Artificial Intelligence for Quantifying Cumulative Small Bowel Disease Severity on CT-Enterography in Crohn's Disease

INTRODUCTION

Assessing the cumulative degree of bowel injury in ileal Crohn's disease (CD) is difficult. We aimed to develop machine learning (ML) methodologies for automated estimation of cumulative ileal injury on computed tomography-enterography (CTE) to help predict future bowel surgery.

METHODS

Adults with ileal CD using biologic therapy at a tertiary care center underwent ML analysis of CTE scans. Two fellowship-trained radiologists graded bowel injury severity at granular spatial increments along the ileum (1 cm), called mini-segments. ML segmentation methods were trained on radiologist grading with predicted severity and then spatially mapped to the ileum. Cumulative injury was calculated as the sum (S-CIDSS) and mean of severity grades along the ileum. Multivariate models of future small bowel resection were compared with cumulative ileum injury metrics and traditional bowel measures, adjusting for laboratory values, medications, and prior surgery at the time of CTE.

RESULTS

In 229 CTE scans, 8,424 mini-segments underwent analysis. Agreement between ML and radiologists injury grading was strong (κ = 0.80, 95% confidence interval 0.79-0.81) and similar to inter-radiologist agreement (κ = 0.87, 95% confidence interval 0.85-0.88). S-CIDSS (46.6 vs 30.4, P = 0.0007) and mean cumulative injury grade scores (1.80 vs 1.42, P < 0.0001) were greater in CD biologic users that went to future surgery. Models using cumulative spatial metrics (area under the curve = 0.76) outperformed models using conventional bowel measures, laboratory values, and medical history (area under the curve = 0.62) for predicting future surgery in biologic users.

DISCUSSION

Automated cumulative ileal injury scores show promise for improving prediction of outcomes in small bowel CD. Beyond replicating expert judgment, spatial enterography analysis can augment the personalization of bowel assessment in CD.

Ultrasound of palpable lesions: a pictorial review

Ultrasound (US) is the imaging modality of choice for evaluation of superficial palpable lesions. A large proportion of these lesions have characteristic sonographic appearance and can be confidently diagnosed with US without the need for biopsy or other intervention. The Society of Radiologists in Ultrasound (SRU) recently published a Consensus Conference Statement on superficial soft tissue masses. The goal of this manuscript is (a) to serve as a sonographic pictorial review for palpable lesions based on the SRU statement, (b) present the typical sonographic features of palpable lesions that can be confidently diagnosed with US, and (c) provide an overview of other palpable lesions with a framework to interpret the US studies and advise on appropriate further management.

Local Assessment and Small Bowel Crohn's Disease Severity Scoring using AI

RATIONALE AND OBJECTIVES

We present a machine learning and computer vision approach for a localized, automated, and standardized scoring of Crohn's disease (CD) severity in the small bowel, overcoming the current limitations of manual measurements CT enterography (CTE) imaging and qualitative assessments, while also considering the complex anatomy and distribution of the disease.

MATERIALS AND METHODS

Two radiologists introduced a severity score and evaluated disease severity at 7.5 mm intervals along the curved planar reconstruction of the distal and terminal ileum using 236 CTE scans. A hybrid model, combining deep-learning, 3-D CNN, and Random Forest model, was developed to classify disease severity at each mini-segment. Precision, sensitivity, weighted Cohen's score, and accuracy were evaluated on a 20% hold-out test set.

RESULTS

The hybrid model achieved precision and sensitivity ranging from 42.4% to 84.1% for various severity categories (normal, mild, moderate, and severe) on the test set. The model's Cohen's score (κ = 0.83) and accuracy (70.7%) were comparable to the inter-observer agreement between experienced radiologists (κ = 0.87, accuracy = 76.3%). The model accurately predicted disease length, correlated with radiologist-reported disease length (r = 0.83), and accurately identified the portion of total ileum containing moderate-to-severe disease with an accuracy of 91.51%.

CONCLUSION

The proposed automated hybrid model offers a standardized, reproducible, and quantitative local assessment of small bowel CD severity and demonstrates its value in CD severity assessment.

A Review of the Clinical Applications of Artificial Intelligence in Abdominal Imaging

Artificial intelligence (AI) has been a topic of substantial interest for radiologists in recent years. Although many of the first clinical applications were in the neuro, cardiothoracic, and breast imaging subspecialties, the number of investigated and real-world applications of body imaging has been increasing, with more than 30 FDA-approved algorithms now available for applications in the abdomen and pelvis. In this manuscript, we explore some of the fundamentals of artificial intelligence and machine learning, review major functions that AI algorithms may perform, introduce current and potential future applications of AI in abdominal imaging, provide a basic understanding of the pathways by which AI algorithms can receive FDA approval, and explore some of the challenges with the implementation of AI in clinical practice.

A primer on rectal MRI in patients on watch-and-wait treatment for rectal cancer

Total neoadjuvant treatment (TNT) for rectal cancer is becoming an accepted treatment paradigm and is changing the landscape of this disease, wherein up to 50% of patients who undergo TNT are able to avoid surgery. This places new demands on the radiologist in terms of interpreting degrees of response to treatment. This primer summarizes the Watch-and-Wait approach and the role of imaging, with illustrative "atlas-like" examples as an educational guide for radiologists. We present a brief literature summary of the evolution of rectal cancer treatment, with a focus on magnetic resonance imaging (MRI) assessment of response. We also discuss recommended guidelines and standards. We outline the common TNT approach entering mainstream practice. A heuristic and algorithmic approach to MRI interpretation is also offered. To illustrate management and common scenarios, we arranged the illustrative figures as follows: (I) Clinical complete response (cCR) achieved at the immediate post-TNT "decision point" scan time; (II) cCR achieved at some point during surveillance, later than the first post-TNT MRI; (III) near clinical complete response (nCR); (IV) incomplete clinical response (iCR); (V) discordant findings between MRI and endoscopy where MRI is falsely positive, even at follow-up; (VI) discordant cases where MRI seems to be falsely positive but is proven truly positive on follow-up endoscopy; (VII) cases where MRI is falsely negative; (VIII) regrowth of tumor in the primary tumor bed; (IX) regrowth outside the primary tumor bed; and (X) challenging scenarios, i.e., mucinous cases. This primer is offered to achieve its intended goal of educating radiologists on how to interpret MRI in patients with rectal cancer undergoing treatment using a TNT-type treatment paradigm and a Watch-and-Wait approach.

