Liver Masses: What Physicians Need to Know About Ordering and Interpreting Liver Imaging.

PURPOSE OF REVIEW: This paper reviews diagnostic imaging techniques used to characterize liver masses and the imaging characteristics of the most common liver masses. RECENT FINDINGS: The role of recently adopted ultrasound and magnetic resonance imaging contrast agents will be emphasized. Contrast-enhanced ultrasound is an inexpensive exam which can confirm benignity of certain liver masses without ionizing radiation. Magnetic resonance imaging using hepatocyte-specific gadolinium-based contrast agents can help confirm or narrow the differential diagnosis of liver masses.

Case 233: Blastomycosis.

History A 35-year-old man from the upper Midwest region of the United States who had no relevant medical history initially presented to an acute care clinic with multiple small tender skin lesions. His temperature was 38.1°C, and physical examination revealed several small fluctuant masses that were draining purulent material. Skin culture of one of the draining lesions was performed at this time, but there was no subsequent bacterial growth. A diagnosis of furunculosis was made, and Bactrim (sulfamethoxazole-trimethoprim; AR Scientific, Philadelphia, Pa) and a regimen of chlorhexidine washes were prescribed. Two weeks later, the number of skin lesions had increased, and the patient had begun to experience night sweats and fevers. After an episode of hemoptysis and some unusual pain in the patient's right testicle, he presented to the emergency department. At this time, chest radiographs were obtained. The patient was admitted for additional work-up, and computed tomographic (CT) images of the chest were obtained. Physical examination at the time of admission revealed scattered 1-3-cm firm pink hyperpigmented subcutaneous nodules, several of which had overlying pustules. This examination was also notable for a palpable fullness within the right testicle. The patient was afebrile at admission. He denied a history of contact with sick people, illicit drug use, or recent travel. His social history was notable for a 20-pack-year smoking history and a recent relocation to a neighborhood with several new construction sites. Laboratory evaluation revealed leukocytosis (white blood cell count, 15.4 × 10(9)/L; normal range, [3.5-10.5] × 10(9)/L), a chemistry panel revealed a low sodium level (132 mEq/L [132 mmol/L]; normal range, 134-142 mEq/L [134-142 mmol/L]), and serum α-fetoprotein and human chorionic gonadotropin levels were normal. Ultrasonography (US) of the scrotum was performed. Serum analysis was negative for human immunodeficiency virus type 1 and type 2 RNA, and Venereal Disease Research Laboratory and rapid plasma regain test results were negative. Blood cultures were negative for bacterial growth. On the basis of chest CT findings, bronchoscopy with bronchoalveolar lavage was performed. Magnetic resonance (MR) imaging of the abdomen also was performed to further evaluate a focal area of hypoenhancement within the pancreatic tail seen on chest CT images.

When Timing Is Everything: Are Placental MRI Examinations Performed Before 24 Weeks' Gestational Age Reliable?

OBJECTIVE: The objective of our study was to determine if placental MRI examinations performed for the detection of abnormal placentation earlier than 24 weeks' gestational age (GA) are more or less reliable than examinations performed at a later GA. MATERIALS AND METHODS: Two radiologists blinded to clinical, surgical, and pathologic reports retrospectively and independently reviewed 69 placental MRI examinations for nine imaging signs associated with abnormal placentation. A consensus of the suspicion of abnormal placentation (including accreta, increta, or percreta) was determined using a 5-point (low to high suspicion) Likert scale and compared with pathologic or surgical findings or both. RESULTS: Seventeen placental MRI examinations were performed at GA 14-23 weeks, and 52 placental MRI examinations were performed at GA 24-41 weeks. Reviewer agreement (Cronbach alpha) among the nine imaging signs was 0.86 (95% CI, 0.72-0.92) and 0.92 (95% CI, 0.92-0.94) for MRI examinations at GA 14-23 weeks and GA 24-41 weeks, respectively. Pathologic or surgical evidence of abnormal placentation was found in 41% and 65% of the cases between GA 14-23 weeks and GA 24-41 weeks, respectively. The AUC for the MRI-based consensus score and the presence of abnormal placentation for GA 14-23 weeks was 0.49 (95% CI, 0.21-0.78) compared with 0.92 (95% CI, 0.83-1.0) for GA 24-41 weeks (p = 0.002). CONCLUSION: Placental MRI examinations performed before 24 weeks' GA unreliably predict abnormal placentation.

