Nodules Identified on Surveillance Ultrasound for HCC: CEUS or MRI as the Initial Test?

OBJECTIVES: Following positive surveillance ultrasound (US), magnetic resonance imaging (MRI) is recommended for further characterization. We propose contrast-enhanced ultrasound (CEUS) shows equivalent efficacy. METHODS: This prospective institutional review board approved study recruited 195 consecutive at-risk patients with a positive surveillance US. All had CEUS and MRI. Biopsy (n = 44) and follow-up are gold standard. MRI and CEUS results are classified according to liver imaging reporting and data system (LI-RADS) and patient outcome. RESULTS: As an US-based modality, CEUS is superior in confirming findings from surveillance US, correlation in 189/195 (97%) on CEUS compared to 153/195 (79%) on MRI. Within these negative MRI examinations, there are 2 hepatocellular carcinoma (HCC) and 1 cholangiocarcinoma (iCCA) diagnosed on CEUS and proven by biopsy. From 195 patients, there are 71 malignant diagnoses from all sources, including 58 LR-5 (45 on MRI and 54 on CEUS) and 13 others, including HCC outside of LR-5 category, and LR-M with biopsy proven iCCA (3 on MRI and 6 on CEUS). CEUS and MRI show concordant results in the majority of patients (146/195, 75%), including 57/146 malignant and 89/146 benign diagnoses. There are 41/57 concordant LR-5 and 6/57 concordant LR-M. When CEUS and MRI are discordant, CEUS upgraded 20 (10 biopsy-proven) from MRI LR-3/4 to CEUS LR-5 or LR-M by showing washout (WO) that MRI failed to show. Additionally, CEUS characterized time and intensity of WO and diagnosed 13/20 LR-5 by showing late and weak WO and 7 LR-M by showing fast and marked WO. CEUS is 81% sensitive and 92% specific in diagnosing malignancy. MRI is 64% sensitive and 93% specific. CONCLUSIONS: CEUS performance is at least equivalent if not superior to MRI for initial evaluation of lesions from surveillance US.

Risk stratification of patients with nonalcoholic fatty liver disease using a case identification pathway in primary care: a cross-sectional study.

BACKGROUND: Identification of patients with nonalcoholic fatty liver disease (NAFLD) with advanced liver fibrosis in primary care remains an unmet need. Our primary objective was to implement a pathway driven by shear wave elastography (SWE) to facilitate risk stratification of patients with NAFLD within primary care and evaluate whether SWE assessment can reduce referrals of patients with NAFLD at low risk for fibrosis to hepatology. METHODS: A multidisciplinary NAFLD clinical care pathway was codeveloped by hepatologists, radiologists and primary care physicians in Calgary to provide access to SWE-based screening of patients with NAFLD risk factors in primary care. The study outcome measures were estimated NAFLD-related referrals to the hepatology service in Calgary after implementation of the NAFLD pathway and characteristics of patients with NAFLD at risk for advanced fibrosis. The NAFLD pathway was implemented in January 2018 and was made available to all primary care physicians in the Calgary Health Zone. Patients with NAFLD who had liver stiffness (SWE value ≥ 8.0 kPa) or an inconclusive assessment were referred to hepatology. A serum liver fibrosis score was also measured with the fibrosis-4 (FIB-4) index, and performance of an FIB-4 index score of 1.30 or greater to risk stratify patients with NAFLD was evaluated. Demographic, clinical and laboratory characteristics of study groups were compared. RESULTS: Between March and October 2018, 2084 patients with suspected NAFLD were evaluated. Nonalcoholic fatty liver disease was confirmed by ultrasonography in 1958 (94.1%). A majority of the cohort had elevated liver enzyme values (1028 [52.5%]) and obesity (body mass index ≥ 30) (1063/1764 [60.3%]). Most patients with NAFLD (1791 [91.5%]) had an SWE value less than 8.0 kPa and were not referred to hepatology. Sixty-seven patients (3.4%) had an SWE value of 8.0 kPa or more, and 100 (5.1%) had an inconclusive SWE; these patients were referred to hepatology. Using an FIB-4 index score cut-off of 1.30 would have led to hepatology referral of 396/1251 patients (31.6%). INTERPRETATION: Implementation of a primary care-accessible SWE pathway for patients with NAFLD facilitated fibrosis risk stratification and greatly reduced hepatology referrals. Using the FIB-4 index score alone would led to higher rates of referral of patients with NAFLD.

