Fei Miao

Differentiation between benign and malignant solid pseudopapillary tumor of the pancreas by MDCT.

PURPOSE The purpose of this study was to determine if characteristic features on computed tomographic and (or) magnetic resonance imaging can differentiate benign and malignant solid pseudopapillary neoplasms (SPN). MATERIALS AND METHODS A total of 82 pathologically diagnosed SPN patients were included. CT and MRI were reviewed by 3 radiologists. Each tumor was analyzed through the clinical and imaging features. RESULTS The highest occurrence of malignant SPN was observed in the group of patients (11-19 years old) followed by the group of patients (50-65 years old). When the tumor was located in the tail and the size was equal or larger than 6.0 cm, the positive and predictive value, the predictive value, sensitivity and specificity for a malignant SPN were 61.5%, 100%, 100% and 78.6%, respectively. Presence of complete encapsulation was more frequent in benign SPNs, but focal discontinuity in the malignant SPNs. Amorphous or scattered calcifications, all near-solid tumors and presence of upstream pancreatic ductal was found in the benign SPNs. CONCLUSION A focal discontinuity of the capsule, large tumor size (>6.0 cm) and a pancreatic tail location may suggest malignancy of SPN. In contrast, tumors with amorphous or scattered calcifications, and all near-solid tumors may be indicative of benignancy. Age (less than 20 or more than 50 years old) is a possible risk factor of SPN. In comparison to other pancreatic neoplasms, such as ductal adenocarcinoma, a complete/incomplete pseudo-capsule, without upstream pancreatic duct dilatation and lymph nodes metastasis, and the presence of internal calcification and hemorrhage are more likely SPN.

Differentiation of Crohn's disease from intestinal tuberculosis by clinical and CT enterographic models.

Background:Crohns disease (CD) and intestinal tuberculosis (ITB) have similar clinical, radiological, and endoscopic features. The objective of our study was to investigate the values of clinical features and computed tomographic (CT) enterographic manifestations in the differential diagnosis between CD and ITB. Methods:Clinical features and CT enterographic manifestations in a cohort of 141 patients with CD and 47 patients with ITB were reviewed retrospectively. Parameters were screened by logistic regression analysis. Furthermore, the diagnostic efficacy of screened parameters was analyzed by regression equation (mathematical model) and receiver operating characteristic curve. Results:The clinical features indicative of CD were hematochezia and perianal disease; features indicative of ITB include positive purified protein derivative skin test, occurrence of ascites, pulmonary tuberculosis, and night sweats. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of regression mathematical model established by clinical features were 94.3, 80.4, 91.0, 93.7, and 82.6%, respectively. CT enterographic manifestations indicative of CD were the involvement of the left colon, asymmetric pattern of involvement and abscess, comb sign; manifestations indicative ITB were the distribution of the lymph nodes along the right colic artery, contracture of ileocecal valve, fixed patulous ileocecal valve and lymph nodes with central necrosis The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of regression mathematical model established by CT enterographic parameters were 96.5, 93.6, 95.7, 97.8, and 89.8%, respectively. Conclusions:The accuracy of CT enterographic model suggests the possibility of using CT enterography as an alternative to endoscopy in the differentiation between CD and ITB.

Hepatoid Adenocarcinoma : Computed Tomographic Imaging Findings With Histopathologic Correlation in 6 Cases

Objective: Hepatoid adenocarcinoma (HAC) is a special type of primary tumor with aberrant hepatocellular differentiation occurring in extrahepatic organs. Our objective was to review the computed tomographic findings of HAC and to correlate the imaging features with histopathologic findings. Institutional review board approval was obtained for this study. Methods: The computed tomographic findings images in 6 consecutive patients with pathologically proven HAC were reviewed retrospectively. Five patients were men and 1 was a woman (mean age, 56 years; age range, 36-68 years). All patients underwent contrast-enhanced computed tomography (CT) performed on a 4-slice multidetector row CT scanner. The mean time interval between CT and surgery was 5 days. Two radiologists who were unaware of the final histological diagnosis reviewed all computed tomographic images retrospectively. Lesion characteristic (ie, number, location, size, density, enhancement, heterogeneity, margin, distribution, presence of necrosis, lymphadenopathy, and distant metastasis) were evaluated. The correlation between the imaging and the pathological findings was analyzed. Results: Most patients had elevated serum &agr;-fetoprotein levels (n = 4). The HAC appeared as large tumors (mean size, 4.2 × 3.4 × 3.9 cm), isodense at unenhanced CT (n = 4), moderately enhanced (n= 5), with necrotic areas (n = 6), regional lymphadenopathy (n = 5), and distant metastases (n = 4). The heterogeneity on computed tomographic images correlated well with the presence of hemorrhage and necrosis. Conclusions: In an old patient with a large necrotic and moderately vascular tumor, the presence of distant metastases, regional lymphadenopathy, and characteristic increased serum &agr;-fetoprotein level may suggest a diagnosis of HAC.

