Imaging of Fontan-Associated Liver Disease.

ABSTRACT: The Fontan procedure is the definitive treatment for patients with single-ventricle physiology. Surgical advances have led to a growing number of patients surviving into adulthood. Fontan-associated liver disease (FALD) encompasses a spectrum of pathologic liver changes that occur secondary to altered physiology including congestion, fibrosis, and the development of liver masses. Assessment of FALD is difficult and relies on using imaging alongside of clinical, laboratory, and pathology information. Ultrasound, computed tomography, and magnetic resonance imaging are capable of demonstrating physiologic and hepatic parenchymal abnormalities commonly seen in FALD. Several novel imaging techniques including magnetic resonance elastography are under study for use as biomarkers for FALD progression. Imaging has a central role in detection and characterization of liver masses as benign or malignant. Benign FNH-like masses are commonly encountered; however, these can display atypical features and be mistaken for hepatocellular carcinoma (HCC). Fontan patients are at elevated risk for HCC, which is a feared complication and has a poor prognosis in this population. While imaging screening for HCC is widely advocated, no consensus has been reached regarding an optimal surveillance regimen.

Acute Adverse Events After Iodinated Contrast Agent Administration of 359,977 Injections: A Single-Center Retrospective Study.

OBJECTIVE: To assess the effects of patient variables, examination variables, and seasonality on allergic-like and physiologic reactions to iodinated contrast material (ICM). PATIENTS AND METHODS: All ICM-enhanced computed tomography (CT) examinations performed from June 1, 2009, to May 9, 2017, at our institution were included. Reactions were identified and categorized as allergic-like or physiologic and mild, moderate, or severe. The effect of patient and examination variables on reactions was evaluated by logistic regression models. RESULTS: A total of 359,977 CT examinations performed on 176,886 unique patients were included. A total of 1150 allergic-like reactions (0.32%; 19 severe [0.005%]) and 679 physiologic reactions (0.19%; 3 severe [0.0008%]) occurred. On multivariable analysis, iopromide had higher rates of reactions compared with iohexol (allergic-like reactions: odds ratio [OR], 3.07 [95% CI, 2.37 to 3.98], P<.0001; physiologic reactions: OR, 2.60 [1.92 to 3.52], P<.0001). Non-White patients had higher rates of reactions compared with White patients (allergic-like reactions: OR, 1.77 [1.36-2.30], P<.0001; physiologic reactions: OR, 1.76 [1.27-2.42], P=.0006). Patient age, sex, prior ICM reaction, ICM dose, CT location, and CT type were also significantly associated with reactions. No significant seasonality trend was observed (P=.07 and .80). CONCLUSION: Non-White patients and patients administered iopromide had higher rates of acute reactions compared with White patients and patients administered iohexol. Younger patients (<50 years vs 51 to 60 years), female sex, history of ICM allergy or other allergies, ICM dose, and contrast-enhanced CT location and type also correlated with higher acute reaction rates.

Novel approach to prenatal predictors of outcomes for fetuses with severe Ebstein anomaly.

OBJECTIVE: Ebstein anomaly (EA) is a cardiac malformation with highly variable presentation and severity with limited perinatal management options. We present incorporation of fetal lung measurements into a multidisciplinary evaluation for counseling and predicting postnatal outcomes in patients with severe EA. METHODS: Five fetuses with severe fetal EA were reviewed. Third trimester sonographic observed/expected total lung area (O/E TLA) and lung to head ratio (O/E LHR), fetal MRI total fetal lung volume ratio (O/E-TFLV), echocardiographic cardio-thoracic ratio (CT ratio), sonographic estimated fetal weight (EFW) by Hadlock formula and presence of hydrops, were used to guide perinatal management. RESULTS: Three of five had appropriate fetal growth, were delivered at term in a cardiac operative suite, and underwent immediate intervention with good neonatal outcomes. Two had severe fetal growth restriction (FGR), CT ratios > 0.8 and O/E LHR and TLA < 25%. One of which delivered prematurely with neonatal demise and one suffered in utero demise at 34 weeks. CONCLUSIONS: FGR, hydrops, increased CT ratio and reduced O/E LHR and TFLV are potential prognosticators of poor outcomes in severe EA, and should be validated in larger cohorts that would allow for a statistical analysis of the predictive utility of these measurements.

