CT Colonography: Improving Interpretive Skill by Avoiding Pitfalls.

An earlier incorrect version of this article appeared online. This article was corrected on December 20, 2019.

Liver Imaging Reporting and Data System Version 2018: Impact on Categorization and Hepatocellular Carcinoma Staging.

The purpose of this study was to assess the concordance in categorization and radiologic T staging using Liver Imaging Reporting and Data System (LI-RADS, LR) version 2017 (v2017), version 2018 (v2018), and the Organ Procurement and Transplantation Network (OPTN) criteria. All magnetic resonance imaging and computed tomography reports using a standardized LI-RADS macro between April 2015 and March 2018 were identified retrospectively. The major features (size, arterial phase hyperenhancement, washout, enhancing capsule, or threshold growth) were extracted from the report for each LR-3, LR-4, and LR-5 observation. Each observation was assigned a new category based on LI-RADS v2017, v2018, and OPTN criteria. Radiologic T stage was calculated based on the size and number of LR-5 or OPTN class 5 observations. Categories and T stages assigned by each system were compared descriptively. There were 398 patients (66.6% male; mean age, 63.4 years) with 641 observations (median size, 14 mm) who were included. A total of 73/182 (40.1%) observations categorized LR-4 by LI-RADS v2017 were up-categorized to LR-5 by LI-RADS v2018 due to changes in the LR-5 criteria, and 4/196 (2.0%) observations categorized as LR-5 by LI-RADS v2017 were down-categorized to LR-4 by LI-RADS v2018 due to changes in the threshold growth definition. The T stage was higher by LI-RADS v2018 than LI-RADS v2017 in 49/398 (12.3%) patients. Compared with the OPTN stage, 12/398 (3.0%) patients were upstaged by LI-RADS v2017 and 60/398 (15.1%) by LI-RADS v2018. Of 101 patients, 5 (5.0%) patients with T2 stage based on LI-RADS v2017 and 10/102 (9.8%) patients with T2 stage based on LI-RADS v2018 did not meet the T2 criteria based on the OPTN criteria. Of the 98 patients with a T2 stage based on OPTN criteria, 2 (2.0%) had a T stage ≥3 based on LI-RADS v2017 and 6 (6.1%) had a T stage ≥3 based on LI-RADS v2018.

Practical guide to dynamic pelvic floor MRI.

Pelvic floor dysfunction encompasses a spectrum of functional disorders that result from impairment of the ligaments, fasciae, and muscles supporting the pelvic organs. It is a prevalent disorder that carries a lifetime risk over 10% for undergoing a surgical repair. Pelvic floor weakness presents as a wide range of symptoms, including pain, pelvic pressure or bulging, urinary and fecal incontinence, constipation, and sexual dysfunction. A correct diagnosis by clinical examination alone can be challenging, particularly in cases involving multiple compartments. Magnetic resonance imaging (MRI) allows noninvasive, radiation-free, high soft-tissue resolution evaluation of all three pelvic compartments, and has proved a reliable technique for accurate diagnosis of pelvic floor dysfunction. MR defecography with steady-state sequences allows detailed anatomic and functional evaluation of the pelvic floor. This article provides an overview of normal anatomy and function of the pelvic floor and discusses a practical approach to the evaluation of imaging findings of pelvic floor relaxation, pelvic organ prolapse, fecal incontinence, and obstructed defecation. LEVEL OF EVIDENCE: 5 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1155-1170.

Liver Imaging Reporting and Data System: Discordance Between Computed Tomography and Gadoxetate-Enhanced Magnetic Resonance Imaging for Detection of Hepatocellular Carcinoma Major Features.

