Per-patient Negative Predictive Value of the CT and MRI Liver Imaging Reporting and Data System Version 2018 Treatment Response Algorithm for Hepatocellular Carcinoma.

Background The Liver Imaging Reporting and Data System version 2018 (LI-RADS) treatment response algorithm (TRA) is a high-specificity, lower-sensitivity grading system to diagnose hepatocellular carcinoma (HCC) and recurrence after local-regional therapy. However, the emphasis on specificity can result in disease understaging, potentially leading to poorer posttransplant outcomes. Purpose To determine the negative predictive value (NPV) of pretransplant CT and MRI assessment for viable HCC on a per-patient basis using the LI-RADS TRA, considering explant pathology as the reference standard. Materials and Methods Patient records from 218 consecutive adult patients from a single institution with HCC who underwent liver transplant from January 2011 to November 2017 were retrospectively reviewed. Two readers blinded to the original report reviewed immediate (within 90 days) pretransplant imaging and characterized observations according to the LI-RADS TRA. Based on this, patients with LR-4, LR-5, or LR-TR (treatment response) viable tumors were designated as viable tumor; patients with solely LR-3 or LR-TR equivocal tumors were designated as equivocal; and patients with only LR-TR nonviable lesions were designated as no viable disease. Patients were designated as within or outside the Milan criteria. These per-patient designations were compared with the presence of viable disease at explant pathology. Fisher exact test was used to compare the differences between CT and MRI. Weighted κ values were used to calculate interreader reliability. Results Final study sample consisted of 206 patients (median age, 61 years [IQR, 57-65 years]; 157 male patients and 49 female patients). Per-patient LI-RADS TRA assessment of pretransplant imaging had an NPV of 32% (95% CI: 27, 38) and 26% (95% CI: 20, 33) (readers 1 and 2, respectively) for predicting viable disease. Seventy-five percent (reader 1) and 77% (reader 2) of patients deemed equivocal had residual tumors at explant pathology. Weighted interreader reliability was substantial (κ = 0.62). Conclusion Patient-based stratification of viable, equivocal, and nonviable disease at pretransplant CT or MRI, based on LI-RADS TRA, demonstrated low negative predictive value in excluding HCC at explant pathology. © RSNA, 2023 See also the editorial by Tamir and Tau in this issue.

Cervical Lymph Node Features Predictive of Suboptimal Adequacy During Ultrasound-Guided Fine-Needle Aspiration in Thyroid Cancer Patients.

PURPOSE: To determine the rate of cytologic and diagnostic adequacy and identify features associated with suboptimal tissue sampling in ultrasound-guided fine-needle aspiration (US-FNA) of suspected nodal disease in thyroid cancer patients. METHODS: A single-institution pathology database was queried for lymph node FNA reports in thyroid cancer patients from 2014 to 2019. Charts were reviewed for demographics, body mass index (BMI), prior thyroidectomy, cancer type, and subsequent surgery. Ultrasound images were retrospectively reviewed for location, size, depth from skin, cystic components, macrocalcification, echogenic foci, and internal vascularity score. Pathology reports were categorized as cellular and diagnostic, hypocellular/acellular but diagnostic with abnormal cells or thyroglobulin levels, or hypocellular and nondiagnostic. Correlation and multivariate regression analyses were performed. RESULTS: Initial query yielded 552 lesions in 343 subjects. Following exclusion, 377 lesions in 255 subjects were included. Mean patient age was 48.5 years (14-90), BMI 28.5, and 66.7% female and 33.3% male. The majority (95.3%) had papillary thyroid carcinoma (PTC); and 65.5% had prior thyroidectomy. 17.7% of lesions were hypocellular/acellular (suboptimal), and 5.6% nondiagnostic. Patient factors had no association (P >.05). Right-sidedness and hypovascularity were associated with hypocellularity (P <.05). Higher long/short-axis ratio and cystic foci were weakly associated. On multivariate analysis, right-sidedness (odds ratio [OR] 1.99; confidence interval [CI] 1.10-3.57) and lower vascularity score (OR 0.54; CI 0.39-0.73) were predictive of suboptimal sampling. CONCLUSION: US-FNA has high diagnostic yield and cellular sample rate. Lesion size had no effect. Right-sidedness and lower vascularity scores were predictive of suboptimal tissue. Identifying these features and expected sample adequacy rates can inform management decisions for thyroid cancer patients with cervical lymphadenopathy.