Crohn's disease: CT enterography manifestations before and after treatment

PURPOSE The purpose of this study was to determine whether CT enterography (CTE) changes of Crohns disease (CD) after treatment correlated with clinical remission. MATERIALS AND METHODS We retrospectively studied 50 known CD patients (male: 35; female: 15) with clinical remission in a period of 3 years (2005-2008). CD was diagnosed by clinical, enteroscopic and pathologic manifestations. Clinical remission was identified by experienced gastroenterologists using the combing criteria of clinical, endoscopy and laboratory tests. First CTE and endoscopy exams were performed during their first hospitalization in our hospital meanwhile CD diagnosis was made during that time. Repeated CTE and endoscopy exams were done after treatment. CTE findings were determined by two experienced radiologists with double-blind approach. Each patient was analyzed for the CTE parameters including bowel wall attenuation, bowel wall thickening (>3mm), bowel wall thickening types (type A: multilayered mural stratification; type B: two layers with strong mucosal enhancement and prominent low-density submucosa; type C: two layers without strong mucosal enhancement; type D: homogeneous enhancement) comb sign, luminal stenosis (mild: luminal diameter 2-3 cm; moderate: luminal diameter 1-2 cm; severe: luminal diameter<1cm) and the presence of extraenteric complications (such as fistulas and abscess). All the quantitative parameters were measured three times by each review. RESULTS After treatment, bowel wall thickening was attenuated in 88% of CD patients. Thickness of bowel wall was decreased from 8.8 ± 2.8mm to 6.4 ± 1.9 mm (P<0.001). CT value of bowel wall in portal stage was also declined from 90.0 ± 15.4 (HU) to 73.4 ± 14.2 (HU (P<0.001). The percentage of patients with type A or B bowel wall thickening was decreased from 78.7% to 35.4%, while those with type C or D thickening was increased from 21.2% to 64.6% (P<0.001). The percentage of patients with comb sign was decreased from 88% to 60% (P=0.001). The percentage of patients with moderate or severe luminal stenosis was reduced from 74% to 32% (P<0.001). The ROC (receiver operating characteristic) analysis showed bowel wall attenuation (A(z)=0.89) and bowel wall thickness (A(z)=0.81) were the two best parameters to predict disease activity, and combining of these two values was better than using them solely (κ=0.71, P<0.001). The bowel wall attenuation (OR=9.56, P<0.001) and bowel wall thickness (OR=3.32, P=0.001) were significantly correlated with the disease activity in the following logistic regression analysis. CONCLUSION Therapeutic effect of CD and disease activity can be properly evaluated by CTE.

New progress in CT and MRI examination and diagnosis of small intestinal tumors.

Precise examination and diagnosis of small intestinal tumors is difficult because of the curved course and overlapping canal of the small intestine. Traditional technology for intestinal canal examination and endoscopy cannot exhibit the intestinal wall and extra-luminal structure well. With the development and advancement of multi-slice spiral computed tomography and magnetic resonance imaging (MRI), computed tomography enteroclysis (CTE) and magnetic resonance enteroclysis (MRE) are widely used in the examination and diagnosis of small intestinal tumors. CTE and MRE, with three-dimensional imaging capabilities and excellent soft-tissue contrast, can analyze the abnormalities of peripheral intestinal structure as well as the tunica mucosa. In addition, these two technologies can clearly reveal the localization, appearance, degree of mesenteric infiltration and remote tumor metastasis, which increases our cognition of the imaging diagnosis for intestinal tumors. Here we review recent progress in imaging (CT and MRI) examination and diagnosis of small intestinal tumors.

A Functional CT Contrast Agent for In Vivo Imaging of Tumor Hypoxia

Hypoxia, which has been well established as a key feature of the tumor microenvironment, significantly influences tumor behavior and treatment response. Therefore, imaging for tumor hypoxia in vivo is warranted. Although some imaging modalities for detecting tumor hypoxia have been developed, such as magnetic resonance imaging, positron emission tomography, and optical imaging, these technologies still have their own specific limitations. As computed tomography (CT) is one of the most useful imaging tools in terms of availability, efficiency, and convenience, the feasibility of using a hypoxia-sensitive nanoprobe (Au@BSA-NHA) for CT imaging of tumor hypoxia is investigated, with emphasis on identifying different levels of hypoxia in two xenografts. The nanoprobe is composed of Au nanoparticles and nitroimidazole moiety which can be electively reduced by nitroreductase under hypoxic condition. In vitro, Au@BSA-NHA attain the higher cellular uptake under hypoxic condition. Attractively, after in vivo administration, Au@BSA-NHA can not only monitor the tumor hypoxic environment with CT enhancement but also detect the hypoxic status by the degree of enhancement in two xenograft tumors with different hypoxic levels. The results demonstrate that Au@BSA-NHA may potentially be used as a sensitive CT imaging agent for detecting tumor hypoxia.