Resolution of indeterminate MRI with CEUS in patients at high risk for hepatocellular carcinoma.

PURPOSE: To show the contribution of CEUS to characterization of indeterminate MRI observations in high-risk patients for hepatocellular carcinoma (HCC). METHODS: From July to December 2015, 42 consecutive patients referred to CEUS with indeterminate MRI scans comprise our study cohort. There are 50 indeterminate nodule-like observations and 10 arterial phase hyperenhancing foci, suggesting pseudolesions/arterio-portal shunts. MRI and CEUS lesions are classified according to their enhancement features in all phases and Liver Imaging and Reporting Data System (LI-RADS) in a blind read format. Clinical pathologic correlation and 24 months follow-up are performed. RESULTS: A majority, 37/50 (74%), of indeterminate nodule-like observations have arterial phase enhancement without washout on MRI. CEUS further characterizes enhancement and shows washout in 14/37 (38%). In total, CEUS diagnoses 16 malignant lesions in 14 patients including 14 HCC and 2 ICC. 12/16 (75%) malignant lesions are confirmed by biopsy or follow-up. Ultrasound identification of a nodule differentiates real nodules from pseudolesions. Of the ten suspected arterial-portal shunts on MRI, two show a real nodule on ultrasound, confirmed as an HCC and a regenerative nodule. 15/42 (36%) patients have LI-RADS escalated from LR-3 or 4 on MRI to LR-4 or 5 on CEUS. Overall, the sensitivity of CEUS is (13/16) 81.3% and specificity is (37/37) 100% for malignant diagnosis. CONCLUSION: Grayscale ultrasound detects true nodules. Dynamic CEUS detects and characterizes washout, correctly predicting HCC. CEUS is complimentary to MRI and can serve as a problem-solving tool when MRI is indeterminate.

MR venography using time-resolved imaging in interventional management of pelvic venous insufficiency.

PURPOSE OF REVIEW: To evaluate the utility of magnetic resonance venography with time-resolved imaging (MRV TRI) in the diagnosis of pelvic vein insufficiency (PVI). RECENT FINDINGS: A retrospective single-center review of N = 17 consecutive patients who underwent pelvic MRI for the assessment of PVI was performed. N = 8/17 (47%) studies were positive for PVI. TRI imaging demonstrated N = 6/8 patients with Grade 0-3 PVI and N = 2/8 patients with May-Thurner Syndrome. N = 4/8 patients underwent elective endovascular management, all of which were technically successful. In the assessment of PVI, MRV TRI provides a dynamic assessment of venous insufficiency, serving as an adjunct to the imaging diagnosis of this pathology.

Intravenous and Oral Contrast vs Intravenous Contrast Alone Computed Tomography for the Visualization of Appendix and Diagnosis of Appendicitis in Adult Emergency Department Patients.

PURPOSE: The study sought to compare radiologist's ability to 1) visualize the appendix; 2) diagnose acute appendicitis; and 3) diagnose alternative pathologies responsible for acute abdominal pain among adult patients undergoing computed tomography (CT) scan with 3 different protocols: 1) intravenous (IV) contrast only; 2) IV and oral contrast with 1-hour transit time; and 3) IV and oral contrast with 3-hour transit time. METHODS: We collected data of 225 patients; 75 consecutive patients with a clinical suspicion of appendicitis received oral contrast for 3 hours and IV contrast, 75 received oral contrast for 1 hour and IV contrast, and 75 trauma patients received IV contrast only. Three independent reviewers, blinded to final pathology, retrospectively analysed the cases and documented visualization of the appendix, periappendiceal structures, and their confidence in diagnosing appendicitis. Clinical diagnoses were derived from a combination of clinical, surgical, pathologic, or radiologic follow-up. RESULTS: Frequency of visualizing the appendix within IV group alone was 87.3%, IV with oral for 1 hour was 94.1%, and IV with oral for 3 hours was 93.8%. Both oral contrast groups had 100% sensitivity and negative predictive value in diagnosis of acute appendicitis. Specificity for the 1- and 3-hour oral contrast groups was 94.1% and 96.1%, respectively and positive predictive value for both groups was 92%. CONCLUSIONS: Our findings suggest that reader confidence in visualizing the appendix improved with addition of oral contrast as compared to IV contrast alone. One- and 3-hour oral regimens have a similar diagnostic performance in diagnosing appendicitis.

