Can absolute arterial phase hyperenhancement improve sensitivity of detection of hepatocellular carcinoma in indeterminate nodules on CT?

OBJECTIVES: To determine if quantitative assessment of relative (R) and absolute (A) arterial phase hyperenhancement (APHE) and washout (WO) applied to indeterminate nodules on CT would improve the overall sensitivity of detection of hepatocellular carcinoma (HCC). METHODS: One-hundred and fourteen patients (90 male; mean age, 65 years) with 210 treatment-naïve HCC nodules (190 HCCs, 20 benign) who underwent 4-phase CT were included in this retrospective study. Four radiologists independently assigned a qualitative LR (LI-RADS) category per nodule. LR-3/4 nodules were then quantitatively analyzed by the 4 readers, placing ROIs within nodules and adjacent liver parenchyma. A/R-APHE and WO were calculated, and per-reader sensitivity and specificity updated. Interobserver agreement and AUCs were calculated per reader. RESULTS: Qualitative readers 1-4 categorized 57, 69, 57, and 63 nodules as LR-3/4 respectively with moderate to substantial agreement in LR category (kappa 0.56-0.69, p < 0.0001); their diagnostic performances in the detection of HCC were 80%, 73.2%, 77.4%, and 77.4% sensitivity, and 100%, 95%, 70%, and 100% specificity, respectively. A threshold of ≥ 20 HU for A-APHE increased overall sensitivity of HCC detection by 0.5-3.1% without changing specificity for the subset of nodules APHE - /WO + on qualitative read, with 2, 6, 6, and 1 additional HCC detected by readers 1-4. Relative and various A-WO formulae and thresholds all increased sensitivity, but with a drop in specificity for some/all readers. CONCLUSION: Quantitatively assessed A-APHE showed potential to increase sensitivity and maintain specificity of HCC diagnosis when selectively applied to indeterminate nodules demonstrating WO without subjective APHE. Quantitatively assessed R and A-WO increased sensitivity, however reduced specificity. CLINICAL RELEVANCE STATEMENT: A workflow using selective quantification of absolute arterial enhancement is routinely employed in the CT assessment of renal and adrenal nodules. Quantitatively assessed absolute arterial enhancement is a simple tool which may be used as an adjunct to help increase sensitivity and maintain specificity of HCC diagnosis in indeterminate nodules demonstrating WO without subjective APHE. KEY POINTS: • In indeterminate nodules categorized as LI-RADS 3/4 due to absent subjective arterial phase hyperenhancement, a cut-off for absolute arterial phase hyperenhancement of ≥ 20 HU may increase the overall sensitivity of detection of HCC by 0.5-3.1% without affecting specificity. • Relative and various absolute washout formulae and cut-offs increased sensitivity of HCC detection, but with a drop in specificity for some/all readers.

Autosomal Dominant Polycystic Kidney Disease: Role of Imaging in Diagnosis and Management.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disorder with progressive renal function decline, and disease severity is determined based on the type of genetic mutation. The diagnosis is usually established at imaging, primarily at US, and is based on age-dependent criteria and the number of visible cysts. ADPKD is classified into class 1 (typical) and class 2 (atypical) according to the Mayo Clinic Imaging Classification (MCIC) system. Height-adjusted total kidney volume (TKV) has emerged as a predictor of future renal function decline and renal failure in ADPKD, and several methods can be used for estimation. MCIC class 1 ADPKD is further subdivided into five types based on height-adjusted TKV (A, B, C, D, and E). Patients with a larger height-adjusted TKV (ie, MCIC 1C-E) are at high risk for progression to end-stage renal disease and will potentially benefit from vasopressin receptor antagonists, which have been shown to reduce the rate of cyst growth and slow renal function decline. Other renal complications primarily relate to hemorrhage within cysts or cyst infections. Subtraction images are key for assessment of complex cysts when malignancy is suspected, as the presence of protein and blood can limit the assessment for an enhancing component. The radiologist has a central role in establishing a diagnosis, excluding mimics, identifying complications, assessing severity, and predicting future renal failure. Interventional radiologists play a therapeutic role in management of complications by cyst drainage, sclerotherapy, or embolization. © RSNA, 2022 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Patterns of Relapse and Complications of Immunoglobulin G4-Related Disease.

