Time-Intensity Curves Obtained after Microbubble Injection Can Be Used to Differentiate Responders from Nonresponders among Patients with Clinically Active Crohn Disease after 6 Weeks of Pharmacologic Treatment.

Purpose To assess whether contrast material-enhanced ultrasonography (US) can be used to differentiate responders from nonresponders among patients with clinically active Crohn disease after 6 weeks of pharmacologic treatment. Materials and Methods This prospective study was approved by our ethics committee, and written informed consent was obtained from all patients. Fifty consecutive patients (26 men and 24 women; mean age, 34.76 years ± 9) with a proved diagnosis of active Crohn disease who were scheduled to begin therapy with biologics (infliximab or adalimumab) were included, with enrollment from June 1, 2013, to June 1, 2015. In each patient, the terminal ileal loop was imaged with contrast-enhanced US before the beginning and at the end of week 6 of pharmacologic treatment. Time-intensity curves obtained in responders (those with a decrease in the Crohn disease endoscopic index of severity score of 25-44 before treatment to 10-15 after treatment, an inflammatory score <7, and/or a decrease ≥70 in the Crohn disease activity index score compared with baseline) and nonresponders were compared with Mann-Whitney test. Results Responders (n = 31) and nonresponders (n = 19) differed (P < .05) in the percent change of peak enhancement (-40.78 ± 62.85 vs 53.21 ± 72.5; P = .0001), wash-in (-34.8 ± 67.72 vs 89.44 ± 145.32; P = .001) and washout (-5.64 ± 130.71 vs 166.83 ± 204.44; P = .002) rate, wash-in perfusion index (-42.29 ± 59.21 vs 50.96 ± 71.13; P = .001), area under the time-intensity curve (AUC; -46.17 ± 48.42 vs 41.78 ± 87.64; P = .001), AUC during wash-in (-43.93 ± 54.29 vs 39.79 ± 70.85; P = .001), and AUC during washout (-49.36 ± 47.42 vs 42.65 ± 97.09; P = .001). Responders and nonresponders did not differ in the percent change of rise time (5.09 ± 49.13 vs 6.24 ± 48.06; P = .93) and time to peak enhancement (8.82 ± 54.5 vs 10.21 ± 43.25; P = .3). Conclusion Analysis of time-intensity curves obtained after injection of microbubble contrast material 6 weeks after beginning pharmacologic treatment can be used to differentiate responders from nonresponders among patients with clinically active Crohn disease. © RSNA, 2016.

Value of percent change in tumoral volume measured at T2 -weighted and diffusion-weighted MRI to identify responders after neoadjuvant chemoradiation therapy in patients with locally advanced rectal carcinoma.

PURPOSE: To evaluate the percent change in tumoral volume measured at T2 -weighted magnetic resonance imaging (T2 WMRI) and diffusion-weighted (DWI) as a method to identify responders after chemo- and radiation therapy (CRT) in patients with locally advanced rectal carcinoma. MATERIALS AND METHODS: Forty-five consecutive patients (mean age ± SD: 72 years ± 9.7; male/female = 24/21) with locally advanced rectal carcinoma underwent CRT followed by surgery. Each patient underwent T2 WMRI and DWI at 1.5T before and 6 weeks after the completion of CRT. The percent change in tumoral volume before and 6 weeks after CRT was compared in patients classified as responders and nonresponders according to rectal cancer regression grade. RESULTS: Twenty-five patients were classified as responders with either partial (n = 20) or complete response (n = 5), while 20 patients were classified as nonresponders due to stable disease (n = 18) or disease progression (n = 2). Responders vs. nonresponders differed in the percent change of tumoral volume at T2 WMRI (-67% ± 26% vs. -29% ± 26%; P < 0.05) and DWI images (-72% ± 24% vs. -33% ± 28%; P < 0.05) with a cutoff ≤ -70% for T2 WMRI (sensitivity = 69%, 95% confidence interval [CI]: 48-85%; specificity = 100%, 95% CI 81-100%) and ≤66% for DWI (sensitivity = 73%, 95% CI: 52-88%; specificity = 100%, 95% CI 81-100%). CONCLUSION: The percent change in tumoral volume at T2 WMRI and DWI images can differentiate responders from nonresponders in patients with locally advanced rectal carcinoma after neoadjuvant CRT. J. Magn. Reson. Imaging 2016;44:1415-1424.

