean gray level, hepatic-renal echo-intensity ratio (H/R), and hepatic-portal blood echo-intensity ratio. The (1)H-MRS degree of steatosis was determined as percentage fat by wet weight. Regression equations were used to estimate quantitatively hepatic fat content. The hepatic fat content by (1)H-MRS analysis ranged from 0.10% to 28.9% (median value, 4.8%). Ultrasound H/R was correlated with the degree of steatosis on (1)H-MRS (R(2)= 0.92; P < .0001), whereas no correlation with (1)H-MRS was found for hepatic mean gray level and hepatic-portal blood echo-intensity ratio. A receiver operating characteristic curve identified the H/R of 2.2 as the best cutoff point for the prediction of (1)H-MRS of at least 5%, yielding measures of sensitivity and specificity of 100% and 95%, respectively. In this pilot study, US H/R exhibits high sensitivity and specificity for detecting liver fatty changes. Our results indicate that quantitative evaluation of hepatic fat content can be performed using US H/R and could therefore be a valuable analytic tool in clinical investigation.

Comparison between multislice CT and MR imaging in the diagnostic evaluation of patients with pancreatic masses

PurposeThis study compared the results of multislice computed tomography (MSCT) and high-field magnetic resonance imaging (MRI) in the diagnostic evaluation of pancreatic masses.Materials and methodsForty patients with clinical and ultrasonographic evidence of pancreatic masses underwent MSCT and MRI. The majority of patients (31/40, 78%) had proven malignant pancreatic tumours (24 ductal adenocarcinoma, six mucinous cystadenocarcinoma, one intraductal papillary mucinous carcinoma), whereas the remaining patients (9/40, 22%) were found to have benign lesions (eight chronic pancreatitis, one serous cystadenoma). Results of the imaging studies were compared with biopsy (n=33) and/or histology (n=7) findings to calculate sensitivity, specificity, accuracy and positive (PPV) and negative (NPV) predictive value for correct identification of tumours and evaluation of resectability of malignancies.ResultsBoth for tumour identification and resectability, MSCT and MRI had comparable diagnostic accuracy, with no statistically significant differences between them. Tumour identification CT/MRI: accuracy 98/98%, sensitivity 100/100%, specificity 88/88%, PPV 97/97%, NPV 100/100%; tumour resectability CT/MRI: accuracy 94/90%, sensitivity 92/88%, specificity 100/100%, PPV 100/100%, NPV 78/70%.ConclusionsMRI represents a valid diagnostic alternative to CT in the evaluation of patients with pancreatic masses, both for correct identification and characterisation of primary lesions and to establish resectability in the case of malignancies. New high-field MRI equipment allows optimal imaging quality with good contrast resolution in evaluating the upper abdomen.RiassuntoObiettivoScopo del nostro studio è stato effettuare un confronto dei risultati della tomografia computerizzata (TC) multistrato e della risonanza magnetica (RM) ad alto campo nella valutazione diagnostica di pazienti con masse pancreatiche.Materiali e metodiSono stati studiati 40 pazienti con evidenza clinico-ecografica di masse pancreatiche, di cui la maggioranza (78%; n=31) con tumori pancreatici maligni di diverso tipo istologico (adenocarcinoma duttale=24, cistoadenocarcinoma mucinoso=6, carcinoma mucinoso papillifero intraduttale=1); nei restanti 9 pazienti (22%) sono state dimostrate lesioni espansive di tipo benigno da pancreatite cronica (n=8) o da cistoadenoma sieroso (n=1); tutti i pazienti sono stati sottoposti a TC ed RM; i risultati degli esami di imaging sono stati confrontati con i dati bioptici (n=33) e/o istologici (n=7) ai fini del calcolo dei valori diagnostici di sensibilità, specificità, accuratezza, valori predittivi positivo (VPP) e negativo (VPN) per la corretta identificazione dei tumori maligni e la valutazione dell’eventuale resecabilità chirurgica delle lesioni.RisultatiSia per l’identificazione delle lesioni neoplastiche che per la valutazione della resecabilità chirurgica, la TC e la RM hanno mostrato valori di accuratezza diagnostica comparabili senza differenze statisticamente significative; identificazione del tumore TC/RM: accuratezza=98%/98%, sensibilità=100%/100%, specificità=88%/88%, VPP=97%/97%, VPN=100%/100%; resecabilità del tumore TC/RM: accuratezza=94%/90%, sensibilità=92%/88%, specificità=100%/100%, VPP=100%/100%, VPN=78%/70%.ConclusioniLa RM rappresenta una valida alternativa diagnostica all’esame TC nei pazienti con lesioni espansive del pancreas; in particolare, la RM consente sia la corretta identificazione e caratterizzazione delle masse pancreatiche che la valutazione dell’eventuale resecabilità chirurgica in caso di malignità; l’alto campo magnetico delle nuove apparecchiature permette di ottenere un’ottima qualità delle immagini RM che mostrano un’elevata risoluzione di contrasto nello studio dell’addome superiore.