PURPOSE: The goal of this study was to compare agreement between computed tomography (CT) and magnetic resonance imaging (MRI) in the evaluation of the major Liver Imaging Reporting and Data System (LI-RADS) features used in assessment of hepatocellular carcinoma: arterial phase hyperenhancement (APHE), portal venous phase washout (WO), capsule appearance (capsule), and largest diameter (diameter). METHODS: Patients with liver protocol CT and gadoxetate-enhanced MRI within 1 month of each other and at least 1 discrete untreated liver lesion were included. Two readers independently reviewed hepatic arterial phase and portal venous phase of each lesion on both CT and MRI, presented at random. The APHE, WO, capsule, and diameter were assessed for each lesion on CT and MRI. The LI-RADS category was assigned based on the recorded major features. Interobserver agreements between the readers for both imaging modalities and for each of the major features were assessed using κ statistics. Agreement between CT and MRI for each reader and for each feature was assessed using κ statistics. Agreement was interpreted based on κ as follows: 0.20 or less, slight agreement; 0.21 to 0.40, fair agreement; 0.41 to 0.60, moderate agreement; 0.61 to 0.80, substantial agreement; and 0.81 to 1.00, almost perfect agreement. Intraclass correlation coefficient was used to assess concordance of diameter measurements. RESULTS: There were 42 patients (mean age, 62.2 ± 7.0 years; 33 men [78.6%]) with 50 lesions. On CT, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.85), WO (κ = 0.83), and capsule (κ = 0.86). On MRI, the interobserver agreement between the readers was almost perfect for APHE (κ = 0.86) and WO (κ = 0.83) and moderate for capsule (κ = 0.59). Intraclass correlation coefficient for diameter measurement was 0.99 for CT and 0.98 for MRI. For reader 1, the agreement between CT and MRI was fair for APHE (κ = 0.39) and capsule (κ = 0.26) and moderate for WO (κ = 0.49). For reader 2, the agreement between CT and MRI was moderate for APHE (κ = 0.43) and capsule (κ = 0.43) and fair (κ = 0.38) for WO. Agreement between readers for final LI-RADS category was substantial for CT (κ = 0.79) and moderate for MRI (κ = 0.60). Agreement for final LI-RADS categories between MRI and CT was fair for both reader 1 (κ = 0.33) and reader 2 (κ = 0.39). CONCLUSIONS: Interobserver agreement for the major LI-RADS features varies from moderate to almost perfect, for both CT and MRI. However, the agreement between CT and MRI for each of the major LI-RADS features is poor, ranging from fair to moderate. This poor agreement contributes to substantial differences between final LI-RADS category assigned on CT versus MRI.

Diagnosis of acute cholecystitis: why do patients get multiple studies?

The aim of this study is to establish factors affecting total number of imaging studies performed for acute cholecystitis (AC) prior to surgery. The study included subjects with cholecystectomy and pathologic diagnosis of AC 1/1/05-1/1/14 and imaging studies (computed tomography (CT), ultrasound (US), and/or cholescintigraphy) within 7 days of surgery. The subjects were separated into groups based on modality of the first study. For each subject, report of the first study was reviewed for report's confidence in diagnosis of AC (scored 1-5 on Likert scale: 5 = definitely AC, 1 = definitely no AC), recommendation of additional study, clinical history concerning for AC (history of right upper quadrant pain, cholelithiasis, and/or "rule out AC"). There were 219, 339, and 38 subjects in CT, US, and cholescintigraphy groups, respectively, with mean confidence scores of 3.7 (± 1.2), 3.7 (± 1.1), and 4.7 (± 0.9), respectively (p < 0.001). Prior to surgery, only one study was performed in 21.9 % (48/219) of CT group, 70.2 % (238/339) of US group, and 71.1 % (27/38) of cholescintigraphy group (p < 0.0001). Compared to the US group, the odds of undergoing additional study were 11.8 times higher (p < 0.001) in CT group and 1.7 times higher (p = 0.229) in cholescintigraphy group, adjusting for age, sex, time interval between first study and the surgery, confidence score, recommendation of follow-up study, and clinical history concerning for AC. Patients with AC and CT as the first study are more likely to undergo additional imaging studies prior to surgery as compared to US or cholescintigraphy.

Incidental pancreatic cystic lesions: is there a relationship with the development of pancreatic adenocarcinoma and all-cause mortality?