BACKGROUND: Immunoglobulin G4-related disease (IgG4-RD) is a multisystemic fibroinflammatory condition potentially resulting in organ dysfunction. We aimed to evaluate imaging characteristics of disease relapse and complications in this cohort of patients. METHODS: This was a cohort study of IgG4-RD patients imaged between 2010 and 2020. Radiological manifestations of disease activity (remission/stability vs. relapse and complications) were correlated with clinical symptoms. Univariate analyses were performed with χ2 , Fisher exact, and Mann-Whitney U tests. Times to relapse and organ atrophy were studied with Kaplan-Meier analyses. RESULTS: A total of 69 patients had imaging surveillance over a median duration of 47 months. Radiological relapse occurred in 50.7% (35/69) with median time to relapse at 74 months (95% confidence interval, 45-122 months); 42.8% (15/35) of this cohort had different-site relapse with the following recognized primary-secondary patterns: pancreas-hepatobiliary ( p = 0.005), hepatobiliary-pancreas ( p = 0.013), and periaortitis-mesenteric ( p = 0.006). Clinical symptoms were significantly associated with imaging characteristics ( p < 0.001). Abdominal complications were detected in 52.2% (36/69) of patients, mostly solid organ atrophy (97.2% [35/36]). New-onset diabetes was more likely in pancreatic IgG4-RD (n = 51) when accompanied by gland atrophy (4/21 vs. 0/30 nonatrophy, p = 0.024). CONCLUSION: Radiological relapse of IgG4-RD is common over prolonged imaging surveillance and is significantly associated with symptomatic relapse. A multisystem review to detect new/different sites of disease and abdominal complications may help predict future organ dysfunction.

Contrast-enhanced US of the Liver and Kidney: A Problem-solving Modality.

Contrast-enhanced US (CEUS) has an important role as a supplement to CT or MRI in clinical practice. The main established utilizations are in the liver and the kidney. The primary advantages of CEUS compared with contrast-enhanced CT or MRI relate to its superior contrast resolution, real-time continuous scanning, pure intravascular nature, portability, and safety-especially in patients with renal impairment or CT or MRI contrast agent allergy. This article focuses on the use of CEUS in the liver and kidney.

Monoallelic Mutations to DNAJB11 Cause Atypical Autosomal-Dominant Polycystic Kidney Disease.

Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by the progressive development of kidney cysts, often resulting in end-stage renal disease (ESRD). This disorder is genetically heterogeneous with ∼7% of families genetically unresolved. We performed whole-exome sequencing (WES) in two multiplex ADPKD-like pedigrees, and we analyzed a further 591 genetically unresolved, phenotypically similar families by targeted next-generation sequencing of 65 candidate genes. WES identified a DNAJB11 missense variant (p.Pro54Arg) in two family members presenting with non-enlarged polycystic kidneys and a frameshifting change (c.166_167insTT) in a second family with small renal and liver cysts. DNAJB11 is a co-factor of BiP, a key chaperone in the endoplasmic reticulum controlling folding, trafficking, and degradation of secreted and membrane proteins. Five additional multigenerational families carrying DNAJB11 mutations were identified by the targeted analysis. The clinical phenotype was consistent in the 23 affected members, with non-enlarged cystic kidneys that often evolved to kidney atrophy; 7 subjects reached ESRD from 59 to 89 years. The lack of kidney enlargement, histologically evident interstitial fibrosis in non-cystic parenchyma, and recurring episodes of gout (one family) suggested partial phenotypic overlap with autosomal-dominant tubulointerstitial diseases (ADTKD). Characterization of DNAJB11-null cells and kidney samples from affected individuals revealed a pathogenesis associated with maturation and trafficking defects involving the ADPKD protein, PC1, and ADTKD proteins, such as UMOD. DNAJB11-associated disease is a phenotypic hybrid of ADPKD and ADTKD, characterized by normal-sized cystic kidneys and progressive interstitial fibrosis resulting in late-onset ESRD.

