Diffuse Heterogeneous Enhancement Research Articles

Comparison of MRI findings of hypothalamic-optic chiasmatic gliomas and craniopharyngiomas.

Differential diagnosis of hypothalamic-optic chiasmatic gliomas (HOCGs) and craniopharyngiomas on magnetic resonance imaging (MRI) can be quite challenging. To compare the MRI features of HOCGs and cranipharyngiomas. Patients diagnosed with HOCG or craniopharyngioma in histopathological evaluation between 2012 and 2022 and who underwent preoperative contrast-enhanced brain MRI were included. Various MRI features were retrospectively evaluated for each lesion: T2-weighted imaging and fluid attenuation inversion recovery hyperintensity, calcification, cystic change, T1-weighted (T1W) imaging hyperintensity of the cystic component, hemorrhage, involvement of sellar, suprasellar or other adjacent structures, lobulated appearance, presence of hydrocephalus, and contrast enhancement pattern. Apparent diffusion coefficient (ADC) values were also evaluated and compared. Among 38 patients included, 13 (34%) had HOCG and 25 (66%) had craniopharyngioma. Craniopharyngiomas had a significantly higher rate of cystic changes, calcification, and T1W imaging hyperintensity of the cystic component than HOCGs (P <0.05). Of HOCGs, 92% had chiasm involvement, 23% had optic nerve involvement, and 31% had brain stem involvement. On the other hand, chiasm involvement was observed in 8% of craniopharyngiomas, but none had optic nerve and/or brain stem involvement (P <0.05). While 62% (8/13) of HOCGs had diffuse homogeneous enhancement, 80% (20/25) of craniopharyngiomas had a diffuse heterogeneous enhancement pattern. Mean ADC values were significantly higher in craniopharyngiomas compared to HOCGs (2.1 vs. 1.6 ×10-3mm2/s, P <0.05). Although some neuroimaging findings may overlap, features such as presence of cyst and calcification, brain stem and optic pathway involvement, different enhancement patterns, and ADC values may be helpful in the differential diagnosis of HOCGs and craniopharyngiomas.

Development of a novel prediction model for differential diagnosis between spinal myxopapillary ependymoma and schwannoma

Spinal myxopapillary ependymoma (MPE) and schwannoma represent clinically distinct intradural extramedullary tumors, albeit with shared and overlapping magnetic resonance imaging (MRI) characteristics. We aimed to identify significant MRI features that can differentiate between MPE and schwannoma and develop a novel prediction model using these features. In this study, 77 patients with MPE (n = 24) or schwannoma (n = 53) who underwent preoperative MRI and surgical removal between January 2012 and December 2022 were included. MRI features, including intratumoral T2 dark signals, subarachnoid hemorrhage (SAH), leptomeningeal seeding, and enhancement patterns, were analyzed. Logistic regression analysis was conducted to distinguish between MPE and schwannomas based on MRI parameters, and a prediction model was developed using significant MRI parameters. The model was validated internally using a stratified tenfold cross-validation. The area under the curve (AUC) was calculated based on the receiver operating characteristic curve analysis. MPEs had a significantly larger mean size (p = 0.0035), higher frequency of intratumoral T2 dark signals (p = 0.0021), associated SAH (p = 0.0377), and leptomeningeal seeding (p = 0.0377). Focal and diffuse heterogeneous enhancement patterns were significantly more common in MPEs (p = 0.0049 and 0.0038, respectively). Multivariable analyses showed that intratumoral T2 dark signal (p = 0.0439) and focal (p = 0.0029) and diffuse enhancement patterns (p = 0.0398) were independent factors. The prediction model showed an AUC of 0.9204 (95% CI 0.8532–0.9876) and the average AUC for internal validation was 0.9210 (95% CI 0.9160–0.9270). MRI provides useful data for differentiating spinal MPEs from schwannomas. The prediction model developed based on the MRI features demonstrated excellent discriminatory performance.

Ultrasonography and magnetic resonance imaging features of kaposiform hemangioendothelioma and tufted angioma.

