CT/MRI technical pitfalls for diagnosis and treatment response assessment using LI-RADS and how to optimize.

Hepatocellular carcinoma (HCC), the most common primary liver cancer, is a significant global health burden. Accurate imaging is crucial for diagnosis and treatment response assessment, often eliminating the need for biopsy. The Liver Imaging Reporting and Data System (LI-RADS) standardizes the interpretation and reporting of liver imaging for diagnosis and treatment response assessment, categorizing observations using defined categories that are based on the probability of malignancy or post-treatment tumor viability. Optimized imaging protocols are essential for accurate visualization and characterization of liver findings by LI-RADS. Common technical pitfalls, such as suboptimal postcontrast phase timing, and MRI-specific challenges like subtraction misregistration artifacts, can significantly reduce image quality and diagnostic accuracy. The use of hepatobiliary contrast agents introduces additional challenges including arterial phase degradation and suboptimal uptake in advanced cirrhosis. This review provides radiologists with comprehensive insights into the technical aspects of liver imaging for LI-RADS. We discuss common pitfalls encountered in routine clinical practice and offer practical solutions to optimize imaging techniques. We also highlight technical advances in liver imaging, including multi-arterial MR acquisition and compressed sensing. By understanding and addressing these technical aspects, radiologists can improve accuracy and confidence in the diagnosis and treatment response assessment for hepatocellular carcinoma.

Association of imaging and pathological findings of breast cancer in very young women: Report of a twenty-year retrospective study.

PURPOSE: In this study, we aimed to assess the new trends in characteristics, molecular subtypes, and imaging findings of breast cancer in very young women. METHODS: We retrospectively reviewed the database of a primary breast cancer referral center in southern Iran in 342 cases of 30-year-old or younger women from 2001 to 2020. Pathologic data, including nuclear subtype and grade, tumor stage, presence of in situ cancer, imaging data including lesion type in mammogram and ultrasound, and treatment data were recorded. Descriptive statistics were applied. Differences between categorical values between groups were compared using Pearson's Chi-square test. RESULTS: The mean age was 27.89 years. The tumor type was invasive ductal carcinoma in 82 % of cases. Fourteen patients (4.4 %) had only in situ cancer, and 170 patients had in situ components (49.7 %). Molecular subtypes were available in 278 patients, including 117 (42.1 %) Luminal A, 64 (23.0 %) Luminal B, 58 (20.9 %) triple negative, and 39 (14 %) HER2 Enriched. In those with mammograms available, 63 (30.1 %) had no findings, 53 (25.3 %) had mass, 27 (12.9 %) had asymmetry, whether focal or global, 21 (10 %) had microcalcifications solely, and 45 (21.5 %) had more than one finding. Microcalcifications were significantly more common in Luminal cancers than HER2 and triple-negative cancers (p = 0.041). CONCLUSION: Our study shows the most common subtype to be Luminal A cancer, with 74 % of the tumors being larger than 2 cm at the time of diagnosis. Irregular masses with non-circumscribed margins were the most common imaging findings.

A Multicenter Assessment of Interreader Reliability of LI-RADS Version 2018 for MRI and CT.

Background Various limitations have impacted research evaluating reader agreement for Liver Imaging Reporting and Data System (LI-RADS). Purpose To assess reader agreement of LI-RADS in an international multicenter multireader setting using scrollable images. Materials and Methods This retrospective study used deidentified clinical multiphase CT and MRI and reports with at least one untreated observation from six institutions and three countries; only qualifying examinations were submitted. Examination dates were October 2017 to August 2018 at the coordinating center. One untreated observation per examination was randomly selected using observation identifiers, and its clinically assigned features were extracted from the report. The corresponding LI-RADS version 2018 category was computed as a rescored clinical read. Each examination was randomly assigned to two of 43 research readers who independently scored the observation. Agreement for an ordinal modified four-category LI-RADS scale (LR-1, definitely benign; LR-2, probably benign; LR-3, intermediate probability of malignancy; LR-4, probably hepatocellular carcinoma [HCC]; LR-5, definitely HCC; LR-M, probably malignant but not HCC specific; and LR-TIV, tumor in vein) was computed using intraclass correlation coefficients (ICCs). Agreement was also computed for dichotomized malignancy (LR-4, LR-5, LR-M, and LR-TIV), LR-5, and LR-M. Agreement was compared between research-versus-research reads and research-versus-clinical reads. Results The study population consisted of 484 patients (mean age, 62 years ± 10 [SD]; 156 women; 93 CT examinations, 391 MRI examinations). ICCs for ordinal LI-RADS, dichotomized malignancy, LR-5, and LR-M were 0.68 (95% CI: 0.61, 0.73), 0.63 (95% CI: 0.55, 0.70), 0.58 (95% CI: 0.50, 0.66), and 0.46 (95% CI: 0.31, 0.61) respectively. Research-versus-research reader agreement was higher than research-versus-clinical agreement for modified four-category LI-RADS (ICC, 0.68 vs 0.62, respectively; P = .03) and for dichotomized malignancy (ICC, 0.63 vs 0.53, respectively; P = .005), but not for LR-5 (P = .14) or LR-M (P = .94). Conclusion There was moderate agreement for LI-RADS version 2018 overall. For some comparisons, research-versus-research reader agreement was higher than research-versus-clinical reader agreement, indicating differences between the clinical and research environments that warrant further study. © RSNA, 2023 Supplemental material is available for this article. See also the editorials by Johnson and Galgano and Smith in this issue.

