Enhancement In Arterial Phase Research Articles

Diagnosis and treatment of focal nodular hyperplasia

Objective To summarize the diagnosis and treatment experiences of focal nodular hyperplasia (FNH) . Methods The clinical data of 48 patients with FNH who were admitted to the Xiangya Hospital from February 2010 to August 2014 were retrospectively analyzed. All the patients received complete serologic tests, abdomen B ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) examinations. The pathological examinations were done on the patients undergoing surgical treatment. The surgical treatment was done on the unconfirmed FNH patients according to location of space-occupying lesions. The conservative treatment was done on the confirmed FNH patients without clinical symptoms. All the patients were followed up via outpatient examination and telephone interview up to September 2014, and the follow-up included the history review, clinical symptoms and medical examinations. Results Forty-seven patients had normal liver function and 1 had high level of total bilirubin (TBil) . The serum tumor markers including AFP, CEA and CA19-9 in all the patients were negative. Fifty-five foci were detected by imaging examination, 41 foci were single mass and 7 foci were multifocality. Forty-eight patients were definitively unconfirmed with FNH by B ultrasound. The results of CT examinations in 38 patients showed as follows: low density was in 31 patients and isodensity in 7 patients, including striped and radiated low density showing in the center of tumor in 20 patients and 3 patients with the confirmed FNH. The results of MRI examinations in 10 patients showed as follows: 3 patients were confirmed as with FNH; all the 10 patients showed rather homogeneous enhancement in arterial phase; 5 patients were accompanied with radiated foci in the center of tumor, and showed high signal on T2WI, no enhancement in early arterial phase and enhancement in delayed arterial phase. The central scar showed low signal on T1WI and high signal on T2WI. Two patients were confirmed as with FNH by percutaneous trans-hepatic histopathological examinations. Forty patients without the confirmed FNH underwent surgical treatment, including 31 undergoing open hepatectomy and 9 undergoing laparoscopic hepatectomy. No patients had cirrhosis of liver. During operation, 47 foci were detected, 16 of which located at the left lobe of liver and 31 of which located at the right lobe of liver. Local tumor resection of liver was carried out on 30 patients, right hemihepatectomy or extended right hepatectomy on 7 patients, left hemihepatectomy on 3 patients and combined treatment of cholecystectomy on 12 patients. The operation time, volume of blood loss and diameter of foci were (78-255) minutes, (80-720) mL and (4. 6 ±1. 6) cm (range, 1. 5-11. 5 cm) . Forty patients were confirmed as with FNH by pathological examination, and 8 patients were cured by conservative treatment. All the 48 patients were followed up for 21 months (range, 1-56 months) and survived well without recurrence and complications. Conclusions The clinical symptoms of FNH are atypical and unobvious. The preoperative enhanced CT and MRI examinations can help improve the diagnosis and differential diagnosis of FNH. The surgical treatment could be performed on the patients with significant clinical symptoms and without definitive diagnosis, and the patients with definitive diagnosis should be treated by conservative treatment with the good prognosis. Key words: Focal nodular hyperplasia; Hepatectomy; Diagnosis; Therapy

