Utility of combined gadoxetic acid and ferumoxytol-enhanced liver MRI for preoperative detection of colorectal cancer liver metastases: a pilot study.

BACKGROUND: Colorectal cancer (CRC) is the second-leading cause of cancer-related death worldwide and resection of CRC metastases confined to the liver is the treatment of choice when feasible. Ferumoxytol is an off-label contrast agent that opacifies vasculature and may be helpful in distinguishing metastases from small hemangiomas and blood vessels on gadoxetic acid-enhanced magnetic resonance imaging (MRI). PURPOSE: To compare the diagnostic accuracy of MRI using a standard gadoxetic acid protocol and a combined gadoxetic acid/ferumoxytol protocol in patients with suspected colorectal hepatic metastases. MATERIAL AND METHODS: In this institutional review board-approved, single-institution, retrospective study, eight patients underwent gadoxetic acid-enhanced liver MRI, supplemented with additional T1-weighted ferumoxytol enhanced sequences. Two radiologists in consensus identified all metastases using all available sequences, which served as the reference standard. Two different radiologists reviewed each exam twice, once using the standard protocol and once with additional ferumoxytol sequences. The detection rate was estimated as the predicted probability of a metastasis along with the 95% confidence interval (CI) using hierarchical logistic regression models. RESULTS: A total of 49 metastases were identified. The mean diameter was 10 mm, measured in greatest axial dimension (median=7 mm; range=2-70 mm). Readers 1 and 2 had detection rates of 69.6% (95% CI = 48.2-85.0) and 53.1% (95% CI = 35.2-70.3) for gadoxetic acid alone and 98.0% (95% CI = 86.3-99.7) and 83.5% (95% CI = 59.3-94.7) for combined protocol. CONCLUSION: In this preliminary investigation, adding ferumoxytol-enhanced sequences to gadoxetic acid liver MRI protocol increased the detection rate of CRC hepatic metastases and may aid in preoperative decision making.

Sonographic Assessment of Acute Versus Chronic Cholecystitis: An Ultrasound Probability Stratification Model.

OBJECTIVES: What sonographic variables are most predictive for acute cholecystitis? What variables differentiate acute and chronic cholecystitis? METHODS: The surgical pathology database was reviewed to identify adult patients who underwent cholecystectomy for cholecystitis and had a preceding ultrasound of the right upper quadrant within 7 days. A total of 236 patients were included in the study. A comprehensive imaging review was performed to assess for gallstones, gallbladder wall thickening, gallbladder distension, pericholecystic fluid, gallstone mobility, the sonographic Murphy's sign, mural hyperemia, and the common hepatic artery peak systolic velocity. RESULTS: Of 236 patients with a cholecystectomy, 119 had acute cholecystitis and 117 had chronic cholecystitis on surgical pathology. Statistical models were created for prediction. The simple model consists of three sonographic variables and has a sensitivity of 60% and specificity of 83% in predicting acute versus chronic cholecystitis. The most predictive variables for acute cholecystitis were elevated common hepatic artery peak systolic velocity, gallbladder distension, and gallbladder mural abnormalities. If a patient had all three of these findings on their preoperative ultrasound, the patient had a 96% chance of having acute cholecystitis. Two of these variables gave a 73-93% chance of having acute cholecystitis. One of the three variables gave a 40-76% chance of having acute cholecystitis. If the patient had 0 of 3 of the predictor variables, there was a 29% chance of having acute cholecystitis. CONCLUSIONS: Gallbladder distension, gallbladder mural abnormalities, and elevated common hepatic artery peak systolic velocity are the most important sonographic variables in predicting acute versus chronic cholecystitis.

Utilization and Yield of CT Urography: Are the American Urological Association Guidelines for Imaging of Patients With Asymptomatic Microscopic Hematuria Being Followed?