PURPOSE: To establish the effect of incidental pancreatic cysts found by using computed tomographic (CT) and magnetic resonance (MR) imaging on the incidence of pancreatic ductal adenocarcinoma and overall mortality in patients from an inner-city urban U.S. tertiary care medical center. MATERIALS AND METHODS: Institutional review board granted approval for the study and waived the informed consent requirement. The study population comprised cyst and no-cyst cohorts drawn from all adults who underwent abdominal CT and/or MR November 1, 2001, to November 1, 2011. Cyst cohort included patients whose CT or MR imaging showed incidental pancreatic cysts; no-cyst cohort was three-to-one frequency matched by age decade, imaging modality, and year of initial study from the pool without reported incidental pancreatic cysts. Patients with pancreatic cancer diagnosed within 5 years before initial CT or MR were excluded. Demographics, study location (outpatient, inpatient, or emergency department), dates of pancreatic adenocarcinoma and death, and modified Charlson scores within 3 months before initial CT or MR examination were extracted from the hospital database. Cox hazard models were constructed; incident pancreatic adenocarcinoma and mortality were outcome events. Adenocarcinomas diagnosed 6 months or longer after initial CT or MR examination were considered incident. RESULTS: There were 2034 patients in cyst cohort (1326 women [65.2%]) and 6018 in no-cyst cohort (3,563 [59.2%] women); respective mean ages were 69.9 years ± 15.1(standard deviation) and 69.3 years ± 15.2, respectively (P = .129). The relationship between mortality and incidental pancreatic cysts varied by age: hazard ratios were 1.40 (95% confidence interval [ CI confidence interval ]: 1.13, 1.73) for patients younger than 65 years and 0.97 (95% CI confidence interval : 0.88, 1.07), adjusted for sex, race, imaging modality, study location, and modified Charlson scores. Incidental pancreatic cysts had a hazard ratio of 3.0 (95% CI confidence interval : 1.32, 6.89) for adenocarcinoma, adjusted for age, sex, and race. CONCLUSION: Incidental pancreatic cysts found by using CT or MR imaging are associated with increased mortality for patients younger than 65 years and an overall increased risk of pancreatic adenocarcinoma.

T1-hyperintense renal lesions: can high signal predict lack of enhancement?

OBJECTIVE: To establish highly specific criteria for predicting non-enhancement in T1-hyperintense non-fat-containing (T1-high) renal lesions using unenhanced fat-suppressed T1-weighted (T1-FS) images. MATERIALS AND METHODS: This IRB-approved, HIPAA-compliant, retrospective study included T1-high renal lesions found between 7/1/2012 and 7/1/2014. The largest lesion diameter and heterogeneity, mean signal intensity of lesion, and adjacent renal cortex were recorded from T1-FS images. The presence/absence of lesion enhancement was determined from subtraction images. T1 signal ratio (T1-SR) was calculated as (mean SI of lesion)/(mean SI of cortex). Logistic regression with binary outcome of the presence or absence of lesion enhancement was performed. Cut-off T1-SR to maximize specificity was established from receiver operator curve analysis. RESULTS: There were 101 patients (58 [57.4%] male) with non-enhancing lesions and 80 patients (51 [63.8%] male) with enhancing lesions, mean ages 64.0 ± 13.3 and 62.1 ± 13.8 years, respectively. Median sizes were 11 mm (IQR 8-16) and 20.5 mm (IQR 15-29) for non-enhancing and enhancing lesions, respectively (p < 0.0001). 19/101 (18.8%) of non-enhancing and 56/80 (70.0%) of enhancing lesions were heterogeneous (p < 0.0001). T1-SR was 1.77 ± 0.6 and 1.25 ± 0.42 for non-enhancing and enhancing lesions, respectively (p < 0.0001). For each increase of 0.5 in T1-SR, odds ratio for non-enhancement was 3.3 (95% CI 1.85-5.79), adjusted for lesion size and heterogeneity. T1-SR alone had area under the curve of 0.88 (95% CI 0.78-10.89) for non-enhancement. T1-SR ≥ 2.15 had positive likelihood ratio of 9.5 for non-enhancement. CONCLUSION: Signal ratio of lesion to cortex ≥ 2.15 on unenhanced T1-weighted images is a highly specific predictor for non-enhancement.