Kaposiform hemangioendothelioma (KHE) and tufted angioma (TA) primarily occurring in infants are difficult to distinguish. This study evaluated ultrasonography (US) and magnetic resonance imaging (MRI) features of KHE and TA. Pathologically proven TA (n=21) and KHE (n=40 [11 KHE+Kasabach-Merritt phenomenon [KMP]]) occurring between January 2015 and December 2017 were reviewed. US (n=61) and MRI (n=50) findings were retrospectively evaluated. On US, KHE and TA lesions were subcutaneous, while 40% of KHE exhibited an infiltrative pattern extending into adjacent muscles. Of TA lesions, 42.9% were hyperechoic and 96.15% of KHE lesions exhibited mixed echogenicity. Of TA lesions, 76.2% exhibited well-defined margins and all KHE lesions exhibited ill-defined margins. The depth and vascular density of KHE and KHE+KMP were significantly increased compared with TA. The arterial peak systolic blood flow velocity of KHE+KMP was significantly higher than that in TA and KHE. KHE and KHE+KMP were significantly harder than TA on elastography. 3-D color Doppler revealed branch-shape blood flow for KHE and KHE+KMP lesions; for TA, it revealed a dot-like and striped pattern. Considering MRI findings, KHE and KHE+KMP were more likely to exhibit diffuse heterogeneous enhancement after contrast than TA. KHE was infiltrative and more likely to be thick, hypoechoic, ill-defined, richly vascular and hard than TA on US. KHE lesions were subcutaneous and reticular, with heterogeneous enhancement on MRI. Awareness of these features should prompt radiologists in the differential diagnosis of pediatric masses.

Imaging findings of metallic implants associated lymphoma

Purpose Chronic inflammatory condition such as metallic implants insertion state has relevance to develop diffuse large B-cell lymphoma (DLBCL). The purpose of this study is to introduce the imaging features of the metallic implants associated lymphoma. Materials and Methods In 2016 September, a 58 years-old male underwent high tibial osteotomy at right leg after took a knee magnetic resonance image (MRI). After 15 months later, he underwent hardware removal operation. 2 weeks later after operation, he complained right leg pain and swelling. He was hospitalized and radiologic studies including ultrasound (US) and MRI were performed. Soft tissue mass in right popliteal fossa was seen and US-guided biopsy was done to confirm the mass. Results MRI which was taken after hardware removal, showed iso to slightly low signal intensity on T1 weighted image(WI), high signal intensity on T2WI with diffuse marrow involvement and heterogeneous patchy enhancement in right proximal tibia. Also extensive extraosseous soft tissue component was seen, with relatively preserved trabecular pattern in proximal tibia. This intraosseous and extraosseous lesions were not seen in previous MRI which taken before high tibial osteotomy. On US image, it was showed heterogeneous hypoechoic and hypervascular lesion in popliteal fossa of left lower leg. US guided biopsy was done on extraosseous soft tissue mass in left popliteal fossa. It was histologically confirmed as DLBCL. Conclusion Hypoechoic and hypervascular disproportionally large extraosseous soft tissue mass without prominent bone destruction is preferential finding of bone lymphoma. Lymphoma should be considered above all, when these findings were seen in patient who has metallic implant.

Imaging features of combined hepatocellular–cholangiocarcinoma on contrast-enhanced ultrasound: correlation with clinicopathological findings

To evaluate the relationship between the imaging features of combined hepatocellular-cholangiocarcinoma (CHC) on contrast-enhanced ultrasound (CEUS) and clinicopathological findings. From August 2004 to August 2016, 40 patients (29 males, 11 females; mean age 52.8±11.2 years) with histopathologically proven CHC were investigated. The CEUS imaging features and clinicopathological findings of CHC were analysed and compared retrospectively. On CEUS, peripheral irregular rim-like enhancement, diffuse heterogeneous enhancement, and diffuse homogeneous enhancement was illustrated in 13 (32.5%), 21 (52.5%), and six (15%) lesions, respectively. Histopathological findings showed hepatocellular carcinoma (HCC) predominance and cholangiocarcinoma (CC) predominance throughout the tumour were illustrated in 21 (52.5%) and 19 (47.5%) cases, respectively. HCC-predominant CHCs displayed diffuse heterogeneous enhancement more frequently than peripheral irregular rim-like enhancement (p=0.005), whereas CC-predominant CHCs displayed peripheral irregular rim-like enhancement more frequently than diffuse heterogeneous enhancement and homogeneous enhancement (p=0.005 and p=0.01, respectively). CHCs >5 cm displayed diffuse heterogeneous enhancement more frequently than diffuse homogeneous enhancement, whereas CHCs ≤5 cm displayed diffuse homogeneous enhancement more frequently than diffuse heterogeneous enhancement (p=0.004). The enhancement pattern of CHC on CEUS depended on the relative proportionsof the HCC and CC components and showed size-dependent characteristics.