OBJECTIVE: The purposes of this study were to determine whether patients with asymptomatic microscopic hematuria undergoing CT urography (CTU) meet the American Urological Association criteria for radiologic evaluation and to determine the yield of CTU for upper tract malignancy. MATERIALS AND METHODS: A retrospective review was conducted of consecutive CTU examinations performed for asymptomatic microscopic hematuria in adult patients. Patients with clinical evidence suggestive of a benign cause of hematuria (stone, urinary tract infection, trauma) or prior urologic malignancy were excluded. The study group included 419 patients (173 men, 246 women). CT reports were reviewed to identify causes of hematuria in all cases. Evaluate for appropriateness was conducted with 200 randomly allocated patients. Urinalysis results were reviewed, and appropriate use of CTU was defined as more than 3 RBCs per high-power field in the absence of urinary tract infection. Cystoscopy results after CTU were noted. RESULTS: In total, 58 of 200 patients (29.0%; 95% CI, 23.2-35.6%) did not meet American Urological Association criteria for radiologic evaluation. Fifteen (7.5%) received dipstick analysis only. Thirty-eight (19.0%) had urinalysis results showing 0-2 RBCs per high-power field. Five patients (2.5%) were found to have urinary tract infections. No upper tract urothelial neoplasms were identified (0/419; 95% CI, 0.0-0.9%). One solid renal mass was identified without pathologic confirmation. One possible bladder mass was seen at CTU but not visualized at subsequent cystoscopy. CONCLUSION: In 29.0% of examinations, CTU is performed for patients who do not meet the criteria for radiologic evaluation. The yield of CTU for upper urinary tract malignancy is low.

Clinical Importance of Incidentally Detected Hyperenhancing Liver Observations on Portal Venous Phase Computed Tomography in Patients Without Known Malignancy or Liver Disease.

OBJECTIVE: The aim of the study was to determine the prevalence of clinically important masses among incidental hyperenhancing liver observations on portal venous phase computed tomography (CT) in patients without known malignancy or liver disease. METHODS: Retrospective search of portal venous phase CTs was performed to identify hyperenhancing liver observations in patients without cancer or liver disease. Observations were assigned a morphology of homogeneous, hemangioma, or heterogeneous. The reference standard was pathology (n = 2), liver protocol CT/magnetic resonance imaging (n = 40), follow-up portal venous phase CT for 2 years or more (n = 81), or clinical follow-up for 5 years or more (n = 107). RESULTS: There were no clinically important masses among 83 observations with homogeneous morphology or 110 with hemangioma morphology. There were 2 clinically important masses (1 hepatocellular carcinoma and 1 hepatic adenoma) among 37 (5.4%) heterogeneous morphology observations. CONCLUSIONS: Incidental hyperenhancing liver observations on portal venous phase CT with homogeneous or typical hemangioma morphology in patients without known cancer or liver disease are highly likely benign.

Utility of Intraprocedural Contrast-Enhanced CT in Ablation of Renal Masses.

OBJECTIVE. The purpose of this study was to evaluate the efficacy of radiofrequency ablation (RFA) of renal masses comparing a group who did not undergo intraprocedural CT and a group who did. MATERIALS AND METHODS. A retrospective review included 45 consecutively registered patients who underwent RFA of renal masses. If an adequate biopsy specimen was not obtained or follow-up was inadequate, the patient was eliminated from review from calculation of primary technical efficacy. The inclusion criterion was having undergone RFA with two cooled-tip electrodes. Baseline demographics (age, body mass index, and sex), renal mass characteristics (diameter, side, location, position, morphologic features, type of mass, and grade), technical details (repositioning and hydrodissection), and complications were evaluated. Follow-up images were evaluated to determine the presence of recurrence at the ablation site in the two groups. RESULTS. Among the 45 patients who underwent RFA, 13 did not undergo intraprocedural CT and 32 intraprocedural did. Thirty-five patients met the criteria for follow-up and positive biopsy results. For calculation of recurrence, 10 patients were in the group who did not and 25 were in group who did undergo intraprocedural contrast-enhanced CT. No correlation was found between baseline demographics, renal mass characteristics, and technical results of the two groups. There was an 89% overall technical efficacy rate with a 96% primary technical efficacy rate in the group who underwent intraprocedural CT compared with a 70% rate in the group who did not undergo intraprocedural CT. Negative correlation was found between the groups with respect to technical efficacy rate at p < 0.05. CONCLUSION. Intraprocedural contrast-enhanced CT yields important information about completeness of ablation during the procedure, allowing probe repositioning and thus better therapeutic effect.