The added value of contrast-enhanced ultrasound in evaluation of indeterminate small solid renal masses and risk stratification of cystic renal lesions.

OBJECTIVES: To investigate accuracy of contrast-enhanced ultrasound (CEUS) to characterize indeterminate small solid renal masses (sSRMs), excluding lipid-rich AMLs, and cystic renal masses (CRMs) according to the proposed Bosniak Classification 2019 MATERIALS AND METHODS: CEUS of pathology-proven CRMs and sSRMs (without definite enhancement or macroscopic fat on CT/MRI), and CRMs with ≥18 months follow-up were retrospectively reviewed. Two radiologists blindly categorized CRMs according to new Bosniak Classification on CT/MRI. On CEUS, two other radiologists evaluated arterial-phase enhancement of sSRMs relative to renal cortex and categorized CRMs following new Bosniak Classification. Fisher's exact/chi-squared test was used to compare categorical variables, and Cohen κ statistics for inter-observer agreement RESULTS: A total of 237 patients had 241 lesions: 161 pathology-proven sSRMs (122 malignant and 39 benign), 29 pathology-proven CRMs, 51 CRMs with adequate follow-up. Arterial-phase enhancement < renal cortex predicted malignancy with specificity of 97.4% (38/39) (CI 85.6-99.9%), and positive predictive value (PPV) of 98.2% (54/55) (CI 90.4-99.9%). Inter-observer kappa was 0.95. In pathology-proven CRMS, sensitivity of CEUS vs CT/MRI was 100% (15/15) (CI 79.6-100%) vs 60% (9/15) (CI 35.8-80.1%) (p value = .002) and negative predictive value (NPV) 100% (2/2) (CI 17.8-100%) vs 25% (2/8 ) (CI 4.4-59.1%) (p value < 0.0001), with similar specificity (50%) and PPV- 88.2% (15/17) (CI 65.7-97.9%) vs 81.8% (9/11) (CI 52.3-96.8%) ( p value = 0.586). Bosniak Classification inter-observer kappa was 0.92 for CEUS vs 0.68 for CT/MRI (p value = 0.009). CONCLUSION: In our cohort, CEUS had high specificity and PPV to diagnose RCC in sSRMs excluding lipid-rich AML. CEUS had significantly higher sensitivity/NPV to diagnose malignancy in CRMs as compared to CT/MRI. KEY POINTS: • Once lipid-rich AML is excluded by the other modalities, sSRM arterial phase hypo-enhancement relative to renal cortex on CEUS yielded high specificity (97.4%) and PPV (98.2%) to diagnose RCC. • When applying the proposed Bosniak Classification 2019, CEUS showed higher sensitivity compared to CT/MRI (100% vs 60%), p value=.0024, in the stratification of cystic renal masses to diagnose malignancy. • CEUS may reduce the number of CT/MRI Bosniak IIF lesions by assigning them to either II or III/IV categories.

The Renal Vasculature: What the Radiologist Needs to Know.

The physiologic role of the kidneys is dependent on the normal structure and functioning of the renal vasculature. Knowledge and understanding of the embryologic basis of the renal vasculature are necessary for the radiologist. Common anatomic variants involving the renal artery (supernumerary arteries and prehilar branching) and renal vein (supernumerary veins, delayed venous confluence, retroaortic or circumaortic vein) may affect procedures like renal transplantation, percutaneous biopsy, and aortic aneurysm repair. Venous compression syndromes (anterior and posterior nutcracker syndrome) can be symptomatic and can be diagnosed with a combination of radiologic features. Renal artery stenosis is commonly atherosclerotic and is diagnosed with Doppler US, CT angiography, or MR angiography. Fibromuscular dysplasia, the second most common cause of renal artery narrowing, has a characteristic string-of-beads appearance resulting from multifocal stenoses and dilatations. Manifestations of renal vasculitis differ depending on whether the affected vessels are large, medium, or small. Renal vascular injury is graded according to the American Association for the Surgery of Trauma (AAST) renal injury scale, which defines vascular injury and active bleeding in renal injuries. Both renal arteries and veins are affected by primary neoplasms or secondarily by neoplasms from adjacent structures. Differentiation between bland thrombus and tumor thrombus and the extent of involvement dictate management in malignancies, especially renal cell carcinoma. Aneurysms, pseudoaneurysms, arteriovenous malformations, and arteriovenous fistulas can affect renal vessels and can be diagnosed with specific imaging features. The radiologist has a critical role in identification of specific imaging characteristics and establishing the diagnosis in the varied pathologic conditions affecting the renal vasculature, which is critical for directing management. Thus, the renal vasculature should be an integral part of radiologists' checklist. ©RSNA, 2021.