Pancreatic Transplantation: Surgical Anatomy and Complications

Pancreatic transplantation is a complex surgical procedure performed for patients with chronic severe diabetes, often performed in combination with renal transplantation. Vascular and exocrine drainage anatomy varies depending on the surgical technique. Radiology plays a critical role in the diagnosis of postoperative complications, requiring an understanding of grayscale/Doppler ultrasound as well as computed tomography and MR imaging. In this review, we detail usual surgical methods and normal postoperative imaging appearances. We then review the most common complications following pancreatic transplants, emphasizing diagnostic features of vascular (arterial/venous), surgical, and diffuse parenchymal pathologic conditions on multiple imaging modalities.

MRI assessment of rectal cancer response to neoadjuvant therapy: a multireader study

OBJECTIVES

A watch and wait strategy with the goal of organ preservation is an emerging treatment paradigm for rectal cancer following neoadjuvant treatment. However, the selection of appropriate patients remains a challenge. Most previous efforts to measure the accuracy of MRI in assessing rectal cancer response used a small number of radiologists and did not report variability among them.

METHODS

Twelve radiologists from 8 institutions assessed baseline and restaging MRI scans of 39 patients. The participating radiologists were asked to assess MRI features and to categorize the overall response as complete or incomplete. The reference standard was pathological complete response or a sustained clinical response for > 2 years.

RESULTS

We measured the accuracy and described the interobserver variability of interpretation of rectal cancer response between radiologists at different medical centers. Overall accuracy was 64%, with a sensitivity of 65% for detecting complete response and specificity of 63% for detecting residual tumor. Interpretation of the overall response was more accurate than the interpretation of any individual feature. Variability of interpretation was dependent on the patient and imaging feature investigated. In general, variability and accuracy were inversely correlated.

CONCLUSIONS

MRI-based evaluation of response at restaging is insufficiently accurate and has substantial variability of interpretation. Although some patients' response to neoadjuvant treatment on MRI may be easily recognizable, as seen by high accuracy and low variability, that is not the case for most patients.

KEY POINTS

• The overall accuracy of MRI-based response assessment is low and radiologists differed in their interpretation of key imaging features. • Some patients' scans were interpreted with high accuracy and low variability, suggesting that these patients' pattern of response is easier to interpret. • The most accurate assessments were those of the overall response, which took into consideration both T2W and DWI sequences and the assessment of both the primary tumor and the lymph nodes.

Adnexal Mass Imaging: Contemporary Guidelines for Clinical Practice

Several recent guidelines have been published to improve accuracy and consistency of adnexal mass imaging interpretation and to guide management. Guidance from the American College of Radiology (ACR) Appropriateness Criteria establishes preferred adnexal imaging modalities and follow-up. Moreover, the ACR Ovarian-Adnexal Reporting Data System establishes a comprehensive, unified set of evidence-based guidelines for classification of adnexal masses by both ultrasound and MR imaging, communicating risk of malignancy to further guide management.

Sonographic Predictors of Ovarian Torsion in Premenarchal Girls

STUDY OBJECTIVE

To identify preoperative transabdominal sonographic predictors of surgically-confirmed ovarian torsion (OT) in premenarchal girls.

METHODS

Retrospective case-control study of 32 premenarchal girls aged 0-12 undergoing surgery for OT (cases) or a non-torsed ovarian mass (controls) from 2006-2017 at a single academic center. Cases had ICD-9/10 codes for torsion of the ovary, adnexa, ovarian pedicle, or fallopian tube and surgically-confirmed OT; controls had codes for ovarian mass or cyst and surgically-confirmed absence of OT. Preoperative transabdominal ultrasounds were analyzed by three radiologists blinded to final diagnosis. Chi-square, Fisher's exact, and Student's t-test were used for statistical comparisons.

RESULTS

From 2016-2017, 32 patients presented with acute abdominal pain or symptoms concerning for ovarian mass requiring ultrasound imaging and subsequent diagnostic laparoscopy-24 (75.0%) had confirmed OT by laparoscopy; eight (25.0%) did not. Mean age in both groups was similar (7.3±2.9 years). Preoperative sonographic variables significantly associated with OT included presence of a simple cyst (20.8% vs 12.5%), ovarian heterogeneity (100% vs 12.5%), presence of peripheralized follicles (70.8% vs 0%), and asymmetry of color Doppler (75.0% vs 37.5%)-all p<0.05. Presence of free fluid, arterial color Doppler, and a whirlpool sign were not predictive of OT.

CONCLUSION

In premenarchal patients, while certain variables on transabdominal sonography predicted surgically-confirmed OT, only the presence of peripheralized follicles was unique to girls with OT. The decision to proceed with diagnostic laparoscopy for suspected OT can be aided by these specific sonographic findings but should ultimately be based on high clinical suspicion.

Imaging Care for Transgender and Gender Diverse Patients: Best Practices and Recommendations

Transgender and gender diverse (TGD) people experience health disparities, and many avoid necessary medical care because of fears of discrimination or mistreatment. Disparate care is further compounded by limited understanding of gender-affirming hormone therapy (GAHT) and gender-affirming surgery among the medical community. Specific to radiology, TGD patients report more negative imaging experiences than negative general health encounters, highlighting the need for guidance and best practices for inclusive imaging care. A patient's imaging journey provides numerous opportunities for improvement. Inclusive practice in a radiology department starts with ordering and scheduling the examination, facilitated by staff education on appropriate use of a patient's chosen name, gender identity, and pronouns. Contemporary electronic health record systems have the capacity for recording detailed sexual orientation and gender identity data, but staff must be trained to solicit and use this information. A welcoming environment can help TGD patients to feel safe during the imaging experience and may include institutional nondiscrimination policies, gender-neutral signage, and all-gender single-user dressing rooms and bathrooms. Image acquisition should be performed using trauma-informed and patient-centered care. Finally, radiologists should be aware of reporting considerations for TGD patients, such as avoiding the use of gender in reports when it is not medically relevant and using precise, respectful language for findings related to GAHT and gender-affirming surgical procedures. As a field, radiology has a range of opportunities for improving care delivery for TGD patients, and the authors summarize recommended best practices. See the invited commentary by Stowell in this issue. ^© RSNA, 2023 Quiz questions for this article are available in the supplemental material.

