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.

Diagnostic impact of digital tomosynthesis in oncologic patients with suspected pulmonary lesions on chest radiography.

OBJECTIVES: To assess the actual diagnostic impact of digital tomosynthesis (DTS) in oncologic patients with suspected pulmonary lesions on chest radiography (CXR). METHODS: A total of 237 patients (135 male, 102 female; age, 70.8 ± 10.4 years) with a known primary malignancy and suspected pulmonary lesion(s) on CXR and who underwent DTS were retrospectively identified. Two radiologists (experience, 10 and 15 years) analysed in consensus CXR and DTS images and proposed a diagnosis according to a confidence score: 1 or 2 = definitely or probably benign pulmonary or extrapulmonary lesion, or pseudolesion; 3 = indeterminate; 4 or 5 = probably or definitely pulmonary lesion. DTS findings were proven by CT (n = 114 patients), CXR during follow-up (n = 105) or histology (n = 18). RESULTS: Final diagnoses included 77 pulmonary opacities, 26 pulmonary scars, 12 pleural lesions and 122 pulmonary pseudolesions. DTS vs CXR presented a higher (P < 0.05) sensitivity (92 vs 15 %), specificity (91 vs 9 %), overall accuracy (92 vs 12 %), and diagnostic confidence (area under ROC, 0.997 vs 0.619). Mean effective dose of CXR vs DTS was 0.06 vs 0.107 mSv (P < 0.05). CONCLUSIONS: DTS improved diagnostic accuracy and confidence in comparison to CXR alone in oncologic patients with suspected pulmonary lesions on CXR with only a slight, though significant, increase in radiation dose. KEY POINTS: • Digital tomosynthesis (DTS) improves accuracy of chest radiography (CXR) in oncologic patients. • DTS improves confidence of CXR in oncologic patients. • DTS allowed avoidance of CT in about 50 % of oncologic patients.

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.

Intraoperative Comparison Between Strain Elastography and Preoperative Magnetic Resonance Imaging Features in High-Grade Gliomas Using Fusion Imaging: A Pilot Study.

OBJECTIVE: To compare the elastographic patterns of high-grade gliomas (HGGs) solid portions and those of adjacent healthy brain parenchyma, on intraoperative ultrasound, with magnetic resonance image (MRI) characteristics. METHODS: Clinical records and images of HGGs patients, operated between June and December 2018, were retrospectively reviewed. Fusion images were used to compare preoperative gadolinium-enhanced T1-weighted MRI/fluid-attenuated inversion recovery images (Gd-T1 MRI/FLAIR) to intraoperative strain elastography (SE). FLAIR/Gd-T1 MRI images were used to define enhancement patterns (absent/whole lesion/peripheral) and lesions' characteristics (primary and secondary pattern, further subdivided in solid/necrotic/cystic/infiltrating). HGGs SE patterns were categorized as homogeneous/inhomogeneous, while lesions' primary and secondary patterns as stiff/intermediate/elastic. The SE motive of neighboring healthy brain parenchyma was defined similarly. RESULTS: Eighteen patients (M:F, 11:7; mean age: 53 years) harboring 14 glioblastomas (77.8%) and 4 anaplastic astrocytomas (22.2%) were compared. Glioblastomas typically enhanced peripherally and had a primary necrotic pattern (78.6% and 64.3%, respectively), while anaplastic astrocytomas did not enhance and were solid (75% both) at T1-Gd MRI and FLAIR images. At SE anaplastic astrocytomas had a homogeneous stiff primary pattern, whereas the majority of glioblastomas primary patterns were heterogeneous (85.7%) and intermediate (78.6%). CONCLUSIONS: Three major SE patterns defined HGGs and adjacent healthy brain parenchyma. SE patterns varied according to HGG histotypes and Gd-T1 MRI/FLAIR characteristics.

Lesion volume and spike frequency on EEG impact perfusion values in focal cortical dysplasia: a pediatric arterial spin labeling study.