Primary hepatic neuroendocrine tumors: multi-modal imaging features with pathological correlations

BackgroundPrimary hepatic neuroendocrine carcinomas (PHNECs) are rare and asymptomatic, and are therefore difficult to distinguish radiologically from other liver carcinomas. In this study, we aimed to determine the computed tomography (CT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) features of PHNECs.MethodsA retrospective analysis of 11 patients with pathologically proven PHNECs was performed from January 2009 to September 2014. The CT, MRI, and DSA image features were analysed.ResultsTen of the eleven patients exhibited two or more lesions, and one patient exhibited a single lesion. Abdominal CT of 8 cases revealed multiple round or oval-shaped masses with well-defined borders, which were heterogeneous and hypodense on precontrast CT images. Significant diffuse heterogeneous enhancement was observed during the arterial phase in 8 cases, and the enhancement was slightly higher than the attenuation of the surrounding normal liver parenchyma and indistinct edges of small lesions during the portal phase. Well circumscribed (11 cases), lobulated (5 cases) or multiple nodular masses (4 cases), nodule (1 case) and irregular masses (1 case) of high signal intensity were observed on T2WI and DWI of MR images. The masses were well circumscribed, heterogeneous, and hypointense on T1WI, with significant enhancement of the solid carcinoma portion in the early arterial phase and continued enhancement in the portal venous phase. Characteristic lobulated or multiple nodular masses were observed in MRI. DSA showed multiple hypervascular carcinoma-staining lesions with sharp edges in the arterial phase.ConclusionThe CT, MRI, and DSA images of PHNECs exhibit specific characteristic features. Appropriate combinations of the available imaging modalities could therefore optimize the evaluation of patients with PHNECs.

Value of Contrast-Enhanced Ultrasound in Differential Diagnosis of Focal Liver Lesions

Purpose:to evaluate the diagnostic value of contrastenhanced ultrasound (CEUS) with SonoVue in differential diagnosis of focal liver lesions (FLL) in a multidisciplinary clinic in Russian Federation.Materials and methods. Bolus intravenous administration of 1.2 ml of SonoVue (Bracco Swiss CA, Switzerland) followed with 5ml saline flush was used for liver CEUS. We utilized the scanners Mindray DC-8 (Mindrаy, China), Logiq S8 (GE, USA), Philips Epiq 7 (Philips, Holland), SonoScape S9 (SonoScape, China), Hitachi Ascendus (Hitachi, Japan) with 3.0–5.0 MHz convex probes in specialized “contrast” mode with low mechanic index (MI 0.08–0.1). The study conferred 73 patients in the age between 18 and 84 years (mean age 49 years) with FLL. CEUS was performed in 22 patients with previously verified diagnosis, while the rest of patients underwent CEUS before the final diagnosis. Contrast-enhanced liver CT was performed in all patients. In 49 (67.12%) of 73 cases, a pathology was performed after a targeted core-needle biopsy or autopsy. Qualitative features of US contrast enhancement of FLL were evaluated.Results. Qualitative aspects of CEUS for differentiation of FLL were defined. The principal sign for diagnosis between benign and malignant masses with CEUS was hypoenhancement of malignant lesions in comparison to surrounding normal parenchyma in portal and late venous phase (p ≤ 0.01). Alternatively, hyper- or isoenhancement throughout late venous phase was characteristic for benign FLL. Diffuse heterogeneous contrast enhancement was indicative of malignant FLL, and homogeneous – for benign. Additional diagnostic feature (p ≤ 0.05) was the type of contrast enhancement in the arterial phase. Heterogeneous diffuse contrast enhancement was observed in malignant FLL, while homogeneous – in benign FLL. Peripheral nodular contrast enhancement with centripetal filling was characteristic for liver hemangioma, centrifugal filling with “spoke-wheel” vascular pattern – for FNH, and peripheral rim-like hyperenhancement with rapid achievement of hypoenhancement at the beginning of the portal phase – for liver metastasis.Conclusion.Complex analysis of qualitative characteristics of CEUS with SonoVue is a promising option for differential diagnosis of FLL (sensitivity 92.85%, specificity 91.3%, diagnostic accuracy 92.15%) and can be utilized in daily practice.

Imaging features on contrast-enhanced ultrasound and pathological analysis of combined hepatocellular-cholangiocarcinoma

Objective To evaluate the correlation between the imaging features on contrast-enhanced ultrasound (CEUS) and pathological characteristics of combined hepatocellular-cholangiocarcinoma (CHC). Methods Forty patients with pathologically proven hepatic CHC were evaluated, the CEUS imaging findings and pathological characteristics of CHC were retrospectively analyzed. Results On CEUS, peripheral irregular rim-like enhancement, diffuse heterogeneous enhancement and diffuse homogeneous enhancement were illustrated in 13(32.5%), 21(52.5%) and 6(15.0%) lesions, respectively. Pathological findings showed that HCC-predominance, CC-predominant, and similar proportions of the two components were illustrated in 16(40.0%), 19(47.5%) and 5(12.5%) cases, respectively. The presence of necrosis were illustrated in 28(70.0%) cases. On CEUS, when the enhancement pattern was peripheral irregular rim-like enhancement, CC-predominance and necrosis were presented in 11(84.6%) and 10(76.9%) cases, respectively. When the enhancement pattern was diffuse heterogeneous enhancement, CC-predominance and necrosis were presented in 11(52.4%) and 18(85.7%) cases, respectively. When the enhancement pattern was diffuse homogeneous enhancement, HCC-predominance and necrosis were presented in 4(66.6%) and 0(0%) cases, respectively. There were significant differences in relative proportion of HCC, CC components and tumor necrosis among the three types of enhancement pattern on CEUS (P=0.009 and P 5 cm, peripheral irregular rim-like enhancement, diffuse heterogeneous enhancement and diffuse homogeneous enhancement were illustrated in 8, 18 and 1 cases, respectively. There were significant differences in the three types of enhancement pattern between lesion size of ≤5 cm and >5 cm on CEUS (P=0.006). Conclusions The imaging findings of CHC on CEUS depends on the relative proportions of HCC and CC component and on size-dependent patterns. Key words: Contrast-enhanced ultrasound; Liver neoplasms; Combined hepatocellular-cholangiocarcinoma