ACR Appropriateness Criteria® Fibroids

Uterine fibroids (leiomyomas or myomas) are the most common neoplasm of the uterus. Though incompletely understood, fibroid etiology is multifactorial, a combination of genetic alterations and endocrine, autocrine, environmental, and other factors such as race, age, parity, and body mass index. Black women have greater than an 80% incidence of fibroids by age 50, whereas White women have an incidence approaching 70%. Fibroid symptoms are protean, and menorrhagia is most frequent. The societal economic burden of symptomatic fibroids is large, 5.9 to 34.3 billion dollars annually. There are a variety of treatment options for women with symptomatic fibroids ranging from medical therapy to hysterectomy. Myomectomy and uterine fibroid embolization are the most common uterine sparing therapies. Pelvic ultrasound (transabdominal and transvaginal) with Doppler and MRI with and without intravenous contrast are the best imaging modalities for the initial diagnosis of fibroids, the initial treatment of known fibroids, and for surveillance or posttreatment imaging. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Virtual Mentoring: A Guide to Navigating a New Age in Mentorship

Mentorship is a fundamental part of professional and personal growth. Over time, the fabric of mentorship has been transforming from typical one-on-one mentor-mentee relationship to other types including peer, group, speed, and virtual mentoring. When the COVID-19 pandemic hit, it caused major disruptions in many facets of life and career, including mentoring. In response to the COVID-19 pandemic, live meetings were canceled, and social distancing measures were enacted at many institutions. Thus, the traditional set-up, with a face-to-face mentor and mentee interaction, was impossible. Many virtual platforms were utilized to navigate through these restrictions. In this review, we highlight challenges in mentorship during the COVID-19 pandemic and how we implemented different strategies to promote mentorship.

ACR Appropriateness Criteria® Newly Diagnosed Palpable Scrotal Abnormality

Palpable scrotal abnormalities are caused by a variety of disorders, ranging from indolent benign conditions to aggressive tumors, and infectious and vascular processes. In these patients the diagnostic workup typically begins with a complete clinical, history, and physical examinations, including analysis of risk factors. If imaging is required, ultrasound examination is the diagnostic modality of choice. In few select patients with very large scrotal masses, MRI may be appropriate. However, the use of gadolinium-based contrast should be evaluated critically depending on specific patient factors. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Pelvic Floor Dysfunction in Females

Pelvic floor disorders including pelvic organ prolapse (POP), urinary dysfunction, defecatory dysfunction, and complications after pelvic floor surgery are relatively common in the female population. Imaging tests are obtained when the initial clinical evaluation is thought to be incomplete or inconclusive or demonstrates findings that are discordant with patients' symptoms. An integrated imaging approach is optimal to evaluate the complex anatomy and dynamic functionality of the pelvic floor. Fluoroscopic cystocolpoproctography (CCP) and MR defecography are considered the initial imaging tests of choice for evaluation of POP. Fluoroscopic voiding cystourethrography is considered the initial imaging test for patients with urinary dysfunction. Fluoroscopic CCP and MR defecography are considered the initial imaging test for patients with defecatory dysfunction, whereas ultrasound pelvis transrectal is a complementary test in patients requiring evaluation for anal sphincter defects. MRI pelvis without and with intravenous contrast, MRI pelvis with dynamic maneuvers, and MR defecography are considered the initial imaging tests in patients with suspected complications of prior pelvic floor surgical repair. Transperineal ultrasound is emerging as an important imaging tool, in particular for screening of pelvic floor dysfunction and for evaluation of midurethral slings, vaginal mesh, and complications related to prior pelvic floor surgical repair. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Ultrasound Liver Imaging Reporting and Data System (US LI-RADS): An Overview with Technical and Practical Applications

The Ultrasound Liver Imaging Reporting and Data System (US LI-RADS), introduced in 2017 by the American College of Radiology, standardizes the technique, interpretation, and reporting of screening and surveillance ultrasounds intended to detect hepatocellular carcinoma in high-risk patients. These include patients with cirrhosis of any cause as well as subsets of patients with chronic hepatitis B viral infection. The US LI-RADS scheme is composed of an ultrasound category and a visualization score: ultrasound categories define the exam as negative, subthreshold, or positive and direct next steps in management; visualization scores denote the expected sensitivity of the exam, based on adequacy of liver visualization with ultrasound. Since its introduction, multiple institutions across the United States have implemented US LI-RADS. This review includes a background of hepatocellular carcinoma and US LI-RADS, definition of screening/surveillance population, recommendations and tips for technique, interpretation, and reporting, and preliminary outcomes analysis.

Noninterpretive Uses of Artificial Intelligence in Radiology

We deem a computer to exhibit artificial intelligence (AI) when it performs a task that would normally require intelligent action by a human. Much of the recent excitement about AI in the medical literature has revolved around the ability of AI models to recognize anatomy and detect pathology on medical images, sometimes at the level of expert physicians. However, AI can also be used to solve a wide range of noninterpretive problems that are relevant to radiologists and their patients. This review summarizes some of the newer noninterpretive uses of AI in radiology.

ACR Appropriateness Criteria® Postmenopausal Acute Pelvic Pain

Acute pelvic pain is a common presenting complaint in both the emergency room and outpatient settings. Pelvic pain of gynecologic origin in postmenopausal women occurs less frequently than in premenopausal women; however, it has important differences in etiology. The most common causes of postmenopausal pelvic pain from gynecologic origin are ovarian cysts, uterine fibroids, pelvic inflammatory disease, and ovarian neoplasm. Other etiologies of pelvic pain are attributable to urinary, gastrointestinal, and vascular systems. As the optimal imaging modality varies for these etiologies, it is important to narrow the differential diagnosis before choosing the initial diagnostic imaging examination. Transabdominal and transvaginal ultrasound are the best initial imaging techniques when the differential is primarily of gynecologic origin. CT with intravenous (IV) contrast is more useful if the differential diagnosis remains broad. MRI without IV contrast or MRI without and with IV contrast, as well as CT without IV contrast may also be used for certain differential considerations. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Contemporary Guidelines for Adnexal Mass Imaging: A 2020 Update

Incidental adnexal masses are commonly encountered at ultrasound, computed tomography, and magnetic resonance imaging. Since many of these lesions are surgically resected and ultimately found to be benign, patients may be exposed to personal and economic costs related to unnecessary oophorectomy. Thus, accurate non-invasive risk stratification of adnexal masses is essential for optimal management and outcomes. Multiple consensus guidelines in radiology have been published to assist in characterization of these masses as benign, indeterminate, or likely malignant. In the last two years, several new and updated stratification systems for assessment of incidental adnexal masses have been published. The purpose of this article is to offer a concise review of four recent publications: ACR 2020 update on the management of incidental adnexal findings on CT and MRI, SRU 2019 consensus update on simple adnexal cysts, O-RADS ultrasound risk stratification system (2020), and O-RADS MRI risk stratification system (2020).

MDCT imaging in Spigelian hernia, clinical, and surgical implications

OBJECTIVE

Spigelian hernia is an uncommon congenital or acquired defect in the transversus abdominis aponeurosis with non-specific symptoms posing a diagnostic challenge. There is a paucity of radiology literature on imaging findings of Spigelian hernia. The objective of this study is to explore the role of MDCT in evaluating Spigelian hernia along with clinical and surgical implications.