Pulmonary hypoplasia is associated with severe morbidityThere are limited prognosticating tools to risk stratify and guide management in cases of severe prenatal Ebstein anomaliesFetal MRI may improve prognostication for fetuses with EA.

Cancer Therapy-related Hepatic Injury in Children: Imaging Review from the Pediatric LI-RADS Working Group.

The liver is the primary organ for the metabolism of many chemotherapeutic agents. Treatment-induced liver injury is common in children undergoing cancer therapy. Hepatic injury occurs due to various mechanisms, including biochemical cytotoxicity, hepatic vascular injury, radiation-induced cytotoxicity, and direct hepatic injury through minimally invasive and invasive surgical treatments. Treatment-induced liver injury can be seen contemporaneous with therapy and months to years after therapy is complete. Patients can develop a combination of hepatic injuries manifesting during and after treatment. Acute toxic effects of cancer therapy in children include hepatitis, steatosis, steatohepatitis, cholestasis, hemosiderosis, and vascular injury. Longer-term effects of cancer therapy include hepatic fibrosis, chronic liver failure, and development of focal liver lesions. Quantitative imaging techniques can provide useful metrics for disease diagnosis and monitoring, especially in treatment-related diffuse liver injury such as hepatic steatosis and steatohepatitis, hepatic iron deposition, and hepatic fibrosis. Focal liver lesions, including those developing as a result of treatment-related vascular injury such as focal nodular hyperplasia-like lesions and hepatic perfusion anomalies, as well as hepatic infections occurring as a consequence of immune suppression, can be anxiety provoking and confused with recurrent malignancy or hepatic metastases, although there often are imaging features that help elucidate the correct diagnosis. Radiologic evaluation, in conjunction with clinical and biochemical screening, is integral to diagnosing and monitoring hepatic complications of cancer therapy in pediatric patients during therapy and after therapy completion for long-term surveillance. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material See the invited commentary by Ferraciolli and Gee in this issue.

Clinical Follow-up in Patients With Moderate or Severe Allergic-Like Reactions to Iodinated Contrast Material.

OBJECTIVE: To examine follow-up care in patients with a history of acute allergic-like reaction to iodinated contrast material (ICM), including subsequent imaging management, allergy consultation, and repeat ICM exposure and reactions. METHODS: All patients who had a moderate or severe acute allergic-like reaction to ICM after contrast-enhanced CT (CECT) examination from June 1, 2009, to January 1, 2022, at our institution were included. Chart review was performed to determine (1) whether subsequent imaging was not performed or was altered in these patients, (2) whether the patient underwent a subsequent CECT examination, and (3) whether the patient had an allergist consultation. RESULTS: A total of 251 patients were identified. One-third of patients (90 of 251, 36%) had at least one change to their subsequent imaging management due to their reaction, including performing an unenhanced CT (62 of 251, 25%) or MRI (22 of 251, 8.8%) instead of a CECT or not performing a CECT when otherwise clinically indicated (20 of 251, 8.0%). Patients with a prior severe reaction were more likely to have a change in management than patients with a prior moderate reaction (severe: 22 of 32 [69%] versus moderate: 68 of 219 [31%], P < .0001). Only 17 patients (6.8%) had an allergy consult for their ICM reaction. A total of 90 patients underwent 274 subsequent CECT examinations. Repeat allergic-like reactions were observed in one quarter of patients (24 of 90, 27%) and a tenth of CECT examinations (29 of 274, 11%). DISCUSSION: One-third of patients with a history of a moderate or severe allergic-like reaction to ICM had their subsequent imaging care modified due to their reaction.