FGD‐PET in the follow‐up of recurrent colorectal cancer

Objective  The current methods of detection of recurrent colorectal cancer after surgical treatment are inaccurate using conventional imaging. This study set out to detect early recurrence by means of PET in patients treated surgically for colorectal cancer by curative resection.

Diagnostic accuracy of radionuclide imaging using 131I nor-cholesterol or meta-iodobenzylguanidine in patients with hypersecreting or non-hypersecreting adrenal tumours

The aim of this retrospective study was to evaluate the diagnostic accuracy of nor-cholesterol and meta-iodobenzylguanidine radionuclide imaging in two separate groups of patients with adrenal tumours to characterize lesions as adenoma or pheochromocytoma. We studied 75 patients (22 male and 53 female, mean age 47±15 years) with hypersecreting (n = 32) or non-hypersecreting (n = 43) unilateral adrenal tumours detected by computerized tomography or magnetic resonance scans. 131I nor-cholesterol adrenal scintigraphy was performed in 41 patients. Meta-[131I]iodobenzylguanidine (131I-MIBG) imaging was acquired in the other 34 patients. Pathology examinations (n = 58) or computerized tomography follow-up studies (n = 17) were obtained. Adrenal lesions were represented by 44 adenomas, four cysts, one myelolipoma, one pseudotumour, one ganglioneuroma, 16 pheochromocytomas, three carcinomas, four metastases and one sarcoma. Radionuclide studies were qualitatively evaluated and the corresponding results were classified as true positive, true negative, false positive and false negative. Diagnostic sensitivity, specificity and accuracy as well as positive and negative predictive values were calculated. The diagnostic values of nor-cholesterol scintigraphy in identifying adrenal adenomas were sensitivity 100%, specificity 71%, accuracy 95%, positive predictive value 94% and negative predictive value 100%; of note, two false positive cases were observed represented by a pheochromocytoma and a myelolipoma. The diagnostic values of MIBG scintigraphy in recognizing pheochromocytoma were sensitivity 100%, specificity 95%, accuracy 97%, positive predictive value 94% and negative predictive value 100%; only one false positive case occurred consisting of a carcinoma. It is concluded that, in the large majority of cases, adrenal scintigraphy using nor-cholesterol or MIBG is able to characterize specific lesions such as adenoma and pheochromocytoma, respectively. These findings show relevant clinical impact, particularly in patients with non-hypersecreting adrenal lasions. Radiotracer selection depends on clinical patient history and department availability; since benign adenomas are the most common cause of non-hypersecreting tumours, nor-cholesterol should be the first choice followed by MIBG if nor-cholesterol shows normal images. However, rare as well as unusual findings may be observed; nor-cholesterol uptake may occasionally be also found in non-adenoma tumours such as myelolipoma and pheochromocytoma. Similarly, MIBG accumulation may occur not only in lesions arising from medullary chromaffin tissue, but also rarely in cortical adrenal carcinoma.

MRI Characterization of Myocardial Tissue in Patients with Fabry's Disease

OBJECTIVE Fabrys disease is a multisystem X-linked disorder of lysosomal metabolism frequently associated with left ventricular (LV) hypertrophy. In this study, we aimed to assess whether myocardial T2 relaxation time determined by a black blood multiecho multishot MRI sequence could be used to evaluate cardiac involvement in patients with Fabrys disease. CONCLUSION Myocardial T2 relaxation time is prolonged in patients with Fabrys disease compared with that of hypertrophic patients and healthy control subjects. MRI may be useful for the characterization of myocardial tissue in patients with Fabrys disease.

