Diagnostic accuracy of state-of-the-art rectal MRI sequences for the diagnosis of extramural vascular invasion in locally advanced rectal cancer after preoperative chemoradiotherapy: dos or maybes?

OBJECTIVES: The aim of this study was to determine the accuracy of three state-of-the-art MRI sequences for the detection of extramural venous invasion (EMVI) in locally advanced rectal cancer (LARC) patients after preoperative chemoradiotherapy (pCRT). METHODS: This retrospective study included 103 patients (median age 66 years old [43-84]) surgically treated with pCRT for LARC and submitted to preoperative contrast-enhanced pelvic MRI after pCRT. T2-weighted, DWI, and contrast-enhanced sequences were evaluated by two radiologists with expertise in abdominal imaging, blinded to clinical and histopathological data. Patients were scored according to the probability of EMVI presence on each sequence using a grading score ranging from 0 (no evidence of EMVI) to 4 (strong evidence of EMVI). Results from 0 to 2 were ranked as EMVI negative and from 3 to 4 as EMVI positive. ROC curves were drawn for each technique, using histopathological results as reference standard. RESULTS: T2-weighted, DWI, and contrast-enhanced sequences demonstrated an area under the ROC curve (AUC) respectively of 0.610 (95% CI: 0.509-0.704), 0.729 (95% CI: 0.633-0.812), and 0.624 (95% CI: 0.523-0.718). The AUC of DWI sequence was significantly higher than that of T2-weighted (p = 0.0494) and contrast-enhanced (p = 0.0315) sequences. CONCLUSIONS: DWI is more accurate than T2-weighted and contrast-enhanced sequences for the identification of EMVI following pCRT in LARC patients. CLINICAL RELEVANCE STATEMENT: MRI protocol for restaging locally advanced rectal cancer after preoperative chemoradiotherapy should routinely include DWI due to its higher accuracy for the diagnosis of extramural venous invasion compared to high-resolution T2-weighted and contrast-enhanced T1-weighted sequences. KEY POINTS: • MRI has a moderately high accuracy for the diagnosis of extramural venous invasion in locally advanced rectal cancer after preoperative chemoradiotherapy. • DWI is more accurate than T2-weighted and contrast-enhanced T1-weighted sequences in the detection of extramural venous invasion after preoperative chemoradiotherapy of locally advanced rectal cancer. • DWI should be routinely included in the MRI protocol for restaging locally advanced rectal cancer after preoperative chemoradiotherapy.

Nodal staging with MRI after neoadjuvant chemo-radiotherapy for locally advanced rectal cancer: a fast and reliable method.

OBJECTIVES: In patients with locally advanced rectal carcinoma (LARC), negative nodal status after neoadjuvant chemoradiotherapy (nCRT) may allow for rectum-sparing protocols rather than total mesorectal excision; however, current MRI criteria for nodal staging have suboptimal accuracy. The aim of this study was to compare the diagnostic accuracy of different MRI dimensional criteria for nodal staging after nCRT in patients with LARC. MATERIALS AND METHODS: Patients who underwent MRI after nCRT for LARC followed by surgery were retrospectively included and divided into a training and a validation cohort of 100 and 39 patients, respectively. Short-, long-, and cranial-caudal axes and volume of the largest mesorectal node and nodal status based on European Society of Gastrointestinal Radiology consensus guidelines (i.e., ESGAR method) were assessed by two radiologists independently. Inter-reader agreement was assessed in the training cohort. Histopathology was the reference standard. ROC curves and the best cut-off were calculated, and accuracies compared with the McNemar test. RESULTS: The study population included 139 patients (median age 62 years [IQR 55-72], 94 men). Inter-reader agreement was high for long axis (κ = 0.81), volume (κ = 0.85), and ESGAR method (κ = 0.88) and low for short axis (κ = 0.11). Accuracy was similar (p > 0.05) for long axis, volume, and ESGAR method both in the training (71%, 74%, and 65%, respectively) and in the validation (83%, 78%, and 75%, respectively) cohorts. CONCLUSION: Accuracy of the measurement of long axis and volume of the largest lymph node is not inferior to the ESGAR method for nodal staging after nCRT in LARC. CLINICAL RELEVANCE STATEMENT: In MRI restaging of rectal cancer, measurement of the long axis or volume of largest mesorectal lymph node after preoperative chemoradiotherapy is a faster and reliable alternative to ESGAR criteria for nodal staging. KEY POINTS: • Current MRI criteria for nodal staging in locally advanced rectal cancer after chemo-radiotherapy have suboptimal accuracy and are time-consuming. • Measurement of long axis or volume of the largest mesorectal lymph node on MRI showed good accuracy for assessment of loco-regional nodal status in locally advanced rectal cancer. • MRI measurement of the long axis and volume of largest mesorectal lymph node after chemo-radiotherapy could be a faster and reliable alternative to ESGAR criteria for nodal staging.