Clinical and imaging features of hepatic focal nodular hyperplasia in 19 cases

Objective To explore the clinical and imaging features of focal nodular hyperplasia (FNH) of the liver. Methods From January 2006 to April 2014, 19 patients with FNH of the liver were collected. The serum levels of alpha fetoprotein (AFP), alanine aminotransferase (ALT), aspartate transaminase (AST) and total bilirubin (TBil) were examined. Liver tissues were underwent regular hematoxylin-eosin (HE) staining and pathological analysis. The expression of glypican-3 (Gpc3), CD34 and cytokeratin 19 (CK19) in liver tissues was detected by immunohistochemistry. The results of ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) examination were analyzed. Results Among 19 patients with FNH of the liver (11 males and eight females, the median age was 32 years old), there were two with hepatitis B liver cirrhosis, two with fatty liver disease, one with chronic hepatitis B and the remaining 14 without any chronic liver diseases. Three cases had abdominal pain, one case had diarrhea and one case had abdominal distension, the remaining 14 cases didn't have any symptoms. Nodules were formed by proliferated hepatocytes, there were star shaped scar with radial fiber separator in the central of the lesions with positive CK19 and negative CD34 and Gpc3. The serum AFP level of patients was normal. Both ALT and AST increased in three patients. TBil increased in five patients. Among 10 patients received ultrasound examination, hypoechoic nodules were found in five cases, hyperechoic nodules in two cases, multi hypoechoic to hyperechoic nodules in two cases, and one case was found no nodule, none of them was diagnosed as FNH of the liver. Among 12 received CT examination patients, 10 had low density nodules, two equal density nodules. Nodules of 11 patients had enhancement in arterial phase, five cases showed high density during portal phase or delay phase, three cases showed equal density during portal phase or delay phase, three cases showed low density during portal phase or delay phase, one case had no enhancement in arterial phase and showed equal density during portal phase or delay phase, only two cases were diagnosed as FNH of the liver. Among nine cases who received MRI examination, one case showed equal T1 signal, six cases had low signal, and two cases had high signal; eight cases had long echo T2 signal and one case had equal echo T2 signal; eight cases significantly enhanced during arterial phase, six cases continuously strengthened during portal phase and weakened during equilibrium phase and delay phase, two cases had cyclic strengthen, one case had strip signal without enhancement in arterial phase and strip signal enhanced in the equilibrium phase. One case did not strengthen during enhancement scan in the arterial phase and showed low signal in venous phase, however the central of the lesion showed punctate enhancement. Only one case was diagnosed as FNH of the liver. Nine patients were diagnosed with liver biopsy but without any treatment, seven patients received operation, two patients received radiofrequency treatment during biopsy, and one patient received transcatheter arterial chemoembolization (TACE) treatment. Seven cases were followed up, the follow-up time was one month to three years. New lesion was found in only one case. Conclusion Most FNH of the liver have no clinical symptoms. Combination of CT and MRI may increase the diagnostic rate. Key words: Focal nodular hyperplasia; Neoplasms; Liver; Computed tomography; Magnetic resonance imaging

Value of MR imaging in the diagnosis of intraductal papillary neoplasm of the bile duct

To analyze the value of MR imaging in diagnosis of intraductal papillary neoplasm of the bile duct (IPN-B). Fourteen patients with intraductal papillary neoplasms of the bile duct confirmed by surgical pathology were included in this study. The patients underwent MR routine plain scanning and enhancement scanning (including T1WI, T2WI with fat suppression, FALSH T1WI, and three-phase enhancement scanning), diffusion weighted imaging(DWI) and magnetic resonance cholangiopancreatography (MRCP) before operation. The imaging data were reviewed and analyzed retrospectively in comparison with the surgical and pathological results. In these patients, 7 cases had tumors located in the left lobe, 2 cases had tumors in both the left and right lobes, 2 cases in the hepatic hilum, 2 cases in the common bile duct, and 1 case in both the right lobe and the common bile duct. Solitary or multiple intraductal masses could be found in 12 cases, with 11 cases appeared as papillary masses and one case as flat mass. In the other two cases the tumor was not visible (one case had too many stones, and in another case the tumor was too small). The tumors in the 12 cases showed hypointensity on T1WI and hyperintensity on T2WI. On the dynamic contrast-enhanced MRI, 11 cases showed mild and one showed moderate enhancement in arterial phase, and all the cases showed mildly and gradually delayed enhancement. On DWI, the lesion areas showed high signal intensity in all the cases, and the ADC value of the tumor area (1.697×10(-3)mm(2)/s) was significantly lower than that of the normal bile (3.973×10(-3)mm(2)/s) (t = -10.94, P < 0.05). Twelve cases demonstrated filling defects on primary MRCP coronary thin section images. On 3D-reconstruction MRCP images, 7 cases exhibited diffuse bile duct dilatation with the tumor areas more prominent, 3 cases exhibited aneurysmal bile dilatation, while the rest 4 cases exhibited segmental or lobar bile duct dilatation ( including 2 with invisible tumors ). In the 3 cases with aneurysmal bile dilatation, the multiple directions of MRCP images helped to find the communication between the aneurysmal dilatation and the bile duct. All the cases showed significant proximal bile duct dilatation (the extent of dilatation >100%), and 9 cases also showed distal bile duct dilatation. Bile duct stones were noted in 6 cases, 4 at the tumor area, and the other 2 away from the tumor area. No adjacent tissue invasion and no distal tissue or lymph node metastasis were observed. Intraductal papillary neoplasms of the bile ducts have characteristic imaging appearances on MRI, and MRI is an important method helpful to making correct diagnosis.