Resting technetium-99m methoxyisobutylisonitrile cardiac imaging in chronic coronary artery disease : comparison with rest-redistribution thallium-201 scintigraphy

We studied 19 patients with angiographically proven coronary artery disease and left ventricular dysfunction (ejection fraction 33% ± 8%) by resting technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) and rest-redistribution thallium-201 cardiac imaging. Thallium and (99mTc-MIBI) studies were visually analysed. Of 285 segments, 203 (71%) had normal thallium uptake, 48 (17%) showed reversible thallium defects and 34 (12%) showed irreversible thallium defects. Of these 34 irreversible thallium defects, 19 (56%) were moderate and 15 (44%) were severe. Of the corresponding 285 segments, 200 (70%) had normal 99mTc-MIBI uptake, while 37 (13%) showed moderate and 48 (17%) showed severe reduction of 99 99mTc-MIBI uptake. Myocardial segmental agreement for regional uptake score between initial thallium and resting (99mTc-MIBI) images was 90% (κ=0.78). Segmental agreement between delayed thallium and resting 99Tc-MIBI images was 77% (κ=0.44). In particular, in 26 (9%) segments 99mTc-MIBI uptake was severely reduced while delayed thallium uptake was normal or only moderately reduced. These data suggest that although rest-redistribution thallium and resting (99mTc-MIBI) cardiac imaging provide concordant results in the majority of myocardial segments, some segments with severely reduced resting 99mTc-MIBI uptake may contain viable but hypoperfused myocardium. Thus, conclusions on myocardial viability based on 99mTc-MIBI uptake should be made with caution in chronic coronary artery disease.

Technetium-99m tetrofosmin imaging in thyroid diseases: comparison with Tc-99m-pertechnetate, thallium-201 and Tc-99m-methoxyisobutylisonitrile scans.

Technetium-99m tetrofosmin is a lipophilic phosphine used for myocardial perfusion imaging. Biodistribution studies have shown significant thyroid uptake of tetrofosmin and preliminary reports have suggested that tetrofosmin imaging may be of value in patients with thyroid cancer. In this study, tetrofosmin whole-body scintigraphy was performed in 35 patients with evidence of thyroid diseases. All patients underwent laboratory evaluation of thyroid function as well as99mTc pertechnetate scan, thallium-201 (n=16)99mTc-methoxyisobutylisonitrile (MIBI) (n=19) whole-body studies. Thyroid images were semi-quantitatively analysed by a 4-point score: O=no significant uptake; 1=uptake increased as compared to background activity, but inferior to normal thyroid tissue; 2=uptake equal to normal thyroid tissue; 3=uptake superior to normal thyroid tissue. Pathology examinations were obtained. A total of 41 thyroid nodules were detected, of which 15 were goitre nodules, 13 adenomas and 13 malignant lesions. In goitre nodules, concordant results of tetrofosmin and pertechnetate uptake (score 1 or 0) were observed in the majority of lesions (87%). In function adenomas (n=10), both tetrofosmin uptake and pertechnetate uptake were score 3. In non-function adenomas (n=3), tetrofosmin uptake was score 3, while pertechnetate uptake was score 0. In six malignant lesions, tetrofosmin uptake was score 3, while pertechnetate uptake was score 0; in the other seven lesions, where a prevalence of goitre abnormalities was observed, results of tetrofosmin and pertechnetate uptake were similar (score 0 or 1). In seven (70%) of the ten patients with malignant nodules, whole-body tetrofosmin images showed increased abnormal uptake in a total of 28 extra-thyroid tumour sites, as subsequently confirmed by other techniques. When tetrofosmin images were compared to 201T1 and99mTc-MIBI scans, concordant results were observed in all cases. In conclusion, tetrofosmin imaging may be particularly useful to characterize and stage patients with malignant thyroid nodules; it shows similar results to thallium but provides better image quality. Comparable findings were observed between tetrofosmin and MIBI studies. Thus, tetrofosmin may be an alternative to thallium and MIBI in the aforementioned patients.