Pancreatic fatty replacement as risk marker for altered glucose metabolism and cardiac iron and complications in thalassemia major.

OBJECTIVES: This multicenter study assessed the extent of pancreatic fatty replacement and its correlation with demographics, iron overload, glucose metabolism, and cardiac complications in a cohort of well-treated patients with thalassemia major (TM). METHODS: We considered 308 TM patients (median age: 39.79 years; 182 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Magnetic resonance imaging was used to quantify iron overload (IO) and pancreatic fat fraction (FF) by T2* technique, cardiac function by cine images, and to detect replacement myocardial fibrosis by late gadolinium enhancement technique. The glucose metabolism was assessed by the oral glucose tolerance test. RESULTS: Pancreatic FF was associated with age, body mass index, and history of hepatitis C virus infection. Patients with normal glucose metabolism showed a significantly lower pancreatic FF than patients with impaired fasting glucose (p = 0.030), impaired glucose tolerance (p < 0.0001), and diabetes (p < 0.0001). A normal pancreatic FF (< 6.6%) showed a negative predictive value of 100% for abnormal glucose metabolism. A pancreatic FF > 15.33% predicted the presence of abnormal glucose metabolism. Pancreas FF was inversely correlated with global pancreas and heart T2* values. A normal pancreatic FF showed a negative predictive value of 100% for cardiac iron. Pancreatic FF was significantly higher in patients with myocardial fibrosis (p = 0.002). All patients with cardiac complications had fatty replacement, and they showed a significantly higher pancreatic FF than complications-free patients (p = 0.002). CONCLUSION: Pancreatic FF is a risk marker not only for alterations of glucose metabolism, but also for cardiac iron and complications, further supporting the close link between pancreatic and cardiac disease. KEY POINTS: • In thalassemia major, pancreatic fatty replacement by MRI is a frequent clinical entity, predicted by a pancreas T2* < 20.81 ms and associated with a higher risk of alterations in glucose metabolism. • In thalassemia major, pancreatic fatty replacement is a strong risk marker for cardiac iron, replacement fibrosis, and complications, highlighting a deep connection between pancreatic and cardiac impairment.

Electronic platform-based education for radiology residents: results of a two-year survey.

BACKGROUND: Electronic platform based-learning for residents is increasing. The aim of this study was to identify the most reliable predictor variables related to the usage of electronic platform-based educational material for radiology residents which can predict a successful multiple-choice test during the academic year. METHODS: A two year survey was conducted based on the records of electronic platform-based educational material for radiology residents. Radiology resident education was based on the educational content of two educational electronic platform databases named RADPrimer and STATdx (Elsevier, Amsterdam) consisting in evidence-based and expert-vetted summary information to support learning and diagnosing in radiology. A pool of multiple-choice questions was addressed in RADPrimer by each resident after 6 months from the beginning of each academic year, and at the end of the respective residency year as part of end of the year assessment. A per-resident analysis was performed to analyze the correlation between the amount of electronic platform content accessed by residents (measured by total login times, login frequency per month, and the number of per-topic addressed questions) in preparation for the electronic test during the academic year (predictor variables) and per-resident average percentage of correct answers on electronic test (outcome variable). Statistical significance (p < 0.05) was determined using logistic regression and correlation analysis. RESULTS: Total login times (OR, 3; 95% CI, 2.2 -4), login frequency per month (OR, 4; 95% CI, 3.1-5.3), the number of per-topic addressed questions (OR, 3; 95% CI, 2.2 -4), and the number of topic-verified correct answers to multiple choice test (OR, 30.5; 95% CI, 12.8-80.9) all showed a statistically significant correlation with final percentage of correct answers on final year electronic test. CONCLUSION: The number of correct answers to multiple choice test was related to the number and frequency of login access, the number of per-topic addressed questions and the number of topic-verified correct answers to multiple choice test. The electronic-based educational material contributes significantly to a successful radiology residency program.