Imaging of adrenal and renal hemorrhage.

Hemorrhage of the kidneys and adrenal glands has many etiologies. In the adrenal glands, trauma, anticoagulation, stress, sepsis, surgery, and neoplasms are common causes of hemorrhage. In the kidneys, reasons for hemorrhage include trauma, bleeding diathesis, vascular diseases, infection, infarction, hemorrhagic cyst rupture, the Antopol-Goldman lesion, and neoplasms. Angiomyolipoma and renal cell carcinoma are the neoplasms most commonly associated with hemorrhage in the kidneys and adrenal cortical carcinoma, metastases, and pheochromocytoma are associated with hemorrhage in the adrenal glands. Understanding the computed tomography and magnetic resonance imaging features, and causes of hemorrhage in the kidneys and adrenal glands is critical. It is also important to keep in mind that mimickers of hemorrhage exist, including lymphoma in both the kidneys and adrenal glands, and melanoma metastases in the adrenal glands. Appropriate imaging follow-up of renal and adrenal hemorrhage should occur to exclude an underlying malignancy as the cause. If there is suspicion for malignancy that cannot be definitively diagnosed on imaging, surgery or biopsy may be warranted. Angiography may be indicated when there is a suspected underlying vascular disease. Unnecessary intervention, such as nephrectomy, may be avoided in patients with benign causes or no underlying disease. Appropriate management is dependent on accurate diagnosis of the cause of renal or adrenal hemorrhage and it is incumbent upon the radiologist to determine the etiology.

Fluoroscopic findings post-peroral esophageal myotomy.

Natural orifice transluminal endoscopic surgery (NOTES) is a surgical technique that has been evolving rapidly. Endoscopic submucosal dissection was initiated in 1999, in Japan, for en-bloc resection of large lesions of the stomach (Zhou et al., World J Gastroenterol 19:6962-6968, 2013, ; Kobara et al., Clin Exp Gastroenterol 7:67-74, 2014). Since then, many additional therapies utilizing natural transluminal endoscopic approach have evolved. Peroral endoscopic myotomy (POEM) is a minimally invasive type of transluminal endoscopic surgery that was recently developed for the treatment of achalasia and esophageal motility disorders. The peroral endoscopic myotomy is a less invasive surgical treatment that is suitable for all types of achalasia and used as an alternate to the Heller myotomy. The radiographic findings of achalasia and surgical changes after Heller myotomy have been described, however, very little is available on the post-POEM esophagram appearance. The purpose of this article is to illustrate the anatomy, surgical procedure, and normal and abnormal findings seen on esophagrams in patients who have undergone a POEM.

Imaging features of benign and malignant ampullary and periampullary lesions.

The ampulla of Vater is an important anatomic landmark where the common bile duct and main pancreatic duct converge in the major duodenal papilla. Imaging evaluation of the ampulla and periampullary region poses a unique diagnostic challenge to radiologists because of the region's complex and variable anatomy and the variety of lesions that can occur. Lesions intrinsic to the ampulla and involved segment of the biliary tree can be neoplastic, inflammatory, or congenital. Neoplastic lesions include ampullary adenocarcinomas and adenomas, which often are difficult to differentiate, as well as pancreatic or duodenal adenocarcinomas, pancreatic neuroendocrine tumors, and cholangiocarcinomas. Ultrasonography (US), computed tomography, magnetic resonance (MR) imaging, and MR cholangiopancreatography are commonly used to evaluate this region. Endoscopic retrograde cholangiopancreatography or endoscopic US examination may be necessary for more definitive evaluation. Periampullary conditions in the duodenum that may secondarily involve the ampulla include neoplasms, duodenitis, duodenal diverticula, and Brunner's gland hyperplasia or hamartomas. Because these lesions can exhibit a wide overlap of imaging features and subtle or nonspecific imaging findings, diagnosis is made on the basis of patient age, clinical history, and imaging and laboratory findings. Given the complexity of imaging evaluation of the ampulla and periampullary region, it is essential for radiologists to understand the variety of lesions that can occur and recognize their imaging characteristics.