MRI with hepatobiliary contrast

Hepatobiliary contrast agents currently are essentially gadolinium based agents (Gd-EOB-DTPA and Gd-BOPTA) with dual ability to perform dynamic contrast enhanced imaging similar to extracellular gadolinium contrast as well as providing hepatobiliary uptake and excretion in later phases. Hepatobiliary uptake and excretion with gadoxetic acid (Gd-EOB-DTPA) is related to OATP and cMOAT and MRP2 receptors presence on hepatocytes. Since gadoxetic acid has a recommended dose which is 25 %( 0.025mmol/kg) of Gd-DTPA attention to technical parameters is crucial. Improved arterial phase enhancement is obtained by MR fluoroscopic or bolus-tracking type triggering technique and either a lower injection flow rate of 1 mL/s or less as opposed to 2 mL/s, or contrast dilution. To improve liver-lesion contrast-to-noise ratio, 3D T1-weighted gradient-echo acquisition for the hepatobiliary phase should be performed with higher flip angles (20-35°). In order to optimize workflow, Diffusion-weighted and T2-weighted imaging can be performed after gadoxetic acid administration without compromising diagnostic capability; however, MRCP pulse sequences should be acquired before the contrast injection. The clinical utilization of Hepatobiliary contrast agents is predominantly for staging of liver metastases, characterization of hepatocellular lesions such as adenoma and FNH as well as diagnosis of HCC and cirrhosis related nodules. In the preoperative setting for accurate evaluation of colorectal liver metastases and appropriate surgical planning, gadoxetic acid-enhanced liver MRI is recommended because it has superior sensitivity and specificity compared to ultrasound, PET, and CT. In the assessment of patients with colorectal liver metastases who have been treated with chemotherapy, preoperative imaging with gadoxetic acid may be of particular benefit. For the differentiation of focal nodular hyperplasia from hepatic adenoma, gadoxetic acid-enhanced MRI should be considered due to its discriminative ability between the two based on hepatobiliary phase features. The combination of hypointensity on hepatobiliary phase images and mild-to-moderate arterial enhancement for adenoma versus strong enhancement on arterial phase images and iso- or hyperintensity on hepatobiliary phase images for FNH showed sensitivity and specificity of 83.7% and 100% and 83.8% and 98.5%, respectively. However a small percentage of adenomas can exhibit hepatobiliary uptake and surveillance and or biopsy should be considered when imaging appearances are not typical. Although gadoxetic acid-enhanced MRI yields significantly higher diagnostic accuracy and sensitivity compared with multiphasic CT for the diagnosis of HCC in cirrhosis, its role in the clinical management of HCC has yet to be defined in North America while it has seen widespread implementation in Asia/Japan. There is insufficient evidence supporting cost-effectiveness or outcomes for recommending the utilization of gadoxetic acid-enhanced MRI for HCC screening at this time. A significant percentage of nodules with hepatobiliary phase hypoenhancement but atypical enhancement on the dynamic phases have been associated with a diagnosis of HCC or future development of HCC. Biopsy or close surveillance of these lesions is recommended. Off label applications include evaluation of biliary disorders, bile leaks and hepatic function. Gadoxetic acid-enhanced liver MRI is an evolving technique with potential for non-invasive quantification of liver function and staging of hepatic fibrosis.

P2-12-2 - Neuroendocrine Tumor Evaluated as Pr by Treating 14 Months by Everolimus

Background: Everolimus is recognized as a standard treatment for pancreatic neuroendocrine tumors(pNET), although the response rate is low. We experienced an informative case of pNET, obtaining a PR after 14 months starting the treatment.Case: A 40-year-old man was diagnosed as non-hormone producing low grade pancreatic neuroendocrine tumor (NET-G2).His tumor was progressive disease even he was treated with chemotherapy, hepatic embolization, and hepatic intra-arterial chemotherapy. Since his portal vein tumor thrombosis worsened after his visit to our clinic, we started on Everolimus (10mg/day) in Sep. 2012. The target lesions were pancreatic body, both liver lobes, and para-aortic lymph node, which was in total 245 mm large on August 2012. 3 months later, it was 211 mm (14% reduction), 6 months later 207 mm (16% reduction), 10 months later 183 mm (25% reduction), 14 months later 159 mm (35% reduction) and has finally showed a PR. We had difficulty to differentiate the border of the tumor on the arterial phase enhancement CT scan images.Conclusion: This case was a difficult case for the evaluation of the tumor size and the response of Everolimus. In pNET, response may be seen gradually over time, suggesting for a precise anti-tumor evaluation.