MP12-12 CONTRAST-ENHANCED ULTRASOUND FOR SMALL RENAL MASSES

You have accessJournal of UrologyImaging/Radiology III1 Apr 2014MP12-12 CONTRAST-ENHANCED ULTRASOUND FOR SMALL RENAL MASSES Tae Hoon Oh, Seong Hoon Ahn, Whi An Kwon, Jea Whan Lee, Dong Youp Han, Seung Chul Park, Hee Jong Jeong, and Ill Young Seo Tae Hoon OhTae Hoon Oh More articles by this author , Seong Hoon AhnSeong Hoon Ahn More articles by this author , Whi An KwonWhi An Kwon More articles by this author , Jea Whan LeeJea Whan Lee More articles by this author , Dong Youp HanDong Youp Han More articles by this author , Seung Chul ParkSeung Chul Park More articles by this author , Hee Jong JeongHee Jong Jeong More articles by this author , and Ill Young SeoIll Young Seo More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.447AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Introduction : Ultrasonography (US) is highly sensitive in the detection of the renal mass. However, it may not show characterized findings to differentiate benign and malignant in small masses. The purpose of this study is to determine the diagnostic efficacy of contrast-enhanced ultrasound (CEUS), US using contrast media, for small renal masses. METHODS Materials and Methods: From January 2011 to September 2013, 71 patients underwent CEUS for evaluation of renal masses. Among of them, CEUS findings of small renal masses, renal cell carcinoma (RCC) cases (n = 25) and angiomyolipoma (AML) cases (n = 10) were retrospectively analyzed. The tumor echogenicity and enhancement patterns and degrees were evaluated. The diagnostic efficacy of CEUS in differentiating the two diseases was compared. RESULTS Results: On CEUS of small renal tumors with less than 4 cm diameter, the findings of diffuse heterogeneous enhancement (observed in 76.0% of RCC and 30.0% of AML; p = 0.020), wash-out from hyper-enhancement or isoenhancement to hypo-enhancement in late phase (64.0% of RCC and 20.0% of AML; p = 0.027), and perilesional rim-like enhancement (60.0% of RCC and 10.0% of AML; p = 0.010) achieved significant difference between AML and RCC cases. The corresponding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 80.0% (20 of 25), 70.0% (7 of 10), 87.0% (20 of 23), 58.3% (7 of 12), and 77.1% (27 of 35), respectively. CONCLUSIONS Conclusion: Our results suggest that the characteristic findings of CEUS features could have a potential diagnostic factor in evaluation of small renal mass. It showed a better diagnostic efficacy than US for differentiating RCC and AML. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e109-e110 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Tae Hoon Oh More articles by this author Seong Hoon Ahn More articles by this author Whi An Kwon More articles by this author Jea Whan Lee More articles by this author Dong Youp Han More articles by this author Seung Chul Park More articles by this author Hee Jong Jeong More articles by this author Ill Young Seo More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Diagnostic efficacy of contrast-enhanced ultrasound for small renal masses.

PurposeUltrasound (US) is highly sensitive in the detection of renal masses. However, it may not be able to differentiate benign and malignant lesions in smaller masses. The purpose of this study was to determine the diagnostic efficacy of contrast-enhanced ultrasound (CEUS) for small renal masses.Materials and MethodsFrom January 2011 to December 2013, a total of 85 patients underwent CEUS for evaluation of renal masses. Of these patients, CEUS findings were retrospectively analyzed for small renal cell carcinoma (RCC) cases (n=38) and angiomyolipoma (AML) cases (n=11). The tumor echogenicity and enhancement patterns and degrees were evaluated. The diagnostic efficacy of CEUS in differentiating the two diseases was compared.ResultsOn CEUS, the findings of diffuse heterogeneous enhancement (observed in 78.9% of RCCs and 27.3% of AMLs, p=0.003), washout from hyperenhancement or iso-enhancement to hypoenhancement in late phase (73.7% of RCCs and 18.2% of AMLs, p=0.001), and perilesional rim-like enhancement (57.9% of RCCs and 9.1% of AMLs, p=0.006) were significantly different between AML and RCC cases. The corresponding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 86.8% (33/38), 63.6% (7/11), 89.2% (33/37), 58.3% (7/12), and 81.6% (40/49), respectively.ConclusionsOur results suggest that the characteristic CEUS features could have diagnostic value in the evaluation of small renal mass. CEUS showed a higher diagnostic efficacy than conventional US for differentiating RCC and AML.