Bolus versus continuous infusion of microbubble contrast agent for liver ultrasound by using an automatic power injector in humans: A pilot study.

PURPOSE: To evaluate the feasibility of using continuous infusion, in comparison with bolus injection, of a sulfur hexafluoride-microbubble contrast agent to prolong the duration of hepatic parenchymal enhancement in humans during sonographic examination. METHODS: This pilot study was approved by our institution's ethics committee. Ten patients (5 men and 5 women; mean age ± SD, 65 ± 10 years) each received two injections: a bolus injection (2 ml/s) and then continuous infusion (0.5 ml/min) of the contrast agent by using an automatic injector. Acquired cine clips were transferred to a personal computer, and the video intensity was quantified by dedicated software. RESULTS: From the time of the first microbubble visualization in the scanning plane, maximal enhancement was reached in 6.3 ± 0.94 seconds after bolus injection and in 13.9 ± 1.44 seconds during continuous infusion (p = 0.002, Wilcoxon's test for paired data). Compared with bolus injection, continuous infusion prolonged the duration of contrast enhancement (4.3 minutes ± 42 seconds versus 7.3 minutes ± 40 seconds; p = 0.002), although no statistically significant difference in maximal enhancement was observed (45 ± 18% for bolus injection and 39 ± 6% for continuous infusion; p = 0.62). CONCLUSIONS: Continuous infusion of sulfur hexafluoride-filled microbubbles via an automatic power injector prolongs hepatic contrast enhancement without significantly modifying the maximal enhancement over that at baseline. These data, coming from a pilot study, can be used to design a larger study with adequate statistical power.

Impact of gadolinium-based contrast agent in the assessment of Crohn's disease activity: Is contrast agent injection necessary?

PURPOSE: To determine whether magnetic resonance enterography (MRE) performed without intravenous contrast injection is diagnostically noninferior to conventional contrast-enhanced MRE (CE-MRE) in patients with Crohn's disease (CD). MATERIALS AND METHODS: This was an Institutional Review Board (IRB)-approved retrospective study. Ninety-six patients (52 male and 44 female; 47.18 years ± 13.6) with a diagnosis of CD underwent MRE at 1.5T including T2 -weighted single-shot turbo-spin-echo, T2 -weighted spectral fat presaturation with inversion recovery (SPAIR), T1 -weighted balanced fast-field-echo MR sequences, and CE-MRE consisting in T1 -weighted breath-hold THRIVE 3D MRI sequences after administration of gadobenate dimeglumine (0.2 mL/kg of body weight). Unenhanced MRE, CE-MRE, and unenhanced MRE plus CE-MRE were reviewed in separate sessions with blinding by two readers in consensus, and subsequently by two other readers independently considering a subgroup of 20 patients. Crohn's Disease Endoscopic Index of Severity (CDEIS) and/or histologic analysis of the surgical specimen were considered as reference standards for the assessment of inflammatory activity. RESULTS: Patients revealed prevalently active (n = 55 patients) or quiescent CD (n = 41 patients). The agreement between unenhanced MRE vs. CE-MRE in interpreting active bowel inflammation was 96% (123/128 bowel segments; one-sided 95% confidence interval [CI], >94.4%). Unenhanced MRE vs. CE-MRE vs. unenhanced MRE plus CE-MRE revealed a diagnostic accuracy of 93% [90/96] vs. 92% [88/96] vs. 97% [93/96] (P > 0.05) in the diagnosis of active CD. Interreader agreement was very good for all variables (κ value = 0.8-0.9) except for the measurement of the length of disease (κ value = 0.45). CONCLUSION: Unenhanced MRE was noninferior to CE-MRE in diagnosing active inflammation in patients with CD.

Predictors of intrahepatic cholangiocarcinoma in cirrhotic patients scanned by gadobenate dimeglumine-enhanced magnetic resonance imaging: diagnostic accuracy and confidence.

OBJECTIVE: To identify predictors of intrahepatic cholangiocarcinoma in cirrhotic patients scanned by gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging. METHODS: Fifty cirrhotic patients with 120 nodules, including 10 mass-forming intrahepatic cholangiocarcinomas and two combined hepatocellular carcinoma-cholangiocarcinomas, were scanned by Gd-BOPTA-enhanced MR imaging. RESULTS: T1 hypointensity [odds ratio (OR), 20.12], peripheral hyperintense rim at hepatic arterial phase (OR, 13.5), and iso-hyperintensity at hepatobiliary phase (OR 21.32) were found to be independent predictors of intrahepatic cholangiocarcinoma. CONCLUSIONS: T1 hypointensity, peripheral hyperintense rim at hepatic arterial phase, and iso-hyperintensity at hepatobiliary phase are independent predictors of intrahepatic cholangiocarcinoma diagnosis in patients with liver cirrhosis.