Fully integrated [18F]FDG PET/MR in large vessel vasculitis.

BACKGROUND: The aim of this study is to evaluate the usefulness of [18F] fluorodeoxyglucose (FDG) positron emission tomography (PET)/magnetic resonance (MR) in large vessels vasculitis (LVV) patients. METHODS: We performed an observational retrospective study based on our records. Images were acquired on a PET/MR scanner using [18F]FDG-PET whole body imaging. For each PET scan, a qualitative analysis and a semi-quantitative measure using the maximum of the standardized uptake value (SUVmax) were performed. SUVmax measurements normalized to the liver uptake were categorized using a grading scale. Vessel's wall thickness (WT) was measured at five fixed points (inferior margin of T5, T9, T12, L3, thickest area [max WT]). RESULTS: Twenty-three LVV patients were included, 56.5% giant cells arteritis, 34.8% Takayasu's arteritis and 8.7% isolated aortitis, all Caucasian, mostly females (82%). We considered 32 PET scans for the LVV group (from a minimum of one to a maximum of three scans per patient) mainly during follow-up (29/32 scans), and 23 PET scans from a control group of non-metastatic malignancies patients. We found higher SUVmax compared to controls, in all sites, irrespective of clinical disease activity. Mean WT resulted higher in patients than in controls but was not correlated to SUVmax. Mean WT positively correlated with age in both cohorts, inversely correlated to disease duration, while no correlation with SUVmax was observed. The concordance between clinically active disease and PET hypermetabolism was poor (Cohen' κ=0.33). CONCLUSIONS: PET/MR is a safe imaging technique capable of detecting inflammation in aortic wall. Low radiological exposure of PET/MR should be considered especially in young women receiving follow-up studies.

Diagnostic Accuracy of CT Texture Analysis in Adrenal Masses: A Systematic Review.

Adrenal incidentalomas (AIs) are incidentally discovered adrenal neoplasms. Overt endocrine secretion (glucocorticoids, mineralocorticoids, and catecholamines) and malignancy (primary or metastatic disease) are assessed at baseline evaluation. Size, lipid content, and washout characterise benign AIs (respectively, <4 cm, <10 Hounsfield unit, and rapid release); nonetheless, 30% of adrenal lesions are not correctly indicated. Recently, image-based texture analysis from computed tomography (CT) may be useful to assess the behaviour of indeterminate adrenal lesions. We performed a systematic review to provide the state-of-the-art of texture analysis in patients with AI. We considered 9 papers (from 70 selected), with a median of 125 patients (range 20-356). Histological confirmation was the most used criteria to differentiate benign from the malignant adrenal mass. Unenhanced or contrast-enhanced data were available in all papers; TexRAD and PyRadiomics were the most used software. Four papers analysed the whole volume, and five considered a region of interest. Different texture features were reported, considering first- and second-order statistics. The pooled median area under the ROC curve in all studies was 0.85, depicting a high diagnostic accuracy, up to 93% in differentiating adrenal adenoma from adrenocortical carcinomas. Despite heterogeneous methodology, texture analysis is a promising diagnostic tool in the first assessment of patients with adrenal lesions.

Sarcopenia in juvenile localized scleroderma: new insights on deep involvement.