Arterial spin labelling (ASL), an MRI sequence non-invasively imaging brain perfusion, has yielded promising results in the presurgical workup of children with focal cortical dysplasia (FCD)-related epilepsy. However, the interpretation of ASL-derived perfusion patterns remains unclear. Hence, we compared ASL qualitative and quantitative findings to their clinical, EEG, and MRI counterparts. We included children with focal structural epilepsy related to an MRI-detectable FCD who underwent single delay pseudo-continuous ASL. ASL perfusion changes were assessed qualitatively by visual inspection and quantitatively by estimating the asymmetry index (AI). We considered 18 scans from 15 children. 16 of 18 (89%) scans showed FCD-related perfusion changes: 10 were hypoperfused, whereas six were hyperperfused. Nine scans had perfusion changes larger than and seven equal to the FCD extent on anatomical images. Hyperperfusion was associated with frequent interictal spikes on EEG (p = 0.047). Perfusion changes in ASL larger than the FCD corresponded to larger lesions (p = 0.017). Higher AI values were determined by frequent interictal spikes on EEG (p = 0.004). ASL showed FCD-related perfusion changes in most cases. Further, higher spike frequency on EEG may increase ASL changes in affected children. These observations may facilitate the interpretation of ASL findings, improving treatment management, counselling, and prognostication in children with FCD-related epilepsy.

Diffusion tensor imaging discriminates focal cortical dysplasia from normal brain parenchyma and differentiates between focal cortical dysplasia types.

OBJECTIVES: Although diffusion tensor imaging (DTI) may facilitate the identification of cytoarchitectural changes associated with focal cortical dysplasia (FCD), the predominant aetiology of paediatric structural epilepsy, its potential has thus far remained unexplored in this population. Here, we investigated whether DTI indices can differentiate FCD from contralateral brain parenchyma (CBP) and whether clinical features affect these indices. METHODS: In this single-centre, retrospective study, we considered children and adolescents with FCD-associated epilepsy who underwent brain magnetic resonance (MRI), including DTI. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity, were calculated in both FCD and CBP. The DTI indices best discriminating between FCD and CBP were subsequently used to assess the link between DTI and selected clinical and lesion-related parameters. RESULTS: We enrolled 32 patients (20 male; median age at MRI 4 years), including 15 with histologically confirmed FCD. FA values were lower (p = 0.03), whereas MD values were higher in FCD than in CBP (p = 0.04). The difference in FA values between FCD and CBP was more pronounced for a positive vs. negative history of status epilepticus (p = 0.004). Among histologically confirmed cases, the difference in FA values between FCD and CBP was more pronounced for type IIb versus type I FCD (p = 0.03). CONCLUSIONS: FA and MD discriminate between FCD and CBP, while FA differentiates between FCD types. Status epilepticus increases differences in FA, potentially reflecting changes induced in the brain. Our findings support the potential of DTI to serve as a non-invasive biomarker to characterise FCD in the paediatric population.

Lesion Extent Negatively Impacts Intellectual Skills in Pediatric Focal Epilepsy.

BACKGROUND: Cognitive development in children and adolescents with focal lesional epilepsy is determined by the underlying epileptogenic lesion, in addition to epilepsy itself. However, the impact of lesion-related variables on intelligence quotient (IQ) and developmental quotient (DQ) remains largely unexplored. Here, we aimed to determine the effect of lesion-related predictors and their relation with epilepsy-related predictors of intellectual functioning. METHODS: We retrospectively analyzed data from children with focal lesional epilepsy who underwent standardized cognitive evaluation yielding IQ/DQ in our institution. RESULTS: We included 50 consecutive patients aged 0.5 to 17.5 years (mean, 9.3; S.D., 4.9) at cognitive assessment. Epilepsy duration was 0 to 15.5 years (mean, 3.8; S.D., 4.1). Of the total cohort, 30 (60%) patients had unilobar lesions, seven (14%) multilobar, 10 (20%) hemispheric, and three (6%) bilateral. Etiology was congenital in 32 (64%) cases, acquired in 14 (28%), and progressive in four (8%). For patients with unilobar lesions, the mean IQ/DQ was 97.1 ± 15.7, for multilobar 98.9 ± 20.2, for hemispheric 76.1 ± 20.5, and for bilateral 76.3 ± 4.5. Larger lesion extent, earlier epilepsy onset, and longer epilepsy duration correlated with lower IQ/DQ in the univariate analysis, whereas only lesion extent and epilepsy duration contributed significantly to the explanatory model in the multivariable analysis. CONCLUSIONS: The present study demonstrates that lesion extent and epilepsy duration are important risk factors for intellectual impairment in pediatric patients with focal lesional epilepsy. These findings are useful for family counseling and the early consideration of interventions that may limit the duration of epilepsy.