Hepatobiliary MR contrast agents in hypovascular hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) develops via multistep hepatocarcinogenesis, during which hypovascular/early HCC precedes the typical hypervascular HCC. The hypovascular HCC lacks the typical hallmark imaging features of HCC, such as late arterial phase enhancement and portal venous washout, limiting early detection using conventional extracellular contrast agents for dynamic magnetic resonance imaging (MRI) or computed tomography (CT) imaging. In recent years, gadolinium-based contrast agents with hepatobiliary uptake have garnered interest from radiologists and hepatologists due to their potential for improved detection of HCC during hepatobiliary phase MRI. Lesions with reduced or absent hepatocyte function appear hypointense in the hepatobiliary phase of gadoxetic acid-enhanced MRI. This behavior can be exploited for earlier detection of hypovascular HCC. This review describes the general characteristics and advantages of gadoxetic acid for the diagnosis of HCC with a particular focus on hypovascular/early HCC.

Utility of contrast-enhanced ultrasound with perflubutane for diagnosing the macroscopic type of small nodular hepatocellular carcinomas.

To clarify the diagnostic value of contrast-enhanced ultrasound (CEUS) with perflubutane in the macroscopic classification of small nodular hepatocellular carcinomas (HCCs). A total of 99 surgically resected nodular HCCs with a maximum diameter of 3cm or less were analysed. HCCs were macroscopically categorized as simple nodular (SN) and non-SN. CEUS findings were evaluated during the arterial phase (vascularity, level and shape of enhancement), portal phase (presence or absence of washout) and post-vascular phase (echo intensity and shape). Sixty-eight HCCs were categorized as SN and the remaining 31 were categorized as non-SN. For diagnosis of non-SN HCC, the areas under the receiver operating characteristic curve (A z) value for the shape of enhancement in the late arterial phase and the shape of the post-vascular image were 0.824 (95% confidence interval [CI] 0.721-0.895) and 0.878 (95% CI 0.788-0.933), respectively. The A z value for the combination of the shape of enhancement in the late arterial phase and the shape of the post-vascular image for the diagnosis of non-SN HCC was 0.907 (95% CI 0.815-0.956), corresponding to a high diagnostic value. CEUS can provide high-quality imaging assessment for determining the macroscopic classification of small nodular HCCs. • Non-SN is one of the poor prognostic factors in patients with HCC • Assessment of macroscopic type provides valuable information for the management of HCC • CEUS can provide high-quality imaging assessment for macroscopic classification of HCC • For non-SN HCC diagnosed using CEUS, hepatectomy is preferred as curative treatment.

Computed tomography predictors of hepatocellular carcinoma tumour necrosis after chemoembolization

BackgroundRadiographical features associated with a favourable response to trans-arterial chemoembolization (TACE) are poorly defined for patients with hepatocellular carcinoma (HCC). MethodsFrom 2008 to 2012, all first TACE interventions for HCC performed at the University of Alabama at Birmingham (UAB) were retrospectively reviewed. Only patients with a pre-TACE and a post-TACE computed tomography (CT) scan were included in the analyses (n = 115). HCC tumour response to TACE was quantified via the the modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. Univariate and multivariable analyses were constructed. ResultsThe index HCC tumours experienced a > 90% or complete tumour necrosis in 59/115 (51%) of patients after the first TACE intervention. On univariate analysis, smaller tumour size, peripheral tumour location and arterial enhancement were associated with a > 90% or complete tumour necrosis, whereas, only smaller tumour size [odds ratio (OR) 0.62; 95% confidence interval (CI) 0.48, 0.81] and peripheral location (OR 6.91; 95% CI 1.75, 27.29) were significant on multivariable analysis. There was a trend towards improved survival in the patients that experienced a > 90% or complete tumour necrosis (P = 0.08). ConclusionsPeripherally located smaller HCC tumours are most likely to experience a > 90% or complete tumour necrosis after TACE. Surprisingly, arterial-phase enhancement and portal venous-phase washout were not significantly predictive of TACE-induced tumour necrosis. The TACE response was not statistically associated with improved survival.

Computed tomographic diagnosis of intrahepatic cholangiocarcinoma

To explore the computed tomographic (CT) manifestations and their values in the diagnosis of intrahepatic cholangiocarcinoma (IHC) and improve the understanding of IHC. A total of 58 IHC patients confirmed pathologically from January 2006 to December 2012 were reviewed. On plain CT scans, all lesions were of low density with lower density region (n = 37), retraction of liver capsule (n = 11), dilation of intrahepatic biliary duct (n = 22), bile duct calculus (n = 13) and atrophy of liver lobe (n = 14).On enhanced scans, most tumor showed obvious circular enhancement on arterial phase, stripe and network enhancement of internal region on portal phase and obvious enhancement on delayed phase. CT manifestations of intrahepatic cholangiocarcinoma are specific for its diagnosis.

