Progressive Contrast Enhancement Research Articles

Radiologic Clue to Cavernous Sinus Hemangioma Diagnosis

We describe a case of a 57-year-old woman presenting initially with diplopia and later developing retro-orbital and retro-auricular pain. Examination showed right abducens nerve palsy and subsequent right trigeminal nerve hyperesthesia. Neuroimaging revealed a well-defined mass confined to right cavernous sinus, with high T2 signal intensity and homogeneous enhancement on post-gadolinium T1WI. A meningioma was initially considered as the most likely diagnosis. The lesion grew over months, extending to the Meckel's cave and pituitary fossa. Dynamic T1WI revealed striking and progressive centripetal enhancement, leading to a revised diagnosis of cavernous sinus hemangioma (CSH). CSH is a rare benign extra-axial tumor, highly vascularized, frequently misdiagnosed as meningioma or schwannoma. The combination of very high T2 signal intensity and progressive centripetal contrast enhancement highly suggest CSH diagnosis. Given the significant risk of bleeding and mortality associated with surgical intervention, it is crucial to recognize CSH preoperatively to plan a meticulous surgical approach.

Diagnostic Value of Pericholedochal Hypointense Ring Sign in MRI T2W Images in Cases of Pancreatic Ductal Adenocarcinoma.

To determine the value of hypointense pericholedocal ring sign in magnetic resonance imaging (MRI) T2W sequence images in the diagnosis of pancreatic ductal adenocarcinoma (PDA). Retrospective observational study. Place and Duration of the Study: Department of Radiology, Bakirkoy Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkiye, from January 2016 and March 2022. Retrospective analysis of MRI scans was performed on 70 patients with postoperative histopathological confirmation of a diagnosis of periampullary cancer. The patients' demographic information, the results of their histopathological examinations, and the findings of their MRIs were recorded. The results of the MRI were statistically analysed and compared between the PDA and the non-PDA groups. The study included 43 (61.4%) male and 27 (38.5%) female patients, with a mean age of 62.2 ± 8.4 years. The means of Wirsung diameter and tumour diameter were significantly higher in PDA group (p = 0.034, p = 0.010, respectively). A progressive contrast enhancement pattern of 95.3% was observed in PDA group, while 40.7% rapid contrast enhancement pattern was observed in the non-PDA group. Hypointense pericholedochal ring sign, observed in T2W sequences, was detected in 74.2% (n = 32) of the PDA group and 11.1% (n = 3) of the non-PDA group, and the findings were statistically significant (p <0.001). Hypointense pericholedochal ring sign in axial T2W sequences in periampullary tumours is a complementary MRI finding in the distinction between the PDA and the non-PDA groups. Magnetic resonance imaging, Pancreatic ductal adenocarcinoma, Periampullary tumours, Pericholedochal ring sign.

Characteristics of imaging in hepatic inflammatory pseudotumors: a comparison between IgG4-related and IgG4-unrelated cases