Asymmetric spermatic cord vessel enhancement on CT: a sign of epididymitis or testicular neoplasm.

PURPOSE: To determine whether asymmetric spermatic cord vessel enhancement (ASE) on contrast-enhanced computed tomography (CECT) indicates scrotal pathology. METHODS: Sixty-one male patients with scrotal symptoms who underwent both scrotal ultrasound (US) and CECT within 24 h were identified through a radiology information system. Twenty-eight emergency department patients who underwent CECT only for unrelated symptoms were included for comparison. Two blinded radiologists independently reviewed each CECT scan for qualitative ASE. These data were compared with US diagnoses, when present. A third blinded radiologist reviewed each CECT scan for quantitative ASE by measuring Hounsfield unit (HU) density ratios. McNemar, Kappa, Student's t test, and ANOVA were used for analysis. RESULTS: Eighty-nine total patients included 28 with CECT only and 61 with CECT and US, of which 41 had abnormal US: 15 acute epididymitis and/or orchitis, 7 testicular neoplasms, 11 varicoceles, and 8 with other pathologies. Twenty patients with normal US and 28 patients with CECT only served as control groups. Identification of ASE agreed with US diagnosis of epididymitis (and/or orchitis) or testicular neoplasm (reader 1: κ = 0.79, reader 2: κ = 0.75) with average 95.5% sensitivity and 88.8% specificity, and no significant difference between readers (p = 0.58). For epididymitis (and/or orchitis) or testicular neoplasm patients, the average ratio of spermatic cord HU density (ipsilateral:contralateral) was significantly different from other patients (4.01 vs. 1.26, p = 0.0025). CONCLUSION: ASE on CECT shows stronger correlation with epididymitis (and/or orchitis) and testicular neoplasm compared with other scrotal pathologies. If discovered on CECT, this should prompt further clinical and/or imaging workup.

Gender Disparities in Academic Radiology Authorship: A 13-Year Review.

RATIONALE AND OBJECTIVES: Underrepresentation of women in many scientific fields has been linked to biases against female-authored publications in peer-reviewed journals, thereby reducing their opportunities for career development and promotions. The objective of this study is to determine the representation of female academic radiologists in four flagship general radiology journals to elucidate gender-specific trends and disparities in academic radiology. MATERIALS AND METHODS: We analyzed 23,741 peer-reviewed articles published in Radiology, American Journal of Roentgenology, Journal of the American College of Radiology and Academic Radiology from 2007 to 2020. Data abstraction and statistical analysis were performed for author gender, first and last authorship, research funding, and number of citations and grants. Baseline demographics data of academic radiologists was obtained from the Association of American Medical Colleges (AAMC). RESULTS: A total of 72.4% of authors were male with 54% of articles were written by a male first author and male last author. When compared with assumed random pairing, there were significantly fewer Male/Female author combinations and more Female/Female author combinations than expected (p<0.01). Over the 13-year time period, the rate of increase in the number of female authors exceeded the rate of increase in women in academic radiology as reported by the AAMC. Female last authors received on average 3.2 less citations than their male counterparts (p=.03). Of manuscripts with last female authors, 31.7% of female last authors were funded compared to 25.9% of last male authors. CONCLUSION: This study showed the increasing numbers and higher productivity of female authors in academic radiology, suggesting progress is being made in overcoming gender disparities.

Resident Perspective of the Virtual Diagnostic Radiology Residency Interview Process: A National Survey From the Association of Program Directors in Radiology.