Aesthetic surgery of the buttocks: imaging appearance.

Familiarity with the imaging appearance and potential complications of buttocks aesthetic surgery is important for radiologists. In this review, we illustrate the spectrum of imaging features after buttocks implants, liposuction, fat injections and silicone injections. Complications such as fat necrosis, abscess, and silicone migration are also presented.

Outside the inside: a review of soft-tissue abnormalities seen on thoracoabdominal computed tomography.

In this review, we illustrate the computed tomographic features of thoracoabdominal soft-tissue abnormalities, which may be easily overlooked and often can provide important information regarding systemic processes. Examples include necrotizing fasciitis, heterotopic ossification, fat necrosis, benign and malignant neoplasms, endometriosis, and collagen vascular disease as well as systemic and congenital pathology.

Imaging features of intra-abdominal and intra-pelvic causes of hirsutism.

Hirsutism is a relatively common disorder which affects approximately 5% to 15% of women. It is defined by excessive growth of terminal hair in women, which primarily affects areas dependent on androgens, such as the face, abdomen, buttocks, and thighs. Hirsutism can be caused by a variety of etiologies, which are most often not lifethreatening. However, in some cases, hirsutism can be an indicator of more serious underlying pathology, such as a neoplasm, which may require further elucidation with imaging. Within the abdomen and pelvis, adrenal and ovarian pathologies are the primary consideration. The goal of this manuscript is to review the etiologies and imaging features of various intra-abdominal and intra-pelvic causes of hirsutism.

Adrenal cysts: natural history by long-term imaging follow-up.

OBJECTIVE: The purpose of this article is to determine the natural history of adrenal cysts on the basis of long-term imaging follow-up. MATERIALS AND METHODS: This retrospective study included patients with adrenal cysts who had at least 12 months of imaging follow-up (1993-2010). Medical records were reviewed. Two radiologists reviewed imaging examinations in consensus and recorded wall thickness (thin, ≤ 3 mm; thick, > 3 mm), septations, and calcification. CT attenuation value, MRI signal intensity, the presence or absence of enhancement, and typical sonographic features were used to confirm fluid content of the lesions. Cyst wall enhancement was recorded (thin, ≤ 3 mm and smooth; thick, > 3 mm). Cyst diameter on the initial and most remote follow-up examinations was compared. The Wilcoxon matched-pairs signed rank test was applied to assess statistically significant differences in size and CT attenuation on follow-up examinations. RESULTS: Twenty patients with unilateral adrenal cysts (seven male and 13 female patients; mean age, 44 years; range, 10-75 years) had a mean imaging follow-up period of 64 months (range, 12-198 months). CT, MRI, and ultrasound examinations were obtained in 19, 11, and 13 patients, respectively. Cysts were diagnosed by lack of enhancement on CT or MRI in 12 patients, typical sonographic features in three patients, and combination of CT and sonographic or MRI features in five patients. Signal intensities typical for fluid were found on all MRI examinations, attenuations of less than 20 HU on 17 of 19 (89%) CT examinations, and features of either simple or mildly complicated cysts on all sonograms. Thin walls, wall calcifications, and thin septations were found in 20 (100%), 12 (60%), and four (20%) lesions, respectively. During the follow-up of 20 lesions, the median cyst diameter increased by 26.0% (interquartile range, 6.8-68.4%) in 12 (60%) patients, decreased by 32.9% (interquartile range, 7.1-42.8%) in six (30%) patients, and was unchanged in two (10%) patients. The median baseline CT attenuation values did not significantly change on follow-up CT examinations (p = 0.72). No patient developed a complication of adrenal cyst. Four patients had histologically confirmed benign adrenal cysts. CONCLUSION: Interval enlargement of an adrenal cyst is frequent and as an isolated finding does not indicate malignancy or presence of a complication. However, some adrenal cysts may decrease or remain stable in size over time.