Reproducibility of 2 Liver 2-Dimensional Shear Wave Elastographic Techniques in the Fasting and Postprandial States.

OBJECTIVES: The purpose of this study was to compare the reliability and agreement of 2 methods of 2-dimensional (2D) shear wave elastography (SWE) on liver stiffness in healthy volunteers. We also assessed effects of the prandial state and operator experience on measurements. METHODS: Two operators, 1 experienced and 1 novice, independently examined 20 healthy volunteers with 2D SWE on 2 ultrasound machines (Aixplorer [SuperSonic Imagine, Aix-en-Provence, France] and Aplio 500 [Canon Medical Systems Corporation, Otawara, Japan]). Volunteers were scanned 8 times by the operators using both machines in fasting and postprandial states. Agreement was evaluated by a Bland-Altman analysis, and the correlation was assessed by the Pearson correlation and intraclass correlation coefficients (ICCs). An analysis of variance was conducted to determine the contribution of the machine, prandial state, and operator experience to the variability. RESULTS: Agreement assessed by Bland-Altman plots showed no statistically significant difference in measured liver stiffness between the machines (mean difference, -0.8%; 95% confidence interval, -3.7%, 2.1%), with a critical difference of 1.36 kPa. The correlation was good to excellent for both the crude overall Pearson coefficient and the ICC, both measuring 0.88 (95% confidence interval, 0.82, 0.92). Subclass ICCs for the fasting state, postprandial state, novice operator, and experienced operator were 0.89, 0.88, 0.90, and 0.86, respectively. The 2-way mixed effect analysis of variance showed that the volunteers accounted for 86.3% of variation in median liver stiffness, with no statistically significant contribution from operator experience, the prandial state, or the machine (P = .108, .067, and .296, respectively). CONCLUSIONS: Our study showed that the 2D SWE techniques had a high degree of reliability and agreement in measurement of liver stiffness in a healthy population. Operator experience and the prandial state did not impart significant variability to stiffness measurements.

Negative Predictive Value of Contrast-Enhanced Ultrasound of Liver and Kidney Thermal Ablation Sites for Local Tumour Progression During Long-term Follow-up: A Retrospective Consecutive Study.

PURPOSE: To determine negative predictive value (NPV) of contrast-enhanced ultrasound (CEUS) to demonstrate local tumour progression (LTP) at thermal ablation (TA) sites. METHODS: Our institutional review board approved this retrospective study; acquisition of consent was waived. Consecutive CEUS examinations performed between 2004-2014 for TA site evaluation on patients who could not undergo enhanced computed tomography (CT) or magnetic resonance imaging (MRI), or had inconclusive CT or MRI, were retrospectively reviewed. Those reported as no abnormal enhancement in or surrounding TA site were included. CEUS examination was considered true-negative based on stability or lack of enhancement/washout on follow-up imaging for at least 1 year, and false-negative (FN), if there was an arterially enhancing focus with wash-out at or surrounding TA site on subsequent follow-up imaging. RESULTS: Study population included 56 tumours in 54 patients, 11 women, 43 men; mean age 71 years. Two patients had TA of two different hepatocellular carcinomas. Thirty-six examinations were for hepatic TA and twenty for renal TA. Lesion sizes ranged from 1 cm to 7 cm (mean 3.1 ± 1.2). Mean diameter of 7 recurrences was 13.8 mm. Overall FN rate was 12.5% (7/56). Corresponding numbers were 0% (0/20) for renal TA and 19.4% (7/36) for hepatic TA. Overall NPV of CEUS was 87.5% (49/56) (confidence interval [CI]: 78.8%-96.2%). NPV for renal TA was 100% (20/20) (CI: 100%-100%) and for hepatic TA 81.5% (29/36) (CI: 67.6 %-93.5%). CONCLUSION: In this cohort, CEUS showed high NPV for exclusion of LTP at renal TA sites. NPV for hepatic TA sites was high but lower than renal TA.