The adoption of LI-RADS: a survey of non-academic radiologists.

PURPOSE: To understand the practice and determinants of non-academic radiologists regarding LI-RADS and the four current LI-RADS algorithms: CT/MRI, contrast-enhanced ultrasound (CEUS), ultrasound (US), and CT/MRI Treatment Response. MATERIALS AND METHODS: Seven themes were covered in this international survey, as follows: (1) demographics of participants and sub-specialty, (2) HCC practice and interpretation, (3) reporting practice, (4) screening and surveillance, (5) HCC imaging diagnosis, (6) treatment response, and (7) CT and MRI technique. RESULTS: Of the 232 participants, 69.4% were from the United States, 25.0% from Canada, and 5.6% from other countries and 45.9% were abdominal/body imagers. During their radiology training or fellowship, no formal HCC diagnostic system was used by 48.7% and LI-RADS was used by 44.4% of participants. In their current practice, 73.6% used LI-RADS, 24.7% no formal system, 6.5% UNOS-OPTN, and 1.3% AASLD. Barriers to LI-RADS adoption included lack of familiarity (25.1%), not used by referring clinicians (21.6%), perceived complexity (14.5%), and personal preference (5.3%). The US LI-RADS algorithm was used routinely by 9.9% of respondents and CEUS LI-RADS was used by 3.9% of the respondents. The LI-RADS treatment response algorithm was used by 43.5% of the respondents. 60.9% of respondents thought that webinars/workshops on LI-RADS Technical Recommendations would help them implement these recommendations in their practice. CONCLUSION: A majority of the non-academic radiologists surveyed use the LI-RADS CT/MR algorithm for HCC diagnosis, while nearly half use the LI-RADS TR algorithm for assessment of treatment response. Less than 10% of the participants routinely use the LI-RADS US and CEUS algorithms.

Resuming Breast Imaging Services in the Aftermath of the COVID-19 Pandemic: Safety and Beyond.

As the Coronavirus disease 2019 (COVID-19) epidemic begins to stabilize, different medical imaging facilities not directly involved in the COVID-19 epidemic face the dilemma of how to return to regular operation. We hereby discuss various fields of concern in resuming breast imaging services. We examine the concerns for resuming functions of breast imaging services in 2 broad categories, including safety aspects of operating a breast clinic and addressing potential modifications needed in managing common clinical scenarios in the COVID-19 aftermath. Using a stepwise approach in harmony with the relative states of the epidemic, health care system capacity, and the current state of performing breast surgeries (and in compliance with the recommended surgical guidelines) can ensure avoiding pointless procedures and ensure a smooth transition to a fully operational breast imaging facility.

Evaluation of the relationship between inpatient COVID-19 mortality and chest CT severity score.

OBJECTIVES: There is scarce data available on the prognostic application of chest CT. The main purpose of this study was to evaluate the performance of a semi-quantitative CT severity score in identifying the risk of mortality in COVID-19 patients. METHODS: This retrospective cohort study was performed on 262 hospitalized COVID-19 patients. The CT severity score was assessed by two independent radiologists using a method previously used to score the severity of acute respiratory distress syndrome on thin slice lung CT. RESULTS: Multivariate regression analysis showed increasing odds of in-hospital death associated with older age, and the presence of coronary artery disease at the time of admission. The mean CT severity score was 7.5 in the survivor group and 14.5 in the deceased group. Overall, the lower zones were the most frequently affected sites in COVID-19. There was significant difference between the survivor and deceased groups regarding CT severity scores. Multivariate regression analysis showed increasing odds of in-hospital death associated with higher CT severity score at admission. CONCLUSIONS: Our results show that mortality was significantly higher in patients with higher CT severity score even after adjustment for clinical, demographics and laboratory parameters. However, this study is performed retrospectively and needs to be validated in a prospective study.