Invasive Micropapillary Carcinoma of the Breast: Imaging Features With Clinical and Pathologic Correlation

The purpose of this article is to present imaging findings of invasive ductal carcinoma with micropapillary features with clinical and pathologic correlation. We retrospectively searched our institution's surgical pathology database for patients with pathologically proven invasive ductal carcinoma with micropapillary features. Forty-one patients with images available for review were included in the study. Mammographic, sonographic, and MRI findings were assessed using the American College of Radiology's BI-RADS lexicon. Molecular breast imaging findings were reviewed using a molecular breast imaging lexicon. Imaging findings were correlated with clinical presentation and pathologic findings. Mammographically, the most common finding was an irregular spiculated mass. Sonographically, the most common finding was an irregular hypoechoic mass with spiculated margins and posterior acoustic shadowing. With MRI, the most common finding was an irregular mass with washout kinetics, but we also observed diffuse heterogeneous nonmasslike enhancement throughout the breast. Molecular breast imaging was available for one patient and showed multicentric radiotracer uptake. Analysis of 39 pathologic specimens showed 27 (69%) with angiolymphatic invasion. Axillary nodal metastases were present in 23 patients (59%), nine (23%) with extranodal extension. The imaging features of invasive ductal carcinoma of the breast with micropapillary features typically were highly suggestive of malignancy. The malignancies were strongly associated with lymphovascular invasion and lymph node metastases. Radiologists should be aware of the imaging features of this unusual variant and should consider axillary sonography if this entity is found in a core needle biopsy specimen.

Combined hepatocellular carcinoma‐cholangiocarcinoma: Report of MR appearance in eleven patients

To describe the magnetic resonance imaging (MRI) appearance of hepatic combined hepatocellular-cholangiocarcinoma (cHCC-CC) in 11 patients. The database of the Department of Pathology was cross-referenced with the MRI database to identify patients with confirmed cHCC-CC who had undergone MRI. Eleven consecutive patients were included (seven female, mean age 57.6 years). All patients were Caucasian. Five of 11 had a clinical history of chronic liver disease. Two radiologists retrospectively analyzed the images in consensus. cHCC-CC was a single mass in 10/11 patients. Margins were well-defined in 6/11. All tumors showed heterogeneous hyperintensity on T2. On postcontrast imaging, 6/11 showed early ring-enhancement (four noncirrhotic), with progressive enhancement in central portions, and 5/11 patients showed a diffuse heterogeneous early enhancement. Three of these five were cirrhotic and displayed partial washout with portions of contrast retention on later phases. Other findings included: late capsule enhancement (two patients), biliary dilatation (one), venous invasion (three), lymphadenopathy (six), and findings of cirrhosis (five). cHCC-CC presents most commonly as a single mass. Five of 11 had MR findings of cirrhosis. Clues to the diagnosis were moderately high signal on T2, portions of tumor that show progressive enhancement/contrast retention, and frequent lack of capsule. Early enhancement patterns included early ring-enhancement and diffuse heterogeneous enhancement.

Multi-modality imaging findings of splenic hamartoma: a report of nine cases and review of the literature

To investigate the presentation of splenic hamartomas (SHs) on ultrasonography (US), CT and MRI. Nine patients (5 males and 4 females, mean age, 52.8 years) with pathologically proven SHs were included in this study. US, CT and MRI images were analyzed retrospectively, and imaging features were correlated with pathological findings. SHs appeared solitary lesion (n = 8) and multiple lesions (n = 1) in the present study. (1) In 8 cases of solitary lesion, the lesions appeared as solid nodules or masses with well-defined margins and varying echogenicity (hyperecho = 5, hypoecho = 2, strong echo = 1) on ultrasound. The lesions showed iso-attenuation (n = 3) or slightly hypo-attenuation (n = 4) on unenhanced CT, and calcification were revealed in 3 lesions. MRI showed isointensity (n = 3) or hypointensity (n = 2) on the T1-weighted image, and heterogeneous hypointensity (n = 2), slightly hyperintensity (n = 2) and hyperintensity (n = 1) on the T2-weighted image. The enhanced patterns of SHs showed mild diffuse heterogeneous enhancement (n = 6) and prominent enhancement (n = 1) during arterial phase and above 7 lesions were demonstrated progressive enhancement at delayed phase on enhanced CT. One lesion without any enhancement was revealed in another patient. (2) One case of multiple lesions included 1 cystic lesion with irregular calcification and 7 solid lesions with progressive enhancement on CT images. Combination of a variety of imaging modalities could more fully reflect the pathological characteristics and contribute to the diagnosis of SH.