Laser interstitial thermal therapy in pediatric cerebellar epilepsy.

Cerebellar lesional epilepsy is rare, commonly manifesting in early life and posing diagnostic and treatment challenges. Seizure semiology may be subtle, with repetitive eye blinking, face twitching, and irregular breathing, while EEG commonly remains unremarkable. Pharmacoresistance is the rule, and surgical intervention is the only treatment with the potential for cure. Novel minimally invasive techniques, such as laser interstitial thermal therapy (LITT), are emerging for surgically less accessible, deep-seated epileptogenic lesions. We report the case of a patient who presented with peculiar eye and face movements occurring episodically and stereotypically since the first weeks of life and was later diagnosed with cerebellar epilepsy related to a hamartoma. Refractory daily seizures, unresponsive to antiseizure medication, were followed by increasingly prominent gait ataxia and delayed speech development. Staged LITT was performed in two consecutive sessions at 3 and 4 years, leading to seizure cessation, neurological improvement, and developmental gains over a postsurgical follow-up period of 8 months. Our case highlights cerebellar lesional epilepsy as a rare but important differential diagnosis in children with paroxysmal disorders predominantly involving the face. Furthermore, we illustrate the radiological correlates of neurocognitive deficit related to the cerebellar lesion, manifesting as cerebello-cerebral diaschisis. Most importantly, our observations showcase LITT as a safe and effective therapeutic approach in cerebellar lesional epilepsy and an attractive alternative to open brain surgery, especially for deep-seated lesions in the pediatric population.

Role of computed tomography in COVID-19.

Coronavirus disease 2019 (COVID-19) has become a rapid worldwide pandemic. While COVID-19 primarily manifests as an interstitial pneumonia and severe acute respiratory distress syndrome, severe involvement of other organs has been documented. In this article, we will review the role of non-contrast chest computed tomography in the diagnosis, follow-up and prognosis of patients affected by COVID-19 pneumonia with a detailed description of the imaging findings that may be encountered. Given that patients with COVID-19 may also suffer from coagulopathy, we will discuss the role of CT pulmonary angiography in the detection of acute pulmonary embolism. Finally, we will describe more advanced applications of CT in the differential diagnosis of myocardial injury with an emphasis on ruling out acute coronary syndrome and myocarditis.

Advanced intraoperative ultrasound (ioUS) techniques in focal cortical dysplasia (FCD) surgery: A preliminary experience on a case series.