Optimizing Imaging of Pediatric Liver Lesions: Guidelines from the Pediatric LI-RADS Working Group.

A differential diagnosis based on a patient's age, clinical presentation, and serum α-fetoprotein level will help guide the initial imaging workup in children with a liver lesion. Children vary significantly in size, the ability to stay still, and the ability to breath hold for imaging examinations. Choosing and tailoring imaging techniques and protocols for each indication and age group is important for optimal care with minimal invasiveness. The need for sedation or anesthesia can be obviated by using techniques like feed and bundle, distraction, contrast-enhanced US, and motion-insensitive sequences for MRI. US is often the first imaging modality used in children with a suspected abdominal mass. Once a hepatic lesion is confirmed, multiphasic contrast-enhanced MRI is recommended for most lesions as the next imaging modality allowing full characterization of the lesion and assessment of the liver parenchyma. Contrast-enhanced CT can also be performed for assessment of pediatric focal liver lesions, especially in patients who have a contraindication to MRI. Contrast-enhanced US has shown promise to decrease the need for MRI or CT in some lesions such as hemangioma and focal nodular hyperplasia. Children with a history of malignancy can develop multiple types of hepatic lesions at various stages, including infections during an immunocompromised state, manifesting as focal liver lesions. Based on available limited data in the literature and the collective experiences of the Liver Imaging and Reporting Data System Pediatric Working Group, the authors provide guidelines for the imaging workup of pediatric focal liver lesions with an indication- and age-based approach and discuss the selection and performance of various imaging techniques and modalities. ©RSNA, 2022 See the invited commentary by Chojniak and Boaventura in this issue.

Meckel diverticulum in the pediatric population: Patient presentation and performance of imaging in prospective diagnosis.

PURPOSE: To determine the most common presentations of Meckel diverticulum (MD) in children and the performance of imaging modalities in prospective diagnosis. MATERIALS AND METHODS: A 28-year retrospective review was performed of children under 18 years of age with MD listed as a diagnosis on pathology and/or surgical reports. The medical record was reviewed to determine presenting clinical scenarios. All imaging performed for each case was reviewed. RESULTS: Seventy-six patients met inclusion criteria. Of the surgically removed MD, most presented with abdominal symptoms (n = 31, 41%); gastrointestinal (GI) bleeding (n = 15, 20%), or both abdominal symptoms and GI bleeding (n = 7, 9%). Twenty-nine percent of MD were discovered incidentally at surgery performed for other reasons. Of the symptomatic MD, only 31% were prospectively diagnosed. For patients with abdominal symptoms, CT had a sensitivity of 13% (3/24) while nuclear medicine (NM) scan had a sensitivity of 0% (0/2). For patients with GI bleed, CT had a sensitivity of 29% (2/7) and NM scan had a sensitivity of 71% (10/14). For patients with both abdominal symptoms and GI bleed, CT was 0% (0/2) and NM scan 75% (3/4) sensitive. CONCLUSION: MD as a cause of abdominal symptoms and gastrointestinal bleeding may be difficult to diagnose due to nonspecific presentations and nonspecific findings. Most prospectively diagnosed MD are on NM scan in patients with GI bleed with abdominal pain (sensitivity of >70%). CT is relatively insensitive for MD in all symptomatology groups (0 to 29%).

NUT carcinoma of the thorax in a 7-year-old child.

We present a rare case of NUT midline carcinoma of the thorax in a 7-year-old-male who presented with nonspecific abdominal pain. The patient was initially evaluated with an abdominal ultrasound, which was negative, followed by an abdominopelvic CT that demonstrated a partially visualized infiltrative mediastinal mass. Subsequent, chest CT showed a large, aggressive appearing heterogenous middle mediastinal mass with pulmonary parenchyma, hilar, and posterior mediastinal invasion. Given its epicenter in the middle mediastinum and its irregular and invasive appearance, the primary consideration was NUT midline carcinoma, subsequently confirmed on biopsy.