Delayed periportal enhancement: a characteristic finding on contrast ultrasound in idiopathic portal hypertension

Differentiation of idiopathic portal hypertension (IPH) from cirrhosis is not always easy because of their similar clinical features. This prospective study aimed to use contrast-enhanced ultrasound (US) in studying dynamic behavior of microbubble for characteristic enhancement features in IPH. The study had 101 subjects: 8 IPH, 47 cirrhosis, and 36 controls, and additional ten cirrhosis for data validation. Contrast-enhanced US with perflubutane microbubble agent was performed in the early-phase (0-60s) to compare hepatic enhancements among the three groups. Onset time of enhancement in the hepatic artery was not different among the groups, but that in the portal vein was longer in cirrhosis (19.9±5.2s; p=0.0014) and IPH (22.9±5.0s; p=0.0007) than in controls (16.6±3.4s). As for parenchymal enhancement, all controls showed homogeneous enhancement, while all IPH showed delayed periportal enhancement. Cirrhosis had three patterns: 14 with homogeneous enhancement, 28 with diffuse heterogeneous enhancement, and 5 with IPH-like delayed periportal enhancement. Homogeneous enhancement was more frequent in controls than in cirrhosis/IPH (p<0.0001), and delayed periportal enhancement was more frequent in IPH than in control/cirrhosis (p<0.0001). The duration of intensity difference between hypoenhancement/delayed enhancement area and surrounding parenchyma which exceeded the half of the mean value of the maximum intensity difference (8.75dB for IPH, 6.95dB for cirrhosis) was longer in IPH (15.6±6.9s) than cirrhosis (10.2±5.3s; p=0.0119). The data in cirrhosis were validated in the additional ten subjects. Delayed periportal enhancement on the sonograms based on perflubutane microbubble agent may be a characteristic of IPH.

Lo studio dei neurinomi con mezzo di contrasto ecografico: valutazione dei patterns caratteristici di riconoscimento diagnostico

The aim of this study was to evaluate whether there exists a characteristic distribution pattern of vessels within neurinomas that may be used to characterise this type of lesion by employing a contrast-specific ultrasound technique. Between January 2003 and May 2010, 66 suspected neurinomas were evaluated according to their sonographic features (solid fusiform mass with well-defined margins located in direct continuity with the nerve that was not always discernible and heterogeneous as a result of the presence of small cystic areas or calcifications). The lesions were examined using a sonographic contrast medium consisting of sulphur hexafluoride microbubbles and equipment with dedicated contrast-specific software [contrast tuned imaging (CnTI)]. Of these lesions, five were excluded from the analysis because the definitive diagnosis was not available (in two cases, the follow-up was still in progress, whereas in the remaining three, there was no follow-up). Our study, therefore, is based on 61 surgically excised lesions that were confirmed to be neurinomas by histology, which is regarded as the gold standard. In 41/61 cases (67.2%), we identified an enhancement pattern that we termed reticular owing to the interweaving of blood vessels, of which two subtypes were identified depending on whether the interwoven vessels were densely or sparsely packed: loose-knit reticular in 18/41, and tight-knit reticular in 23/41. In 20/61 (32.8%) cases, we observed a vascular pattern of diffuse heterogeneous enhancement, which was divided into two subtypes based on the presence of one (7/20) or more (13/20) avascular areas. Results showed that all neurinomas studied could be divided into two groups according to the type of enhancement pattern observed: reticular or diffuse heterogeneous.

Hepatic Arteriovenous Malformations from Hereditary Hemorrhagic Telangiectasia: Treatment with Liver Transplantation