ObjectivesThe objective of this study was to examine the imaging features of hepatic inflammatory pseudotumors (IPTs) associated with IgG4-related and IgG4-unrelated conditions and to enhance the approach toward distinguishing between these two types of IPTs.MethodsA retrospective study was conducted, involving 20 patients diagnosed with hepatic IPTs. Imaging procedures were conducted within a timeframe of 4 weeks prior to hepatectomy or biopsy. The imaging features were then analyzed and compared using chi-squared analysis.ResultsSeventeen (81.0%) IPTs were located in the hepatic subcapsular area; six (66.7%) IgG4-related IPTs were distributed around the hepatic hilum; and eleven (91.7%) IgG4-unrelated and three (33.3%) IgG4-related IPTs had unclear boundaries. All lesions exhibited similar characteristics in CT scans, T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI), with the apparent diffusion coefficient (ADC) values slightly higher than the surrounding liver tissue. Delayed hypoenhancement, observed in five cases (55.6%), was exclusively present in IgG4-related IPTs. The remaining IPT lesions displayed progressive enhancement, septal and marginal enhancement, and persistent enhancement. Central enhancement was absent in three IgG4-related IPTs (33.3%) and ten IgG4-unrelated IPTs (83.3%). The duct-penetrating sign was identified in two IgG4-unrelated IPTs (16.7%) and seven IgG4-related IPTs (77.8%). Furthermore, seven patients with IgG4-related IPTs had additional lesions outside the liver.ConclusionsIgG4-related lesions are frequently found in the vicinity of the hepatic hilum; they display the duct-penetrating sign and affect other organs as well. Both groups exhibited progressive or persistent contrast enhancement in typical IPT lesions, but delayed hypoenhancement was only observed in the IgG4-related IPT group. IgG4-unrelated IPT lesions often exhibited indistinct boundaries lacking central enhancement.Critical relevance statementDifferences in imaging features differentiate IgG4-related and -unrelated inflammatory pseudotumors (IPT). IgG4-related lesions are frequently near the hepatic hilum, display duct-penetrating sign, and affect other organs. Only the IgG4-related group demonstrated delayed hypoenhancement. IgG4-unrelated IPT lesions often exhibited indistinct boundaries lacking central enhancement.Key PointsCompared with IgG 4-unrelated IPTs, IgG4-related IPTs show delayed hypoenhancement and affect other organs.IgG4-unrelated IPTs have unclear boundaries and lack central enhancement.Improved IPT diagnostic capabilities can help minimize additional, potentially unnecessary, interventions.Graphical

Radiologic Features of Well-circumscribed Orbital Tumors With Histopathologic Correlation: A Multi-center Study.

To delineate specific imaging characteristics of solitary fibrous tumors, schwannomas, cavernous venous malformations, and well-circumscribed orbital lymphoma. Patients undergoing excisional biopsy of solitary fibrous tumor, schwannomas, cavernous venous malformations, or well-circumscribed orbital lymphoma with preoperative MRIs available for review were identified at 3 academic centers in the United States and Australia. An exploratory statistical analysis was performed to identify important radiologic features, which were subsequently included in a random forest model. Histopathologic correlates were evaluated in representative cases. A total of 91 cases were included with a mean age of 52.9 ± 17.2 years. Nearly all solitary fibrous tumors were located in the anterior or mid orbit (87.5%) and they more commonly demonstrated intralesional heterogeneity on T2-weighted imaging (45.5%) ( p < 0.01). Compared with the other tumors, schwannomas tended to be intraconal (66.7%) and were often in the mid or posterior orbit (83.4%) ( p < 0.01). Cavernous venous malformations characteristically demonstrated progressive contrast enhancement (93.9%; p < 0.01). Most lesions in all 4 groups were hypointense on T1-weighted imaging (80%-100%; p = 0.14) and only well-circumscribed orbital lymphoma tended to also be hypointense on T2 (81.8%) ( p < 0.01). Finally, cases of lymphoma had significantly lower apparent diffusion coefficient ratios (0.9 ± 0.2) ( p < 0.001), while the other 3 groups were not significantly different from one another (cavernous venous malformations: 1.8 ± 0.4; schwannomas: 1.8 ± 0.5; and solitary fibrous tumor: 1.6 ± 0.6) ( p = 0.739). Key features that aid in the differentiation of these 4 tumors from one another include T2 intensity and homogeneity, early contrast-enhancement pattern, and ADC ratio.

Giant hepatic hemangioma in a patient with cirrhosis: challenging to manage.

Giant hepatic hemangiomas are occasional in patients with cirrhosis. It remains a challenge to decide on the need for treatment and choose the most appropriate intervention. A 62-year-old woman was recently diagnosed with cirrhosis and complained of upper abdominal fullness, reduction in oral food intake, and weight loss of 6 kg over the last three years. Upper digestive endoscopy evidenced thin-caliber esophageal varices and significant extrinsic compression of the lesser gastric curvature. Abdominal computed tomography revealed an exophytic tumor in the left hepatic lobe, measuring 11.5 cm, which had progressive centripetal contrast enhancement from the arterial phase, compatible with hepatic hemangioma. Serum tumor markers were negative, and her liver function was unimpaired. The patient underwent surgical resection (non-anatomical hepatectomy of segments II and III) which had no immediate complications, and the histopathological evaluation confirmed cavernous hepatic hemangioma. Two weeks later, she was admitted to the emergency room with jaundice, signs of hepatic encephalopathy, and moderate ascites, and was further diagnosed with secondary bacterial peritonitis. As no perforations, abscesses, or fistulas were observed on subsequent imaging tests, clinical management was successfully carried out. This case highlights that giant hepatic hemangiomas may be symptomatic and warrant treatment. In the setting of cirrhosis and portal hypertension, physicians should be aware of the risk of hepatic decompensation following surgical resection, even in patients with Child-Pugh class A.