Implementation and validation of a combined MRI-CT-based cervical cancer brachytherapy program using existing infrastructure.

PURPOSE: To describe the implementation of an MRI-CT-based cervical cancer brachytherapy (BT) program using existing infrastructure. To evaluate its impact on treatment planning. METHODS AND MATERIALS: A step-wise method was used to design and implement three-dimensional-based planning. Prospective risk analysis was used to create a process map and planning protocol. To evaluate the program, charts of cervical cancer patients treated curatively between January 2013 and December 2014, with at least one MRI during BT planning, were reviewed. Dosimetric comparisons were made between prescription point used and that of the traditional Point A and between MRI-planned treatments and CT-planned treatments. They were evaluated for differences between plans as well as adherence to Groupe Européen de Curiethérapie-European Society for Radiotherapy & Oncology (GEC-ESTRO) recommendations for high-risk clinical target volume coverage and organs-at-risk constraints. RESULTS: Implementation of the MRI-CT planning program occurred using existing infrastructure. Key to the implementation was communication between departments and the use of a process map to document the workflow. Eighty percent of treatments were prescribed to a point other than Point A, there were no major differences between the MRI-planned and CT-planned (with MRI guidance) treatments, and GEC-ESTRO recommendations were met for target coverage and organs at risk dose constraints. CONCLUSIONS: It was feasible to implement an MRI-CT-based cervical cancer BT planning program using existing infrastructure and that resulting plans meet GEC-ESTRO recommendations.

Consensus statements from a multidisciplinary expert panel on the utilization and application of a liver-specific MRI contrast agent (gadoxetic acid).

OBJECTIVE. This systematic review presents evidence-based consensus statements as reported by a multidisciplinary expert panel (six abdominal radiologists, four hepatobiliary surgeons, and two hepatologists) regarding the use of gadoxetic acid for liver MRI. CONCULSION. Although this review highlights the incremental diagnostic value of hepatobiliary phase imaging with gadoxetic acid-enhanced liver MRI in multiple clinical scenarios, there remains a need for further impact studies for some clinical applications, such as hepatocellular carcinoma in cirrhosis.

Validity of the diagnostic criteria for chronic cerebrospinal venous insufficiency and association with multiple sclerosis.

BACKGROUND: The chronic cerebrospinal venous insufficiency theory proposes that altered cerebral venous hemodynamics play a role in the pathophysiology of multiple sclerosis. We aimed to explore the validity of this hypothesis by assessing the diagnostic criteria for chronic cerebrospinal venous insufficiency in persons with and without multiple sclerosis. METHODS: We compared the proportion of venous outflow abnormalities between patients with multiple sclerosis and healthy controls using extracranial Doppler ultrasonography and gadolinium-enhanced magnetic resonance venography. Interpreting radiologists were blinded to the clinical status of participants. RESULTS: We enrolled 120 patients with multiple sclerosis and 60 healthy controls. High proportions of both patients (67/115 [58%]) and controls (38/60 [63%]) met 1 or more of the proposed ultrasound criteria for diagnosis of chronic cerebrospinal venous insufficiency (p = 0.6). A minority of patients (23/115 [20%]) and controls (6/60 [10%]) fulfilled 2 or more of the proposed criteria (p = 0.1). There were no differences between patients and controls in the prevalence of each individual ultrasound criterion. Similarly, there were no differences in intracranial or extracranial venous patency between groups, as measured by magnetic resonance venography. INTERPRETATION: We detected no differences in the proportion of venous outflow abnormalities between patients with multiple sclerosis and healthy controls. Moreover, our study revealed significant methodologic concerns regarding the proposed diagnostic criteria for chronic cerebrospinal venous insufficiency that challenge their validity.

Hypervascular liver masses on contrast-enhanced ultrasound: the importance of washout.