RATIONALE AND OBJECTIVES: The purpose of this study was to assess differences in first-year radiology resident perception of the match process and early satisfaction with residency programs between those who matched in 2020 versus 2021, the first virtual application cycle after the start of the COVID-19 pandemic. MATERIALS AND METHODS: A 33-question survey was distributed to first-year diagnostic radiology residents at programs throughout the United States through the Association of Program Directors in Radiology. Responses were collected in June of 2022 from residents who matched in 2020 and in July of 2022 from residents who matched in 2021. Questions were designed to assess applicant demographics, outcomes and attitudes towards the interview process. Comparison was made between the two cohorts. RESULTS: Of the 2231 matched residents in the 2020 and 2021 match years, 108 residents (4.8%) received, responded, and met inclusion criteria for the survey. Forty-three of 46 (92.5%) respondents that matched in 2020 interviewed in-person compared to one of 60 (1.7%) that matched in 2021 (p < 0.0001). There was no difference in satisfaction of match results, current training programs, work culture, satisfaction with facilities, and depiction of residency structure. Applicants from the 2021 cohort were more likely to express concerns about interview hoarding, having enough time to ask questions on interview days, and ability to accurately present themselves in interviews but were more likely to favor virtual interviews for future cycles. CONCLUSION: The virtual interview process is perceived neutrally or positively by most early diagnostic radiology residents and produced similar satisfactory results compared to applicants that interviewed in person. Attention should be given to concerns of those who matched virtually if the virtual interview process is to be continued.

Imaging of Benign Hepatic lesions.

As abdominal imaging volumes have increased, the incidence of incidentally identified benign hepatic lesions has substantially increased. Familiarity with imaging appearances of benign hepatic tumors, both common and less commonly encountered, allows the radiologist to give an informed differential diagnosis. In addition to clinical history, awareness of imaging findings of benign hepatic lesions on ultrasound, computed tomography and magnetic resonance imaging is useful in evaluating these lesions and avoiding unnecessary diagnostic interventions or imaging surveillance.

Imaging of Intrahepatic Cholangiocarcinoma.

Cholangiocarcinoma is the second most common primary hepatic malignancy and is a heterogeneous tumor of biliary epithelium. We discuss the risk factors, anatomic classification of cholangiocarcinoma (CC) as well as the different morphologic subtypes of CC. Imaging findings of CC on different modalities are described, focusing on intrahepatic CC. Recently recognized imaging features that carry prognostic significance, such as a worse prognosis in tumors that have more desmoplastic stroma, are detailed. Other benign and malignant entities that should be considered in the differential diagnosis of CC will also be discussed.

Does multidetector CT attenuation change in colon cancer liver metastases treated with 90Y help predict metabolic activity at FDG PET?

PURPOSE: To evaluate the correlation between change in attenuation and tumor metabolic activity assessed by using fluorodeoxyglucose (FDG) positron emission tomography (PET) in colon cancer liver metastases treated with yttrium 90 ((90)Y) radioembolization. MATERIALS AND METHODS: This Health Insurance Portability and Accountability Act-compliant retrospective study was approved by the institutional review board; patient informed consent was waived. Unresectable chemorefractory colon cancer liver metastases treated with (90)Y radioembolization in 28 patients were evaluated at pre- and posttreatment multidetector computed tomographic (CT) and FDG PET scans. Maximum cross-sectional diameter, volume, and overall attenuation of target lesions were calculated. The percentage change (%Delta) in these parameters after treatment was calculated and correlated with the standardized uptake value (SUV) analysis at FDG PET. The accuracy of the radiologic parameters in helping predict response to treatment at FDG PET was assessed. Data were analyzed by using the Student t, Wilcoxon matched pair, Mann-Whitney, Spearman rank correlation, and chi(2) tests. The significance level was set at .05. RESULTS: Seventy-four metastatic lesions in 10 women and 18 men (mean age, 61.5 years +/- 14.3 [standard deviation]) were evaluated. Mean follow-up interval for multidetector CT after treatment was 30 days. A significant reduction in maximum cross-sectional diameter, volume, and attenuation was observed from pre- to posttreatment multidetector CT (P < .05). The %Delta in attenuation had higher correlation with %Delta in SUV (r = 0.61) than diameter (r = 0.39) or volume (r = 0.49) and also predicted the metabolic activity at FDG PET with higher sensitivity (P < .001). By using a threshold level of a reduction in attenuation of 15% or greater, attenuation showed 84.2% sensitivity and 83.3% specificity in predicting response at FDG PET evaluation. CONCLUSION: Changes in attenuation of colon cancer liver metastases treated with (90)Y radioembolization correlate highly with metabolic activity at FDG PET and may be useful as an early surrogate marker for assessing treatment response.