Dynamic MR defecography: assessment of the usefulness of the defecation phase.

OBJECTIVE: The purpose of this study was to assess the usefulness of the defecation phase during dynamic MR defecography. MATERIALS AND METHODS: The images from 85 MR defecographic examinations (83 patients; age range, 20-88 years; mean, 52.7) were retrospectively reviewed in consensus by two observers. Images from each of four phases (rest, maximal sphincter contraction and squeezing, maximal straining, and defecation) were evaluated and scored independently with a modified previously published grading system. Features evaluated included the presence and degree of bladder, vaginal, and rectal descent and the presence and size of rectocele, enterocele, and intussusception. Statistical analysis was performed with a variety of tests. RESULTS: Compared with images obtained in the other phases, defecation phase images helped in identification of additional cases of abnormal bladder descent in 43 examinations (50.6%), abnormal vaginal descent in 52 examinations (61.2%), and abnormal rectal descent in 11 examinations (12.9%). Similarly, only defecation phase images depicted previously undetected rectoceles 2 cm or larger in 31 examinations (36.5%), enteroceles in 34 examinations (40%), and intussusceptions in 22 examinations (25.9%). The number of additional cases of abnormalities identified on defecation phase images was significantly greater than the number identified on images obtained in the other phases (p < 0.005). The average total scores for the rest, squeeze, strain, and defecation phases were 1.4, 0.7, 2.3, and 6.6. The average total defecation phase score was significantly greater than the average total score in any of the other phases (p < 0.001). CONCLUSION: During dynamic MR defecography, defecation phase imaging yields important additional information on the presence and degree of pelvic floor abnormalities and is therefore an essential component of MR defecographic examinations.

IgG4 aortitis of the ascending thoracic aorta: A case report and literature review.

IgG4 aortitis is a recently recognized entity that can have clinical and imaging features that mimic acute aortic syndrome. Therefore, it is imperative for radiologists to be aware of how to potentially differentiate the two. Although this entity has been previously described via case reports and meta-analysis in the context of inflammatory abdominal aortic aneurysm, very few cases of ascending aortic involvement have been reported. In this case report, we present a case of a 60-year-old female transferred from another facility for an initial diagnosis of intramural hematoma of the ascending aorta and later found to have IgG4 aortitis post aortic root repair. This is a histologically confirmed case of multi-segmented IgG4 aortitis with rare involvement of both ascending and infra-renal aorta. We will briefly discuss the pathophysiology of IgG4 aortitis, along with review of literature.

Small lymphocytic lymphoma of the prostate mimicking a PIRADS 5 lesion that resolved after systemic treatment.

Prostatic PIRADS 4 and 5 lesions on multiparametric MRI typically represent adenocarcinoma with small lymphocytic lymphoma being a rare pathological finding. We report a case of small lymphocytic lymphoma masquerading as PIRADS 4 and 5 lesions with associated lymphadenopathy in a 69-year-old male on active surveillance for low-risk prostate cancer that was subsequently confirmed on targeted and systematic prostate biopsy. Following treatment of lymphoma with ibrutinib, there was complete resolution of the PIRADS lesions on follow-up mpMRI.

MR defecography review.

Pelvic floor dysfunction is a relatively common but often complex condition, presenting with a variety of clinical symptoms, especially when it involves multiple compartments. Clinical exam alone is often inadequate and requires a complementary imaging study. Magnetic resonance defecography (MRD) is an excellent noninvasive diagnostic study with its multiplanar capability, lack of ionizing radiation and excellent soft tissue resolution. It can identify both anatomic and functional abnormalities in the pelvic floor and specifically excels in its ability to simultaneously detect multicompartmental pathology and help with vital pre-operative assessment. This manuscript reviews the relevant anatomical landmarks, describes the optimal technique, highlights an approach to the interpretation of MRD, and provides an overview of the various pelvic floor disorders in the different anatomical compartments.