Imaging pediatric acute appendicitis during the coronavirus disease 2019 (COVID-19) pandemic: collateral damage is variable.

BACKGROUND: Since coronavirus disease 2019 (COVID-19) was declared a worldwide pandemic in March 2020, many authors have noted the collateral damage on non-COVID-19-related illnesses. These indirect effects of the pandemic have resulted in people presenting later and with more severe stages of disease, even if their diagnoses are not directly related to SARS-CoV-2, the virus that causes COVID-19. OBJECTIVE: We studied these indirect effects of COVID-19 on the imaging workup and outcomes for pediatric patients at our center who had acute appendicitis during the pandemic. MATERIALS AND METHODS: We performed a retrospective review of cases in children ≤18 years who were evaluated for acute appendicitis during the same period, March 1 to May 31, in both 2019 and 2020. We compared demographic and clinical data as well as surgical and pathological findings, and we graded imaging findings according to severity. Differences in patient outcomes were assessed using the Wilcoxon rank sum test and the Pearson chi-square test. RESULTS: The total number of pediatric patients evaluated with imaging for acute appendicitis dropped by 43% between 2019 and 2020 (298 vs. 169), but the total number of children treated remained similar (59 vs. 51). There was proportionate use of US and CT in each timeframe but a higher percentage of positive imaging findings in 2020 (50/169, 29.6% vs. 56/298, 18.7% in 2019, P=0.04). There were more imaging examinations with features of complicated appendicitis among positive cases (9/51, 18% vs. 5/59, 8% in 2019, P=0.08) and more pathologically proven perforated cases during the pandemic (14/51, 27% vs. 6/59, 10% in 2019, P=0.11), although these results did not reach statistical significance. There were no changes in surgical management, vital signs, laboratory values, length of stay or complication rates. CONCLUSION: There was a large drop in the number of pediatric patients imaged for acute appendicitis during the acute phase of the COVID-19 pandemic despite similar numbers of patients treated. The utilization trends of US vs. CT remained stable between time periods. The differences in imaging findings and perforation rates were less pronounced compared to other published studies.

Prevention of Allergic-like Reactions at Repeat CT: Steroid Pretreatment versus Contrast Material Substitution.

Background It is unclear whether steroid premedication is an effective means of preventing repeat allergic-like reactions in high-risk patients with a previous allergic-like reaction to iodinated contrast material (ICM). Purpose To compare the effectiveness of ICM substitution (ie, using iohexol in a patient with a previous iopromide reaction) with 12- and 2-hour steroid premedication for preventing repeat acute allergic-like reactions in high-risk patients. Materials and Methods This retrospective study identified all high-risk (ie, having a previous allergic-like reaction) adult and pediatric patients who underwent a contrast-enhanced CT examination at the institution from June 1, 2009, to May 9, 2017. Prophylactic treatments and repeat reactions were identified using chart review. The effectiveness of prophylactic treatments on repeat reaction rates was examined with multivariable regression models that used generalized estimating equations. Results A total of 1973 high-risk patients who underwent 4360 subsequent ICM-enhanced CT examinations were included. Of the 4360 examinations, a total of 280 allergic-like reactions occurred (6%) in 224 of the 1973 patients (11% of patients), with only 19 of 280 reactions (7%) that were more severe than the previous reaction being demonstrated. After adjustment, patients who received a different ICM with and without steroid premedication had a significantly lower rate of repeat reactions than did patients who received steroid premedication and the same ICM (same ICM and steroid premedication: 80 of 423 examinations [19%]; different ICM and no steroid premedication: 10 of 322 examinations [3%]; odds ratio [OR], 0.14 [95% CI: 0.06, 0.33]; P < .001; different ICM and steroid premedication: five of 166 patients [3%]; OR, 0.12 [95% CI: 0.04, 0.36]; P < .001). When examining the first scan only, patients who received the same ICM had a similar risk of repeat reactions regardless of whether they received steroid premedication (steroid premedication: 44 of 172 patients [26%] vs no premedication: 73 of 298 patients [25%]; OR, 1.00 [95% CI: 0.64, 1.57]; P = .99). Conclusion In this cohort, using an iodinated contrast material (ICM) substitution was more effective for preventing repeat allergic-like reactions than using steroid premedication and the same ICM that caused the previous reaction. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Davenport and Weinstein in this issue.