INTRODUCTION: Focal Cortical Dysplasia (FCD) represents a broad spectrum of histopathological entities that cause drug-resistant epilepsy. Surgery has been shown to be the treatment of choice, but incomplete resection represents the leading cause of seizure persistence. Preliminary experiences with intraoperative ultrasound (ioUS) have proven its potential in defining and characterizing the lesion. In this study we analyzed the feasibility of advanced ultrasound techniques such as sono-elastography (SE) and contrast enhancement ultrasound (CEUS) in a small cohort of patients with FCD. MATERIAL AND METHODS: We retrospectively reviewed all clinical records and images of patients with drug resistant epilepsy who underwent at least one advanced sonographic technique (SE and/or CEUS) during ioUS guided surgery between November 2014 and October 2017. We excluded from our analysis all patients with lesions other than FCD or those who had FCD associated with other pathological entities. RESULTS: Four patients with type IIb FCD in the right frontal lobe were evaluated. All of them underwent SE, which highlighted heterogeneous stiffness in the dysplastic foci, also multiple areas of higher consistency were detected in all patients. Three patients evaluated with CEUS had visible enhancement in the FCD. Neither SE nor CEUS were better than ioUS in the identification of lesion boundaries. In the three patients who underwent both SE and CEUS we found no correspondence between stiffer areas and enhancement in the dysplastic areas. CONCLUSION: Ourpreliminary report confirms the feasibility of SE and CEUS in FCD surgery and describes the imaging findings in this category of patients. Studies on larger cohorts of patients are warranted to better clarify the role of these advanced intraoperative ultrasound techniques in patients with FCD.

Intraoperative ultrasonography (ioUS) characteristics of focal cortical dysplasia (FCD) type II b.

PURPOSE: Focal cortical dysplasia (FCD) is one of the major causes of drug-resistant epilepsy. Surgery has proved to be the treatment of choice, however up to a third of patients experience only partial resection. Ill-defined borders and lesions embedded in eloquent areas are two of the main drawbacks of FCD surgery. Preliminary experiences with intraoperative ultrasound (ioUS) have proved its feasibility and potential. We analyzed FCD' ioUS findings in our patients with FCD and compared them with magnetic resonance (MRI) ones. METHODS: We retrospectively reviewed all records of patients with focal medically refractory epilepsy who underwent ioUS guided surgery between November 2014 and October 2017. Lesions other than FCD or FCD associated with other pathological entities were not considered. Patients' preoperative MRI and ioUS features were analyzed according to up-to-date literature and than compared. RESULTS: A homogeneous population of five patients with type IIb FCD was evaluated. Focal cortical thickening and cortical ribbon hyper-intensity, blurring of the grey-white matter junction and hyper-intensity of the subcortical white matter on T2-weighted/FLAIR images were present in all patients. Cortical features had a complete concordance between ioUS and MRI. In particular ioUS thickening and hyper-echogenicity of cortical ribbon were identified in all cases (100%). Contrary, hyper-echoic subcortical white matter was detected in 60% of the patients. IoUS images resulted in clearer lesion borders than MRI images. CONCLUSION: Our study confirms the potentials of ioUS as a valuable diagnostic tool to guide FCD surgeries.

Intraoperative Strain Elastosonography in Brain Tumor Surgery.

BACKGROUND: Sonoelastography is an ultrasound imaging technique able to assess mechanical properties of tissues. Strain elastography (SE) is a qualitative sonoelastographic modality with a wide range of clinical applications, but its use in brain tumor surgery has been so far very limited. OBJECTIVE: To describe the first large-scale implementation of SE in oncological neurosurgery for lesions discrimination and characterization. METHODS: We analyzed retrospective data from 64 patients aiming at (i) evaluating the stiffness of the lesion and of the surrounding brain, (ii) assessing the correspondence between B-mode and SE, and (iii) performing subgroup analysis for gliomas characterization. RESULTS: (i) In all cases, we visualized the lesion and the surrounding brain with SE, permitting a qualitative stiffness assessment. (ii) In 90% of cases, lesion representations in B-mode and SE were superimposable with identical morphology and margins. In 64% of cases, lesion margins were sharper in SE than in B-mode. (iii) In 76% of cases, glioma margins were sharper in SE than in B-mode. Lesions morphology/dimensions in SE and in B-mode were superimposable in 89%. Low-grade (LGG) and high-grade (HGG) gliomas were significantly different in terms of stiffness and stiffness contrast between tumors and brain, LGG appearing stiffer while HGG softer than brain (all P < ·001). A threshold of 2.5 SE score had 85.7% sensitivity and 94.7% specificity in differentiating LGG from HGG. CONCLUSION: SE allows to understand mechanical properties of the brain and lesions in examination and permits a better discrimination between different tissues compared to B-mode. Additionally, SE can differentiate between LGG and HGG.