Diagnosis of acute mesenteric ischemia assisted by dual-energy CT: a case report.

In this case report, dual-energy CT was critical in the diagnosis of acute mesenteric ischemia by differentiating normal contrast-enhanced bowel and hemorrhagic necrosis. Iodine map showed a segment of small bowel with minimal contrast enhancement, and virtual non-contrast imaging revealed hyperattenuating bowel. This finding changed management for the patient and prevented complications from impending bowel perforation. Histopathological analysis confirmed hemorrhagic necrosis of the bowel segment. In cases of suspected bowel ischemia, dual-energy CT can distinguish bowel wall hemorrhage from contrast enhancement and allow for accurate diagnosis.

Multi-institutional Experience with Patient Image Access Through Electronic Health Record Patient Portals.

The objective is to determine patients' utilization rate of radiology image viewing through an online patient portal and to understand its impact on radiologists. IRB approval was waived. In this two-part, multi-institutional study, patients' image viewing rate was retrospectively assessed, and radiologists were anonymously surveyed for the impact of patient imaging access on their workflow. Patient access to web-based image viewing via electronic patient portals was enabled at 3 institutions (all had open radiology reports) within the past 5 years. The number of exams viewed online was compared against the total number of viewable imaging studies. An anonymized survey was distributed to radiologists at the 3 institutions, and responses were collected over 2 months. Patients viewed 14.2% of available exams - monthly open rate varied from 7.3 to 41.0%. A total of 254 radiologists responded to the survey (response rate 32.8%); 204 were aware that patients could view images. The majority (155/204; 76.0%) felt no impact on their role as radiologists; 11.8% felt negative and 9.3% positive. The majority (63.8%) were never approached by patients. Of the 86 who were contacted, 46.5% were contacted once or twice, 46.5% 3-4 times a year, and 4.7% 3-4 times a month. Free text comments included support for healthcare transparency (71), concern for patient confusion and anxiety (45), and need for attention to radiology reports and image annotations (15). A small proportion of patients viewed their radiology images. Overall, patients' image viewing had minimal impact on radiologists. Radiologists were seldom contacted by patients. While many radiologists feel supportive, some are concerned about causing patient confusion and suggest minor workflow modifications.

Pearls and Pitfalls in Imaging of Pelvic Adnexal Torsion: Seven Tips to Tell It's Twisted.

Pelvic adnexal torsion is a collective term referring to twisting of an ovary, fallopian tube, or paraovarian cyst on its axis with varying degrees of vascular compromise. Although it is the fifth most common gynecologic emergency, the diagnosis is challenging and often missed due to symptoms, physical examination findings, and imaging features that are nonspecific. Delay in salvage surgery may lead to ovarian or tubal loss, dysfunction, and infertility. The tips shared herein are based on the authors' observations of key clinical and imaging features of torsion, with the intent of heightening radiologists' index of suspicion and diagnostic accuracy in a clear and memorable fashion. Clinically, severe acute pain with a known adnexal mass or of severity to elicit nausea or vomiting should raise concern. At imaging, features of ovarian edema are key to the diagnosis, including asymmetric ovarian enlargement, peripheralized follicles, adjacent free fluid, and foci of stromal hemorrhage. The converse finding of symmetric nonenlarged ovaries in a normal location with any imaging modality has a high negative predictive value for torsion, obviating the need for additional imaging. The whirlpool sign (twisted vascular pedicle), abnormal ovarian location, and uterine tilting are additional key imaging manifestations. The presence of color Doppler flow or contrast enhancement only suggests that an ovary is still viable and should not be used to exclude the diagnosis of torsion. In cases of isolated tubal or paraovarian cyst torsion, the ovaries may appear normal; therefore, recognition of this entity along with appreciation of several key imaging findings may assist with this difficult diagnosis. An invited commentary by Dighe is available online. Online supplemental material is available for this article. ©RSNA, 2021.