Preparing for the next pandemic: It is more than just about numbers.

The COVID-19 pandemic has brought enormous hardships to our country and healthcare system. We present our experience navigating through this pandemic with emphasis on reactivating our practice while keeping patients and staff safe. It is hoped that the methods and thought processes provided in this manuscript will help those who are in various stages of managing their practice or provide lessons learned as our country eventually moves beyond this pandemic. Lastly, we aspire to provide a guide for those who are in a position to prepare for the next pandemic.

Reproducibility of Lung and Liver Volume Measurements on Fetal Magnetic Resonance Imaging in Left-Sided Congenital Diaphragmatic Hernia.

INTRODUCTION: Congenital diaphragmatic hernia (CDH) affects 1 in 3,000 live births and is associated with significant morbidity and mortality. METHODS: A review of fetal magnetic resonance imaging (MRI) examinations was performed for fetuses with left CDH and normal lung controls. Image review and manual tracings were performed by 4 pediatric radiologists; right and left lung volumes in the coronal and axial planes as well as liver volume above and below the diaphragm in the coronal plane were measured. Intra- and interreviewer reproducibility was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS: Excellent intra- and interreviewer reproducibility of the right and left lung volume measurements was observed in both axial planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.99; left lung: 0.97, 95% CI: 0.95-0.98) and coronal planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95-0.98; left lung: 0.96, 95% CI: 0.93-0.98). Moderate-to-good interreviewer reproducibility was observed for liver volume above the diaphragm (ICC 0.7, 95% CI: 0.59-0.81). Liver volume below the diaphragm had a good-to-excellent interreviewer reproducibility (ICC 0.88, 95% CI: 9.82-0.93). CONCLUSIONS: The present study demonstrated an excellent intra- and interreviewer reproducibility of MRI lung volume measurements and good-to-moderate inter- and intrareviewer reproducibility of liver volume measurements after standardization of the methods at our fetal center.

Pediatric scurvy MRI appearance.

We present a rare case of pediatric scurvy in a 9-year-old male who presented with nontraumatic knee pain. MRI was obtained due to the puzzling presentation. MRI demonstrated a systemic bone marrow abnormality which led to a conversation with the clinician and further elucidation of an extremely narrow diet lacking sufficient vitamin C (ascorbic acid). Diagnosis was confirmed biochemically with undetectable ascorbic acid level and clinically with compatible exam and history. This case highlights a thought process for unexpected bone marrow abnormality on MRI.

Asymptomatic macrocephaly: to scan or not to scan.

BACKGROUND: Macrocephaly is a common finding in infants and is often idiopathic or familial. In the absence of clinical signs and symptoms, it can be difficult to determine when concern for underlying pathology is justified. OBJECTIVES: The objectives of this study were to determine the utility of screening head ultrasound (US) in asymptomatic infants with macrocephaly and to identify clinical factors associated with significant US findings. MATERIALS AND METHODS: A 20-year retrospective review was performed of infants undergoing head US for macrocephaly or rapidly increasing head circumference. Data collected included age, gender, head circumference at birth and at the time of US, specialty of the ordering physician, US findings, computed tomography (CT) or magnetic resonance imaging (MRI) findings, and clinical course including interventions. RESULTS: Four hundred and forty infants met inclusion criteria. Two hundred and eighty studies (64%) were found to be normal, 137 (31%) had incidental findings, 17 (3.8%) had indeterminate but potentially significant findings, and 6 (1.4%) had significant findings. Twenty of the 23 infants with indeterminate or significant findings had subsequent CT or MRI. This confirmed significant findings in eight infants (1.8%): three subdural hematomas, two intracranial tumors, two aqueductal stenoses, and one middle fossa cyst. Five of the eight infants required surgical procedures. The only statistically significant association found with having a significant finding on head US was head circumference at birth. CONCLUSION: Ultrasound is a useful initial study to evaluate infantile macrocephaly, identifying several treatable causes in our study and, when negative, effectively excluding significant pathology.