Diagnosis of Infantile Haemangioendothelioma (IHE) of Liver by Triple phase Computed Tomography (CT)

We describe a case of a 9-month male infant who presented with abdominal lump, congestive cardiac failure and skin hemangiomas. Triple phase computed tomography (CT) showed multiple hypodense lesions of variable size in both lobes of the liver. Lesions showed peripheral enhancement in arterial phase and centripetal filling in portal venous phase. Lesions showed further centripetal progression of enhancement and enhanced uniformly in delayed phase. The diagnosis of infantile hemangioendothelioma (IHE) of the liver was suggested based on the typical triple phase CT imaging findings. This case is presented to emphasize the importance of the diagnosis of IHE of liver noninvasively by triple phase CT as needle biopsy is discouraged due to possible uncontrollable bleeding.

Multiphasic multidetector computed tomography study of a rare tracheal tumor: granular cell tumor.

Our aim is to present the case report of a woman affected by tracheal granular cell tumor analysed by multiphasic contrast-enhanced multidetector CT. The tumor presents as polypoid lesion (diameter 13 mm), with smooth and well-defined margins, elevated contrast enhancement in arterial phase, and a modest release of contrast in venous phase. This pattern is quite different from the other tracheal tumours. We have performed a comprehensive review of literature to assess all cases of granular cell tumors of the trachea; only 40 cases are reported. Of these, no one focused on the contrast enhancement aspect, so our work is the first showing a specific pattern in multidetector computed tomography (MDCT) of the tracheal granular cell tumour and may help in differential diagnosis.

Characteristics of Focal Liver Lesions in Arterial Phase on Contrast-enhanced Ultrasound and Contrast- -enhanced Computed Tomography – Comparative Study

To compare the features of focal liver lesions in the arterial phase on contrast-enhanced ultrasonography (CEUS) and contrast-enhanced computed tomography (CECT). A total of 38 lesions in 29 patients with focal liver lesions (FLL) were examined with CEUS and CECT. The characteristics of the enhancement were determined, especially in the early arterial phase (0~25 s). The enhancement of FLL in CEUS and CECT graded as follows: grade 0 - no enhancement; grade I - peripheral enhancement or spotty enhancement at the center; grade II - spoke-like, honeycomb-like or heterogeneous enhancement; grade II - entire enhancement. On CEUS, the arriving time within 25 s was found in 36 out of 38 lesions (94.73%) and the peak time within 25 s in 29 lesions (76.32%). The number of grade II-III FLL was 25 (65.79%) on CEUS, and 13 (34.21%) on CECT showing a significant difference (p < 0.05). Compared with CECT, CEUS plays an important role in the diagnosis of FLL with enhancement in the early arterial phase (< 25 s).

The analysis of enhancement pattern of hepatic inflammatory pseudotumor on contrast-enhanced ultrasound

The aim of this study was to assess the role of contrast-enhanced ultrasound (CEUS) in the characterization of hepatic inflammatory pseudotumor (IPT). We retrospectively reviewed 36 cases of histopathologically diagnosed IPT. Nodule enhancement appearances during the arterial, portal, and delayed phases were defined as hyperenhancement, isoenhancement, hypoenhancement, and non-enhancement compared with the surrounding liver parenchyma. Statistical analysis was performed by the one-way ANOVA and χ (2) tests. Among total 36 cases, 7 nodules were absent of contrast enhancement during all three phrases on CEUS. Twenty-nine nodules appeared different forms of enhancement in arterial phase. Diffuse homogeneous hyperenhancement, diffuse heterogeneous hyperenhancement, peripheral rim-like enhancement, and diffuse iso-enhancement were found in 10, 12, 5, and 2 of the nodules, respectively. Twenty-five nodules showed hypoenhancement in portal and delayed phases. Four nodules showed contrast washed out synchronously with normal liver parenchyma. The median time to enhancement, median time to peak, and median time to wash out of the nodules were 17s (range 11-28s), 23s (range 14-42s), and 45s (range 23-100s), respectively. No statistical significant differences were found in the above parameters of nodule enhancement and proportion of enhancement patterns when dividing the nodules into subgroups by nodule size. IPT displays a variety of enhancement patterns due to pathological changes in the course of disease progression. Some characteristics on CEUS may be helpful in the differential diagnosis of IPT.