Müllerian Duct Anomalies: Role in Fertility and Pregnancy.

Müllerian duct anomalies (MDAs) have important implications for the reproductive health of female patients. In patients with both infertility and recurrent pregnancy loss, the incidence of MDAs is as high as 25%. Congenital uterine anomalies are often only part of a complex set of congenital anomalies involving the cervix, vagina, and urinary tract. Multiple classification systems for MDAs exist, each with different criteria that vary most for the diagnosis of septate uterus. Recognizing the features that guide clinical management is essential for interpretation. Identification of an MDA should prompt evaluation for associated urinary tract anomalies. In patients with infertility who seek to use assisted reproductive technologies such as intrauterine insemination, recognition of MDAs may have an affect on reproductive success, particularly in patients who have an incomplete and clinically occult septum that divides the cervix. Two-dimensional US is the first-line modality for evaluating the uterus and adnexa. Three-dimensional (3D) US or MRI may help to visualize the external uterine fundal contour and internal indentation of the endometrial cavity, which are two morphologic characteristics that are keys to the diagnosis of congenital uterine anomalies. Hysterosalpingo contrast-enhanced US may be performed in conjunction with 3D US to evaluate uterine morphologic characteristics, the endometrial cavity, and tubal patency in a single examination. MRI helps to characterize rudimentary uteri in patients with müllerian hypoplasia and allows assessment for ectopic ureters, abnormally positioned ovaries, or associated deep infiltrative endometriosis. Online supplemental material is available for this article. ©RSNA, 2021.

How common are traumatic injuries to the epididymis? A study of prevalence, imaging appearance, and management implications.

PURPOSE: To evaluate the prevalence of epididymal injuries with scrotal trauma, review imaging appearance, clinical management, and outcomes. METHODS: In this retrospective study, the radiology report database was queried for scrotal ultrasounds containing keywords pertaining to trauma, from 1998 to 2019. Exams with no clinically documented trauma, exams with trauma > 1 year ago, and duplicate exams were excluded. Chart review was conducted for age, trauma mechanism, time interval between trauma and ultrasound, signs of infection, and clinical management. Reports were reviewed to record the presence of scrotal injury, traumatic epididymitis, or epididymal hematoma. Cases with epididymal injury underwent image review. Descriptive statistics, Fisher's exact test, and Mann-Whitney's U test were performed to evaluate for associations between clinical parameters and epididymal injury. RESULTS: Initial search yielded 385 exams. A total of 103 exams met inclusion criteria. Trauma mechanisms included straddle injury (35%), blunt scrotal trauma by ball or other object (29%), assault (28%), penetrating injury (4%), and fall (3%). Sixty-eight patients (66%) had scrotal injury on imaging. Twenty-six (25%) had epididymal injury. Thirteen were isolated to the epididymis, and 13 had associated testicular or extra-testicular findings. There were 12 cases of traumatic epididymitis and 14 epididymal hematomas. All epididymal injuries were managed non-operatively. A total of 7 were prescribed antibiotics, including 1 subject who otherwise had no evidence of infection. CONCLUSION: Epididymal injury is encountered in 25% of scrotal ultrasounds for trauma evaluation. Traumatic epididymitis can be seen in 12%. It is important for radiologists to recognize this entity, as it can be mistaken for infection.

Streamlining Radiologist Workflow for Multidisciplinary Conferences: A Web-Based System to Represent Radiology.