MATERIALS AND METHODS

In this IRB approved, HIPAA compliant retrospective observational analysis MDCT imaging findings of 43 Spigelian hernias were evaluated by two fellowship-trained radiologists. Imaging features evaluated were: presence of Spigelian hernia, laterality, relation to "hernia belt" (between 0 and 6 cm cranial to an imaginary axial line between both anterior superior iliac spines), the hernia neck and sac sizes, hernia content, and other coexistent hernias (umbilical, incisional, inguinal). Patient's demographics (age, gender, BMI, conditions with increased intra-abdominal pressure) were also recorded for any correlation.

RESULTS

60% (26/43) of Spigelian hernias were located below the hernia belt while 33% (14/43) within the hernia belt and 7% (3/43) above the hernia belt. The most common subtype of Spigelian hernia encountered was interparietal (84%). The mean hernia neck diameter was 3.4 cm, mean hernia sac volume was 329 cc. Hernia content included: fat (43/43) bowel (23/43), fluid (3/43). 3 patients had no clinical history provided, the remaining 37 patients' clinical presentation was asymptomatic in 73% (27/37), acute abdominal pain in 5% (2/37) and chronic abdominal pain in 22% (8/37). None of the hernia were incarcerated and none of the patients underwent emergent surgery. No significant correlation was noted between Spigelian hernia and causes of increased intra-abdominal pressure. 90% of our patients had other abdominal hernias. 30.9 was the mean BMI (20.8-69.1).

CONCLUSION

Most of the Spigelian hernia occurred below the traditionally described hernia belt and the majority are of interparietal subtype that can be best diagnosed with MDCT in contrast to physical examination.

Radiologic-Histopathologic Correlation of Transvaginal US and Risk-reducing Salpingo-oophorectomy for Women at High Risk for Tubo-ovarian Carcinoma

Purpose

To examine radiologic-histopathologic correlation and the diagnostic performance of transvaginal US prior to risk-reducing salpingo-oophorectomy (RRSO) in women at high risk for tubo-ovarian carcinoma (TOC).

Materials and Methods

This retrospective study included 147 women (mean age, 49 years; age range, 28-75 years) at high risk for TOC who underwent transvaginal US within 6 months of planned RRSO between May 1, 2007, and March 14, 2018. Histopathologic results were reviewed. Fellowship-trained abdominal radiologists reinterpreted transvaginal US findings by using standardized descriptors. Descriptive statistical analysis and multiple logistic regression were performed.

Results

Of the 147 women, 136 had mutations in BRCA1, BRCA2, Lynch syndrome, BRIP1, and RAD51D genes, and 11 had a family history of TOC. Histopathologic reports showed 130 (88.4%) benign nonneoplastic results, 10 (6.8%) benign neoplasms, five (3.4%) malignant neoplasms, and two (1.4%) isolated p53 signature lesions. Transvaginal US results showed benign findings in 95 (64.6%) women and abnormal findings in 11 (7.5%) women; one or both ovaries were not visualized in 41 (27.9%) women. Hydrosalpinx was absent in all TOC and p53 signature lesions at transvaginal US. Transvaginal US had 20% sensitivity (one of five), 93% specificity (132 of 142), 9% positive predictive value (one of 11), and 97% negative predictive value (132 of 136) for TOC. Cancer was detected in one of five women at transvaginal US, and three of five false-negative lesions were microscopic or very small.

Conclusion

Preoperative transvaginal US had low sensitivity for detecting TOC in women at high risk for TOC. Clinically relevant precursors and early cancers were too small to be detected.Keywords: Genital/Reproductive, UltrasoundSupplemental material is available for this article.© RSNA, 2020.

ACR Appropriateness Criteria® Abnormal Uterine Bleeding

This publication summarizes the relevant literature for the imaging of patients with symptoms of abnormal uterine bleeding, including initial imaging, follow-up imaging when the original ultrasound is inconclusive, and follow-up imaging when surveillance is appropriate. For patients with abnormal uterine bleeding, combined transabdominal and transvaginal ultrasound of the pelvis with Doppler is the most appropriate initial imaging study. If the uterus is incompletely visualized with the initial ultrasou2nd, MRI of the pelvis without and with contrast is the next appropriate imaging study, unless a polyp is suspected on the original ultrasound, then sonohysterography can be performed. If the patient continues to experience abnormal uterine bleeding, assessment with ultrasound of the pelvis, sonohysterography, and MRI of the pelvis without and with contrast would be appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Multimodality imaging of pancreas-kidney transplants

Simultaneous pancreas-kidney transplant remains a treatment option for patients with insulin-dependent diabetes mellitus type 1, aimed at restoring normoglycemia, alleviating insulin dependency, avoiding diabetic nephropathy, and thereby improving the quality of life. Imaging remains critical in the assessment of these transplant grafts. Ultrasound with Doppler remains the primary imaging modality for establishing baseline assessment of the graft as well as for evaluating vascular, parenchymal, and perigraft complications. Noncontrast MR imaging is preferred over non-contrast CT for evaluation of parenchymal or perigraft complications in patients with decreased renal function, although contrast-enhanced CT/MR imaging may be obtained following multidisciplinary consultation in cases with high clinical and laboratory suspicion for graft dysfunction. Catheter angiography is reserved primarily for therapeutic intervention in suspected or confirmed vascular complications. An understanding of the surgical techniques and imaging appearance of a normal graft is crucial to identify potential complications and direct timely management. This article provides an overview of surgical techniques, normal imaging appearance, as well as the spectrum of imaging findings and potential complications in pancreas-kidney transplants.

Advances in MR Imaging of the Female Pelvis

This article focuses on advanced MR imaging techniques of the female pelvis and clinical applications for benign and malignant disease. General and abbreviated protocols for female pelvic MR imaging are reviewed. Diffusion-weighted imaging, dynamic contrast-enhanced MR imaging, and susceptibility-weighted imaging are discussed in the context of adnexal mass characterization using the ADNEx-MR scoring system, evaluation of endometriosis, local staging of cervical and endometrial cancers, assessment of nodal and peritoneal metastasis, and potential detection of leiomyosarcoma. MR defecography is also discussed regarding evaluation of multicompartmental pelvic floor disorders.

Intraductal papillary neoplasm of the bile duct (IPNB): CT and MRI appearance with radiology-pathology correlation

PURPOSE

Intraductal papillary neoplasm of the bile duct (IPNB) is a precursor to invasive carcinoma and is a distinct pathologic diagnosis. The purpose of this study was to evaluate imaging features of IPNB on cross-sectional imaging studies with histopathologic correlation.

MATERIALS AND METHODS

In this IRB approved, HIPAA compliant retrospective observational analysis of 23 pathology proven IPNB tumors 22 imaging studies were reviewed, 14 CT and 8 MRI scans. Features evaluated in consensus by two subspecialty-trained abdominal radiologists included: presence of specific lesion/mass within the bile duct, location within the biliary tree, size, morphology, enhancement characteristics, and bile duct caliber.