Sonographically Diagnosed Urothelial Thickening in Kidney Allografts: A Noninvasive and Clinically Highly Relevant Marker for the Detection of Acute Rejection.

OBJECTIVE. The objective of our study was to investigate the significance of sonographic features in assessing for acute kidney allograft rejection in the modern era. MATERIALS AND METHODS. In this retrospective study, 107 adult patients with a kidney allograft biopsy performed between 2015 and 2018 and diagnostic ultrasound performed within 2 weeks of the biopsy were included. Acute rejection was diagnosed on the basis of biopsy tissue sample results using the Banff criteria. The following ultrasound features were assessed: perfusion, cortical echogenicity, corticomedullary differentiation, urothelial thickening, change in renal length, renal artery velocity, and intraparenchymal arterial resistive index. Subjective measures of perfusion, echogenicity, corticomedullary differentiation, and urothelial thickening were assessed independently and in consensus by three abdominal radiologists; multirater kappa values were calculated for interobserver variability. The Wilcoxon rank sum test and chi-square test were used to evaluate the differences between two groups (rejection vs no rejection) and the sonographic features. Sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were calculated for sonographic features that are associated with acute rejection. RESULTS. Of the sonographic features, only the presence of urothelial thickening was significantly associated with acute rejection (p < 0.001) and had substantial agreement (κ = 0.61) among readers. Urothelial thickening was highly sensitive (96%; 95% CI, 79-100%) with a high NPV (98%; 95% CI, 86-100%). CONCLUSION. Urothelial thickening on ultrasound is a highly sensitive finding for acute kidney rejection with a high NPV and thus may play a role in sonographic prebiopsy screening. Other historically associated sonographic features seem to play little, if any, role in the screening and assessment for kidney allograft rejection in the modern era.

Adrenal Tumors Found During Staging and Surveillance for Colorectal Cancer: Benign Incidentalomas or Metastatic Disease?

OBJECTIVE: To evaluate the incidence of adrenal metastases in patient with colorectal cancer (CRC) and determine the clinical and radiographic features associated metastatic CRC to the adrenal glands. MATERIALS AND METHODS: The review of consecutive adults with newly diagnosed CRC found to have adrenal tumors > 1 cm in size on staging or surveillance CT scans with at least two scans to evaluate progression or stability of disease. RESULTS: Fifty-eight of 856 (6.8%) CRC patients had an adrenal tumor. Forty-three patients (74%) with 46 adrenal tumors had benign adrenal tumors, and 15 (26%) patients with 17 adrenal tumors had metastatic disease. On univariate analysis, patients with metastatic CRC had larger adrenal tumors (26.7 mm vs 12.4 mm, p < 0.01), a higher mean CEA (239 ng/mL vs 14.2 ng/mL, p = 0.03), and were more likely to have other sites of metastatic disease seen on imaging 8/43 (19%) vs 14/15 (93%), p < 0.01. On multivariable analysis, adrenal tumor size > 1.8 cm (OR 49.6 CI 8-306), CEA > 2.5 ng/mL (OR 15.8 CI 1.7-144) and other metastatic disease seen on imaging (OR 68.1 CI 7-661) were independently associated with adrenal metastases. CONCLUSION: CRC patients with small adrenal tumors, normal CEA levels and no evidence of other metastatic disease are unlikely to have spread to the adrenal glands. Adrenal tumors found during staging and surveillance of CRC patients should be evaluated with appropriate imaging and biochemical analysis.