Radiologists are an integral component in patient care and provide valuable information at multidisciplinary tumor boards. However, the radiologists' role at such meetings can be compromised by technical and workflow limitations, typically including the need for complex software such as picture archiving and communication system (PACS) applications which are difficult to install and manage in disparate locations with increasing security and network limitations. Our purpose was to develop a web-based system for easy retrieval of images and notes for presentation during multidisciplinary conferences and tumor boards. Our system allows images to be viewed from any computer with a web browser and does not require a stand-alone PACS software installation. The tool is launched by the radiologist marking the exam in PACS. It stores relevant text-based information in a MySQL server and is indexed to the conference for which it is to be used. The exams are then viewed through a web browser, via the hospital intranet or virtual private network (VPN). A web-based viewing platform, provided by our PACS vendor, is used for image display. In the 28 months following implementation, our web-based conference system was well-received by our radiologists and is now fully integrated into daily practice. Our method streamlines radiologist workflow in preparing and presenting medical imaging at multidisciplinary conferences and overcomes many previous technical obstacles. In addition to its primary role for interdepartmental conferences, our system also functions as a teaching file, fostering radiologist education within our department.

Cinebot: Creation of Movies and Animated GIFs Directly from PACS-Efficiency in Presentation and Education.

The presentation of radiology exams can be enhanced through the use of dynamic images. Dynamic images differ from static images by the use of animation and are especially useful for depicting real-time activity such as the scrolling or the flow of contrast to enhance pathology. This is generally superior to a collection of static images as a representation of clinical workflow and provides a more robust appreciation of the case in question. Dynamic images can be shared electronically to facilitate teaching, case review, presentation, and sharing of interesting cases to be viewed in detail on a computer or mobile devices for education. The creation of movies or animated images from radiology data has traditionally been challenging based on technological limitations inherent in converting the Digital Imaging and Communications in Medicine (DICOM) standard to other formats or concerns related to the presence of protected health information (PHI). The solution presented here, named Cinebot, allows a simple "one-click" generation of anonymized dynamic movies or animated images within the picture archiving and communication system (PACS) workflow. This approach works across all imaging modalities, including stacked cross-sectional and multi-frame cine formats. Usage statistics over 2 years have shown this method to be well-received and useful throughout our enterprise.

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.

Minimizing Barriers in Learning for On-Call Radiology Residents-End-to-End Web-Based Resident Feedback System.

Feedback is an essential part of medical training, where trainees are provided with information regarding their performance and further directions for improvement. In diagnostic radiology, feedback entails a detailed review of the differences between the residents' preliminary interpretation and the attendings' final interpretation of imaging studies. While the on-call experience of independently interpreting complex cases is important to resident education, the more traditional synchronous "read-out" or joint review is impossible due to multiple constraints. Without an efficient method to compare reports, grade discrepancies, convey salient teaching points, and view images, valuable lessons in image interpretation and report construction are lost. We developed a streamlined web-based system, including report comparison and image viewing, to minimize barriers in asynchronous communication between attending radiologists and on-call residents. Our system provides real-time, end-to-end delivery of case-specific and user-specific feedback in a streamlined, easy-to-view format. We assessed quality improvement subjectively through surveys and objectively through participation metrics. Our web-based feedback system improved user satisfaction for both attending and resident radiologists, and increased attending participation, particularly with regards to cases where substantive discrepancies were identified.

Assessing Adherence to US LI-RADS Follow-up Recommendations in Vulnerable Patients Undergoing Hepatocellular Carcinoma Surveillance.