RESULTS

Majority of the subjects (16/18, 90%) had definite intraluminal mass, of which 7 (39%) had a polypoid mass with upstream diffuse biliary ductal dilation and 5 (28%) had a plaque-like mass with focal stricture and upstream biliary ductal dilatation. 6/18 (33%) subjects had low grade dysplasia, most commonly intestinal subtype, 7/18 (39%) subjects presented with invasive component, commonly pancreaticobiliary subtype, and 5/18 (28%) presented with high grade dysplasia.

CONCLUSION

IPNB has increased predilection for extrahepatic bile ducts, commonly presenting as either an intraluminal polypoidal mass with associated upstream biliary ductal dilation or a focal plaque like mass with associated ductal stricture at the site of the tumor.

Assessing Small Bowel Stricturing and Morphology in Crohn's Disease Using Semi-automated Image Analysis

BACKGROUND

Evaluating structural damage using imaging is essential for the evaluation of small intestinal Crohn's disease (CD), but it is limited by potential interobserver variation. We compared the agreement of enterography-based bowel damage measurements collected by experienced radiologists and a semi-automated image analysis system.

METHODS

Patients with small bowel CD undergoing a CT-enterography (CTE) between 2011 and 2017 in a tertiary care setting were retrospectively reviewed. CT-enterography studies were reviewed by 2 experienced radiologists and separately underwent automated computer image analysis using bowel measurement software. Measurements included maximum bowel wall thickness (BWT-max), maximum bowel dilation (DIL-max), minimum lumen diameter (LUM-min), and the presence of a stricture. Measurement correlation coefficients and paired t tests were used to compare individual operator measurements. Multivariate regression was used to model identification of strictures using semi-automated measures.

RESULTS

In 138 studies, the correlation between radiologists and semi-automated measures were similar for BWT-max (r = 0.724, 0.702), DIL-max (r = 0.812, 0.748), and LUM-min (r = 0.428, 0.381), respectively. Mean absolute measurement difference between semi-automated and radiologist measures were no different from the mean difference between paired radiologists for BWT-max (1.26 mm vs 1.12 mm, P = 0.857), DIL-max (2.78 mm vs 2.67 mm, P = 0.557), and LUM-min (0.54 mm vs 0.41 mm, P = 0.596). Finally, models of radiologist-defined intestinal strictures using automatically acquired measurements had an accuracy of 87.6%.

CONCLUSION

Structural bowel damage measurements collected by semi-automated approaches are comparable to those of experienced radiologists. Radiomic measures of CD will become an important new data source powering clinical decision-making, patient-phenotyping, and assisting radiologists in reporting objective measures of disease status.

Role of US LI-RADS in the LI-RADS Algorithm

The US Liver Imaging Reporting and Data System (LI-RADS) was released in 2017 and is the newest of the four American College of Radiology (ACR) LI-RADS algorithms. US LI-RADS provides standardized terminology, technical recommendations, and a reporting framework for US examinations performed for screening or surveillance in patients at risk for developing hepatocellular carcinoma (HCC). The appropriate patient population for screening and surveillance includes individuals who are at risk for developing HCC but do not have known or suspected cancer. This includes patients with cirrhosis from any cause and subsets of patients with chronic hepatitis B virus infection in the absence of cirrhosis. In an HCC screening or surveillance study, US LI-RADS recommends assigning two scores that apply to the entire study: the US category, which determines follow-up, and a visualization score, which communicates the expected level of sensitivity of the examination but does not affect management. Three US categories are possible: US-1 negative, a study with no evidence of HCC; US-2 subthreshold, a study in which an observation less than 10 mm is depicted that is not definitely benign; and US-3 positive, a study in which an observation greater than or equal to 10 mm or a new thrombus in vein is identified, for which diagnostic contrast material-enhanced imaging is recommended. Three visualization scores are possible: A (no or minimal limitations), B (moderate limitations), and C (severe limitations). ^©RSNA, 2019.

Imaging Features Associated With Failure of Nonoperative Management of Intraabdominal Abscesses in Crohn Disease

BACKGROUND

Intraabdominal abscess management decisions in the treatment of Crohn disease (CD) can be challenging. Our aim was to determine the effect of clinical, medication use, and imaging disease characteristics on the need for future surgical management.

METHODS

A retrospective chart review was performed in patients with CD hospitalized for abscess confirmed by imaging between 2008 and 2016. Selection criteria included nonoperative management with intravenous antibiotics at the index hospitalization and a minimum of 2 years of follow up. Demographic, disease, and medication history were extracted from electronic medical records. Radiographic disease features were assessed by an expert abdominal radiologist, blinded to clinical data. The primary outcome was resection of the bowel segment involving the abscess within 2 years of index hospitalization. Cox proportional hazards regression and statistical methods were performed using SAS 9.4.

RESULTS

Of the 121 patients meeting the selection criteria, 36.4% avoided surgery after 2 years of follow up. On adjusted multivariable analysis, disease-activity factors including bowel wall thickness (HR 3.08, 95% CL 1.20-6.21), disease length (HR 2.67, 95% CL 1.40-6.20), bowel dilation (HR 2.19, 95% CL 1.02-4.68), and abscess size of greater than 6 cm (HR 2.47, 95%CL 1.17-5.21) were independent risk factors for future surgery in patients not undergoing immediate bowel resection for abscess management. Biologic use and percutaneous drainage were not risk factors for ultimate surgical management.

CONCLUSIONS

Radiographic CD features and abscess size over 6 cm are predictors of ultimately requiring bowel resection. Radiographic measures may help stratify patients to immediate surgery or conservative management for intraabdominal CD-related abscesses.

Imaging of transgender patients: expected findings and complications of gender reassignment therapy

OBJECTIVES

Gender dysphoria is defined as a conflict between the biological gender and the gender with which the person identifies. Gender reassignment therapy can alter external sexual features to resemble those of the desired gender and are broadly classified into two types, female to male (FTM) and male to female (MTF). In this paper we describe expected findings and complications of gender reassignment therapy.

METHODS

Collaborative multi-institutional project supported by Ovarian and Uterine Cancer Disease Focused panel of Society of Abdominal Radiology.

RESULTS

Gender dysphoria is defined as a conflict between the biological gender and the gender with which the person identifies. Gender reassignment therapy can alter external sexual features to resemble those of the desired gender and are broadly classified into two types, female to male (FTM) and male to female (MTF). These therapies include hormonal treatment as well as surgical procedures. FTM genital reconstructive therapy includes creation of a neophallus, which can be achieved by metoidioplasty or phalloplasty with mastectomy, along with testosterone administration. MTF gender reassignment surgery includes complete removal of external genitalia with penectomy and orchiectomy, with vaginoplasty, clitoroplasty, labiaplasty, and breast augmentation along with estrogen supplements.