Is Ultrasound-Guided Core Biopsy as Safe as Fine-Needle Aspiration, and Does It Add Significantly to the Diagnosis of Suspected Peritoneal Malignancy?

OBJECTIVES: We undertook this retrospective review to compare the safety and diagnostic yield of core biopsy (CB) compared to fine-needle aspiration (FNA) in patients with suspected peritoneal malignancy. METHODS: This retrospective study included 35 patients who underwent ultrasound (US)-guided percutaneous biopsy of a peritoneal mass. Success rates of US-guided biopsy of these masses using the CB technique, FNA, or the combination of the two were compared. Outcomes of tissue adequacy, the final pathologic diagnosis, and complications were recorded. The binary outcome variable was adequate tissue obtained. RESULTS: Adequate specimens were obtained in 94% (33 of 35) of the cases. There were 19 CBs, with 100% of samples sufficient for diagnosis (19 of 19). Thirty-one FNAs were performed, of which 7 were insufficient, with a diagnostic yield of 77% (24 of 31). There was a statistically significant difference between FNA and CB in providing more adequate tissue for diagnosis in our population (P = .035). There were no significant complications in either group. CONCLUSIONS: The use of the CB technique when performing US-guided percutaneous biopsy of peritoneal masses provides better tissue for diagnosis compared to FNA. Additional benefits of CB, including genomic testing and tumor subtyping, make this technique a good addition to FNA, without significant complications.

Effect of shelter-in-place on emergency department radiology volumes during the COVID-19 pandemic.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has led to significant disruptions in the healthcare system including surges of infected patients exceeding local capacity, closures of primary care offices, and delays of non-emergent medical care. Government-initiated measures to decrease healthcare utilization (i.e., "flattening the curve") have included shelter-in-place mandates and social distancing, which have taken effect across most of the USA. We evaluate the immediate impact of the Public Health Messaging and shelter-in-place mandates on Emergency Department (ED) demand for radiology services. METHODS: We analyzed ED radiology volumes from the five University of California health systems during a 2-week time period following the shelter-in-place mandate and compared those volumes with March 2019 and early April 2019 volumes. RESULTS: ED radiology volumes declined from the 2019 baseline by 32 to 40% (p < 0.001) across the five health systems with a total decrease in volumes across all 5 systems by 35% (p < 0.001). Stratifying by subspecialty, the smallest declines were seen in non-trauma thoracic imaging, which decreased 18% (p value < 0.001), while all other non-trauma studies decreased by 48% (p < 0.001). CONCLUSION: Total ED radiology demand may be a marker for public adherence to shelter-in-place mandates, though ED chest radiology demand may increase with an increase in COVID-19 cases.

Markedly elevated hepatic arterial velocity-HAV greater than 200 cm/s-is not specific to hepatobiliary disease.

OBJECTIVE: The aim of the study was to review the different etiologies and outcomes of patients with hepatic artery velocities greater than 200 cm/s. METHODS: This retrospective study included 88 hospitalized patients in whom angle-corrected proper hepatic artery flow velocities greater than 200 cm/s were obtained during an abdominal ultrasonographic examination. Peak systolic hepatic artery flow velocities, hepatic artery resistance index, and portal vein flow velocities were evaluated. The patients were then allocated to one of four groups based on their primary underlying diagnosis: structural liver disease, nonstructural liver disease, generalized infection, or miscellaneous. RESULTS: The median hepatic artery velocity was similar for all groups, ranging from 226 to 238 cm/s. The maximum portal venous velocities were not significantly different between groups. No lab values were statistically different between the groups, except total bilirubin that was greater in the nonstructural liver disease group (8 mg/dL). Overall, 9/88 (10.2%) of patients with elevated hepatic artery velocity died within 30 days of their ultrasonographic examination. CONCLUSION: Elevated hepatic artery velocity greater than 200 cm/s in hospitalized patients is not specific to primary hepatobiliary disease but may indicate acute hepatic dysfunction from other causes such as infection or sepsis.