Utility of diffusion-weighted MRI in characterization of adrenal lesions.

OBJECTIVE: The purpose of our study was to evaluate the utility of apparent diffusion coefficient (ADC) values for characterizing adrenal lesions and determine if diffusion-weighted imaging (DWI) can distinguish lipid-rich from lipid-poor adenomas. MATERIALS AND METHODS: We retrospectively evaluated 160 adrenal lesions in 156 patients (96 women and 60 men; mean age, 63 years). ADCs and signal intensity (SI) decrease on chemical shift imaging were measured in adrenal lesions with a wide variety of pathologies. Lipid-rich and lipid-poor adenomas were identified by unenhanced CT. The overall predictive power of ADC, SI decrease, and lesion size were determined by receiver operating characteristic (ROC) analysis. Areas under the ROC curve (AUC) were compared for equivalence using nonparametric methods. Sensitivity, specificity, and positive and negative predictive values were calculated. Correlation coefficients were used to assess ADCs versus percentage SI decrease and ADCs versus CT attenuation. RESULTS: ADCs of adrenal malignancies (median, 1.67 x 10(-3) mm(2)/s; interquartile range, 1.41-1.84 x 10(-3) mm(2)/s) were not different compared with those of benign lesions (1.61 x 10(-3) mm(2)/s; 1.27-1.96 x 10(-3) mm(2)/s; p > 0.05). Cysts (2.93 x 10(-3) mm(2)/s; 2.70-3.09 x 10(-3) mm(2)/s) showed higher ADCs than the remaining adrenal lesions (p < 0.05). The median ADCs of lipid-rich adenomas did not differ from those of lipid-poor ones (p > 0.05). The CT attenuation had no negative or positive correlation with the ADCs of adrenal adenomas (r = -0.05, p = 0.97). CONCLUSION: Unlike lesion size and percentage decrease in SI, the ADCs were not useful in distinguishing benign from malignant adrenal lesions. Lipid-poor adenomas could not be distinguished from lipid-rich adenomas and all other nonfatty lesions of the adrenal gland with DWI.

Renal Pretransplantation Work-up, Donor, Recipient, Surgical Techniques.

Renal transplant is the single best treatment of end-stage renal disease. Computed tomography (CT) is an excellent method for the evaluation of potential renal donors and recipients. Multiphase CT is particularly useful because of detailed evaluation of the kidneys, including the vascular anatomy and the collecting system. MR imaging has no ionizing radiation, but is limited for stone detection, making it a less preferred method of evaluating donors. Preoperative knowledge of the renal vascular anatomy is essential to minimize risks for donors. Imaging evaluation of recipients is also necessary for vascular assessment and detection of incidental findings.

Imaging spectrum of cholangiocarcinoma: role in diagnosis, staging, and posttreatment evaluation.

Cholangiocarcinoma, a tumor of biliary epithelium, is increasing in incidence. The imaging appearance, behavior, and treatment of cholangiocarcinoma differ according to its location and morphology. Cholangiocarcinoma is usually classified as intrahepatic, perihilar, or distal. The three morphologies are mass-forming, periductal sclerosing, and intraductal growing. As surgical resection is the only cure, prompt diagnosis and accurate staging is crucial. In staging, vascular involvement, longitudinal spread, and lymphadenopathy are important to assess. The role of liver transplantation for unresectable peripheral cholangiocarcinoma will be discussed. Locoregional therapy can extend survival for those with unresectable intrahepatic tumors. The main risk factors predisposing to cholangiocarcinoma are parasitic infections, primary sclerosing cholangitis, choledochal cysts, and viral hepatitis. Several inflammatory conditions can mimic cholangiocarcinoma, including IgG4 disease, sclerosing cholangitis, Mirizzi's syndrome, and recurrent pyogenic cholangitis. The role of PET in diagnosis and staging will also be discussed. Radiologists play a crucial role in diagnosis, staging, and treatment of this disease.