Predictors of mesorectal fascia invasion after gadolinium injection in rectal carcinoma after neoadjuvant therapy.

OBJECTIVE: To assess spectral presaturation inversion-recovery MRI sequence with gadolinium to identify predictors of mesorectal fascia (MRF) invasion in patients with locally advanced rectal carcinoma after neoadjuvant therapy. MATERIALS AND METHODS: Sixty-five patients underwent neoadjuvant concomitant radiation and chemotherapy and surgery. Magnetic resonance images were assessed by two radiologists. RESULTS: Linear (odds ratio, 95% confidence intervals: 19.33, 1.98-188.6) and reticular strands (odds ratio, 95% confidence intervals: 9.75, 1.45-67.77) reaching the MRF are predictors of MRF invasion. CONCLUSION: Linear or reticular mesorectal strands reaching the MRF detected at contrast-enhanced MRI represent a predictor of MRF invasion.

Indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography: assessment of the additional diagnostic value of contrast-enhanced ultrasound in the non-cirrhotic liver.

OBJECTIVE: To assess the additional diagnostic value of contrast-enhanced ultrasound (CEUS) in the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography (CT). METHODS: Fifty-five solid hepatic lesions (1-4 cm in diameter) in 46 non-cirrhotic patients (26 female, 20 male; age±SD, 55±10 years) underwent CEUS after being detected on contrast-enhanced CT which was considered as non-diagnostic after on-site analysis. Two blinded independent readers assessed CT and CEUS scans and were asked to classify retrospectively each lesion as a malignant or benign based on reference diagnostic criteria for the different hepatic lesion histotypes. Diagnostic accuracy and confidence (area--Az--under ROC curve) were assessed by using gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging (n=30 lesions), histology (n=7 lesions), or US follow-up (n=18 lesions) as the reference standards. RESULTS: Final diagnoses included 29 hemangiomas, 3 focal nodular hyperplasias, 1 hepatocellular adenoma, and 22 metastases. The additional review of CEUS after CT images improved significantly (P<.05) the diagnostic accuracy (before vs after CEUS review=49% [20/55] vs 89% [49/55]--reader 1 and 43% [24/55] vs 92% [51/55]--reader 2) and confidence (Az, 95% Confidence Intervals before vs after CEUS review=.773 [.652-.895] vs .997 [.987-1]--reader 1 and .831 [.724-.938] vs .998 [.992-1]--reader 2). CONCLUSIONS: CEUS improved the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced CT by identifying some specific contrast enhancement patterns.

Evidence of diagnostic enhancement pattern in hepatocellular carcinoma nodules ≤2 cm according to the AASLD/EASL revised criteria.

PURPOSE: To define the percentage of small (≤2 cm) hepatocellular carcinoma (HCC) nodules showing the diagnostic enhancement pattern at CEUS, computed tomography (CT), and gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging. METHODS: 42 cirrhotic patients (26 male, 16 female; 67 ± 12 years) with 46 biopsy-proven HCCs ≤2 cm were included. Each HCC was scanned by CEUS, contrast-enhanced CT, and Gd-BOPTA-enhanced MR imaging. Nodule enhancement was evaluated by two readers. Independent analysis was followed by consensual analysis and the proportion of HCCs with the diagnostic enhancement pattern (nodule hyperenhancing on hepatic arterial phase and hypoenhancing on portal venous-late phase) on CEUS, CT, and MR imaging was compared by chi-square test. RESULTS: Very good inter-reader agreement was observed on hepatic arterial phase and portal venous-late phase: CEUS, k = 0.89 and 0.85; CT, k = 0.91 and 0.88; MR imaging, k = 0.96 and 0.94. CEUS and CT did not differ in the percentage of HCC nodules with a diagnostic enhancement pattern (18/46 and 16/46; P = 0.66), while MR imaging revealed the diagnostic pattern in higher percentage of nodules (29/46; P = 0.012) in comparison to CEUS and CT. CONCLUSIONS: CEUS and contrast-enhanced CT did not differ in the percentage of small HCC nodules with diagnostic enhancement pattern, while Gd-BOPTA-enhanced MR imaging revealed the diagnostic pattern in a higher nodule number in comparison to CEUS and CT.