Fetal MRI in Prenatal Diagnosis of Encephalocele.

BACKGROUND: Encephalocele, a rare congenital brain malformation, is herniation of brain tissue with or without meninges through a cranial fossa defect. It is classified by location and is usually associated with other congenital anomalies. CASE: A 29-year-old G2, P1, 36-week pregnant woman was referred for fetal ultrasound delivery planning. Sonographic abnormalities led to fetal magnetic resonance imaging, which revealed a large sac of cerebrospinal fluid herniating through the anterior cranial fossa defect with strands of neurogenic tissue in direct contact with the tongue in the absence of the palate. Agenesis of the corpus callosum and the classic "Viking helmet" appearance of the frontal horns of the lateral ventricles were clearly visible. CONCLUSION: Prenatal diagnosis of encephalocele is rarely reported. Unfortunately, the infant in this case report died at 3 months of age despite intensive medical therapy.

White paper of the Society of Abdominal Radiology hepatocellular carcinoma diagnosis disease-focused panel on LI-RADS v2018 for CT and MRI.

The Liver Imaging and Reporting Data System (LI-RADS) is a comprehensive system for standardizing the terminology, technique, interpretation, reporting, and data collection of liver imaging with the overarching goal of improving communication, clinical care, education, and research relating to patients at risk for or diagnosed with hepatocellular carcinoma (HCC). In 2018, the American Association for the Study of Liver Diseases (AASLD) integrated LI-RADS into its clinical practice guidance for the imaging-based diagnosis of HCC. The harmonization between the AASLD and LI-RADS diagnostic imaging criteria required minor modifications to the recently released LI-RADS v2017 guidelines, necessitating a LI-RADS v2018 update. This article provides an overview of the key changes included in LI-RADS v2018 as well as a look at the LI-RADS v2018 diagnostic algorithm and criteria, technical recommendations, and management suggestions. Substantive changes in LI-RADS v2018 are the removal of the requirement for visibility on antecedent surveillance ultrasound for LI-RADS 5 (LR-5) categorization of 10-19 mm observations with nonrim arterial phase hyper-enhancement and nonperipheral "washout", and adoption of the Organ Procurement and Transplantation Network definition of threshold growth (≥ 50% size increase of a mass in ≤ 6 months). Nomenclatural changes in LI-RADS v2018 are the removal of -us and -g as LR-5 qualifiers.

LI-RADS® ancillary features on CT and MRI.

The Liver Imaging Reporting and Data System (LI-RADS) uses an algorithm to assign categories that reflect the probability of hepatocellular carcinoma (HCC), non-HCC malignancy, or benignity. Unlike other imaging algorithms, LI-RADS utilizes ancillary features (AFs) to refine the final category. AFs in LI-RADS v2017 are divided into those favoring malignancy in general, those favoring HCC specifically, and those favoring benignity. Additionally, LI-RADS v2017 provides new rules regarding application of AFs. The purpose of this review is to discuss ancillary features included in LI-RADS v2017, the rationale for their use, potential pitfalls encountered in their interpretation, and tips on their application.

Implementation of LI-RADS into a radiological practice.

Since its introduction in 2011, Liver Imaging Reporting and Data System (LI-RADS) has become an increasingly utilized method for radiologists to categorize lesions for hepatocellular carcinoma (HCC) in patients at risk (American College of Radiology, www.acr.org/quality-safety/resources/lirads 2016). This overview article presents insight into methods of incorporating LI-RADS into an existing clinical practice, highlighting concrete ways to establish this system as a mainstay in any radiologist's evidence-based armamentarium. We will focus on the importance of standardization to improve the value of our reporting. We will also discuss specific opportunities to favor adoption of LI-RADS including building a community of users composed of radiologists and referring physicians, forming a strategic vision, enlisting a team leader, overcoming barriers to adoption, communicating successes, integrating the system into the departmental culture, and learning from mistakes. The 2017 version of LI-RADS is the most recent update and is based on the most current medical imaging evidence. The details of these updates are described in other articles in this journal's edition. Efforts should be made to increase adherence and to enhance standardized use of LI-RADS internationally. Ultimately, the objective of LI-RADS is to prioritize patient care and optimize medical outcomes.