Successful Integration of Contrast-enhanced US into Routine Abdominal Imaging.

Contrast material-enhanced US is recognized increasingly as a useful tool in a wide variety of hepatic and nonhepatic applications. The modality recently was approved for limited use for liver indications in adult and pediatric patients in the United States. Contrast-enhanced US uses microbubbles of gas injected intravenously as a contrast agent to demonstrate blood flow and tissue perfusion. The growing worldwide application of contrast-enhanced US in multiple organ systems is due largely to its advantages, including high contrast resolution (sensitivity to the contrast agent), real-time imaging, lack of nephrotoxicity, the purely intravascular property of microbubble contrast agents that allows the use of disruption-replenishment techniques, and repeatability during the same examination. Through illustrative cases, common useful clinical scenarios are discussed, including characterization of liver and renal masses, especially indeterminate lesions at CT or MRI; differentiation of neoplastic cysts from nonneoplastic cysts in various organs; differentiation of tumor thrombus from bland thrombus; and assessment after a renal transplant or local ablative therapy. Common applications in the biliary system, pancreas, spleen, and vasculature also are introduced. Successful routine use of contrast-enhanced US requires an efficient setup and workflow and a thorough understanding of appropriate clinical indications and its advantages that provide added value after CT and MRI. This article familiarizes radiologists with common abdominal applications of contrast-enhanced US and guides them to implement contrast-enhanced US successfully in their clinical practice. Online supplemental material is available for this article. ©RSNA, 2018.

Negative Predictive Value of Contrast-Enhanced Ultrasound in Differentiating Avascular Solid-Appearing From Vascularized Masses: A Retrospective Consecutive Study.

OBJECTIVES: To determine the negative predictive value (NPV) of contrast-enhanced ultrasound (CEUS) to establish the lack of vascularity in a mass. METHODS: This work was an Institutional Review Board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study. Acquisition of consent was waived. We included all CEUS examinations performed for tissue characterization between 2004 and 2014 that reported showing no vascularity in a mass. Contrast-enhanced ultrasound findings were considered true-negative when there was stability on imaging for at least 1 year or no evidence of a solid mass, if biopsied, and false-negative if there was lesion growth on imaging within 12 months or an indication of a solid mass on the pathologic examination, if biopsied. One author reviewed all of the reports and follow-up examinations. We conducted a consensus review of all false-negative findings mixed with an equal number of true-negative findings by 2 reviewers, who were blinded to the final results. RESULTS: The study population consisted of 97 CEUS examinations in 97 patients, including 48 women and 49 men (mean age ± SD, 65 ± 14 years). Examinations were performed for lesion characterization in the liver (n = 23), pancreas (n = 17), kidney (n = 54), 1 gallbladder, 1 adnexa, and 1 peritoneal lesion. The overall false-negative rate on the official prospective review was 2% (2 of 97). Two false-negative findings were correctly identified on the consensus review. The NPV of CEUS was 97.9% (95 of 97; 95% confidence interval, 93%- 99%) on the official review. CONCLUSIONS: Contrast-enhanced ultrasound has a very high NPV to exclude the presence of flow in a mass, and it can be used to exclude the presence of a solid mass.

Polycystic Kidney Disease without an Apparent Family History.