CONCLUSION

Surgical techniques alter the standard anatomy and make imaging interpretation challenging if radiologists are unfamiliar with expected post-operative appearances. It is important to recognize the complications related to surgical and non-surgical treatment of gender dysphoria to avoid interpretation errors. Furthermore, increasing the prevalence of transgender patients requires increased sensitivity when interpreting imaging studies to reduce the potential for misdiagnoses in reporting due to frequently incomplete available clinical history.

Perceptual and Interpretive Error in Diagnostic Radiology-Causes and Potential Solutions

Interpretation of increasingly complex imaging studies involves multiple intricate tasks requiring visual evaluation, cognitive processing, and decision-making. At each stage of this process, there are opportunities for error due to human factors including perceptual and ergonomic conditions. Investigation into the root causes of interpretive error in radiology first began over a century ago. In more recent work, there has been increasing recognition of the limits of human image perception and other human factors and greater acknowledgement of the role of the radiologist's environment in increasing the risk of error. This article reviews the state of research on perceptual and interpretive error in radiology. This article focuses on avenues for further error examination, and strategies for mitigating these errors are discussed. The relationship between artificial intelligence and interpretive error is also considered.

Association of advanced hepatic fibrosis and sonographic visualization score: a dual-center study using ACR US LI-RADS

PURPOSE

To evaluate the association between imaging and clinical features and visualization scores, as specified by American College of Radiology (ACR) Ultrasound Liver Imaging Reporting and Data System (LI-RADS), on hepatocellular carcinoma (HCC) screening ultrasound examinations.

METHODS

In this dual-center retrospective study, HCC screening ultrasound reports containing ultrasound elastography measurements (January to September, 2017) were reviewed. Ultrasound point shear wave elastography and 2-dimensional shear wave elastography were used to assess liver stiffness; median shear wave velocity was translated to METAVIR fibrosis scoring, per previously published data. Reports were analyzed for subject age, sex, reason for HCC screening, spleen size, fibrosis scores, and assigned ultrasound visualization scores. Jonckheere-Terpstra trend and Kendall's tau-b coefficient analyses were performed.

RESULTS

714 subjects (mean age 55; 51% male, 49% female) were included. 308 (43%) subjects had clinically declared cirrhosis; 406 (57%) did not. Majority (535, 75%) of exams were adequate (Visualization Score A), 156 (22%) moderately limited (Visualization Score B), and 23 (3%) severely limited (Visualization Score C). Increasing spleen size and patient age were associated with worsening visualization scores (p < 0.001). Suboptimal visualization was also associated with clinically significant fibrosis (≥ F2) by elastography (Kendall's tau-b = 0.181, p < 0.001) and clinically declared cirrhosis (Kendall's tau-b = 0.433, p < 0.001). There was no association with patient sex.

CONCLUSION

Using ACR Ultrasound LI-RADS visualization score assessment, majority (75%) of HCC screening exams were diagnostically adequate, and only 3% were severely limited. Sonoelastographic diagnosis of clinically significant fibrosis, as well as clinical cirrhosis, increased patient age, and spleen size, were associated with greater diagnostic limitations.

Yield of Routine Image-Guided Biopsy of Renal Mass Thermal Ablation Zones: 11-Year Experience

PURPOSE

To determine the yield of routine image-guided core biopsy of renal cell carcinoma (RCC) thermal ablation zones.

METHODS

Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act-compliant quality improvement effort. Routine core biopsy of RCC ablation zones was performed 2 months postablation from July 2003 to December 2014. Routine nicotinamide adenine dinucleotide staining was performed by specialized genitourinary pathologists to assess cell viability. The original purpose of performing routine postablation biopsy was to verify, in addition to imaging, whether the mass was completely treated. Imaging was stratified as negative, indeterminate, or positive for viable malignancy. Histology was stratified as negative, indeterminate, positive, or nondiagnostic for viable malignancy. Histology results were compared to prebiopsy imaging findings.

RESULTS

Routine ablation zone biopsy was performed after 50% (146/292) of index ablations (24 cryoablations, 122 radiofrequency ablations), and postablation imaging was performed more often with multiphasic computed tomography than magnetic resonance imaging (100 vs 46, p < 0.0001). When imaging was negative (n = 117), biopsy added no additional information (92% [n = 108] negative, 0.9% [n = 1] indeterminate, 7% [n = 8] nondiagnostic). When imaging was indeterminate (n = 19), 11% (n = 2) of biopsies had viable RCC and 89% (n = 17) were negative. When imaging was positive, biopsy detected viable neoplasm in only 10% (1/10) of cases; 80% (8/10) were negative and 10% (1/10) were nondiagnostic.

CONCLUSION

Routine biopsy of renal ablation zones to validate postablation imaging results was not value-added and therefore was discontinued at the study institution.

Quantitative Assessment of Liver Stiffness Using Ultrasound Shear Wave Elastography in Patients With Chronic Graft-Versus-Host Disease After Allogeneic Hematopoietic Stem Cell Transplantation: A Pilot Study

OBJECTIVES

The purpose of this study was to compare hepatic stiffness on ultrasound (US) shear wave elastography (SWE) in patients with chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation versus patients with no underlying liver disease.

METHODS

We performed a retrospective analysis of 4901 patients who underwent abdominal US examinations with adjunctive liver SWE between August 2014 and December 2016. Each patient was scanned supine with gentle breath holding on LOGIQ E9 (GE Healthcare, Waukesha, WI) or Epiq (Philips Healthcare, Andover, MA) US machines (3-6 MHz). Three to 10 measurements were made intercostally in the right hepatic lobe, following manufacturers' guidelines before release of the 2015 Society of Radiologists in Ultrasound consensus or the 2015 Society of Radiologists in Ultrasound consensus. The median and standard deviation of the shear wave velocity (SWV) were obtained. A 2-sample t test with the Welch approximation was used for statistical analysis.

RESULTS

Six patients had documented hepatic chronic GVHD or a high clinical suspicion of liver chronic GVHD. All had normal pretransplant liver function test results and no pretransplant or posttransplant hepatic infection. The control group, obtained from the same database, contained 10 patients with normal liver function test results, no abdominal pain, and no history of liver disease or conditions that may have caused liver stiffness changes. The SWVs in patients with chronic GVHD were double those in the control group (1.96 ± 0.28 versus 0.98 ± 0.27 m/s; P < .0001).

CONCLUSIONS

Patients with chronic GVHD had substantially higher hepatic parenchymal SWVs than patients without liver disease, indicating increased tissue stiffness. To our knowledge, this phenomenon has not been previously reported in chronic GVHD and suggests potential utility of SWE for diagnosis and monitoring of disease progression and the treatment response in this cohort of patients.