OBJECTIVES: Juvenile localized scleroderma (JLS) is a rare chronic autoimmune disease which can also affect bones and muscles. Nevertheless, muscle loss was not previously investigated in patients with JLS. Thus, the aim of this study was to retrospectively evaluate deep involvement and assess and quantify sarcopenia in JLS patients using magnetic resonance imaging (MRI). METHODS: Fourteen children with JLS (nine females, mean age ± SD, 7.1 ± 3.6 years) referring to our tertiary center from January 2012 to January 2018 who underwent at least one MRI examination including axial T1-weighted and short tau inversion recovery images were included. Two readers assessed in consensus superficial and deep involvement. Muscle edema, muscle fatty infiltration, and sarcopenia were independently scored (absent, moderate, or severe) and the Cohen's kappa coefficient computed. Skin perimeter, subcutaneous area, muscle area, and muscle volume were independently measured using the contralateral unaffected extremity as reference (paired Student's t test, p < 0.05). The intraclass correlation coefficient (ICC) was used to investigate the reliability of the measurements. RESULTS: All patients showed superficial involvement with subcutaneous fat atrophy being the most common finding (13 patients). Bone marrow edema occurred in five patients. Muscle edema affected ten children (moderate in seven, severe in three; k = 0.89), muscle fatty replacement occurred in one case (severe; k = 1.00), and sarcopenia was detected in eight patients (severe in two; k = 0.78). All quantitative parameters were lower on the affected side than on the unaffected contralateral limb (p < 0.05, each) and all measurements showed a high reliability (ICC > 0.750, each). CONCLUSION: Patients with JLS can be affected by sarcopenia and quantitative analyses allow a robust characterization of such finding. KEY POINTS: • Deep involvement in juvenile localized scleroderma is frequently characterized by sarcopenia. • In juvenile localized scleroderma, muscle edema and sarcopenia are mostly moderate while fatty infiltration, even if rare, can be severe. • Sarcopenia can be reliably quantified in children with juvenile localized scleroderma using MRI.

The role of radiological and hybrid imaging for muscle metastases: a systematic review.

AIM OF THE STUDY: Skeletal muscle metastases (SMM) are a rare entity, mainly detected at autopsy. Nevertheless, radiological and nuclear medicine imaging can contribute to the diagnosis with a significant impact on the treatment and prognosis of neoplastic patients. This study aimed to systematically review the features of SMM at imaging considering the primary tumors and the sites of occurrence. MATERIALS AND METHODS: We conducted a systematic search of three electronic database (i.e., PubMed, Science Direct, and Web of Science) up to May 2019, without any language or time interval restriction. Two reviewers performed the search and selection process, data extraction, and synthesis. We resolved disagreements by consensus and/or involving a third reviewer. The included studies have been classified according to the Oxford Centre for Evidence Based Medicine (CEBM) grading system. RESULTS: Out of 8598 and 1077 articles respectively for radiological and hybrid imaging, 29 papers were included. According to CEBM, twelve were level 4. Computed tomography (CT) is mainly applied and, despite the existence of CT and magnetic resonance-based classifications, these are rarely used. Positron emission tomography/CT allowed the detection of small and subtle lesion also in the extremities. Muscles of the trunk were mostly affected and mainly respiratory tumors are associated with this type of metastatic spread. CONCLUSION: Radiological and hybrid imaging allow a precise characterization of SMM. However, a more systematic approach, including also the application of available classification systems, may increase the diagnostic accuracy for this rare type of metastases. KEY POINTS: • Skeletal muscle metastases have heterogeneous characteristics at imaging but mostly abscess-like features and high metabolic activity are described. • Skeletal muscle metastases mainly affect the muscles of the trunk. • Pulmonary, urological, and gastrointestinal cancers are the most frequent cause of skeletal muscle metastases.

Intra-class and inter-class tool discrimination through micro-CT analysis of false starts on bone.

Micro-CT has successfully been applied to the characterization of false starts (FSs) and, among several parameters, kerf width seems to correlate to the tool blade. The aim of the present study was to evaluate the diagnostic value of micro-CT for the differentiation of saw marks produced by different classes of saws and by saws belonging to the same class and differing only in number of teeth per inches (TPI). A morphological and morphometric analysis of 84 marks, produced by 6 saws belonging to 3 morphological classes, was performed. In the experimental cohort, for each parameter, statistically significant differences in intra- and inter-class analysis were searched for and cut-offs were established. The diagnostic accuracy of cut-offs was assessed through statistical analyses on the validation cohort. The morphological assessment did not allow to differentiate saws differing only in TPI. Angle 1 and top kerf width, respectively for cross-cut and rip-cut saws with alternating set, allowed a good discrimination between FSs produced by tools belonging to the same morphological class. High positive predictive values were found in intra-class analyses, while results in inter-class analyses were less encouraging. In cases of dismemberment, a micro-CT-based analysis of FSs is strongly suggested as a part of a multistep and multimodal methodology of assessment, which includes scanning electron microscopy and stereomicroscopy. A morphological assessment should be followed by an experimental trial and by a morphometric analysis. Further studies are needed to evaluate hampering factors, such as damage by physico-chemical agents.