Erratum: Magnetic Resonance Imaging Features of Adenosis in the Breast.

[This corrects the article on p. 187 in vol. 18, PMID: 26155296.].

The role of ultrasound (US) and magnetic resonance imaging (MRI) in penile fracture mapping for modified surgical repair.

PURPOSE: To determine the accuracy of ultrasound (US) and magnetic resonance imaging (MRI) in the diagnosis of penile fracture and preoperative mapping for modified surgical repair. METHODS: Twenty-five consecutive patients were included in the study prospectively over 29 months (from February 2014 to June 2016). US examination and MRI were performed on all patients and interpreted by two expert radiologists independently. The location of the defect in tunica albuginea was mapped onto a designed scheme preoperatively using each imaging modality. The detection rate, as well as agreement between preoperative radiologic mapping and surgical outcomes, was determined for each modality. RESULTS: The mean age of the patients was 28 ± 7.5 years. The most common etiology was intercourse (88%). The most common location of tunica albuginea rupture was mid-shaft of the penis (60%), and the mean length of tunica defects in their greatest dimension was 13.5 ± 3.95 mm. All patients had associated hematoma, but no urethral injury was detected. The detection rate of US and MRI was 88 and 100%, respectively. US mapped the tear location correctly in 18 patients [61 out of 75 items (81%); κ = 0.66], while MRI mapped it precisely in 23 patients [73 out of 75 items (97%); κ = 0.95]. CONCLUSION: Both modalities are extremely helpful for the diagnosis of penile fracture. Considering the cost-efficiency and accessibility of ultrasonography, US is recommended as the first-line tool for both diagnosis and preoperative mapping. MRI may be used as a complementary study in the patients for whom US fails to visualize or precisely define the tunica defect.

Qualitative and quantitative analysis of diffusion-weighted imaging of gestational trophoblastic disease: Can it predict progression of molar pregnancy to persistent form of disease?

PURPOSE: To describe the diffusion-weighted imaging (DWI) appearance of gestational trophoblastic disease (GTD) and to determine its apparent diffusion coefficient (ADC) values. To evaluate the feasibility of DWI to predict progression of hydatidiform mole (HM) to persistent disease. METHODS: During a period of 6 months, women with preliminary diagnosis of GTD, based on ultrasound and ßhCG levels, underwent 1.5T MRI (T2 high-resolution and DWI; b values 50, 400, 800; sagittal and perpendicular to the endometrium; and T1, T2 Turbo Spin Echo [TSE] axial images). Patients were followed for 6-12 months to monitor progression to persistent form of the disease. ADC values and image characteristics were compared between HM and persistent neoplasia and between GTD and non-molar pregnancy using Mann-Whitney U and Fisher's exact tests, respectively. RESULTS: Among the 23 studied patients, 19 (83%) were classified as molar and 4 (17%) as non-molar, based on pathology reports. After 6-12 months of follow-up, 5 (26%) cases progressed to persistent disease and 14 (74%) cases were benign HM. There was no significant difference between ADC values for HM (1.93±0.33×10-3mm2/s) and persistent neoplasia (2.03±0.28×10-3mm2/s) (P=0.69). The ADC of non-molar pregnancies was (0.96±0.46×10-3mm2/s), which was significantly different from GTD (1.96 ±0.32×10-3mm2/s) (P=0.001). Heterogeneous snowstorm appearance, focal intratumoral hemorrhage, myometrial contraction, and prominent myometrial vascularity were more common in GTD compared to non-molar pregnancy (P<0.05). CONCLUSION: Heterogeneous snowstorm appearance, focal intratumoral hemorrhage, myometrial contraction, and prominent myometrial vascularity are among the imaging characteristics of GTD. We cannot use ADC values to predict progression to persistent disease.

Trauma in pregnant women: assessing detection of post-traumatic placental abruption on contrast-enhanced CT versus ultrasound.

OBJECTIVES: To evaluate detection of post-traumatic placental abruption with contrast-enhanced CT (CECT) and comparison with Ultrasound (US). METHODS: Picture Archive and Date System database at a level-1 trauma center was retrospectively reviewed using keywords pregnancy, trauma, and/or placental abruption over 10 years. CT was compared to US, if performed within 24 h. Two subspecialty-trained radiologists blindly reviewed the studies. Placental features on delivery and pregnancy outcomes were used as reference standard. Lack of adverse pregnancy/fetal outcome was treated as the absence of abruption. RESULTS: CECT was performed in 36 patients, with 27 US within 24 h. There were three complete and eight partial abruptions. Reader sensitivity for CT was 100% for both reviewers; however, specificity was 54.5% and 56.7%. No sonographic abnormality was noted in both partial and complete abruption. Using kappa statistics, inter-observer agreement was low for both CT (0.169) and US (0.078). False-positive reads were from misinterpretation of normal placental structures like cotyledons, age-related infarcts, and marginal sinus of the placenta. CONCLUSIONS: CECT identifies post-traumatic placental abruption with high sensitivity but low specificity for clinically significant abruptions, and performs better than US. Pitfalls from normal placental structures mimicking abruption should be avoided. US markedly underdiagnoses abruption.