Iterative histogram equalization using discrete wavelet transform in low-dynamic range

A progressive histogram equalization (HE) and contrast enhancement method is proposed in the frequency domain. This method has an iterative structure based on the 6-sigma rule in the low-dynamic range using discrete wavelet transform. The proposed method determines an automatic threshold for attenuating the high-frequency amplitude of a signal in the discrete wavelet domain, based on the standard deviation of the absolute power of the high-frequency components in the signal band generated from the probability density function (PDF). Then an iterative quantization procedure is used where the PDF values in the frequency domain are randomly quantized. Besides, the maximum Bhattacharyya coefficient, which matches the original input image’s PDF, is used as a cost function to optimize the histogram smoothing output. For the random number generation, a 32-bit pseudorandom generator is employed to produce the same result for the output image at each runtime. The quantization factor parameter enables a controlled contrast enhancement rate to receive balanced equalization results in images. In the experimental studies, the proposed iterative HE method is compared with the well-known global, local, and brightness preserving algorithms. Experimental studies quantitatively and qualitatively display promising and encouraging results in terms of various state-of-the-art quality assessment metrics such as mean squared error, peak signal-to-noise ratio, structural similarity index measurement, contrast improvement index, absolute mean brightness error, and quality-aware relative contrast measure.

864 ISOLATED CARDIAC METASTASIS FROM CARCINOMA OF THE CERVIX: RARE CASE OF ACS-NSTE. CASE REPORT

Abstract Introduction The heart is a rare site of tumor metastasis. Although rarely, cardiac metastases may be secondary to a primary intra-abdominal tumor. Aim we report the case of a 60-years-old woman, ante-mortem finding of an isolated cardiac metastasis from cervical carcinoma presented as ACS-NSTE, who was evaluated in our Division of Cardiology. Materials and methods electrocardiogram, transthoracic echocardiography, angioTC, cardiac surgery and histopathologic analysis were performed. Results electrocardiogram showed incomplete right branch block with diffuse negative T waves. On the echocardiogram evidence of a voluminous hypo-isoechoic formation almost completely occupying the cavity of the right ventricule (RV) which appeared dilated and dysfunctional; D-shape aspect of the left ventricule as from the overload of the right sections and with moderate pericardial effusion, mildly reduced ejection fraction (EF50%Q). An urgent Angio-CT was performed and revealed a voluminous solid neoformation with inhomogeneous content and progressive contrast enhancement in the right ventricule. Following admission, the patient's haemodynamic status gradually worsened. Therefore, urgent cardiac surgery was performed. After drainage of abundant serum/haematic effusion, probably neoplastic infiltration of RV was seen. Therefore, given the extension it was decided to perform only multiple biopsies. Histopathological examination revealed moderately differentiated squamous cell carcinoma, as from metastasis from K. cervix. Conclusions there is no standardized therapy for the treatment of cardiac metastases, it is necessary to evaluate on a case-by-case basis. The most important prognostic factors are the obstructive effect of the intracardiac mass and the extent of any pericardial effusion. In fact, they can adversely affect hemodynamic stability.

Prediction of pathological complete response to neoadjuvant chemotherapy in patients with breast cancer using a combination of contrast-enhanced ultrasound and dynamic contrast-enhanced magnetic resonance imaging.