Predictors of dysplastic nodule diagnosis in patients with liver cirrhosis on unenhanced and gadobenate dimeglumine-enhanced MRI with dynamic and hepatobiliary phase.

OBJECTIVE: The purpose of this article is to assess whether unenhanced and gadobenate dimeglumine-enhanced MRI with dynamic and hepatobiliary phase may predict the diagnosis of dysplastic nodules in patients with liver cirrhosis. MATERIALS AND METHODS: We retrospectively analyzed 75 cirrhotic patients (47 men and 28 women; mean [± SD] age, 55 ± 12 years) with 82 hepatocellular nodules, including histology-proven dysplastic nodules (n = 25; diameter, 1-3 cm) and hepatocellular carcinomas (n = 57; diameter, 2-3 cm) scanned by MRI before and after gadobenate dimeglumine injection during hepatic arterial phase (HAP), portal venous phase (PVP), equilibrium phase, and hepatobiliary phase. Nodule T1 and T2 intensities before contrast agent injection and nodule HAP, PVP, equilibrium phase, and hepatobiliary phase intensities were compared with the adjacent liver. Univariate and multivariate logistic regression analysis was conducted to assess how the nodule could predict dysplastic nodule diagnosis. RESULTS: Some imaging findings were independent predictors of dysplastic nodule diagnosis-namely, nodule T2 isohypointensity (odds ratio [OR], 12.28; 95% CI, 3.88-38.82), T1 isohyperintensity (OR, 26.74; 95% CI, 7.53-94.90), HAP isohypointensity (OR, 97.16; 95% CI, 20.06-470.49), PVP-equilibrium phase isohyperintensity (OR, 20.53; 95% CI, 5.36-78.62), and hepatobiliary phase isohyperintensity (OR, 119.6; 95% CI, 21.59-662.40). Nodule T2 and HAP isohypointensity (OR 31.47; 95% CI, 7.88-125.58), nodule T2 isohypointensity and hepatobiliary phase isohyperintensity (OR, 28.77; 95% CI, 7.79-106.19), nodule T1 isohyperintensity and HAP isohypointensity (OR, 17.22; 95% CI, 4.85-61.14), and nodule T1 and hepatobiliary phase isohyperintensity (OR, 19.39; 95% CI, 5.38-69.90) were also predictors of dysplastic nodule diagnosis. CONCLUSION: The combination of nodule appearance on T2-weighted MRI and nodule enhancement after gadobenate dimeglumine injection may predict dysplastic nodule diagnosis in patients with liver cirrhosis.

Arterial enhancing-only nodules less than 2 cm in diameter in patients with liver cirrhosis: predictors of hepatocellular carcinoma diagnosis on gadobenate dimeglumine-enhanced MR imaging.

PURPOSE: To assess whether gadobenate dimeglumine (Gd-BOPTA)-enhanced MR imaging could predict hepatocellular carcinoma (HCC) diagnosis in small arterial enhancing-only nodules detected by contrast-enhanced computed tomography (CT) in patients with liver cirrhosis. MATERIALS AND METHODS: We prospectively recruited 125 cirrhotic patients (67 males, and 58 females; age: 68 ± 12.36 years) with 151 small (<2 cm in diameter) arterial enhancing-only nodules identified by contrast-enhanced CT. All patients were scanned by MR imaging before and after Gd-BOPTA injection during the hepatic arterial phase (HAP), portal venous phase (PVP), equilibrium phase (EP), and hepatobiliary phase (HP). Nodule characterization was based on reference imaging criteria (n = 29 nodules), follow-up (n = 105), or histology (n = 17). Two radiologists (5 and 10 years experience) analyzed the MR images, and logistic regression was conducted to assess how well MR imaging findings could predict HCC diagnosis. RESULTS: Final diagnoses included 115 benign nodules and 36 HCCs. Nodule T2 hyperintensity, T1 hypointensity, PVP-EP hypointensity, and HP hypointensity were the best predictors of HCC on univariate analysis. Nodule T2 hyperintensity, T1 hypointensity, and HP hypointensity, were independent predictors of HCC on multivariate analysis. CONCLUSION: Gd-BOPTA-enhanced MR imaging provides imaging findings which may predict a diagnosis of HCC in small arterial enhancing-only nodules in cirrhotic patients.