Acute Reactions to Gadolinium-Based Contrast Agents in a Pediatric Cohort: A Retrospective Study of 16,237 Injections.

BACKGROUND. Incidences and risk factors for acute reactions to gadolinium-based contrast agents (GBCAs) are not fully understood, particularly in pediatric patients. OBJECTIVE. The purpose of this study was to retrospectively examine allergiclike and physiologic acute reactions in pediatric patients who receive GBCAs for MRI examinations. METHODS. The study cohort consisted of all pediatric patients (age < 18 years old) who underwent an MRI examination with a GBCA at our institution from June 1, 2009, to May 9, 2017. Acute reactions were identified by medical record review and classified by severity using the American College of Radiology guidelines. Potential risk factors for reactions were examined using generalized estimating equation methods accounting for rare events. RESULTS. A total of 16,237 GBCA injections (10,141 gadodiamide injections, 4880 gadobutrol injections, and 1216 gadobenate dimeglumine injections) were administered to a study cohort of 10,190 patients (49% [7982/16,237] girls and 51% [8255/16,237] boys). Incidences of 0.10% (17/16,237) for allergiclike and 0.14% (23/16,237) for physiologic reactions were observed. No severe reactions occurred. Allergiclike reaction incidences were significantly higher with gadobenate compared with gadodiamide (0.49% vs 0.04%; p < .001) and in patients who underwent abdominal or pelvic MRI examinations (0.38%) or cardiac examinations (0.55%) compared with head examinations (0.05%; p < .001 and p = .006, respectively). Physiologic reaction incidences were significantly higher in older patients (0.25% in patients 12-17 years old vs 0.03% in patients 2 to < 12 years old; p < .001) and in patients who underwent abdominal or pelvic examinations compared with head examinations (0.38% vs 0.10%; p = .002). Of 16 MRI examinations performed in patients with a prior allergiclike reaction to GBCAs, only one resulted in a repeat reaction. CONCLUSION. In this pediatric cohort, GBCA type, patient age, and MRI type were risk factors for acute reactions. Repeat reactions were rare. CLINICAL IMPACT. Providers must weigh the risks and benefits when choosing a particular GBCA to use in their practices and must consider multiple, potentially disparate risks associated with each GBCA.

Sequential Minimally Invasive Fetal Interventions for Two Life-Threatening Conditions: A Novel Approach.

INTRODUCTION: In utero interventions are performed in fetuses with "isolated" major congenital anomalies to improve neonatal outcomes and quality of life. Sequential in utero interventions to treat 2 anomalies in 1 fetus have not yet been described. CASE PRESENTATION: Here, we report a fetus with a large left-sided intralobar bronchopulmonary sequestration (BPS) causing mediastinal shift, a small extralobar BPS, and concomitant severe left-sided congenital diaphragmatic hernia (CDH). At 26-week gestation, the BPS was noted to be increasing in size with a significant reduction in right lung volume and progression to fetal hydrops. The fetus underwent ultrasound-guided ablation of the BPS feeding vessel leading to complete tumor regression. However, lung development remained poor (O/E-LHR: 0.22) due to the left-sided CDH, prompting fetal endoscopic tracheal occlusion therapy at 28-week gestation to allow increased lung growth. After vaginal delivery, the newborn underwent diaphragmatic repair with resection of the extralobar sequestration. He was discharged home with tracheostomy on room air at 9 months. DISCUSSION/CONCLUSION: Sequential in utero interventions to treat 2 severe major anomalies in the same fetus have not been previously described. This approach may be a useful alternative in select cases with otherwise high morbidity/mortality. Further studies are required to confirm our hypothesis.