Interobserver agreement of semi-automated and manual measurements of functional MRI metrics of treatment response in hepatocellular carcinoma

PurposeTo assess the interobserver agreement in 50 patients with hepatocellular carcinoma (HCC) before and 1 month after intra-arterial therapy (IAT) using two semi-automated methods and a manual approach for the following functional, volumetric and morphologic parameters: (1) apparent diffusion coefficient (ADC), (2) arterial phase enhancement (AE), (3) portal venous phase enhancement (VE), (4) tumor volume, and assessment according to (5) the Response Evaluation Criteria in Solid Tumors (RECIST), and (6) the European Association for the Study of the Liver (EASL). Materials and methodsThis HIPAA-compliant retrospective study had institutional review board approval. The requirement for patient informed consent was waived. Tumor ADC, AE, VE, volume, RECIST, and EASL in 50 index lesions was measured by three observers. Interobserver reproducibility was evaluated using intraclass correlation coefficients (ICC). P<0.05 was considered to indicate a significant difference. ResultsSemi-automated volumetric measurements of functional parameters (ADC, AE, and VE) before and after IAT as well as change in tumor ADC, AE, or VE had better interobserver agreement (ICC=0.830–0.974) compared with manual ROI-based axial measurements (ICC=0.157–0.799). Semi-automated measurements of tumor volume and size in the axial plane before and after IAT had better interobserver agreement (ICC=0.854–0.996) compared with manual size measurements (ICC=0.543–0.596), and interobserver agreement for change in tumor RECIST size was also higher using semi-automated measurements (ICC=0.655) compared with manual measurements (ICC=0.169). EASL measurements of tumor enhancement in the axial plane before and after IAT ((ICC=0.758–0.809), and changes in EASL after IAT (ICC=0.653) had good interobserver agreement. ConclusionSemi-automated measurements of functional changes assessed by ADC and VE based on whole-lesion segmentation demonstrated better reproducibility than ROI-based axial measurements, or RECIST or EASL measurements.

MDCT of Adrenal Masses: Can Dual-Phase Enhancement Patterns Be Used to Differentiate Adenoma and Pheochromocytoma?

The purpose of this study was to compare enhancement of adrenal adenomas and pheochromocytomas during dual-phase (arterial and venous phases) CT performed with currently used MDCT protocols with the goal of defining enhancement patterns predictive of pathologic findings. Pathologically proven pheochromocytomas were retrospectively compared with adrenal adenomas. Inclusion criteria for adenomas, collected by searching the radiology database, were confirmatory adrenal CT (unenhanced with or without washout) and absence of clinical indicators of pheochromocytoma. A fellowship-trained attending radiologist blinded to the pathologic diagnosis reviewed existing images from dual-phase IV contrast-enhanced CT examinations to measure enhancement of adrenal lesions and characterize the appearance (homogeneous versus heterogeneous). Student t test analysis was performed to compare arterial and venous phase enhancement levels. The findings in 39 patients with 41 adenomas were compared with those in 10 patients with 12 pheochromocytomas. Mean arterial and venous enhancement of adenomas at 37 HU (-6 to 85 HU) and 60 HU (16-133 HU) was significantly lower than that of pheochromocytomas at 104 HU (42-190 HU) and 119 HU (61-195 HU) (p < 0.001). No adenoma was more than 85-HU enhancing in the arterial phase, and 58% of pheochromocytomas were more than 110-HU enhancing. Most adenomas (85%) were more enhancing in the venous phase. No adenoma was more enhancing in the arterial phase, but 25% (3/12) of pheochromocytomas were. Most (58%) pheochromocytomas were heterogeneous in appearance, compared with 22% of adenomas. For indeterminate adrenal masses identified at dual-phase IV contrast-enhanced CT, higher enhancement during the arterial phase, arterial phase enhancement levels greater than 110 HU, and lesion heterogeneity should prompt consideration of pheochromocytoma.

Prevalence of the Polar Vessel Sign in Parathyroid Adenomas on the Arterial Phase of 4D CT

The "polar vessel" sign has been previously described on sonography of parathyroid adenomas. We estimated the 4D CT prevalence of the polar vessel sign and determined features of parathyroid adenomas that are associated with this sign. Twenty-eight consecutive patients with parathyroid adenomas underwent 4D CT between 2008 and 2012 at 2 institutions. 4D CT images were reviewed for the presence of the polar vessel sign and a second vascular finding of an enlarged ipsilateral inferior thyroid artery. The polar vessel sign was correlated with adenoma weight and size and arterial phase CT attenuation. Thirty-two parathyroid adenomas in 28 patients were studied, with a mean adenoma weight of 0.66 ± 0.65 g, a mean maximal CT diameter of 11.1 ± 4.9 mm, and a mean arterial attenuation of 148 ± 47 HU. The polar vessel sign was seen in 20/32 (63%) adenomas. Adenomas with a polar vessel had higher arterial phase attenuation than adenomas without a polar vessel (163 and 122 HU, respectively, P < .01). Size and weight were not significantly different for adenomas with and without polar vessels. An enlarged inferior thyroid artery was seen in only 2/28 (7%) patients with unilateral disease. The polar vessel sign was present in nearly two-thirds of parathyroid adenomas on 4D CT and was more likely to be present in adenomas that had greater arterial phase enhancement. This sign can be used along with enhancement characteristics to increase the radiologist's confidence that a visualized lesion is a parathyroid adenoma rather than a thyroid nodule or lymph node.