The absence of a positive family history (PFH) in 10%-25% of patients poses a diagnostic challenge for autosomal dominant polycystic kidney disease (ADPKD). In the Toronto Genetic Epidemiology Study of Polycystic Kidney Disease, 210 affected probands underwent renal function testing, abdominal imaging, and comprehensive PKD1 and PKD2 mutation screening. From this cohort, we reviewed all patients with and without an apparent family history, examined their parental medical records, and performed renal imaging in all available parents of unknown disease status. Subsequent reclassification of 209 analyzed patients revealed 72.2% (151 of 209) with a PFH, 15.3% (32 of 209) with de novo disease, 10.5% (22 of 209) with an indeterminate family history, and 1.9% (four of 209) with PFH in retrospect. Among the patients with de novo cases, we found two families with germline mosaicism and one family with somatic mosaicism. Additionally, analysis of renal imaging revealed that 16.3% (34 of 209) of patients displayed atypical PKD, most of which followed one of three patterns: asymmetric or focal PKD with PFH and an identified PKD1 or PKD2 mutation (15 of 34), asymmetric and de novo PKD with proven or suspected somatic mosaicism (seven of 34), or focal PKD without any identifiable PKD1 or PKD2 mutation (eight of 34). In conclusion, PKD without an apparent family history may be due to de novo disease, missing parental medical records, germline or somatic mosaicism, or mild disease from hypomorphic PKD1 and PKD2 mutations. Furthermore, mutations of a newly identified gene for ADPKD, GANAB, and somatic mosaicism need to be considered in the mutation-negative patients with focal disease.

Toronto HCC risk index: A validated scoring system to predict 10-year risk of HCC in patients with cirrhosis.

BACKGROUND & AIMS: Current guidelines recommend biannual surveillance for hepatocellular carcinoma (HCC) in all patients with cirrhosis, regardless of etiology. However, HCC incidence is not well established for many causes of cirrhosis. We aimed to assess the disease-specific incidence of HCC in a large cohort of patients with cirrhosis and to develop a scoring system to predict HCC risk. METHODS: A derivation cohort of patients with cirrhosis diagnosed by biopsy or non-invasive measures was identified through retrospective chart review. The disease-specific incidence of HCC was calculated according to etiology of cirrhosis. Factors associated with HCC were identified through multivariable Cox regression and used to develop a scoring system to predict HCC risk. The scoring system was evaluated in an external cohort for validation. RESULTS: Of 2,079 patients with cirrhosis and ≥6months follow-up, 226 (10.8%) developed HCC. The 10-year cumulative incidence of HCC varied by etiologic category from 22% in patients with viral hepatitis, to 16% in those with steatohepatitis and 5% in those with autoimmune liver disease (p<0.001). By multivariable Cox regression, age, sex, etiology and platelets were associated with HCC. Points were assigned in proportion to each hazard ratio to create the Toronto HCC Risk Index (THRI). The 10-year cumulative HCC incidence was 3%, 10% and 32% in the low-risk (<120points), medium-risk (120-240) and high-risk (>240) groups respectively, values that remained consistent after internal validation. External validation was performed on a cohort of patients with primary biliary cirrhosis, hepatitis B viral and hepatitis C viral cirrhosis (n=1,144), with similar predictive ability (Harrell's c statistic 0.77) in the validation and derivation cohorts. CONCLUSION: HCC incidence varies markedly by etiology of cirrhosis. The THRI, using readily available clinical and laboratory parameters, has good predictive ability for HCC in patients with cirrhosis, and has been validated in an external cohort. This risk score may help to guide recommendations regarding HCC surveillance among patients with cirrhosis. LAY SUMMARY: HCC incidence varies markedly depending on the underlying cause of cirrhosis. Herein, using readily available clinical and laboratory parameters we describe a risk score, THRI, which has a good predictive ability for HCC in patients with cirrhosis, and has been validated in an external cohort. This risk score may help to guide recommendations regarding HCC surveillance among patients with cirrhosis.

Editorial: Not All Nodules Are Created Equal: A Personalized Approach to Indeterminate (<2 cm) Nodules Identified on HCC Surveillance.