In Utero Restoration of Hindbrain Herniation in Fetal Myelomeningocele as Part of Prenatal Regenerative Therapy Program at Mayo Clinic.

OBJECTIVE: To assess our initial experience with prenatal restoration of hindbrain herniation following in utero repair of myelomeningocele (MMC). PATIENTS AND METHODS: Three consecutive patients with prenatally diagnosed MMC (between January 1, 2018 and September 30, 2018) were managed with open in utero surgery. As per institutional review board approval and following a protocol designed at the Mayo Clinic Maternal & Fetal Center, fetal intervention was offered between 19 0/7 and 25 6/7 weeks of gestation. Prenatal improvement of hindbrain herniation was the declared restorative end point. Obstetrical and perinatal outcomes were also assessed. RESULTS: Diagnosis of MMC was confirmed upon referral between 20 and 21 weeks' gestation by using fetal ultrasound and magnetic resonance imaging. In all cases reported here, the spinal defect was lumbosacral with evidence of hindbrain herniation. Open in utero MMC repair was performed between 24 and 25 weeks' gestation with no notable perioperative complications. Postprocedure fetal magnetic resonance imaging performed 6 weeks after in utero repair documented improvement of hindbrain herniation. Deliveries were at 37 weeks by cesarean section without complications. Most recent postnatal follow-ups were unremarkable at both 11 months (baby 1) and 3 months of age (baby 2), with mild ventriculomegaly. Antenatal and postnatal follow-up of baby 3 at 1 month of age was also unremarkable. CONCLUSION: Our study highlights the prenatal restoration of hindbrain herniation following in utero MMC repair in all cases presented here as an example of a prenatal regenerative therapy program in our institution.

Quantitative Inflammation Assessment for Crohn Disease Using Ultrasensitive Ultrasound Microvessel Imaging: A Pilot Study.

OBJECTIVES: Crohn disease (CD) is a chronic inflammation in the digestive tract that affects millions of Americans. Bowel vascularity has important diagnostic information because inflammation is associated with blood flow changes. We recently developed an ultrasensitive ultrasound microvessel imaging (UMI) technique with high vessel sensitivity. This study aimed to evaluate the feasibility of UMI to assist CD detection and staging. METHODS: Ultrasound microvessel imaging was performed on 76 bowel wall segments from 48 symptomatic patients with CD. Clinically indicated computed tomographic/magnetic resonance enterography was used as the reference standard. The vessel-length ratio (VLR, the number of vessel pixels in the bowel wall segment normalized to the segment length) was derived in both conventional color flow imaging (CFI) and UMI to quantitatively stage disease activity. Receiver operating characteristic curves were then analyzed between different disease groups. RESULTS: The VLR-CFI and VLR-UMI detected similar correlations between vascularization and disease activity: severe inflammation had a higher VLR than normal/mildly inflamed bowels (P < .05). No significant difference was found between quiescent and mild CD due to the small sample size. The VLR-CFI had more difficulties in distinguishing quiescent versus mild CD compared to the VLR-UMI. After combining the VLR-UMI with thickness, in the receiver operating characteristic curve analysis, the areas under the curves (AUCs) improved to AUC1 = 0.996 for active versus quiescent CD, AUC2 = 0.978 for quiescent versus mild CD, and AUC3 = 0.931 for mild versus severe CD, respectively, compared to those using thickness alone (AUC1 = 0.968; P = .04; AUC2 = 0.919; P = .16; AUC3 = 0.857; P = .01). CONCLUSIONS: Ultrasound microvessel imaging offers a safe and cost-effective tool for CD diagnosis and staging, which may potentially assist disease activity classification and therapy efficacy evaluation.