Tc-99m MIBI scintigraphy in patients with lung cancer : Comparison with CT and fluorine-18 FDG PET imaging

Tc-99m MIBI imaging has been used to evaluate patients with different neoplastic disorders, but its role in nuclear oncology has not been definitely established. In this study, we compared the results of Tc-99m MIBI (planar and SPECT imaging) with those of F-18 FDG PET radionuclide studies in 19 patients who had proven lung cancer. One patient was studied in follow-up. All patients underwent chest CT scans. MIBI and FDG images were qualitatively and quantitatively analyzed using region of interest analysis. Quantitative evaluation of MIBI and FDG activities in lung-tumor lesions was performed calculating tumor/nontumor ratios. On CT, 18 lung tumors were detected, while one patient was disease free. For lung lesions, the diagnostic sensitivity of planar MIBI imaging was 83%, while those of MIBI SPECT and FDG PET were both 100%. The quantitative analysis of lung-tumor MIBI and FDG activities showed that FDG uptake was significantly (P < 0.001) higher compared with MIBI uptake (5.5 +/- 3.1 vs 2.1 +/- 0.6); concordant MIBI and FDG images were found in 4 lesions in terms of central activity defect showing central necrotic tumor tissue. For lymph node abnormalities, planar MIBI scan only detected 3 lesions in 3 patients, whereas MIBI SPECT identified 9 lesions in 5 patients. FDG PET showed 13 lymph node abnormalities in 5 patients. This study shows similar results of Tc-99m MIBI SPECT and F-18 FDG PET in the diagnostic evaluation of patients with lung tumors. However, FDG lung tumor uptake was significantly higher compared with MIBI accumulation, suggesting a high glucose tumor metabolism. Thus, MIBI SPECT imaging may be useful to evaluate such patients and may be considered an alternative when PET is not available.

The role of radiolabeled somatostatin analogs in adrenal imaging.

We investigated the role of radiolabeled somatostatin analogs (SAs) in adrenal imaging. We evaluated 15 patients (6 men and 9 women, mean age 47 +/- 17 years) with imaging-detected adrenal tumors. Patient population was divided into two groups on the basis of the nature of adrenal lesions. Group 1 consisted of patients with benign adrenal lesions (n = 10). Group 2 consisted of patients with malignant adrenal lesions (n = 5). Pathology examinations were obtained in 13 cases: 7 pheochromocytomas, 2 adenomas, 2 cysts, 1 carcinoma, and 1 fibro-histiocytoma. One patient had a proven diagnosis of non-small-cell lung cancer associated with the presence of a right adrenal mass. The last patient had a clinical diagnosis of Werner syndrome associated with the presence of a large left adrenal mass. All patients underwent scientigraphic studies using radiolabeled SAs, of which indium-111 (In-111) pentetreotide was used in 11 cases and technetium-99m (Tc-99m)-labeled peptides (P-587 or P-829) were used in the remaining four cases. No significant labeled SAs uptake was observed in the majority (8 of 10, 80%) of the benign adrenal lesions (Group 1); however, increased uptake was found in two benign pheochromocytomas. Conversely, significant labeled SAs uptake was observed in the majority (4 of 5, 80%) of the malignant adrenal lesions (Group 2); however, the last lesion (carcinoma) did not show abnormal uptake. Results of this study show that the majority of benign adrenal tumors do not concentrate radiolabeled SAs; conversely, the majority of malignant adrenal lesions show significant SAs uptake, suggesting the presence of somatostatin receptors. This finding may allow the use of somatostatin as a treatment agent in malignant adrenal tumors. Thus, the main role of labeled SAs in adrenal imaging consists of lesion characterization rather than tumor detection and localization.

Comparative diagnostic evaluation with MR cholangiopancreatography, ultrasonography and CT in patients with pancreatobiliary disease.