Molecular Imaging of Pulmonary Inflammation and Infection.

Infectious and inflammatory pulmonary diseases are a leading cause of morbidity and mortality worldwide. Although infrequently used in this setting, molecular imaging may significantly contribute to their diagnosis using techniques like single photon emission tomography (SPET), positron emission tomography (PET) with computed tomography (CT) or magnetic resonance imaging (MRI) with the support of specific or unspecific radiopharmaceutical agents. 18F-Fluorodeoxyglucose (18F-FDG), mostly applied in oncological imaging, can also detect cells actively involved in infectious and inflammatory conditions, even if with a low specificity. SPET with nonspecific (e.g., 67Gallium-citrate (67Ga citrate)) and specific tracers (e.g., white blood cells radiolabeled with 111Indium-oxine (111In) or 99mTechnetium (99mTc)) showed interesting results for many inflammatory lung diseases. However, 67Ga citrate is unfavorable by a radioprotection point of view while radiolabeled white blood cells scan implies complex laboratory settings and labeling procedures. Radiolabeled antibiotics (e.g., ciprofloxacin) have been recently tested, although they seem to be quite unspecific and cause antibiotic resistance. New radiolabeled agents like antimicrobic peptides, binding to bacterial cell membranes, seem very promising. Thus, the aim of this narrative review is to provide a comprehensive overview about techniques, including PET/MRI, and tracers that can guide the clinicians in the appropriate diagnostic pathway of infectious and inflammatory pulmonary diseases.

State of the Art: LI-RADS for Contrast-enhanced US.

Contrast material-enhanced (CE) US is a recognized imaging tool in the characterization of focal liver lesions and uses microbubble contrast agents to increase signal backscattering from the blood. The European Federation of Societies for Ultrasound in Medicine and Biology and the World Federation for Ultrasound in Medicine and Biology strongly recommend the use of CE US in the characterization of hepatocellular nodules in individuals with liver cirrhosis. CE US was recently approved by the Food and Drug Administration for liver indications in adult and pediatric patients. CE US Liver Imaging Reporting and Data System (LI-RADS) criteria were recently proposed by the American College of Radiology and include eight distinct diagnostic categories: LR-1 (definitely benign), LR-2 (probably benign), LR-3 (intermediate malignancy probability), LR-4 (probably hepatocellular carcinoma [HCC]), LR-5 (definitely HCC), LR-NC (cannot be categorized due to image degradation), LR-TIV (tumor in vein), and LR-M (probably or definitely malignant but not HCC specific). CE US LI-RADS criteria can be used to produce a structured report for HCC diagnosis. However, the variability of US equipment in terms of sensitivity to microbubble signal, interreader variability, large number of HCC nodules classified as LR-3, and wide washout temporal range for LR-M observations are limitations.

Simultaneous bilateral adrenal vein sampling for primary aldosteronism: useful tips to make it simple and safe.

Adrenal vein sampling (AVS) is the key test for subtyping patients with primary aldosteronism (PA) before referring those with unilateral disease for laparoscopic unilateral adrenalectomy. However, it is still not systematically used, despite guidelines recommendations, because it is still considered as an invasive, risky, and challenging procedure. Simultaneous bilateral catheterization is believed to add technical difficulties inherent with attempting to catheterize both adrenal veins at the same time, but can be useful to minimize differences between the sides due to timing. We herein report on the protocol for routine clinical use. Tips for preparation of the patient as well as optimal catheterization of adrenal veins and sampling are provided to propose a protocol that is easy, safe, and reliable. Key Points • Adrenal vein sampling is the reference standard in the case of primary aldosteronism to detect the hyper-functioning side and allow subsequent treatment. • Simultaneous bilateral adrenal vein sampling avoids bias related to sampling timing. • Some technical suggestions concerning patient preparation and catheterization are proposed to make simultaneous adrenal vein sampling easier and safer.

Radiological investigation of gunshot wounds: a systematic review of published evidence.