Multimodality imaging of pelvic floor anatomy.

The pelvic floor is composed of a network of muscles, ligaments, and fasciae, which provide active and passive support for the pelvic organs. Impairment of these pelvic floor elements can result in a variety of functional abnormalities and single or multicompartment organ prolapse. Knowledge of normal pelvic floor anatomy can aid the radiologist in understanding the complex nature of pelvic floor dysfunction and is important for comprehensive image interpretation. This article provides an overview of normal anatomy of the pelvic floor as seen on magnetic resonance imaging, ultrasound, and fluoroscopic studies performed in the evaluation of pelvic floor function.

MR defecography technique: recommendations of the society of abdominal radiology's disease-focused panel on pelvic floor imaging.

PURPOSE: To develop recommendations for magnetic resonance (MR) defecography technique based on consensus of expert radiologists on the disease-focused panel of the Society of Abdominal Radiology (SAR). METHODS: An extensive questionnaire was sent to a group of 20 experts from the disease-focused panel of the SAR. The questionnaire encompassed details of technique and MRI protocol used for evaluating pelvic floor disorders. 75% agreement on questionnaire responses was defined as consensus. RESULTS: The expert panel reached consensus for 70% of the items and provided the basis of these recommendations for MR defecography technique. There was unanimous agreement that patients should receive coaching and explanation of commands used during MR defecography, the rectum should be distended with contrast agent, and that sagittal T2-weighted images should include the entire pelvis within the field of view. The panel also agreed unanimously that IV contrast should not be used for MR defecography. Additional areas of consensus ranged in agreement from 75 to 92%. CONCLUSION: We provide a set of consensus recommendations for MR defecography technique based on a survey of expert radiologists in the SAR pelvic floor dysfunction disease-focused panel. These recommendations can be used to develop a standardized imaging protocol.

Clinical applications of pelvic floor imaging: opinion statement endorsed by the society of abdominal radiology (SAR), American Urological Association (AUA), and American Urogynecologic Society (AUGS).

Pelvic floor dysfunction is prevalent, with multifactorial causes and variable clinical presentations. Accurate diagnosis and assessment of the involved structures commonly requires a multidisciplinary approach. Imaging is often complementary to clinical assessment, and the most commonly used modalities for pelvic floor imaging include fluoroscopic defecography, magnetic resonance defecography, and pelvic floor ultrasound. This collaboration opinion paper was developed by representatives from multiple specialties involved in care of patients with pelvic floor dysfunction (radiologists, urogynecologists, urologists, and colorectal surgeons). Here, we discuss the utility of imaging techniques in various clinical scenarios, highlighting the perspectives of referring physicians. The final draft was endorsed by the Society of Abdominal Radiology (SAR), American Urogynecologic Society (AUGS), and the American Urological Association (AUA).

Variability in utilization and techniques of pelvic floor imaging: findings of the SAR pelvic floor dysfunction disease-focused panel.

Pelvic floor disorders are common and can negatively impact quality of life. Imaging of patients with pelvic floor disorders has been extremely heterogeneous between institutions due in part to variations in clinical expectations, technical considerations, and radiologist experience. In order to assess variations in utilization and technique of pelvic floor imaging across practices, the society of abdominal radiology (SAR) disease-focused panel on pelvic floor dysfunction developed and administered an online survey to radiologists including the SAR membership. Results of the survey were compared with published recommendations for pelvic floor imaging to identify areas in need of further standardization. MRI was the most commonly reported imaging technique for pelvic floor imaging followed by fluoroscopic defecography. Ultrasound was only used by a small minority of responding radiologists. The survey responses demonstrated variability in imaging utilization, patient referral patterns, imaging protocols, patient education, and interpretation and reporting of pelvic floor imaging examinations. This survey highlighted inconsistencies in technique between institutions as well as potential gaps in knowledge that should be addressed to standardize evaluation of patients with pelvic floor dysfunction.