Pancreatic ductal adenocarcinoma and chronic mass-forming pancreatitis: Differentiation with dual-energy MDCT in spectral imaging mode

OBJECTIVE To investigate the value of dual-energy MDCT in spectral imaging in the differential diagnosis of chronic mass-forming chronic pancreatitis (CMFP) and pancreatic ductal adenocarcinoma (PDAC) during the arterial phase (AP) and the pancreatic parenchymal phase (PP). MATERIALS AND METHODS Thirty five consecutive patients with CMFP (n=15) or PDAC (n=20) underwent dual-energy MDCT in spectral imaging during AP and PP. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in iodine concentration between the AP and PP, contrast-to-noise ratio (CNR) and the slope K of the spectrum curve were calculated. RESULTS Normalized iodine concentrations (NICs) in patients with CMFP differed significantly from those in patients with PDAC during two double phases (mean NIC, 0.26±0.04 mg/mL vs. 0.53±0.02 mg/mL, p=0.0001; 0.07±0.02 mg/mL vs. 0.28±0.04 mg/mL, p=0.0002, respectively). There were significant differences in the value of the slope K of the spectrum curve in two groups during AP and PP (K(CMFP)=3.27±0.70 vs. K(PDAC)=1.35±0.41, P=0.001, and K(CMFP)=3.70±0.17 vs. K(PDAC)=2.16±0.70, p=0.003, respectively). CNRs at low energy levels (40-70 keV) were higher than those at high energy levels (80-40 keV). CONCLUSION Individual patient CNR-optimized energy level images and the NIC can be used to improve the sensitivity and the specificity for differentiating CMFP from PDAC by use of dual-energy MDCT in spectral imaging with fast tube voltage switching.

Clinical and CT imaging features of pancreatic acinar cell carcinoma

PurposeThis study was undertaken to analyse the clinical characteristics and computed tomography (CT) imaging features of patients with pancreatic acinar cell carcinoma and to clarify characteristic imaging features.Materials and methodsClinical and CT imaging records of ten patients with pancreatic acinar cell carcinoma (three women and seven men; mean age, 58 years) examined using multidetector CT scanners were retrospectively studied. CT features emphasised included lesion location, size, shape, margin, solid or cystic component, density and enhancement. Imaging results were correlated with intraoperative surgical and pathological results.ResultsLesions were distributed throughout the pancreatic head (n=3), body (n=3), tail (n=2) and both body and tail (n=2). The average diameter was 6.1 cm, varying from 2.3 cm to 15.8 cm. The tumours were round or oval (n=7) or lobular (n=3). Seven tumours appeared as enhanced solid pancreatic masses, with the large masses having hypodense areas; three had >75 % cystic component; seven (70%), including four solid and three cystic masses, had wellcircumscribed or partially well-defined thin, enhanced encapsulation. After contrast injection, the masses presented heterogeneous enhancement.ConclusionsAcinar cell carcinoma should always be considered when a large pancreatic mass with typical imaging is found in solid masses with variably sized central cystic areas or cystic masses.RiassuntoObiettivoLo scopo di questo studio è stato quello di analizzare le caratteristiche cliniche e di imaging TC dei pazienti con carcinoma a cellule acinari del pancreas e di chiarire le caratteristiche imaging del carcinoma a cellule acinari.Materiali e metodiSono stati retrospettivamente esaminate gli aspetti clinici e di imaging TC di 10 pazienti con diagnosi di carcinoma a cellule acinari del pancreas (tre femmine e sette maschi, età media 58 anni) sottoposti ad esame TC multidetettore. Le caratteristiche TC analizzate hanno incluso sede, dimensione, forma, margini, componente solida o cistica, densità ed enhancement delle lesioni. Gli aspetti dell’ imaging sono stati quindi correlati con i risultati intraoperatori chirurgici e patologici.RisultatiLa sede delle lesioni è risultata ubiquitaria a livello di testa (n=3), corpo (n=3), coda (n=2), e sia di corpo che coda (n=2) del pancreas. Il diametro medio della lesione è risultato pari a 6,1 cm, compreso tra 2,3 cm e 15,8 m. I tumori sono risultati di forma rotonda o ovale (n=7) o lobulare (n=3). Sette tumori sono risultate lesioni solide del pancreas, con aree ipodense contestuali; tre presentavano componenti cistica superiore al 75%; sette tumori (70%), di cui quattro solidi e tre con componente cistica, presentavano pareti sottili ben circoscritte o pazialmente sottile, vascolarizzata. Dopo iniezione di mezzo di contrasto, l’enhancement risultava eterogeneo.ConclusioniLa diagnosi di carcinoma a cellule acinari dovrebbe essere presa in considerazione nel caso di lesioni pancreatiche solide di grandi dimensioni con caratteristiche imaging tipiche e presenza di aree centrali cistiche di dimensioni variabili.