This study aimed to evaluate the value of dynamic contrast-enhanced ultrasound (CEUS) combined with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting pathological complete response (pCR) in patients with breast cancer receiving neoadjuvant chemotherapy (NAC). Fifty-seven female patients with breast cancer (mean age, 50.46 years; range, 32-66 years) scheduled for NAC were recruited. CEUS and DCE-MRI were performed before and after NAC. Imaging features and their changes were compared with postoperative pathological results. After the clinical differences were balanced using propensity score matching, univariate and multiple logistic regression analyses were used to derive the characteristics independently associated with pCR. Receiver operating characteristic curve analysis was performed to assess diagnostic performance. After six to eight cycles of NAC, 24 (42.1%) patients achieved pCR, while 33 (57.9%) did not. Multivariate analysis showed that enhancement order on CEUS and DCE-MRI before NAC, reduction in diameter and enhancement shape on CEUS, maximum diameter on DCE-MRI, and the type of progressive dynamic contrast enhancement after NAC were independently associated with pCR after NAC. The area under the receiver operating characteristic curve for CEUS+DCE-MRI was 0.911 (95% confidence interval, 0.826-0.997), and the specificity and positive predictive values were 87.0% and 87.5%. CEUS and DCE-MRI have the potential for assessing the pathological response to NAC in patients with breast cancer; their combination showed the best diagnostic performance. CEUS+DCE-MRI has proved beneficial for comprehensive assessment and personalizing treatment strategies for patients with breast cancer.

Neuro-Oncology Practice Clinical Debate: FDG PET to differentiate glioblastoma recurrence from treatment-related changes.

The ability to accurately differentiate treatment-related changes (ie, pseudoprogression and radiation necrosis) from recurrent glioma remains a critical diagnostic problem in neuro-oncology. Because these entities are treated differently and have vastly different outcomes, accurate diagnosis is necessary to provide optimal patient care. In current practice, this diagnostic quandary commonly requires either serial imaging or histopathologic tissue confirmation. In this article, experts in the field debate the utility of 2-deoxy-2[18F]fluoro-d-glucose positron emission tomography (FDG PET) as an imaging tool to distinguish tumor recurrence from treatment-related changes in a patient with glioblastoma and progressive contrast enhancement on magnetic resonance (MR) following chemoradiotherapy.

Magnetic resonance imaging findings of carcinoma arising from anal fistula: A retrospective study in a single institution.

BACKGROUNDMagnetic resonance imaging (MRI) is currently the standard investigation for suspected perianal diseases. Carcinoma arising from anal fistula is very rare, and early diagnosis is often difficult.AIMTo describe and summarize the MRI findings of carcinoma arising from anal fistula.METHODSIn this retrospective study, records of ten patients diagnosed with carcinoma arising from anal fistula and confirmed by surgery (n = 7) or biopsy (n = 3) between June 2006 and August 2018 were analyzed. All patients underwent preoperative pelvic MRI. Morphologic features, signal characteristics, fistula between the mass and the anus, contrast enhancement of mass, signal and enhancement of peritumoral areas, and regional lymphadenopathy were assessed.RESULTSAll ten tumors were solitary (8 mucinous adenocarcinomas and 2 adenocarcinomas). The maximum diameter of the tumors ranged from 3.4 cm to 12.4 cm (median: 4.15 cm; mean: 5.68 cm). Eight patients had a fistula between the mass and the anus. Contrast enhancement of the peritumoral areas was noted in three (3/5) patients. Perirectal or inguinal lymphadenopathy was noted in seven patients. Most lesions of mucinous adenocarcinoma were multiloculated and cauliflower-like, with a thin capsule and focally unclear boundary. They were markedly hyperintense on fat-suppressed T2WI, slightly hyperintense with focal hyperintensity on diffusion-weighted imaging (DWI), and hyperintense with focal hypointensity on apparent diffusion coefficient (ADC) map, with progressive mesh-like contrast enhancement. Adenocarcinomas had an infiltrative margin without a capsule and appeared heterogeneously hyperintense or slightly hyperintense on fat-suppressed T2WI, hyperintense on DWI, and hypointense on ADC map, with persistent heterogeneous enhancement.CONCLUSIONOur study highlighted several characteristic and potentially helpful MRI findings to diagnose carcinomas arising from anal fistula.