INTRODUCTION: Despite the constantly growing popularity of radiological imaging in forensic pathology, a systematic review investigating the efficiency and limits of radiological techniques, in comparison to forensic autopsy, was still missing. AIM: The present review aims at providing an overview on the current role of radiology in the forensic investigation of fatal gunshot wounds without any restriction to specific radiological techniques. MATERIAL AND METHODS: A systematic literature search on three databases (PubMed, Web of Science, and Science Direct) was performed until December 2017. The Oxford Centre for Evidence Based Medicine (OCEBM) grading system for levels of evidence was applied, in order to weigh published evidence. RESULTS AND DISCUSSION: Eighty-six papers (1.64% of the records) were included. Despite the quite limited general level of evidence, which contrasts with the abundance of the scientific literature on this topic, several recommendations/statements, coupled to their OCEBM grade, were distilled as for the identification of retained bullets, gunshot wounds detection, diagnosis of entrance and exit wounds, trajectories and internal injury detection and estimation of the firing distance. CONCLUSIONS: Imaging radiological technologies represent the present and future of wound ballistics. However, traditional, micro and molecular imaging techniques require further validation through blinded cross-sectional studies with appropriate reference standards (e.g. forensic autopsy).

Early Predictors of the Long-term Response to Therapy in Patients With Crohn Disease Derived From a Time-Intensity Curve Analysis After Microbubble Contrast Agent Injection.

OBJECTIVES: The aim of this study was to identify early predictors of the long-term response to therapy in patients with Crohn disease (CD) from time-intensity curves obtained after microbubble injection. METHODS: One hundred fifteen consecutive patients with a proven diagnosis of CD involving the terminal ileal loop who were scheduled to begin pharmacologic therapy with biologics (infliximab or adalimumab) were scanned after sulfur hexafluoride-filled microbubble injection before the beginning and at the end of the sixth week of treatment. The absolute value and percentage change of each semiquantitative kinetic parameter (peak enhancement, time to peak enhancement, rise time, mean transit time, wash-in and wash-out rates, area under the curve [AUC] for the whole time-intensity curve, AUC during wash-in, AUC during wash-out, and wash-in perfusion index) as measured on the terminal ileal tract and adjacent reactive mesenteric fat were calculated from time-intensity curves. Patients were followed for at least 24 months with redetermination of the Crohn Disease Activity Index and with at least 1 endoscopy within 18 weeks after the beginning of pharmacologic treatment. The absolute values and percentage changes of kinetic parameters were assessed as potential predictors of the therapeutic outcome by a logistic regression analysis. RESULTS: The study group included 66 male and 49 female patients (mean age ± SD, 45.76 ± 11 years). The pretreatment values and percentage changes of the peak enhancement, AUC, AUC during wash-in, and AUC during wash-out were found to be predictors (P < .05) of the long-term therapeutic outcome. CONCLUSIONS: The analysis of time-intensity curves obtained after microbubble contrast agent injection provides early predictors of the long-term therapeutic outcome in patients with CD.

The Most Appropriate Time Delay after Microbubble Contrast Agent Intravenous Injection to Maximize Liver Metastasis Conspicuity on Contrast-Enhanced Ultrasound.

PURPOSE: To identify the most appropriate time delay after microbubble contrast agent injection to maximize liver metastasis conspicuity on contrast-enhanced ultrasound (CEUS). METHODS: Twenty-five consecutive patients (12 male and 13 female; age: 50 ± 13 years) with a known primary tumor and evidence of liver metastases on unenhanced ultrasound (US) underwent CEUS. CEUS consisted of continuous liver parenchyma scanning during arterial (15-35 s after microbubble injection), portal venous (40-120 s), and late phase (from 120 s up to microbubble disappearance). Subjective conspicuity index (ranging from 1 to 5) and objective conspicuity index (Ilesion-Iliver/Iliver, I = signal intensity) were calculated on reference frames selected on arterial phase and every 20 s on portal venous and late phase. RESULTS: A total number of 40 liver metastases were identified after microbubble injection. The highest liver metastasis conspicuity was observed on early portal venous phase (40-60 s after microbubble injection) both on visual (mean subjective conspicuity index ± standard deviation [SD] = 4.36 ± 0.75, reader 1; 4.25 ± 0.65, reader 2) and quantitative analysis (mean objective conspicuity index ± SD = -0.99 ± 0.001). CONCLUSION: The early portal venous phase (40-60 s after microbubble injection) provides the best liver metastases' conspicuity after microbubble contrast agent injection.

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.

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.