Transvaginal Ultrasound Shear Wave Elastography for the Evaluation of Benign Uterine Pathologies: A Prospective Pilot Study

OBJECTIVES

This study evaluated the diagnostic performance of transvaginal ultrasound (TVUS) shear wave elastography (SWE) for evaluating uterine adenomyosis and leiomyomas.

METHODS

Institutional Review Board approval was obtained for prospective enrollment of 34 premenopausal women with pelvic pain and/or bleeding between January 2015 and June 2016. TVUS SWE was performed with regions of interest in multiple uterine segments and shear wave velocities(SWVs) were recorded. Reference pelvic magnetic resonance examinations were performed and reviewed without access to the ultrasound results.

RESULTS

Continuous variables were analyzed using means, t tests, and analysis of variance. Magnetic resonance imaging revealed adenomyosis in 6 women (12 uterine segments) and leiomyomas in 12 women (28 segments). On a per-patient basis, mean SWV in 16 women with no adenomyosis or leiomyoma was 4.3 ± 1.7 m/s, compared with 5.7 ± 2.3 m/s in 18 women with a magnetic resonance diagnosis of myometrial pathology (P < .0002; 95% confidence interval, -2.2, -0.6). On a per-segment basis, SWV in normal myometrium was 4.8 ± 1.9 m/s, compared with 4.9 ± 2.5 m/s in adenomyosis and 5.6 ± 2.5 m/s in leiomyoma (P = .34 by one-way analysis of variance). In pairwise comparison, SWV for adenomyosis and leiomyoma did not differ significantly (P = .40).

CONCLUSIONS

TVUS SWE did not distinguish adenomyosis from leiomyoma. However, our pilot study demonstrated that myometrial SWVs were higher in uteri with adenomyosis and leiomyomas than in uteri with myometrium with no abnormalities suggesting a potential role for SWE in treatment response assessment.

Limitations of the 2015 ATA Guidelines for Prediction of Thyroid Cancer: A Review of 1947 Consecutive Aspirations

BACKGROUND

The 2015 American Thyroid Association (ATA) guidelines have been proposed to aid in the management of thyroid nodules by determining whether fine needle aspiration is indicated.

OBJECTIVE

To determine whether the ATA guidelines contribute to the overdiagnosis of thyroid cancer.

PATIENTS AND METHODS

This was a retrospective cohort study of ultrasound-imaged thyroid nodules (n = 1947) consecutively aspirated at a tertiary care center from 1 October 2009 to 22 February 2016. Nodules were retrospectively reviewed, assigned a 2015 ATA morphology, and placed into one of five 2015 ATA categories of risk (ATA-1, <1% risk of malignancy; ATA-2, <3% risk; ATA-3, 5% to 10% risk, ATA-4: 10% to 20% risk; ATA-5, >70% to 90% risk) by a reader who was blinded to cytology. ATA category was compared with cytopathology. The positive predictive value (PPV) of each ATA category was calculated with respect to cancer. Numbers needed to aspirate and Pearson correlations were calculated. Interrater agreement for ATA category across five readers was assessed.

RESULTS

The PPV for cancer increased by ATA category [category 1 to 5, respectively: 0% (0/14), 2% (4/249), 5% (36/733), 12% (104/850), 28% (28/101)]. The number needed to sample to detect one papillary cancer was 125 (ATA-2), 49 (ATA-3), 13 (ATA-4), and 5 (ATA-5). The overall interrater agreement for ATA score across all five readers was fair (intraclass correlation coefficient 0.460).

CONCLUSIONS

The 2015 ATA guidelines stratify risk for thyroid cancer; however, the stratification system is overly optimistic regarding cancer detection rates for the higher-risk nodules, and there is only fair interrater agreement.

Diagnostic accuracy of MDCT in differentiating gallbladder cancer from acute and xanthogranulomatous cholecystitis

OBJECTIVE

To determine the diagnostic accuracy of multi-detector CT (MDCT) for differentiating gallbladder cancer from acute and xanthogranulomatous cholecystitis using previously described imaging features.

METHODS

In this IRB approved HIPAA-compliant retrospective cohort study, contrast-enhanced MDCT of histologically confirmed acute cholecystitis (n = 17), xanthogranulomatous cholecystitis (n = 25), and gallbladder cancer (n = 18) were reviewed independently by three abdominal radiologists blinded to outcome. The primary outcome was the diagnostic accuracy of MDCT for the differentiation of gallbladder cancer from cholecystitis (acute and xanthogranulomatous) using various imaging parameters. Kappa (κ) statistics and two-way mixed-model single-measure intra-class correlation statistics (ICC) were calculated for each imaging feature and the final radiologic diagnosis.

RESULTS

Inter-rater agreement was moderate to substantial (κ = 0.43-0.70), sensitivity 0.67-0.78, specificity 0.22-0.33 and the positive likelihood ratio was 4.28-8.56 for the differentiation of gallbladder cancer from benign gallbladder pathology. Only three imaging findings: disrupted gallbladder mucosa (κ = 0.68), intraluminal gallstones (κ = 0.66), and gallbladder wall thickness (ICC = 0.63) had substantial inter-rater agreement. The following had slight or no agreement: intramural hypoattenuating nodules (κ = 0.17), transient hepatic attenuation differences (κ = 0.14), gallbladder wall calcification (κ = -0.01), gallbladder wall enhancement (κ = 0.18), and omental or mesenteric invasion (κ = 0.08). In the final multivariate model, the following were significant predictors useful in making or excluding diagnosis of gallbladder cancer: focal gallbladder wall thickening (p = 0.003, OR: 13.09 [95% CI: 2.40-71.48]), pericholecystic "fat stranding" (p = 0.018, OR: 0.10 [95% CI: 0.01-0.66]), and maximum short axis lymph node diameter (p = 0.043, OR: 1.18 [95% CI: 1.00-1.38]).

CONCLUSION

MDCT has moderate sensitivity, poor specificity, and moderate-to-substantial inter-rater repeatability for the differentiation of gallbladder cancer from acute and xanthogranulomatous cholecystitis.