Liver Space Occupying Lesion in a Patient with Secondary Immunodeficiency

A 46-year-old female presented with significant weight loss and low grade fever of 2 months duration. She had cholecystectomy one year back. Ultrasonography abdomen revealed large mass in right lobe of liver. Complete blood count was and peripheral smear were normal. Her hepatitis B virus antigen (HBsAg) and antibody to hepatitis C virus (anti-HCV) were non-reactive. Human immunodeficiency virus (HIV) serology was positive. Subsequently, CT angiography of abdomen was done which revealed a large heterogenous mass of 7 cm × 5.8 cm in segment 4 and 5 of liver infiltrating gall-bladder fossa (Figure 1A & B). CA 19.9 and AFP were normal. Her CD 4 + counts was 43/μl and HIV RNA was 1,90,000/μl. Figure 1 A: Arterial phase of triphasic CT showing infiltrating lesion in segment 4 & 5. There is no enhancement in arterial phase. B: Venous phase of Triphasic CT showing infiltrating lesion in segment 4 & 5. There is no contrast uptake in venous ... Ultrasound guided biopsy from liver mass revealed non-Hodgkin’s Lymphoma (NHL), diffuse large B cell (Figure 2) and positive CD 20 staining (Figure 3). CT chest and bone marrow aspirate was done; both were normal. She was started on highly activated anti-retroviral therapy (HAART) i.e. tenofovir, emtricitabine and efavirenz along with R–CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). Figure 2 Liver biopsy showing infiltration by atypical lymphoid cells (arrow). Figure 3 Strong immunopositivity of atypical lymphoid cells for B cell marker CD 20. (IHC × 400). NHL in acquired immunodeficiency syndrome (AIDS) is a late manifestation of disease, most often associated with CD4+ < 100, though can occur at any CD4+ count.1 Whereas secondary involvement of the liver by NHL is relatively common, involving liver in as many as 21% of advanced NHL cases, primary hepatic lymphoma is extremely rare. NHL associated with AIDS involves primarily extranodal sites, especially the digestive tract and the central nervous system. Primary hepatic lymphoma is an uncommon neoplasm among these patients.2 Lei et al proposed diagnostic criteria for PHL3 (i) the symptoms are mainly caused by liver involvement at presentation, (ii) distant lymphadenopathy is neither palpable clinically at presentation or detected during radiological staging studies and (iii) no leukemic blood picture is observed on the peripheral blood film. Diffuse large B cell lymphoma is the commonest histological type of PHL as was seen in this patient. Incidence of all AIDS-related lymphomas has declined since the use of HAART. Still with better control of opportunistic infections, PHL is a common AIDS-defining illness. There are many histologic types of primary hepatic lymphoma however diffuse large B cell lymphoma is most common type. Chemotherapy with RCHOP regimen is treatment of choice.4 PHL is an aggressive disease with poor response to therapy and survival.

Radiological and histopathological features of hepatic inflammatory myofibroblastic tumour: Analysis of 10 cases

To evaluate the radiological and histopathological features of hepatic inflammatory myofibroblastic tumours (IMTs), and improve the understanding of this tumour. A retrospective analysis of radiological and histopathological features of 10 cases of IMT was carried out from May 2003 to September 2011 at the Second Xiangya Hospital of Central South University. Ten cases (five male and five female patients; age range 4-68 years) were enrolled. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed that the lesions were regular, hypodense or hypointense (T1WI) masses with well-defined borders (n=8) or ill-defined borders (n=2). The maximum diameter ranged from 3.1-13.4cm (mean=6cm). The masses showed homogeneous (n=8) or inhomogeneous (n=2) density. Contrast-enhanced CT and MRI showed the lesions were mildly, irregularly enhanced (n=7) or not enhanced (n=2) in the arterial phase and markedly enhanced in the portal venous phase or delayed phase. Hepatic arteriography revealed that the lesions were hypovascular and had a well-defined border. One patient had lung metastasis with obvious arterial phase enhancement. None of the patients had a history of hepatitis, cirrhosis, or enlarged lymph nodes. Pathology showed that the gross appearance of the tumours was smooth. The tumour cells comprised spindle-shaped fibroblast and myofibroblast cells with abundant inflammatory cells. Immunohistochemistry showed that most were positive for vimentin, smooth muscle actin (SMA), and CD68, but negative for CD34, anaplastic lymphoma kinase (ALK), S-100, and CD117. Radiological features of IMT have some characteristics of an intermediate-grade malignant tumour. However, imaging alone cannot be used to diagnose IMT. Therefore, histopathological examination is necessary for confirmation.