Major and ancillary features according to LI-RADS in the assessment of combined hepatocellular-cholangiocarcinoma

BackgroundThe aim of the study was to investigate the performance of the Liver Imaging Reporting and Data System (LI-RADS) v2018 for combined hepatocellular-cholangiocarcinoma (cHCC-CCA) identifying the features that allow an accurate characterization.Patients and methodsSixty-two patients (median age, 63 years; range, 38–80 years), with pre-surgical biopsy diagnosis of hepatocellular carcinoma (HCC) that underwent hepatic resection, comprised our retrospective study. All patients were subject to multidetector computed tomography (MDCT); 23 patients underwent to magnetic resonance (MR) study. The radiologist reported the presence of the HCC by using LIRADS v2018 assessing major and ancillary features.ResultsFinal histological diagnosis was HCC for 51 patients and cHCC-CCA for 11 patients. The median nodule size was 46.0 mm (range 10–190 mm). For cHCC-CCA the median size was 33.5 mm (range 20–80 mm), for true HCC the median size was 47.5 mm (range 10–190 mm). According to LIRADS categories: 54 (87.1%) nodules as defined as LR-5, 1 (1.6%) as LR-3, and 7 (11.3%) as LR-M. Thirty-nine nodules (63%) showed hyper-enhancement in arterial phase; among them 4 were cHCC-CCA (36.4% of cHCC-CCA) and 35 (68.6%) true HCC. Forty-three nodules (69.3%) showed washout appearance; 6 cHCC-CCAs (54.5% of cHCC-CCA) and 37 true HCC (72.5%) had this feature. Only two cHCC-CCA patients (18.2% of cHCC-CCA) showed capsule appearance. Five cHCC-CCA (71.4% of cHCC-CCA) showed hyperintensity on T2-W sequences while two (28.6%) showed inhomogeneous signal in T2-W. All cHCC-CCA showed restricted diffusion. Seven cHCC-CCA patients showed a progressive contrast enhancement and satellite nodules.ConclusionsThe presence of satellite nodules, hyperintense signal on T2-W, restricted diffusion, the absence of capsule appearance in nodule that shows peripheral and progressive contrast enhancement are suggestive features of cHCC-CCA.

Clinical and imaging features of IgG4-related kidney disease.

To assess the clinical and imaging features of IgG4-RKD for understanding and diagnosis of this disease. CT and MR images of 34 patients with IgG4-RKD were retrospectively analyzed by two radiologists in consensus. The serum IgG4 level was found being increased in all patients. Renal involvement was bilateral (24/34, 70.6%) or unilateral (10/34,29.4%), multiple (29/34, 85.3%) or solitary (5/34, 14.7%). The lesions were wedge-shaped (21) or mass-like (4) in the renal parenchyma, whereas diffusely decreased renal density was noted in 2 patients. All lesions showed progressive contrast enhancement. The 4 mass-like lesions were misdiagnosed as renal malignancy. In 15 patients with follow-up imaging examinations, the number and size of renal lesions decreased after oral hormone treatment. The serum IgG4 levels were significantly decreased after therapy in all patients. IgG4-RKD has various imaging appearances. Although the mass-like appearance mimics renal malignancy in some patients, progressive contrast enhancement in the lesion with elevated serum IgG4 suggests IgG4-RKD.

Low-grade appendiceal mucinous neoplasms confined to the appendix: clinical manifestations and CT findings

The clinical findings and CT images are investigated in order to fulfill an early preoperative diagnosis and increase awareness of low-grade appendiceal mucinous neoplasm (LAMN) confined to the appendix. 17...

Microvascular invasion and grading in hepatocellular carcinoma: correlation with major and ancillary features according to LIRADS.