Indeterminate small (<2 cm) nodules are often discovered in cirrhotics who undergo contrast enhanced imaging for further characterization of lesions detected on ultrasound surveillance for hepatocellular carcinoma (HCC). These are either arterially enhancing (without venous washout or capsule) or are non-enhancing (with washout). Differentials include small HCCs (14-23%), atypical arterio-portal shunts, regenerative, and dysplastic nodules. A risk score that combines imaging features (arterial enhancement and nodule size) with clinical (age, prior h/o HCC) and laboratory features (albumin, AFP, hepatitis B 'e' antigen) appear to be superior to radiological features alone in the risk stratification of these nodules.

Wait Time for Curative Intent Radio Frequency Ablation is Associated with Increased Mortality in Patients with Early Stage Hepatocellular Carcinoma.

INTRODUCTION: Radiofrequency ablation (RFA) is a recommended curative intent treatment option for patients with early stage hepatocellular carcinoma (HCC). We investigated if wait times for RFA were associated with residual tumor, tumor recurrence, need for liver transplantation, or death. MATERIAL AND METHODS: We conducted a retrospective study of patients diagnosed with HCC between January 2010 and December 2013 presenting to University Health Network (UHN) in Toronto, Canada. All patients receiving curative intent RFA for HCC were included. Multivariable Cox regression was used to determine if wait times were associated with clinical outcomes. RESULTS: 219 patients were included in the study. 72.6% were male and the median age was 62.7 years (IQR 55.6-71). Median tumor size at diagnosis was 21.5 mm (IQR 17-26); median MELD was 8.7 (IQR 7.2-11.4) and 57.1% were Barcelona stage 0. The cause of liver disease was viral hepatitis in 73.5% (Hepatitis B and C). The median time from HCC diagnosis to RFA treatment was 96 days (IQR 75-139). In multivariate analysis, wait time was not associated with requiring liver transplant or tumor recurrence, however, each incremental 30-day wait time was associated with an increased risk of residual tumor (HR = 1.09; 95% CI 1.01-1.19; p = 0.033) as well as death (HR = 1.23; 95% CI 1.11-1.36; p ≤ 0.001). CONCLUSION: Incremental 30-day wait times are associated with a 9% increased risk of residual tumor and a 23% increased risk of death. We have identified system gaps where quality improvement measures can be implemented to reduce wait times and allocate resources for future RFA treatment, which may improve both quality and efficiency of HCC care.

Primary cystic peritoneal masses and mimickers: spectrum of diseases with pathologic correlation.

Cystic lesions within the peritoneum have been classified classically according to their lining on histology into four categories-endothelial, epithelial, mesothelial, and others (germ cell tumors, sex cord gonadal stromal tumors, cystic mesenchymal tumors, fibrous wall tumors, and infectious cystic peritoneal lesions). In this article, we will proceed to classify cystic peritoneal lesions focusing on the degree of radiological complexity into three categories-simple cystic, mildly complex, and cystic with solid component lesions. Many intra-abdominal collections within the peritoneal cavity such as abscess, seroma, biloma, urinoma, or lymphocele may mimic primary peritoneal cystic masses and need to be differentiated. Clinical history and imaging features may help differentiate intra-abdominal collections from primary peritoneal masses. Lymphangiomas are benign multilocular cystic masses that can virtually occur in any location within the abdomen and insinuate between structures. Ultrasound may help differentiate enteric duplication cysts from other mesenteric and omental cysts in the abdomen. Double-layered wall along the mesenteric side of bowel may suggest its diagnosis in the proper clinical setting. Characteristic imaging features of hydatid cysts are internal daughter cysts, floating membranes and matrix, peripheral calcifications, and collagenous pericyst. Non-pancreatic psuedocysts usually have a fibrotic thick wall and chylous content may lead to a fat-fluid level. Pseudomyxoma peritonei appears as loculated fluid collections in the peritoneal cavity, omentum, and mesentery and may scallop visceral surfaces. Many of the primary cystic peritoneal masses have specific imaging features which can help in accurate diagnosis and management of these entities. Knowledge of the imaging spectrum of cystic peritoneal masses is necessary to distinguish from other potential cystic abdominal mimicker masses.