PurposeThe aim of this study was to directly compare the results of magnetic resonance cholangiopancreatography (MRCP) with those of ultrasonography (US) and multislice computed tomography (MSCT) in the diagnosis of pancreaticobiliary diseases.Materials and methodsA total of 70 patients (41 men, 29 women) aged 22-89 years were studied either before (n=59) or after cholecystectomy (n=11) for biliary lithiasis. Clinical signs and symptoms were jaundice (n=15), abdominal pain (n=37) and proven biliary lithiasis (n=18). MRCP was performed in all patients, whereas abdominal US was performed in 55 (group 1) and MSCT in 37 (group 2) patients. A regional evaluation of the main structures of the pancreaticobiliary system was performed: gallbladder and cystic duct, intra- and extrahepatic bile ducts and main pancreatic duct. Histology (n=27), biopsy (n=5), endoscopic retrograde cholangiopancreatography (ERCP) (n=28) and/or clinical-imaging follow-up (n=10) were considered standards of reference. In particular, patients were classified as showing benign (n=47) or malignant (n=12) lesions or normal biliary anatomy (n=11).ResultsIn group 1, the results of MRCP and US were concordant in the majority (92%) of cases; however, statistically significant discordance (p<0.01) was found in the evaluation of the extrahepatic ducts, with nine cases (16%) of middle-distal common bile duct stones being detected on MRCP only. In group 2, the results of MRCP and MSCT were also concordant in most cases (87%). However, findings were significantly discordant when the intra- and extrahepatic ducts were analysed, with seven (19%) and six (16%) cases, respectively, of lithiasis being detected on MRCP only (p<0.01 for both).ConclusionsThe results of our study confirm the diagnostic potential of MRCP in the study of the pancreaticobiliary duct system. In particular, the comparison between MRCP and US and MSCT indicates the superiority of MRCP in evaluating bile ducts and detecting stones in the common bile duct.RiassuntoObiettivoScopo dello studio è stato il confronto diretto dei risultati della colangiopancreatografia con risonanza magnetica (CPRM) con quelli dell’ecografia (US) e della TC multistrato (TCMS) nella valutazione diagnostica di pazienti affetti da patologia del sistema bilio-pancreatico.Materiali e metodiSono stati arruolati 70 pazienti (41 maschi, 29 femmine), di età compresa tra 22 e 89 anni, in fase diagnostica pre-chirurgica (n=59) o dopo colecistectomia per litiasi biliare (n=11); i pazienti presentavano ittero (n=15), sintomatologia dolorosa addominale (n=37) e litiasi biliare documentata (n=18). In tutti i pazienti è stata eseguita la CPRM; in 55 casi è stata effettuata US addominale (gruppo 1), mentre 37 pazienti sono stati sottoposti ad esame TCMS (gruppo 2). E stata eseguita un’analisi regionale nei principali distretti del sistema bilio-pancreatico: colecisti e dotto cistico, vie biliari intraepatiche (VBI), via biliare principale (VBP) e dotto pancreatico principale. Per l’interpretazione dei risultati degli esami diagnostici, i dati istologici post-chirurgici (n=27), bioptici (n=5), della colangio-pancreatografia retrograda endoscopica (CPRE) (n=28) o del follow-up (3-6 mesi) clinico-strumentale (n=10) sono stati considerati gli standard di riferimento; in particolare sono stati osservati 47 casi di lesioni biliari benigne, 12 lesioni maligne e 11 casi con normale anatomia delle vie biliari.RisultatiNel gruppo 1, è stata osservata una concordanza globale dei risultati della CPRM e dell’ecografia nel 92% dei casi; tuttavia, è stata riscontrata una discordanza del 16% (n=9) statisticamente significativa (p<0,01) tra i risultati delle due metodiche nella valutazione della VBP ove la CPRM mostrava lesioni litiasiche in sede medio distale non evidenti all’ecografia. Nel gruppo 2, è stata osservata una concordanza globale dei risultati della CPRM e della TCMS nel 87% dei casi; tuttavia, è stata riscontrata una discordanza del 19% (n=7) per il distretto delle VBI e del 16% (n=6) per il distretto della VBP statisticamente significativa (p<0,01) con lesioni prevalentemente litiasiche riconosciute dalla CPRM e non dalla TCMS.ConclusioniI risultati della nostra esperienza confermano le potenzialità diagnostiche della CPRM nello studio del sistema duttale bilio-pancreatico; in particolare, i dati di confronto con l’ecografia e la TCMS dimostrano i vantaggi della CPRM nella valutazione distrettuale dei dotti biliari con particolare riferimento alla coledocolitiasi.