A 47-year-old handyman presented to the emergency department with worsening exertional dyspnea and persistent lassitude at rest for 2 weeks. He had experienced moderate unremitting epigastric pain over the preceding months requiring narcotics, as well as intermittent jaundice and low-grade fever. His epigastric pain frequently worsened after meals, resulting in anorexia and weight loss, but also was present at rest and radiated through to his back. He denied epistaxis, hemoptysis, and gingival or gastrointestinal bleeding. Although he admitted binge drinking of alcohol in the past, without obvious social or medical complications, he had been sober for several years. He continued to chew tobacco daily. His mother reportedly had alcoholic liver disease, and his two children were healthy. Physical examination revealed a slender man with a fever of 102 F but in no obvious distress. His conjunctivae were anicteric, and his oropharynx did not reveal any lesions or bleeding. His breath sounds were normal. Cardiac examination revealed tachycardia, a 3/6 systolic ejection murmur best heard over the apex, and jugular venous distention. His abdomen was soft and not distended, but tender over the epigastrium, where a loud bruit was also present. The liver and spleen were both enlarged. No jaundice, palmar erythema, or rashes were present. The patient was fully alert and oriented, without asterixis. Comprehensive laboratory studies were significant for a normocytic anemia with a hematocrit of 35%, mild thrombocytopenia with a platelet count of 142,000/mm, and abnormal liver tests with a total bilirubin of 3.7 mg/dl, aspartate aminotransferase (AST) 43 U/l, alanine aminotransferase (ALT) 55 U/l, and alkaline phosphatase of 579 U/l. His international normalized ratio for prothrombin time (INR) was normal at 1.1. B-type natriuretic peptide was elevated at 1,067 pg/ml. Blood cultures grew Streptococcus anginosus (a member of the Streptococcus milleri family). Echocardiogram revealed moderate left ventricular enlargement with normal left ventricular systolic function, and mild right ventricular enlargement with mildly decreased right ventricular systolic function. There was trace aortic regurgitation and mild mitral regurgitation, with increased aortic flow velocity with a mean gradient of 19 mmHg. There was also mild tricuspid regurgitation with an estimated right ventricular systolic pressure of 51 mmHg. No other valvular lesions or vegetations were found. Abdominal computed tomography (CT) revealed diffuse angiomatous tissue within the liver, early opacification of all hepatic veins, and low-attenuation tissue in segment 7 of the liver likely representing biliary necrosis (Fig. 1). Abdominal magnetic resonance imaging (MRI) confirmed the diffuse heterogeneous enhancement of the liver and presence of multiple arteriovenous malformations (Fig. 2). Angiography was performed, and the initial aortogram revealed a hugely dilated celiac artery and replaced left hepatic and common hepatic arteries (Fig. 3). The proper M. Lee (&) T. J. Daugherty Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, 300 Pasteur Drive, Alway Building, M211, Stanford, CA 94305-5187, USA e-mail: maxlee@stanford.edu

Magnetic Resonance Imaging of Cystic and Endocrine Pancreatic Neoplasms

This article describes the appearance of miscellaneous cystic and endocrine neoplasms using magnetic resonance imaging (MRI). Magnetic resonance imaging is a useful diagnostic modality in the assessment of various pancreatic neoplasms. Pancreatic endocrine tumors are moderately low in signal intensity on T1-weighted fat-suppressed images and moderately high in signal intensity on T2-weighted fat-suppressed images and demonstrate homogeneous, ring, or diffuse heterogeneous enhancement on immediate postgadolinium gradient echo images. Cystic pancreatic neoplasms, including intraductal papillary mucinous neoplasm, are well demonstrated and subcategorized according to their characteristic cystic configurations on MRI and MR cholangiopancreatography images. Microcystic serous cystadenomas are demonstrated as a honeycombed appearance on T2-weighted images and have a central stellate scar. Mucinous cystic neoplasms usually appear as multilocular cystic masses, with benign forms of macrocystic tumors possessing uniform thickness septations and malignant forms exhibiting irregular septations and tumor nodules. The presence of tumor stroma, invasion of adjacent tissue, or liver metastases can be assessed by MRI. The connection between the pancreatic duct and the cystic tumor is usually well shown on MR cholangiopancreatography images.

Neuroendocrine tumors of the pancreas: spectrum of appearances on MRI.

We reviewed our 8.5 year experience with magnetic resonance imaging (MRI) in the demonstration of neuroendocrine tumors of the pancreas using precontrast fat-suppressed T1-weighted, fat-suppressed T2-weighted, and serial post-gadolinium T1-weighted images, to describe the spectrum of appearances of these tumors. All MR examinations of patients with histologically proven neuroendocrine tumors were retrospectively reviewed. Histological type, tumor location, tumor diameter, signal intensity on precontrast images, enhancement patterns, and presence and appearance of metastases were determined. Twenty-two patients had histologically proved neuroendocrine tumors detected by MRI over the 8.5 year period. Histological types were gastrinoma (n = 8), insulinoma (n = 3), glucagonoma (n = 2), somatostatinoma (n = 1), VIPoma (n = 1), ACTHoma (n = 1), carcinoid (n = 1), and five untyped tumors. Primary tumors ranged in diameter from 1 to 6.2 cm. There was one histopathology-proven false-positive neuroendocrine tumor. The positive predictive value for MRI in the detection of these tumors was 96%. The most common appearance on precontrast images was low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, which was observed in tumors in 18 of 22 patients. Moderate or intense early enhancement of all or portions of the primary tumors was observed in tumors in 19 of 22 patients either as uniform homogeneous, ring, or diffuse heterogeneous enhancement. Enhancement was minimal on these images in the other three patients. Gastrinomas enhanced in a ring pattern in 7 of 8 patients whereas the majority (9 of 11 patients) of noninsulinoma-nongastrinoma and untyped tumors enhanced in a diffuse heterogeneous fashion. Liver metastases were present in 13/22 patients including 3/8 with gastrinoma and 9/11 with noninsulinoma-nongastrinoma tumors. Most neuroendocrine tumors of the pancreas are low signal intensity on fat-suppressed T1-weighted images and moderately high in signal intensity on fat-suppressed T2-weighted images, although variations do exist. Tumors most often enhance in an early moderately intense fashion. Gastrinomas are often different in appearance than other neuroendocrine tumors in that they usually enhance in a ring fashion whereas nongastrinoma-noninsulinoma tumors usually enhance in a heterogeneous fashion.