Radiation Dose Reduction of Unenhanced CT Limited to the Kidneys for Follow-Up of Patients With Known Nephrolithiasis Without Symptoms.

OBJECTIVE. The purpose of this study is to identify the landmarks and associated radiation dose reduction for limited CT of the kidneys of patients requiring follow-up for known nephrolithiasis. MATERIALS AND METHODS. This retrospective study included all adult patients who underwent CT examination type "CT abdomen + pelvis renal stone" at our institution during 2017. Several exclusion criteria were identified, including scoliosis and congenital renal abnormalities. A total of 299 patients met the inclusion and exclusion criteria. The radiation dose and z-axis length associated with the original CT scan were recorded. The upper and lower limits of both kidneys in relation to the vertebral body endplates were recorded, to determine the z-axis length for a CT scan limited to the kidneys. A commercially available radiation dose analytics software package was used to provide estimates of whole-body-and individual organ-equivalent doses for the original CT scan and the limited range CT scan. RESULTS. The superior endplate of T11 and the inferior endplate of L5 are landmarks that will include both kidneys on almost all scans. A limited z-axis range leads to a mean scan length reduction of 50%. The whole-body mean effective dose is reduced by 41.5%, and the doses to the breast and the gonadal and bladder organs are reduced by 71.7%, 73.8%, and 81.8%, respectively. CONCLUSION. For patients without symptoms who are undergoing CT surveillance to evaluate renal calculi growth, new stone formation, or both, a limited-range scan extending from the superior endplate of T11 to the inferior endplate of L5 results in a significant reduction in radiation dose.

Differences in Growth Rate on CT of Adrenal Adenomas and Malignant Adrenal Nodules.

OBJECTIVE. The purpose of this study is to determine the differences in growth rate of adrenal adenomas and malignant adrenal nodules. MATERIALS AND METHODS. This was a retrospective review of adults with an adrenal nodule seen at two different abdominal or chest CT examinations or PET/CT examinations. Patients in the adenoma group were included if they had a CT, MRI, or pathologic diagnosis of an adrenal adenoma. Patients in the malignant group were included if they had a pathologically proven malignant adrenal nodule. Nodule growth was defined as a change in the largest axial diameter greater than or equal to 3 mm. Growth rate was calculated by dividing the change in the longest axial diameter by the time between the first and last imaging examination. RESULTS. There were 105 adenomas and 26 malignant nodules. Of the 105 adenomas, 34 (32.4%; 95% CI, 23.6-42.2%) grew, three (2.9%; 95% CI, 0.6-8.1%) became smaller, and 68 (64.8%; 95% CI, 54.8-73.8%), were unchanged in size. All 26 (100%; 95% CI, 89.1-100%) malignant nodules grew. The mean (± SD) growth rate of adenomas was 1.0 ± 0.67 mm/year (range, 0.3-2.8 mm/year), compared with 58.4 ± 78.5 mm/year (range, 5.8-395.4 mm/year) for malignant nodules (p < 0.001). A growth rate of 3 mm/year distinguished adenomas from malignant nodules with a sensitivity of 100% (95% CI, 86.8-100%) and a specificity of 100% (95% CI, 96.6-100%). CONCLUSION. Approximately one-third of radiologically proven adrenal adenomas grew, all of which grew at a rate less than 3 mm/year. All malignant adrenal nodules grew, and all at a rate greater than 5 mm/year.

Incidentally Detected Focal Fundal Gallbladder Wall Thickening at Contrast-Enhanced Computed Tomography: Prevalence and Computed Tomography Features of Malignancy.