Purpose To assess adherence to the US Liver Imaging Reporting and Data System (LI-RADS) recommendations for hepatocellular carcinoma (HCC) surveillance and associated patient-level factors in a vulnerable, diverse patient sample. Materials and Methods The radiology report database was queried retrospectively for patients who underwent US LI-RADS-based surveillance examinations at a single institution between June 1, 2020, and February 28, 2021. Initial US and follow-up liver imaging were included. Sociodemographic and clinical data were captured from electronic medical records. Adherence to radiologist recommendation was defined as imaging (US, CT, or MRI) follow-up in 5-7 months for US-1, imaging follow-up in 3-6 months for US-2, and CT or MRI follow-up in 2 months for US-3. Descriptive analysis and multivariable modeling that adjusted for age, sex, race, and time since COVID-19 pandemic onset were performed. Results Among 936 patients, the mean age was 59.1 years; 531 patients (56.7%) were male and 544 (58.1%) were Asian or Pacific Islander, 91 (9.7%) were Black, 129 (13.8%) were Hispanic, 147 (15.7%) were White, and 25 (2.7%) self-reported as other race. The overall adherence rate was 38.8% (95% CI: 35.7, 41.9). The most common liver disease etiology was hepatitis B (60.6% [657 of 936 patients]); 19.7% of patients (183 of 936) had current or past substance use disorder, and 44.8% (416 of 936) smoked. At adjusted multivariable analysis, older age (odds ratio [OR], 1.20; P = .02), male sex (OR, 1.62; P = .003), hepatology clinic attendance (OR, 3.81; P < .001), and recent prior US examination (OR, 2.44; P < .001) were associated with full adherence, while current smoking (OR, 0.39; P < .001) was negatively associated. Conclusion Adherence to HCC imaging surveillance was suboptimal, despite US LI-RADS implementation. Keywords: Liver, Ultrasound, Screening, Abdomen/GI, Cirrhosis, Metabolic Disorders, Socioeconomic Issues Supplemental material is available for this article. © RSNA, 2024.

Detection of fatty liver using virtual non-contrast dual-energy CT.

PURPOSE: Determine whether liver attenuation measured on dual-energy CT (DECT) virtual non-contrast examinations predicts the presence of fatty liver. METHODS: Single-institution retrospective review from 2016 to 2020 found patients with DECT and proton density fat fraction MRI (MRI PDFF) within 30 days. MRI PDFF was the reference standard for determining hepatic steatosis. Attenuation measurements from VNC and mixed 120 kVp-like images were compared to MRI PDFF in the right and left lobes. Performance of VNC was compared to measurement of the liver-spleen attenuation difference (LSAD). RESULTS: 128 patients were included (69 men, 59 women) with mean age 51.6 years (range 14-98 years). > 90% of patients received CT and MRI in the emergency department or as inpatients. Median interval between DECT and MRI PDFF was 2 days (range 0-28 days). Prevalence of fatty liver using the reference standard (MRI PDFF > 6%) was 24%. Pearson correlation coefficient between VNC and MRI- DFF was -0.64 (right) and -0.68 (left, both p < 0.0001). For LSAD, correlation was - 0.43 in both lobes (p < 0.0001). Considering MRI PDFF > 6% as diagnostic of steatosis, area under the receiver operator characteristic curve (AUC) was 0.834 and 0.872 in the right and left hepatic lobes, with an optimal threshold of 54.8 HU (right) and 52.5 HU (left), yielding sensitivity/specificity of 57%/93.9% (right) and 67.9%/90% (left). For LSAD, AUC was 0.808 (right) and 0.767 (left) with optimal sensitivity/specificity of 93.3%/57.1% (right) and 78.6%/68% (left). CONCLUSION: Attenuation measured at VNC CT was moderately correlated with liver fat content and had > 90% specificity for diagnosis of fatty liver.

Boba sign with a twist - A variant presentation of a mature cystic teratoma complicated by torsion and rupture.

While mature cystic teratomas are relatively common ovarian neoplasms typically comprising of multiple embryologic cell types, a specific monodermal subtype involving thyroid tissue, struma ovarii, can rarely be seen. This case reviews typical imaging characteristics with MRI and ultrasound of struma ovarii and details possible complications from these masses with intraoperative and histologic correlation.

Placental thickness correlates with placenta accreta spectrum (PAS) disorder in women with placenta previa.