To assess major and ancillary parameters that could be correlated with Microvascular Invasion (MIV) and with histologic grade of HCC. In this retrospective study, we assessed 62 patients (14 women-48 men; mean age, 63years; range 38-80years) that underwent hepatic resection for HCC. All patients were subject to Multidetector computed tomography (MDCT); 40 to Magnetic Resonance (MR) study. The radiologist assessed major and ancillary features according to LIRADS (v.2018) and reported any radiological accessory findings if detected. No major feature showed statistically significant differences and correlation with grading. Mean ADC value was correlated with grading and with MIV status. No major feature was correlated to MIV; progressive contrast enhancement and satellite nodules showed statistically different percentages with respect to the presence of MIV, so as at the monovariate correlation analysis, satellite nodules were correlated with the presence of MIV. At multivariate regression analysis, no factor proved to be strong predictors of grading while progressive contrast enhancement and satellite nodules were significantly associated with the MIV. Mean ADC value is correlated to HCC grading and MIV status. Progressive contrast enhancement and the presence of satellite nodules are correlated to MIV status.

Magnetic Resonance Imaging of Uncommon Hepatic Mesenchymal Tumours: Haemangioendothelioma and Angiosarcoma.

Primary Hepatic Epithelioid Haemangioendothelioma (HEHE) and Primary Hepatic Angiosarcoma (PHA) are rare mesenchymal tumours with different malignant potential. Whereas HEHE demonstrates low to intermediate malignant potential, PHA is an aggressive malignancy with poor prognosis. The knowledge of typical imaging features of these lesions may facilitate correct diagnosis; however, the ultimate diagnosis of HEHE and PHA is based on histopathologic examination. The most typical findings helpful in diagnosing HEHE are: Presence of multiple, confluent nodules located at the liver periphery (in young to middle-aged woman), retraction of the liver capsule, marked hyperintensity on T2-weighted images, "target-sign" appearance, progressive centripetal contrast enhancement, and relatively high Apparent Diffusion Coefficient (ADC) values. More than ≥50% of nodules are hyper- or isointense on Hepatobiliary Phase (HBP) images. The imaging features suggestive of PHA are: Occurrence of metastases (lungs, spleen) at the time of diagnosis, presence of a large dominant mass with smaller satellites, heterogeneity and areas of haemorrhage in a dominant mass, progressive contrast enhancement, slightly elevated ADC values as compared to other malignant liver tumours.

Adrenal schwannoma: CT, MR manifestations and pathological correlation.

This study aimed to describe the computed tomography (CT), magnetic resonance imaging (MRI) imaging features of adrenal schwannoma and to correlate imaging findings with histopathologic findings. The findings from multiphase CT or MRI examinations of seventeen patients with histopathologically confirmed adrenal schwannoma were reviewed. The imaging criteria included shape, size, margin, attenuation, signal intensity, secondary degeneration, and internal mass enhancement pattern. All cases were unilateral, round or oval solitary tumors, with diameters ranging from approximately 2.5 to 8.8 cm (median = 4.5 cm). Of the twelve cases assessed using CT, adrenal schwannoma appeared as well-circumscribed round or oval low-density suprarenal masses with a mean attenuation values of 30.1 HU of solid portions during unenhanced phase. Ten cases exhibited heterogeneous cyst formation, and one case showed calcification. Internal septa were noted in 5 cases. All solid areas displayed early mild heterogeneous enhancement and delayed progressive enhancement. Regarding MRI, solid portions of five masses were hypointense to the liver parenchyma on T1-weighted imaging (T1WI) and were heterogeneously hyperintense on T2-weighted imaging (T2WI). The enhanced pattern of solid areas of adrenal schwannoma on MRI is similar to that of CT. Cystic or hemorrhagic changes were noted in 4 cases and internal septa were noted in 3 cases. Although schwannoma is a rare entity in the adrenal gland, we believe that the following signs may suggest the diagnosis of this entity: a non-lipid containing mass, a well-defined border, a unilateral mass with cystic or hemorrhagic degeneration, septa with delayed enhancement and a characteristic progressive contrast enhancement pattern of the solid portions.