OBJECTIVE: The aim of this study was to determine the prevalence and computed tomography (CT) features of malignancy in incidental focal fundal gallbladder wall thickening. METHODS: Patients with incidental focal fundal gallbladder wall thickening on CT were included if they had an ultrasound or magnetic resonance imaging diagnostic of the etiology (n = 19), stability on CT for 1 year (n = 84), or pathological correlation (n = 13). Morphologies were classified as type 1 (nodular/pinched intramural low attenuation), type 2 (intramural low attenuation), type 3 (homogeneous enhancement), type 4 (nodular/pinched homogeneous enhancement), type 5 (intramural cystic spaces), or type 6 (hyperenhancing/heterogeneous enhancement). RESULTS: One hundred sixteen patients had the following morphologies: type 1 (n = 57), type 2 (n = 10), type 3 (n = 6), type 4 (n = 19), type 5 (n = 14), and type 6 (n = 10). Four cases (3.4%; 95% confidence interval, 0.9%-8.6%) of malignancy were identified (type 6 in 3 and type 3 in 1). CONCLUSIONS: Incidental focal fundal gallbladder wall thickening is usually benign. Computed tomography features help distinguish benign from malignant etiologies.

Prevalence of Solid Tumors in Incidentally Detected Homogeneous Renal Masses Measuring > 20 HU on Portal Venous Phase CT.

OBJECTIVE: The purpose of this study was to determine the prevalence of solid tumors in incidental homogeneous renal masses with attenuation greater than 20 HU on portal venous phase CT images. MATERIALS AND METHODS: In this retrospective study, the records of patients with incidental indeterminate (> 20 HU) homogeneous renal masses on portal venous phase CT scans from September 11, 2007, through March 18, 2017, were identified. Adult patients were included if they had undergone follow-up ultrasound, contrast-enhanced MRI, multiphase contrast-enhanced CT, or pathologic analysis alone to confirm the solid or cystic nature of the lesion. A single ROI was placed in the center of the mass, and lesions were characterized as ≥ 50% exophytic, < 50% exophytic, or entirely surrounded by renal parenchyma. RESULTS: There were 322 masses in 267 patients. The mean lesion size was 16.6 (SD, 9.8) mm (range, 9-45 mm). Lesions were ≥ 50% exophytic in 92 cases, < 50% exophytic in 111 cases, and completely surrounded by renal parenchyma in 119 cases. All nonsolid lesions were characterized as benign cysts. The numbers of solid lesions per total number of lesions in each attenuation group were: 20-30 HU (0/140), 30-40 HU (0/67), 40-50 HU (1/38), 50-60 HU (3/24), 60-70 HU (5/17), 70-80 HU (5/17), and > 80 HU (8/19). All 207 lesions in the 20- to 40-HU range were benign cysts with no solid lesions (0%; 95% CI, 0.0-1.4%). CONCLUSION: Small homogeneous renal masses measuring 20-40 HU on portal venous phase CT images are highly likely to be benign cysts.

Current Clinical Practice Patterns of Self-Identified Interventional Radiologists.

OBJECTIVE: The purpose of this study was to assess patterns of procedural, clinical evaluation and management (E/M), and diagnostic imaging services rendered by self-identified interventional radiologists (IRs) across the United States. MATERIALS AND METHODS: Recent Medicare Physician and Other Supplier Public Use and Physician Compare national downloadable files were linked. IRs were defined as physicians self-identifying interventional radiology as their primary specialty on Medicare claims or as a specialty during Medicare enrollment. The primary outcome measure was percentage of work (in work relative value units [WRVU]) attributed to interventional services (both procedural and E/M) per IR. Secondary outcome measures included sociodemographic factors per interventional WRVU quartile and percentage of E/M service units per IR. Statistical analysis included chi-square and t tests and logistic regression. RESULTS: Overall, 3132 physicians nationally self-identified to Medicare as IRs. The distribution of WRVU attributed to interventional services was strongly bimodal. Procedures and E/M together accounted for ≥ 91% and ≤ 5% of total work for the most and least intervention-oriented quartiles, respectively, but were widely distributed in the middle two quartiles. The most intervention-oriented self-identified IRs were more likely out of medical school ≤ 30 years (odds ratio [OR], 2.5; p < 0.0001), men (OR, 2.2; p < 0.0001), and in academic practice (OR, 4.3; p < 0.0001). E/M accounted for only 1.4% of all billed services. CONCLUSION: Although most self-identified IRs perform both interventional and diagnostic imaging services, the subspecialty distribution is strongly bimodal, one-quarter each focusing ≤ 5% and ≥ 91% of work on interventional services. Despite ongoing emphasis on clinically focused interventional radiology, E/M services remain rarely reported.