Differentiation of Inflammatory From Fibrotic Ileal Strictures among Patients with Crohn's Disease Based on Visual Analysis: Feasibility Study Combining Conventional B-Mode Ultrasound, Contrast-Enhanced Ultrasound and Strain Elastography.

The aim of this pilot study was to assess prospectively the feasibility of conventional B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) combined with real-time strain elastography (SE) in the differentiation of inflammatory from fibrotic ileal strictures among patients with Crohn's disease (CD) based on visual analysis. Twenty non-consecutive patients (15 male and 5 female; mean age ± standard deviation, 40.2 ± 10.22 y) with CD and stricture of the terminal ileal loop were scanned by conventional B-mode US and CEUS and, subsequently, by real-time SE. Two independent readers visually classified each bowel stricture as fibrotic or inflammatory based on conventional B-mode US, CEUS, SE, individually and then for all techniques combined. All techniques combined had a higher (p <0.05) sensitivity (reader 1, 9/20 [45%]; reader 2, 7/20 [35%]), specificity (reader 1, 5/20 [25%]; reader 2, 8/20 [40%]) and diagnostic accuracy (reader 1, 14/20 [70%]; reader 2, 15/20 [75%]) and higher (p <0.05) area under the receiver operating characteristic curve (reader 1, 0.953; reader 2, 0.921) than individual techniques. Inter-reader agreement was fair for conventional B-mode US (k = 0.46) and CEUS (k = 0.39), moderate for SE (k = 0.6) and fair for all techniques combined (k = 0.38). Conventional B-mode US and CEUS, in combination with SE, may improve differentiation of inflammatory from fibrotic ileal strictures among patients with CD based on visual analysis.

Gray Scale Ultrasound, Color Doppler Ultrasound, and Contrast-Enhanced Ultrasound in Renal Parenchymal Diseases.

Ultrasound (US), which may be combination of gray scale and spectral Doppler US, color and power Doppler US, with or without microbubble contrast agents, is usually the first imaging modality to be used in renal parenchymal diseases. The most typical appearance of diffuse renal parenchymal diseases on gray scale US is an increased renal cortical echogenicity and increased or reduced corticomedullary differentiation. Spectral Doppler analysis of intrarenal flows may reveal an increase in intrarenal resistive index value greater than 0.70 in native kidneys, and greater than 0.8 in renal transplants. Gray scale US and spectral Doppler US do not exhibit high specificity and sensitivity because different renal parenchymal diseases often display the same US appearance, whereas the same renal parenchymal disease may present different appearances on US according to disease stage. Consequently, correlation of the US pattern with patient's history and clinical background is essential for a correct characterization.

Differentiation of Inflammatory from Fibrotic Ileal Strictures among Patients with Crohn's Disease through Analysis of Time-Intensity Curves Obtained after Microbubble Contrast Agent Injection.

The aim of the study described here was to assess whether the analysis of time-intensity curves obtained after microbubble contrast agent injection could differentiate inflammatory from fibrotic ileal strictures among patients with Crohn's disease. Sixty-five consecutive patients (40 male and 25 female; mean age ± SD, 42.2 ± 12.22 y) with stricture of the terminal ileal loop from Crohn's disease were scanned after microbubble injection. Time-intensity curves were obtained from quantitative analysis, and peak enhancement, rise time, time to peak, area under the time-intensity curve (AUC), AUC during wash-in (AUCWI) and AUC during wash-out (AUCWO) were compared between patients with inflammatory strictures and patients with fibrotic strictures. Inflammatory (n = 40) and fibrotic (n = 25) strictures differed (p < 0.05) in peak enhancement, wash-in rate, wash-in perfusion index, AUC, AUCWI and AUCWO. The quantitative analysis of small bowel wall contrast enhancement after microbubble contrast agent injection may differentiate inflammatory from fibrotic ileal strictures in patients with Crohn's disease.

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.