Uncommon neoplasms of the biliary tract: radiological findings

To report our cancer centre experience in the biliary tumours incidence other than cholangiocellular-carcinoma, emphasizing the radiological features. 197 patients with biliary disease undergoing Gd-EOB-DTPA-enhanced MRI were reviewed. Four radiologists evaluated retrospectively size, structure, anatomical site and signal intensity of lesions on MRI. Enhancement-pattern during the arterial-, portal- and late-phase on ultrasound, CT and MR study was assessed as well as the enhancement pattern during the hepatobiliary-phase on MRI. 23 patients were selected. The lesion was intraductal in 5 cases, periductal in 14 and intrahepatic in 4. 16 lesions were solid, 5 uniloculated cystic and 2 complex cystic. In five patients the lesion was simple cyst, with a signal intensity in T1 weighted (T1W) and T2 weighted (T2W) similar to the gallbladder. In two patients with complex cystic lesion, the solid component was heterogeneously hypointense in T1 W, hyperintense in T2 W with a restricted diffusion. The solid component showed heterogeneous contrast-enhancement on CT, MR and ultrasound. The tumour was intrahepatic in two patients, with signal hypointense in T1 W and hyperintense in T2 W. Diffusion was restricted. The lesions showed heterogeneous contrast-enhancement. The periductal lesions were hypointense in T1 W, hyperintense in T2 W with restricted diffusion. The lesion showed progressive contrast-enhancement. Peribiliary melanoma was hyperintense in T1 W, hyperintense in T2 W with restricted diffusion and progressively contrast-enhanced. Biliary tumours can have a wide spectrum of radiologic appearances and consequently represent a diagnostic challenge for the radiologist. Advances in knowledge: MRI is the technique of choice in diagnosing biliary tumours, including rare (non-CCC) tumours.

Peribiliary liver metastases MR findings.

We described magnetic resonance (MR) features of peribiliary metastasis and of periductal infiltrative cholangiocarcinoma. We assessed 35 patients, with peribiliary lesions, using MR 4-point confidence scale. T1-weighted (T1-W), T2-weighted (T2-W) and diffusion-weighted images (DWI) signal intensity, enhancement pattern during arterial, portal, equilibrium and hepatobiliary phase were assessed. We identified 24 patients with periductal-infiltrating cholangiocellular carcinoma. The lesions in 34 patients appeared as a single tissue, while in a single patient, the lesions appeared as multiple individual lesions. According to the confidence scale, the median value was 4 for T2-W, 4 for DWI, 3.6 for T1-W in phase, 3.6 for T1-W out phase, 3 for MRI arterial phase, 3.2 for MRI portal phase, 3.2 for MRI equilibrium phase and 3.6 for MRI hepatobiliary phase. According to Bismuth classification, all lesions were type IV. In total, 19 (54.3%) lesions were periductal, 15 (42.9%) lesions were intraperiductal, and 1 (2.8%) lesion was periductal intrahepatic. All lesions showed hypointense signal in T1-W and in ADC maps and hyperintense signal in T2-W and DWI. All lesions showed a progressive contrast enhancement. There was no significant difference in signal intensity and contrast enhancement among all metastases and among all metastases with respect to CCCs, for all imaging acquisitions (p value >0.05). MRI is the method of choice for biliary tract tumors thanks to the possibility to obtain morphological and functional evaluations. T2-W and DW sequences have highest diagnostic performance. MRI does not allow a correct differential diagnosis among different histological types of metastasis and between metastases and CCC.