Indeterminate Adnexal Cysts at US: Prevalence and Characteristics of Ovarian Cancer

Purpose To assess the prevalence of indeterminate adnexal cysts in women presenting to academic medical centers for pelvic ultrasonography (US), determine the incidence of malignancy, and identify cyst and patient characteristics that are predictive of malignancy. Materials and Methods A multicenter study of US-detected adnexal cysts with appropriate follow-up (surgical pathologic examination, imaging and/or clinical examination) was conducted from January 2008 to June 2012. Indeterminate cysts were classified as category 1 (typical benign appearing cysts >5 cm) or category 2 (cysts with avascular solid components) on the basis of a combination of definitions in the existing literature. The incidence of neoplasms and malignant tumors was calculated. Patient and cyst characteristics associated with neoplasm and malignant tumors were evaluated with the χ² test or Fisher exact test for categorical variables and the t test for continuous variables. A backward stepwise logistic regression model was performed for two outcomes: (a) the presence of any neoplasm (benign or malignant) and (b) the presence of a malignant tumor. Results There were 1637 women with an adnexal cyst at US; 391 (mean age = 41.8 years ± 13.5.1; range = 17-91 years) had an indeterminate adnexal cyst at US. The prevalence of indeterminate adnexal cysts was 23.9% (391 of 1637; 95% confidence interval [CI]: 0.22, 0.26). Three hundred three indeterminate cysts in 280 women (mean age = 42.9 years ± 14.1; range = 17-88 years) had adequate follow-up. The incidence of ovarian neoplasms (benign and malignant) was 24.8% (75 of 303 cysts; 95% CI: 0.20, 0.30), and the incidence of malignant tumors was 3.6% (11 of 303 cysts; 95% CI: 0.02, 0.06). The proportion of ovarian neoplasms differed between category 1 and category 2 cysts (17.5% [25 of 143 cysts; 95% CI: 0.12, 0.25] vs 31.3% [50 of 160 cysts; 95% CI: 0.24, 0.39], respectively; P = .001). The proportion of malignant tumors differed between categories 1 and 2 cysts (0% [0 of 143 cysts] vs 6.9% [11 of 160 cysts; 95% CI: 0.03, 0.12]; P < .001). The presence of an avascular nodular component was a significant predictor of malignancy at stepwise logistic regression analysis (odds ratio = 2.83; P ≤ .0001; 95% CI: 1.69, 4.70). Conclusion The presence of an avascular nodular component was the most significant predictor of the presence of malignancy in indeterminate adnexal cysts. The risk of malignancy is higher with category 2 cysts than with category 1 cysts. ^© RSNA, 2018.

Multicenter Research Studies in Radiology

RATIONALE AND OBJECTIVES

Here we review the current state of multicenter radiology research (MRR), and utilize a survey of experienced researchers to identify common advantages, barriers, and resources to guide future investigators.

MATERIALS AND METHODS

The Association of University Radiologists established a Radiology Research Alliance task force, Multi-center Research Studies in Radiology, composed of 12 society members to review MRR. A REDCap survey was designed to gain more insight from experienced researchers. Recipients were authors identified from a PubMed database search, utilizing search terms "multicenter" or "multisite" and "radiology." The survey included investigator background information, reasons why, barriers to, and resources that investigators found helpful in conducting or participating in MRR.

RESULTS

The survey was completed by 23 of 80 recipients (29%), the majority (76%) of whom served as a primary investigator on at least one MRR project. Respondents reported meeting collaborators at national or international (74%) and society (39%) meetings. The most common perceived advantages of MRR were increased sample size (100%) and improved generalizability (91%). External funding was considered the most significant barrier to MRR, reported by 26% of respondents. Institutional funding, setting up a central picture archiving and communication system, and setting up a central database were considered a significant barrier by 30%, 22%, and 22% of respondents, respectively. Resources for overcoming barriers included motivated staff (74%), strong leadership (70%), regular conference calls (57%), and at least one face-to-face meeting (57%).

CONCLUSIONS

Barriers to MRR include funding and establishing a central database and a picture archiving and communication system. Upon embarking on an MRR project, forming a motivated team who meets and speaks regularly is essential.

Screening and Surveillance of Hepatocellular Carcinoma: An Introduction to Ultrasound Liver Imaging Reporting and Data System

Given the high prevalence, increasing incidence, and significant morbidity and mortality related to hepatocellular carcinoma (HCC), a robust and cost-effective screening and surveillance program is needed. Most societies recommend ultrasound for HCC screening, despite lack of standardization in imaging acquisition, reporting content and language, and follow-up recommendations. The American College of Radiology Ultrasound Liver Imaging Reporting and Data System (US LI-RADS) fills this unmet need by providing standardization in the use of US in at-risk patients. It is anticipated that US LI-RADS will improve the performance of ultrasound for HCC screening and surveillance and unify management recommendations.

MR Imaging-Pathologic Correlation in Ovarian Cancer

There are many ovarian cancer subtypes, giving rise to a range of appearances at gross pathology and magnetic resonance (MR) imaging. Certain fundamental concepts at MR, arising from underlying tissue characteristics, can provide guidance to radiologists in suggesting a diagnosis. The ability of multiparametric MR to risk stratify ovarian masses can contribute substantially to clinical decision making and patient management.

Sonographic diagnosis of partial versus complete molar pregnancy: A reappraisal

PURPOSE

To assess the prospective sonographic diagnosis of molar pregnancy and compare sonographic features of complete versus partial molar pregnancy.

METHODS

This institutional review board--approved retrospective chart review conducted between 2001 and 2011 identified 70 women with a histopathologic diagnosis of molar pregnancy and with available sonograms. Clinical data, images, and reports were reviewed, and features enumerated by radiologists blinded to the final diagnosis.

RESULTS

Mean age of patients was 30.5 ± 7.0 (SD) years (range, 16-49 years) with a mean gravidity of 3.2 ± 2.3 (SD) (range 1-11). Mean gestational age was 74.0 ± 19.1 day (range 39-138) and serum β-human chorionic gonadotropin was 131 ± 156 mIU/ml (range 447-662,000). Pathologic results showed 48 partial and 22 complete molar pregnancies. Sonographically, partial moles more commonly showed a yolk sac (56.3% versus 0%, p < 0.0001), fetal pole (62.5% versus 4.6%, p < 0.0001), fine septa within the sac (25.0% versus 4.6%, p = 0.05), and normal (31.3% versus 0%, p = 0.002) or minimally cystic placenta (27.1% versus 4.6%, p = 0.49), while complete moles had larger gestational sacs (612 versus 44 mm, p = 0.005), were more often avascular on color Doppler imaging (45.5% versus 18.8%, p = 0.02), had more often abnormal tissue in the uterus (82.6% versus 20.8%, p < 0.0001) and placental masses (86.9% versus 16.7%, p < 0.0001), and were more often diagnosed prospectively (86.4% versus 41.7%, p = 0.0005).

CONCLUSIONS

Complete molar pregnancy is associated with marked cystic changes and mass formation and is often diagnosed sonographically. Partial molar pregnancy often presents with minor cystic changes of the placenta and remains underdiagnosed sonographically. However, correct prospective diagnosis was made more frequently in this study than in older reports, perhaps due to improved spatial resolution of sonographic equipment. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:72-78, 2017.