Hepatocellular carcinoma in North America: a multiinstitutional study of appearance on T1-weighted, T2-weighted, and serial gadolinium-enhanced gradient-echo images.

The purpose of this study was to define the common appearances of hepatocellular carcinoma (HCC) in patients in North America by analyzing T1-weighted, T2-weighted, and serial gadolinium-enhanced gradient-echo images interpreted by radiologists at multiple institutions in North America. One hundred thirteen consecutive patients with HCC from eight institutions were included in this retrospective case series. Inclusion criteria included MR imaging examinations performed on 1.5-T MR imagers using T1-weighted breath-hold spoiled gradient-echo images, T2-weighted images, and serial gadolinium-enhanced spoiled gradient-echo images. Diagnosis was established by histology in all patients. Images were analyzed retrospectively for lesion count, lesion diameter as less than or equal to 1.5 cm and greater than 1.5 cm, and signal intensity, by individual experienced radiologists at each institution. We found 354 HCC lesions in the 113 patients. Tumors were solitary in 63 patients, multifocal in 45 patients, and diffuse in five patients. Lesion appearance on combined T1-weighted, T2-weighted, and immediate gadolinium-enhanced spoiled gradient-echo images was as follows: 102 lesions (29%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited diffuse heterogeneous enhancement; 52 lesions (15%) were isointense on both T1- and T2-weighted images and exhibited diffuse homogeneous enhancement (all of these lesions measured < or = 1.5 cm in diameter); 50 lesions (14%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited diffuse homogeneous enhancement; 33 lesions (9%) were hypointense on T1-weighted images, were hyperintense on T2-weighted images, and exhibited predominantly peripheral rim enhancement; and 27 lesions (8%) were hypointense on T1-weighted images, were isointense on T2-weighted images, and exhibited diffuse homogeneous enhancement. The remaining 90 lesions showed less common patterns. The appearance of HCCs greater than 1.5 cm and of HCCs less than or equal to 1.5 cm was significantly different (p = .001). The appearance of histologically proven HCCs is separately described. The combination of hypointensity on T1-weighted images, hyperintensity on T2-weighted images, and diffuse heterogeneous enhancement was the most common appearance of HCC on MR images in a multiinstitutional patient population in North America. Small HCCs measuring less than or equal to 1.5 cm were frequently isointense on both T1-weighted and T2-weighted images and may be detected on immediate gadolinium-enhanced images only as diffuse homogeneously enhancing lesions.

Splenic hemangiomas and hamartomas: MR imaging characteristics of 28 lesions.

To determine the magnetic resonance (MR) imaging features of splenic hemangiomas and hamartomas, including their pattern of dynamic contrast material enhancement. The appearance of 28 lesions in 18 patients was retrospectively reviewed on T2-weighted images (16 patients), unenhanced T1-weighted images (18 patients), and dynamic contrast-enhanced T1-weighted images (17 patients). Seventeen of 23 hemangiomas and all five hamartomas were proved at pathologic examination. Of the 22 hemangiomas imaged with T2-weighting, 19 were hyperintense, two were isointense, and one was hypointense relative to the spleen. Dynamic gadolinium-enhanced imaging demonstrated a progressive centripetal pattern of enhancement in 19 of 22 hemangiomas. On delayed images, 19 hemangiomas demonstrated uniform enhancement. Of the five hamartomas, four were imaged with T2-weighting; three were hyperintense and one was hypointense relative to the spleen. All hamartomas demonstrated diffuse heterogeneous enhancement on images obtained early after administration of contrast material and became more uniformly enhanced on delayed images. Splenic hemangiomas showed signal intensity characteristics and enhancement patterns similar to those described for hepatic hemangiomas. Since these features have been shown to reliably distinguish hemangiomas from other benign and malignant liver lesions, it may be reasonable to consider without histologic verification that lesions in the spleen with these imaging features represent hemangiomas.