OBJECTIVE: To evaluate the association of placental thickness with placenta accreta spectrum disorder in placenta previa. METHODS: In this IRB-approved, retrospective study, ultrasound (US) reports were retrospectively queried for keyword previa. US performed closest to mid-gestation were included. Three measurements were performed at the thickest portion of the placenta on longitudinal transabdominal images. Operative reports and surgical pathology were used as the reference standard. Statistical analysis was performed using unpaired T-tests and receiver operating curve (ROC) analysis. RESULTS: Sixty-five patients with placenta previa were included: 38 with PAS disorder and 27 without PAS disorder, clinically or pathologically. 38/38 (100%) patients of PAS group and 16/27 (59.3%) patients of non-PAS group had history of prior cesarean section. The average placental thickness was 4.3 cm (range 1.8 cm to 7.8 cm) for PAS group and 3.0 cm (range 0.6 cm to 5.3 cm) for non-PAS group (p < 0.001). Placental thickness in patients without PAS disorder and history of prior cesarean section was 3.1 (± 1.1) cm. This was statistically different from patients who had history of prior cesarean section with PAS diagnosis (4.3 cm, P<0.01). Using ROC analysis, a threshold measurement of 4.5 cm leads to sensitivity of 50% and specificity of 96%. CONCLUSION: Our results demonstrate that among women with placenta previa, increased placental thickness at lower uterine segment correlates with placenta accreta spectrum disorder. A threshold of 4.5 cm can be useful for screening patients with placenta previa and risks factors for PAS.

Traumatic testicular rupture: Multimodality imaging with intraoperative correlate.

Traumatic testicular rupture is a rare yet serious condition most commonly seen in penetrating trauma victims (e.g. gunshot wounds or motorcycle collisions) that requires immediate surgical management given its potential complications of hypogonadism and infertility. While ultrasound is the most established modality for diagnosing testicular rupture, trauma patients are usually first evaluated with a trauma protocol computed tomography (CT) exam including the chest, abdomen, and pelvis upon presentation, so it is important to recognize CT findings of testicular injury. We present a novel case in which the suspicion for testicular injury was initially raised based upon CT findings of scrotal hematoma/fluid. These findings were then further characterized with ultrasound and confirmed at surgery. In this case, we provide intraoperative imaging that corresponds clearly to findings seen on both CT and ultrasound.

Role of Ultrasound for Chronic Liver Disease and Hepatocellular Carcinoma Surveillance.

Ultrasound plays a vital role in the evaluation of patients with chronic liver disease and in hepatocellular carcinoma (HCC) surveillance in populations at risk for developing HCC. Semiannual ultrasound for HCC surveillance is universally recommended by all liver societies around the world. Advanced ultrasound techniques, such as elastography and contrast-enhanced ultrasound, offer additional benefits in imaging evaluation of chronic liver disease. Major benefits of ultrasound include its high safety profile and relatively low cost.

Ultrasound features help identify patients who can undergo noninvasive management for suspected retained products of conception: a single institutional experience.

OBJECTIVES: To evaluate ultrasound (US) features associated with successful noninvasive management for suspected retained products of conception (RPOC). METHODS: In this IRB-approved retrospective study, the radiology report database was queried for pelvic US with keywords of postpartum hemorrhage (PPH) and/or RPOC over a 2-year period. Follow-up exams, US exams without clinical follow-up, suboptimal image quality, and > 1 year from delivery or pregnancy termination were excluded. Charts were reviewed for clinical presentation and management. Two radiologists reviewed images for endometrial thickness, endometrial echogenicity, endometrial vascularity, and enhanced myometrial vascularity (EMV), as well as inner myometrial peak systolic velocity (PSV) and resistive index (RI) where available. Features were assessed for associations with management approach, and test characteristics were calculated. RESULTS: Initial query yielded 196 exams, and 48 were excluded. A total of 148 patients were included. Mean age was 34.2 years (21-47), and mean time from delivery or pregnancy termination was 40.4 days (0-223). 81 (55%) underwent noninvasive management: 72 (48%) expectant and 9 (6%) medical. 67 (45%) underwent invasive management: 60 (41%) surgical and 7 (5%) uterine artery embolization. There was substantial inter-reader agreement for assessment of EMV (K = 0.78) and endometrial vascularity (K = 0.72). Thin endometrial stripe, avascular endometrium, and absence of EMV were associated with successful noninvasive management (p < 0.05). Thin endometrium (< 10 mm) had specificity (90%), PPV (88%), and likelihood ratio (5.91) in predicting successful noninvasive management. CONCLUSION: Endometrial thickness < 10 mm, avascular endometrium, and absence of EMV are the sonographic features associated with successful noninvasive management for PPH or suspected RPOC.