Renal Collecting System Anatomy in Living Kidney Donors by Computed Tomographic Urography: Protocol Accuracy Compared to Intravenous Pyelographic and Surgical Findings.

OBJECTIVES: To evaluate the accuracy of triple-bolus computed tomography urography (CTU) as a surrogate of intravenous pyelography (IVP) for determining the anatomy of the urinary collecting system in living kidney donors. MATERIALS AND METHODS: In an analytic descriptive cross-sectional study, 36 healthy kidney donors were recruited during 12 months. Preoperative IVP and CTU were utilized to evaluate kidneys' anatomy; major and minor calyces and variation were used as anatomical indices to compare the accuracy of CTU and IVP; the images were then compared to surgical findings. RESULTS: Thirty-six kidney donors (92% male; mean age: 28 ± 6 years) were enrolled in this study. The kappa coefficient value was significant and almost perfect for the CTU and IVP findings in detecting the pattern of calyces (kappa coefficient 0.92, asymptotic 95% confidence interval 0.86-0.97). Anatomic variations or anomalies of the urinary collecting system included the bifid pelvis (5.6%), duplication (8.3%), and extra-renal pelvis (2.8%). Both the sensitivity and specificity of CTU in the detection of the anatomy and variations were 100%; the sensitivity and specificity of IVP were 83.3% and 100%, respectively. CONCLUSIONS: The triple-bolus preoperative CTU can be considered an alternative to IVP for assessing the anatomy of the urinary collecting system.

Magnetic Resonance Imaging Features of Adenosis in the Breast.

PURPOSE: Adenosis lesions of the breast, including sclerosing adenosis and adenosis tumors, are a group of benign proliferative disorders that may mimic the features of malignancy on imaging. In this study, we aim to describe the features of breast adenosis lesions with suspicious or borderline findings on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). METHODS: In our database, we identified 49 pathologically proven breast adenosis lesions for which the final assessment of the breast MRI report was classified as either category 4 (n=45) or category 5 (n=4), according to the Breast Imaging Reporting and Data System (BI-RADS) published by the American College of Radiology (ACR). The lesions had a final diagnosis of either pure adenosis (n=33, 67.3%) or mixed adenosis associated with other benign pathologies (n=16, 32.7%). RESULTS: Of the 49 adenosis lesions detected on DCE-MRI, 32 (65.3%) appeared as enhancing masses, 16 (32.7%) as nonmass enhancements, and one (2.1%) as a tiny enhancing focus. Analysis of the enhancing masses based on the ACR BI-RADS lexicon revealed that among the mass descriptors, the most common features were irregular shape in 12 (37.5%), noncircumscribed margin in 20 (62.5%), heterogeneous internal pattern in 16 (50.0%), rapid initial enhancement in 32 (100.0%), and wash-out delayed en-hancement pattern in 21 (65.6%). Of the 16 nonmass enhancing lesions, the most common descriptors included focal distribution in seven (43.8%), segmental distribution in six (37.5%), clumped internal pattern in nine (56.3%), rapid initial enhancement in 16 (100.0%), and wash-out delayed enhancement pattern in eight (50.0%). CONCLUSION: Adenosis lesions of the breast may appear suspicious on breast MRI. Awareness of these suspi-cious-appearing features would be helpful in obviating unnecessary breast biopsies.

PET/CT for Pancreatic Malignancy: Potential and Pitfalls.

Pancreatic malignancy carries a poor prognosis and is the fourth leading cause of cancer-related deaths in the United States. Although conventional imaging with CT and MR remains the main imaging modality, recent times have seen an increase in the applications of PET/CT in the evaluation of pancreatic malignancy. Newer data are becoming available, highlighting the advantages, limitations, and pitfalls in PET/CT imaging of the pancreas. This article highlights the applications of PET/CT in various stages of management of pancreatic malignancy and compares these with conventional imaging with CT and MR.