Nonstandardized Terminology to Describe Focal Liver Lesions in Patients at Risk for Hepatocellular Carcinoma: Implications Regarding Clinical Communication.

OBJECTIVE: The purpose of this study is to determine the correlation between malignancy risk of focal liver observations in patients at risk for hepatocellular carcinoma (HCC) implied by phrases used in nonstructured radiology reports with the risk inferred by hepatologists. MATERIALS AND METHODS: We performed a retrospective review of nonstructured radiology reports issued before Liver Imaging and Reporting Data System (LI-RADS) adoption from four-phase liver CT examinations of patients at risk for HCC. The phrase used by the radiologist in the report impression to describe each focal liver observation was recorded. Five hepatologists independently inferred the LI-RADS category from each phrase. Two abdominal radiologists independently reviewed the images and, blinded to all other information, assigned a LI-RADS category to each observation. Discrepancies were resolved by consensus. RESULTS: One hundred five observations in 77 patients were reported by 23 radiologists using 29 phrases. The most common phrase, "consistent with HCC" (n = 20), was applied to radiologist-assigned LR-3 (n = 1), LR-4 (n = 5), LR-5 (n = 11), and LR-5V (n = 3) observations. Eleven phrases were used more than once. Sixteen phrases were associated with LR-4 or higher observations; among these, hepatologists misinterpreted 37% of LR-4 or lower observations as definitely HCC and 46% of LR-5 and LR-5V observations as not definitely HCC. Overall, there was modest correlation (r = 0.69) between radiologist-assigned and hepatologist-inferred categories. CONCLUSION: Nonstandardized terminology results in inaccurate communication of HCC risk. Structured reporting systems such as LI-RADS may improve communication by conveying unambiguous estimates of malignancy risk.

Incidentally Detected Bilateral Adrenal Nodules in Patients Without Cancer: Is Further Workup Necessary?

OBJECTIVE: The purpose of this study was to determine the rate of malignancy in incidentally detected bilateral adrenal masses in patients with no known history of cancer. MATERIALS AND METHODS: A retrospective search of CT reports of patients with incidentally detected bilateral adrenal nodules was performed from January 1, 2002, to January 1, 2014. Patients were excluded if they had a known cancer or suspected functioning adrenal tumor; 161 patients were included. Nodules were characterized as benign or malignant on the basis of imaging features at the index CT examination, imaging features at subsequent adrenal protocol CT or MRI, imaging stability for a minimum of 1 year, or clinical follow-up of a minimum of 2 years. RESULTS: Mean nodule size was 1.8 cm (range, 0.7-4.9 cm). There were no cases of primary or secondary adrenal malignancy (95% CI, 0.00-0.023). The nodules diagnosed on index CT scans were 73 adrenal adenomas and two myelolipomas. Seventy-four nodules were subsequently characterized as adrenal adenomas on the basis of imaging findings. Of the 113 indeterminate nodules that had imaging follow-up, 111 were stable at the latest follow-up examination. One nodule grew 26% over 8.1 years, and the other grew 59% over 12.4 years. Clinical follow-up of patients with 60 indeterminate nodules revealed no evidence of adrenal malignancy. CONCLUSION: No case of malignancy was found in 322 incidentally detected bilateral adrenal nodules at CT of patients without known cancer. Imaging follow-up of such lesions may be unnecessary.

Prevalence of Low-Attenuation Homogeneous Papillary Renal Cell Carcinoma Mimicking Renal Cysts on CT.