Correlation of probability scores of placenta accreta on magnetic resonance imaging with hemorrhagic morbidity.

STUDY OBJECTIVE AND DESIGN: To evaluate the hypothesis that assigning grades to magnetic resonance imaging (MRI) findings of suspected placenta accreta will correlate with hemorrhagic outcomes. We chose a single-center, retrospective, observational design. SETTING, PATIENTS, AND MEASUREMENTS: Nulliparous or multiparous women who had antenatal placental MRI performed at a tertiary level academic hospital were included. Cases with antenatal placental MRI were included and compared with cases without MRI performed. Two radiologists assigned a probability score for accreta to each study. Estimated blood loss and transfusion requirements were compared among groups by the Kruskal-Wallis H test. RESULTS: Thirty-five cases had placental MRI performed. MRI performance was associated with higher blood loss compared with the non-MRI group (2600 [1400-4500]mL vs 900[600-1500]mL, P<.001). There was no difference in estimated blood loss (P=.31) or transfusion (P=.57) among the MRI probability groups. CONCLUSIONS: In cases of suspected placenta accreta, probability scores for antenatal placental MRI may not be associated with increasing degrees of hemorrhage. Continued research is warranted to determine the effectiveness of assigning probability scores for antenatal accreta imaging studies, combined with clinical indices of suspicion, in assisting with antenatal multidisciplinary team planning for operative management of this morbid condition.

Ultrasound imaging of placenta accreta with MR correlation.

Placenta accreta is abnormal placental adherence or invasion of the myometrium or extrauterine structures. It is increasing in incidence because of increasing number of cesarean sections and is one of the main causes of excessive postpartum hemorrhage. Recognition of this entity is crucial because improved outcomes have been shown when the antenatal diagnosis of placenta accreta is made. Ultrasound is the first-line tool; magnetic resonance imaging (MRI) is complementary. Ultrasound and MRI features and MRI protocols will be reviewed.

Morphological analysis of pancreatic adenocarcinoma on multidetector row computed tomography: implications for treatment response evaluation.

OBJECTIVES: Response Evaluation Criteria in Solid Tumors (RECIST) guidelines assume spherical shape of tumors. Morphology of pancreatic adenocarcinoma (PAC) on multidetector row computed tomography was investigated to evaluate the applicability of RECIST guidelines. METHODS: Study population comprised 16 patients with histologically confirmed localized PAC enrolled in a phase II clinical trial of chemoradiation. Pancreatic adenocarcinomas were segmented on baseline and follow-up multidetector row computed tomography with commercially available software. Tumor volumes (mL), RECIST diameter (mm), volume equivalent sphere diameter (VESD, mm), maximum 3-dimensional diameter (M3DD, mm), and elongation value were obtained. RECIST diameter, VESD and M3DD of the tumors at baseline and follow-up were compared to determine differences. Elongation values were analyzed. The significance level was set at P less than 0.05. RESULTS: Mean volume, RECIST diameter, VESD, M3DD, and elongation for baseline versus follow-up studies were 23.12 mL versus 19.43 mL (P > 0.05), 41.86 mm versus 39.35 mm (P > 0.05), 33.14 mm versus 32.1 mm (P > 0.05), 51.76 mm versus 51.73 mm (P > 0.05), and 0.67 versus 0.76 (P > 0.05), respectively. There was a significant difference at baseline and follow-up between RECIST diameter, VESD, and M3DD (P < 0.05, in all instances). CONCLUSIONS: Our results suggest that PACs are not spherical in shape. Evaluation of PAC treatment response based on RECIST guidelines may not be accurate.