Special diaphragm-like strictures of small bowel unrelated to non-steroidal anti-inflammatory drugs

AIM To summarize clinical, endoscopic, radiologic and pathologic features of special diaphragm-like strictures found in small bowel, with no patient use of non-steroidal anti-inflammatory drugs (NSAIDs). METHODS From January 2000 to December 2009, 5 cases (2 men and 3 women, with a mean age of 41.6 years) were diagnosed as having diaphragm-like strictures of small bowel on imaging, operation and pathology. All the patients denied the use of NSAIDs. The clinical, endoscopic, radiologic and pathologic findings in these 5 patients were retrospectively reviewed from the hospital database. Images of capsule endoscopy (CE) and small bowel follow-through (SBFT) obtained in 3 and 3 patients, respectively, and images of double-balloon enteroscopy and computed tomography enterography (CTE) obtained in all 5 patients were available for review. RESULTS All patients presented with long-term (2-16 years) symptoms of gastrointestinal bleeding and varying degrees of anemia. There was only one stricture in four cases and three lesions in one case, and all the lesions were located in the middle or distal segment of ileum. Circumferential stricture was shown in the small bowel in three cases in the CE image, but the capsule was retained in the small bowel of 2 patients. Routine abdomen computed tomography scan showed no other abnormal results except gallstones in one patient. The lesions were shown as circumferential strictures accompanied by dilated small bowel loops in the small bowel on the images of CTE (in all 5 cases), SBFT (in 2 cases) and double-balloon enteroscopy (in all cases). On microscopy, a chronic inflammatory infiltrate and circumferential diaphragm were found in all lesions. CONCLUSION Diaphragm-like strictures of small bowel might be a special consequence of unclear damaging insults to the intestine, having similar clinical, endoscopic, radiologic and pathologic features.

First-pass perfusion computed tomography: Initial experience in differentiating adrenal adenoma from metastasis

OBJECTIVE To differentiate adrenal adenoma from metastasis in patients using perfusion computed tomography (PCT) imaging. METHODS Thirty-two patients with adrenal masses underwent first-pass PCT imaging. Of these patients, twenty-one were diagnosed with adrenal adenoma, and the others with metastases. Perfusion maps of blood volume (BV), blood flow (BF), mean transit time (MTT) and permeability surface-area production (PS) were generated with an Advantage Windows workstation using the CT perfusion 3.0 software (General Electric Medical Systems, Milwaukee, WI). Histopathologic sections immunostained for CD34 were quantitatively evaluated for microvessel density (MVD). RESULTS The perfusion parameters such as BV, BF and PS were statistically significant different between the two groups, with adenomas showing higher mean BV (12.18 versus 3.86), BF (97.51 versus 45.99) and PS (21.73 versus 10.93) compared with metastases (p<0.05). For BV, a cutoff point of 7.30 was found to have a sensitivity of 95.2% and a specificity of 100% to differentiate between adenoma and metastasis. The sensitivity and specificity were 81.0 and 80.0%, respectively, for BF with a cutoff point of 71.96; and 85.7 and 86.7%, respectively, for PS with a cutoff point of 12.70 to differentiate adenoma and metastasis. A comparison of MVD counts from adenomas with those from metastases showed a significant difference (p<0.05). However, no significant differences were observed in the four perfusion parameters and MVD between lipid rich and lipid poor adenomas. CONCLUSION PCT may be useful for evaluating the neovascularization of adrenal masses and differentiating adenoma from metastasis on the basis of PCT parameters. Adenomas show higher BV, BF and PS compared with metastases. According our data, the optimal threshold BV is 7.30, resulting in a sensitivity of 95.2% and a specificity of 100% for the differentiation of adenoma from metastasis. Adrenal adenomas have similar hemodynamic profiles, which are apparently independent of the lipid content of an adenoma.