OBJECTIVE: The objective of our study was to determine the role of negative enhancement (washout), its presence and timing, in the differential diagnosis of hypervascular liver masses on contrast-enhanced ultrasound. MATERIALS AND METHODS: One-hundred forty-six hypervascular liver lesions (mean size, 3.9 cm; range, 1.0-17.0 cm) were evaluated with contrast-enhanced ultrasound over a 6-month period. Seventy-four were benign (29 hemangiomas, 31 focal nodular hyperplasia [FNH] lesions, seven adenomas, five inflammatory lesions, two other) and 72, malignant (41 hepatocellular carcinomas [HCCs], 25 metastases, six other). Two independent reviewers retrospectively recorded the presence and timing of washout in the portal venous phase, observing until 4 minutes after injection, of a contrast agent (perflutren microspheres). Diagnoses were confirmed by histopathology (n = 68) or clinicoradiologic follow-up (n = 78). Timing of washout was compared between types of lesion using Fisher's exact test. RESULTS: Washout occurred in both benign (27/74, 36%) and malignant (70/72, 97%) lesions but was more frequently seen in malignancy (p < 0.001) (kappa = 0.91). Metastases showed more rapid washout than HCCs (p < 0.001): 20 of 25 metastases showed washout by 30 seconds after injection and 23 of 41 HCCs, later than 75 seconds. All malignant lesions without washout were HCCs (2/41). Among the benign lesions, all five inflammatory lesions showed rapid washout before 75 seconds and six of seven adenomas showed washout, mostly later than 75 seconds (5/6). Washout also occurred in hemangiomas (6/29) and FNH lesions (9/31), mostly later than 75 seconds after injection (12/15). CONCLUSION: Hypervascular malignant lesions show washout except infrequent cases of HCC. Rapid washout characterizes metastases, whereas HCCs show variable, often slow, washout. However, washout is not unique to malignancy and may be seen in benign lesions.

A multicenter review of deep venous thrombosis prophylaxis practice patterns for blunt hepatic trauma.

BACKGROUND: Non-operative management of blunt hepatic trauma is successful in the majority of hemodynamically stable patients. Due to the risk of recurrent hemorrhage, pharmacologic deep venous thrombosis (DVT) prophylaxis is often delayed. The optimal timing of prophylaxis is unclear. A multi-centre, retrospective review of patients with blunt hepatic injuries presenting between 2000 and 2004 was performed. All patients had an ISS >/= 12 and a CT scan confirming hepatic trauma. Patients were categorized into: (1) early DVT prophylaxis (48 hrs), and (3) no prophylaxis. METHODS AND RESULTS: Thirty-seven (25%) and 45 (42%) patients received early and delayed DVT prophylaxis respectively. The remainder (32%) received none. Mean hepatic injury grades were lower in the early prophylaxis group (II) compared to the delayed and no prophylaxis cohorts (III)(p = 0.002). The number of patients requiring post-admission blood transfusions was highest in the delayed group (44%) compared to the early (26%) and no prophylaxis (6%) groups (p = 0.03). No patient in the early prophylaxis cohort developed a DVT or required delayed angiographic or operative intervention. Two patients in the delayed group failed non-operative management. Eight (18%) patients in the delayed group developed a clinically significant DVT; 1 (2%) progressed to a PE. CONCLUSION: Practice patterns indicate that chemical DVT prophylaxis initiated within 48 hours of admission may be safe in patients with significant blunt hepatic trauma. Delays in prevention result in venothromboembolic events, but not in fewer blood transfusions or a decreased need for subsequent angiographic or operative therapies.

The spectrum of ulnar collateral ligament injuries as viewed on magnetic resonance imaging of the metacarpophalangeal joint of the thumb.

OBJECTIVE: To elucidate the spectrum of ulnar collateral ligament (UCL) injuries detectable by magnetic resonance imaging (MRI). METHODS: Twenty-one patients (12 male and 9 female, aged 14-62 years) with acute hyperabduction injuries of the first metacarpophalangeal joint underwent MRI for clinically suspected UCL injuries. All scans were performed in either a large-bore, 1.5-T imager or an experimental small-bore, 1.9-T imager. MRI findings and clinical evaluations of all patients and surgical reports of those who underwent surgery (n = 10) were reviewed and correlated retrospectively. RESULTS: A total of 6 patients demonstrated injuries that did not fall into previously described categories of UCL injuries and therefore illustrated the existence of a subclass of UCL injuries. We divided the MRI findings into 5 categories: Stener's lesions (n = 6), moderately displaced (> or = 3 mm) complete tears (n = 5), minimally displaced (< 3 mm) complete tears (n = 4), nondisplaced complete tears (n = 3) and partial tears (n = 3). None of the MRI scans demonstrated a normal UCL. Although sensitivity and specificity were not calculated, only 2 cases demonstrated discordance between the MRI results and surgical findings or clinical outcomes. CONCLUSION: There is a spectrum of UCL injuries that have not previously been described.