An automated method for accurate vessel segmentation

Vessel segmentation is a critical task for various medical applications, such as diagnosis assistance of diabetic retinopathy, quantification of cerebral aneurysm’s growth, and guiding surgery in neurosurgical procedures. Despite technology advances in image segmentation, existing methods still suffer from low accuracy for vessel segmentation in the two challenging while common scenarios in clinical usage: (1) regions with a low signal-to-noise-ratio (SNR), and (2) at vessel boundaries disturbed by adjacent non-vessel pixels. In this paper, we present an automated system which can achieve highly accurate vessel segmentation for both 2D and 3D images even under these challenging scenarios. Three key contributions achieved by our system are: (1) a progressive contrast enhancement method to adaptively enhance contrast of challenging pixels that were otherwise indistinguishable, (2) a boundary refinement method to effectively improve segmentation accuracy at vessel borders based on Canny edge detection, and (3) a content-aware region-of-interests (ROI) adjustment method to automatically determine the locations and sizes of ROIs which contain ambiguous pixels and demand further verification. Extensive evaluation of our method is conducted on both 2D and 3D datasets. On a public 2D retinal dataset (named DRIVE (Staal 2004 IEEE Trans. Med. Imaging 23 501–9)) and our 2D clinical cerebral dataset, our approach achieves superior performance to the state-of-the-art methods including a vesselness based method (Frangi 1998 Int. Conf. on Medical Image Computing and Computer-Assisted Intervention) and an optimally oriented flux (OOF) based method (Law and Chung 2008 European Conf. on Computer Vision). An evaluation on 11 clinical 3D CTA cerebral datasets shows that our method can achieve 94% average accuracy with respect to the manual segmentation reference, which is 23% to 33% better than the five baseline methods (Yushkevich 2006 Neuroimage 31 1116–28; Law and Chung 2008 European Conf. on Computer Vision; Law and Chung 2009 IEEE Trans. Image Process. 18 596–612; Wang 2015 J. Neurosci. Methods 241 30–6) with manually optimized parameters. Our system has also been applied clinically for cerebral aneurysm development analysis. Experimental results on 10 patients’ data, with two 3D CT scans per patient, show that our system’s automatic diagnosis outcomes are consistent with clinicians’ manual measurements.

P16.16 * INFLUENCE OF DETERMINATION OF PROGRESSION ON PATTERNS OF FLAIR FAILURE ANALYSIS IN PATIENTS WITH GRADE III ANAPLASTIC ASTROCYTOMA (AA) AND ASSOCIATION OF PATTERN OF FAILURE (POF) WITH SURVIVAL

PURPOSE/OBJECTIVES: RANO criteria have recently been proposed as response guidelines for contrast-enhancing high grade gliomas, but the utility of these guidelines has not been established in AA. In this report we evaluated the utility of RANO criteria in determining progression and POF in AA and evaluated the association of POF with overall survival (OS). MATERIALS/METHODS: We performed a retrospective review of MR images for 21 consecutive patients with AA and radiologically-proven recurrence after irradiation at the Mayo Clinic (Rochester, MN). Three different criteria for identification of progression were used for each patient: 1) standard RANO-based criteria (RANO-C; most often met by development of new contrast enhancement or enlargement of contrast-enhancing lesion), 2) RANO criteria for progression based on significant FLAIR increase (RANO-F) and 3) clinical progression based on oncologist interpretation of imaging and clinical status usually resulting in change in treatment (Clinical). Time to progression was assessed among the three criteria using Friedman's test, and pairwise criteria using a sign test. After subtraction of tumor volume occurring on the best-response MR study, final structure was dosimetrically analyzed and different POF were characterized by the % volume encompassed within the 95% dose as follows: central (V95% ≥ 95%), in-field (80% ≤ V95% < 95%), marginal (20% ≤ V95% < 80%), or distant (V95% < 20%). RESULTS: Time to progression based on RANO criteria preceeded the clinical diagnosis of progression by a median of 3.13 months (9.2 vs 12.6 mo p < 0.0001, Sign test). New or progressive contrast enhancement (RANO-C) was almost entirely central or in-field (95% and 5%, respectively). POF of FLAIR component differed based on timepoint used to determine progression. FLAIR POF was significantly more often marginal or distant when progression was defined clinically compared to either RANO-C or RANO-F criteria (p = .03 and .007 respectively). POF for FLAIR abnormality at the time of RANO-C was 33% central, 24% in-field and 43% marginal; at RANO-F was 47%, 16% and 37% respectively, and at the time of Clinical recurrence were more often peripheral with 19% central, 24% in-field, 52% marginal and 1 patient (5%) distant. No association with POF and OS was seen when evaluated at the time of RANO defined progression. Central POF at Clinical determination of progression was associated with poorer OS (9.8 vs 29.7 months, p = 0.017). CONCLUSION: POF analysis in AA is dependent on method of progression determination. Time to progression based on RANO criteria generally preceeded clinician impression. POF at the time of RANO determination of progression was not associated with survival. Central recurrence as evaluated at the time of clinical progression is strongly associated with poorer OS.