Contrast-enhanced US-guided Radiofrequency Ablation of Hepatocellular Carcinoma

PurposeContrast-enhanced ultrasound (US) has been shown to be an efficient imaging modality in guiding radiofrequency (RF) ablation of hepatocellular carcinomas (HCC). The purpose of the present study was to assess the usefulness of contrast-enhanced US in guiding RF ablation in patients with early-stage HCC that was not clearly visible on grayscale US or noncontrast computed tomography (CT). Materials and MethodsDuring a 17-month period, contrast-enhanced US–guided RF ablation was performed in 14 patients with 19 early-stage lesions that were poorly defined on grayscale US and noncontrast CT. Contrast-enhanced US was repeated after 30 minutes, and complete ablation was defined as absence of any arterial-phase enhancement within the ablated lesion. Patients were followed periodically with clinical evaluation, liver function tests, α-fetoprotein measurement, and multiphasic CT or magnetic resonance (MR) imaging for a minimum of 1 year after ablation to look for local recurrence or disease progression. Survival probability was estimated with the Kaplan–Meier method. ResultsComplete tumor ablation was achieved in all 19 lesions, with no evidence of residual or recurrent tumor in the ablated areas after a mean follow-up of 16 months. No major complications were observed in any patient. However, new lesions developed in other parts of the liver on follow-up scans in three patients, and were accordingly treated with RF ablation. Two patients died of disease progression or liver failure within the 1-year follow-up. ConclusionsFor early-stage HCCs not well visualized on unenhanced US or CT, contrast-enhanced US provides an additional tool to guide RF ablation.

Reply to A. Levy et al

In their letter, Levy et al provide thoughtful comments with respect to some of RECIST’s limitations and highlight recent developments regarding techniques toevaluatenovel targetedcompounds.LikeLevyetal, we too celebrate adaptations of response methodologies in the evaluation of anticancer therapies. Examples include incorporation of tumor morphology by computed tomography (CT) in colorectal cancer, tumoral enhancement in arterial CT phases for hepatocellular carcinoma, metabolic response by [F]fluorodeoxyglucose positron emission tomography (PET) for GI stromal tumors, and even modifying criteria to allow for agents that may have a slower time course to action than traditional anticancerdrugs(eg, immune-relatedresponsecriteria). Additionally, as Levy et al point out, adaptations that incorporate information regarding tumor dynamics such as tumor growth rate or the nonprogression index can also add valuable information when assessing tumor response to treatment. Despite the fact that these and other modifications are becoming available, our data suggest that the traditional RECIST assessment of change in tumor size is still generally meaningful when assessing tumor response, even in the current era of targeted agents. As we reported, more than 90% of patients included in our study had treatment regimens that included only targeted agents without traditional cytotoxic drugs. Additionally, our data were generated by analyzing a wide variety of tumor types across trials of agents with diverse mechanisms of action, but modified response methodologies have often been studied in limited settings only. Although specialized tumor response evaluation methodologies can be difficult to implement in a uniform fashion across global cancer treatment sites, traditional methods of evaluating change in tumor size by CT or magnetic resonance imaging are relatively straightforward to implement and have been in use by the global community for more than 30 years. Certainly no single tumor response methodology is better than others in all cases. There are trade-offs between using a generally applicable methodology versus measures that are more specific to individual settings. RECIST’s benefits are that it is straightforward and supported by many years of global experience. Our data suggest that incorporating RECIST evaluation of change in tumor size into early-phase clinical trials of novel agents as a key end point is reasonable and can provide critical information in assessing a novel drug’s potential efficacy. As we report, this is particularly true when tumor size changes are evaluated on a continuous scale rather than by RECIST’s complete response/partial response/stable disease/progressive disease response categorizations. In many cases, RECIST data may be well supplemented by a second, concurrently employed methodology that is appropriate for the situation such as [F]fluorodeoxyglucose PET, fluoro-l-thymidine PET, dynamic contrast-enhanced magnetic resonance imaging, magnetic resonance spectroscopy, modified RECIST criteria as referenced by Levy et al, and others. We look forward to the further refinement of RECIST and other tumor response methodologies, which will ultimately help our patients with cancer.