OBJECTIVE: The objective of our study was to determine the attenuation range of homogeneous papillary renal cell carcinomas (RCCs) on contrast-enhanced CT. MATERIALS AND METHODS: This retrospective study was performed at two institutions from January 1, 2007, to January 1, 2017. Multiphasic CT studies with and without IV contrast material of 114 patients with pathologically proven papillary RCCs were independently reviewed by two sets of two abdominal radiologists. Seventy-two cases were excluded because of subjective lesion heterogeneity, leaving 42 homogeneous RCCs. Three ROIs were placed on all lesions for all CT phases, and the mean attenuations were calculated. RESULTS: Mean lesion size was 2.8 cm (range, 1.2-11.0 cm). The attenuation range for each CT phase was as follows: unenhanced, 14.7-50.7 HU; corticomedullary, 32.2-99.5 HU; portal venous, 40.8-95.1 HU; nephrographic, 17.9-90.8 HU; and excretory, 18.0-73.0 HU. Two of 114 (1.8%; 95% CI, 0.2-6.5%) RCCs were homogeneous and less than 30 HU on the portal venous or nephrographic phase. One of these RCCs was a solid hypoenhancing mass, and the other was a homogeneous cystic RCC. Of the cases with an unenhanced phase, three of 107 (2.8%; 95% CI, 0.6-8.8%) were both homogeneous and were less than 20 HU in attenuation. CONCLUSION: Papillary RCCs are rarely both subjectively homogeneous and less than 20 HU at unenhanced CT and less than 30 HU at portal venous or nephrographic phase CT.

Automated Radiology Report Summarization Using an Open-Source Natural Language Processing Pipeline.

Diagnostic radiologists are expected to review and assimilate findings from prior studies when constructing their overall assessment of the current study. Radiology information systems facilitate this process by presenting the radiologist with a subset of prior studies that are more likely to be relevant to the current study, usually by comparing anatomic coverage of both the current and prior studies. It is incumbent on the radiologist to review the full text report and/or images from those prior studies, a process that is time-consuming and confers substantial risk of overlooking a relevant prior study or finding. This risk is compounded when patients have dozens or even hundreds of prior imaging studies. Our goal is to assess the feasibility of natural language processing techniques to automatically extract asserted and negated disease entities from free-text radiology reports as a step towards automated report summarization. We compared automatically extracted disease mentions to a gold-standard set of manual annotations for 50 radiology reports from CT abdomen and pelvis examinations. The automated report summarization pipeline found perfect or overlapping partial matches for 86% of the manually annotated disease mentions (sensitivity 0.86, precision 0.66, accuracy 0.59, F1 score 0.74). The performance of the automated pipeline was good, and the overall accuracy was similar to the interobserver agreement between the two manual annotators.

Digitizing an Analog Radiography Teaching File Under Time Constraint: Trade-Offs in Efficiency and Image Quality.

We digitized the radiography teaching file at Black Lion Hospital (Addis Ababa, Ethiopia) during a recent trip, using a standard digital camera and a fluorescent light box. Our goal was to photograph every radiograph in the existing library while optimizing the final image size to the maximum resolution of a high quality tablet computer, preserving the contrast resolution of the radiographs, and minimizing total library file size. A secondary important goal was to minimize the cost and time required to take and process the images. Three workers were able to efficiently remove the radiographs from their storage folders, hang them on the light box, operate the camera, catalog the image, and repack the radiographs back to the storage folder. Zoom, focal length, and film speed were fixed, while aperture and shutter speed were manually adjusted for each image, allowing for efficiency and flexibility in image acquisition. Keeping zoom and focal length fixed, which kept the view box at the same relative position in all of the images acquired during a single photography session, allowed unused space to be batch-cropped, saving considerable time in post-processing, at the expense of final image resolution. We present an analysis of the trade-offs in workflow efficiency and final image quality, and demonstrate that a few people with minimal equipment can efficiently digitize a teaching file library.