Accumulation of iodine or other similar K-edge equivalent element within renal cysts mimics enhancing masses at single-phase dual-energy CT.

OBJECTIVE: To describe instances of iodine, or other element with similar K-edge to iodine, accumulating in benign renal cysts and simulating solid renal masses (SRM) at single-phase contrast-enhanced (CE) dual-energy CT (DECT). METHODS: During the course of routine clinical practice, instances of benign renal cysts (reference standard true non-contrast enhanced CT [NCCT] homogeneous attenuation <10 HU and not enhancing, or MRI) simulating SRM at follow-up single-phase CE-DECT due to iodine (or other element) accumulation were documented in two institutions over a 3-month observation period in 2021. RESULTS: Five Bosniak one renal cysts (12 ± 7 mm) in five patients changed nature on follow-up imaging simulating SRM at CE-DECT. At time of DECT, cyst attenuation on true NCCT (mean 91 ± 25 HU [Range 56-120]) was significantly higher compared to virtual NCCT (mean 11 ± 22 HU [-23-30], p = 0.003) and all five cysts showed internal iodine content on DECT iodine maps with concentration >1.9 mg ml-1 (mean 8.2 ± 7.6 mg ml-1 [2.8-20.9]). CONCLUSION: The accumulation of iodine, or other element with similar K-edge to iodine, in benign renal cysts could simulate enhancing renal masses at single-phase contrast-enhanced DECT.

Ultrasound Workflow in a Pandemic: Lessons Learned from COVID-19.

The 2019 novel coronavirus (COVID-19) pandemic has posed unique, sudden challenges to health care systems. This is true particularly in the context of ultrasound logistics given the risks of inherent prolonged close contact of patients with sonographers and equipment during sonographic image acquisition. We describe the adaptations and modifications in scheduling, workflow, and imaging protocols implemented in our radiology department ultrasound division (a large urban academic center). The hierarchy of controls to minimize exposures to occupational hazards to protect workers, outlined by The National Institute for Occupational Safety and Health (NIOSH) are listed from most effective to least effective: elimination, substitution, engineering controls, administrative controls, and PPE (personal protective equipment (PPE)). Most of the mitigation techniques used in the ultrasound department to reduce hazards to workers involved administrative controls and PPE. We reduced preventable risks by using sterile precautions, imaging triage, and strategically minimizing image acquisition times. These implementations provide a modifiable framework for rapid adaptation during the evolving COVID-19 pandemic, including resurgences of variant strains. This framework ensures a level of preparedness for possible future pandemics or other widespread emergencies.

Gallbladder Carcinoma and Its Differential Diagnosis at MRI: What Radiologists Should Know.

Gallbladder carcinoma is the most common cancer of the biliary system. It is challenging to diagnose because patients are often asymptomatic or present with nonspecific symptoms that mimic common benign diseases. Surgical excision is the only curative therapy and is best accomplished at early non-locally advanced stages. Unfortunately, gallbladder cancer often manifests at late locally advanced stages, precluding cure. Early tumors are often incidentally detected at imaging or at cholecystectomy performed for another indication. Typical imaging features of localized disease include asymmetric gallbladder wall thickening, polyps larger than 1.0 cm, and a solid mass replacing the gallbladder lumen. Advanced tumors are often infiltrative and can be confusing at CT and MRI owing to their large size. Determination of the origin of the lesion is paramount to narrow the differential diagnosis but is often challenging. It is important to identify gallbladder cancer and distinguish it from other benign and malignant hepatobiliary processes. Since surgical resection is the only curative treatment option, radiologist understanding and interpretation of pathways of nodal and infiltrative tumor spread can direct surgery or preclude patients who may not benefit from surgery. While both CT and MRI are effective, MRI provides superior soft-tissue characterization of the gallbladder and biliary tree and is a useful imaging tool for diagnosis, staging, and evaluation of treatment response. ©RSNA, 2020.

Imaging assessment of local recurrence of prostate cancer after radical prostatectomy.

Definitive therapy for prostate cancer includes radical prostatectomy and radiation therapy. Treatment is elected based on patient preference, biological tumor factors, and underlying health. Post prostatectomy, men are surveyed for disease recurrence with serial PSA measurements, digital rectal exam, and imaging studies depending on nomogram predicted risk of local disease recurrence and distant metastasis. In men with rising PSA levels, pathologically incomplete surgical margins or, if symptoms of metastasis develop, imaging may be obtained to localize disease. In cases of known biochemical recurrence, imaging is used to target biopsy, to contour in salvage radiation therapy and to assess disease response. For local disease recurrence, the most commonly performed exams are pelvic MRI and transrectal US. CT can evaluate for lymph node metastasis, but is suboptimal in the evaluation of the prostatectomy bed. PET/CT and PET/MRI have been used successfully to evaluate for local disease recurrence. The PI-RADSv2.1 manual provides a risk level and lexicon for use in description of prostate carcinoma prior to prostatectomy, but does not address imaging features post-surgery. A detailed description of nodal, bony, and visceral metastasis is given elsewhere. This manuscript outlines the context in which appropriate imaging exams may be obtained and focuses on imaging findings concerning for local disease recurrence after prostatectomy on various imaging modalities including CT, US, MRI, and PET.

Prostate MRI: staging and decision-making.

Multi-parametric prostate MRI (mpMRI) plays a critical role in the diagnosis, staging, and evaluation of treatment response in patients with prostate cancer. Radiologists, through an accurate and standardized interpretation of mpMRI, can clinically stage prostate cancer and help to risk stratify patients who may benefit from more invasive treatment or exclude patients who may be harmed by overtreatment. The purpose of this article is to describe key findings to accurately stage prostate cancer with mpMRI and to describe the contexts in which mpMRI is best applied.

Novel, anatomically appropriate balloon dilation technique of the glottis to treat posterior glottic stenosis in a 3D-printed model.

OBJECTIVE: Posterior glottic stenosis (PGS) often requires a destructive surgical treatment. Early PGS treatment involves glottic dilation to reduce airway constriction associated with chronic PGS. Round laryngeal dilation may not optimize posterior glottic dilation due to the teardrop shape of the glottis and may injure vocal fold tissue. We compared pressure applied to the glottis during traditional single balloon dilation and a novel, anatomically appropriate dilation technique (teardrop-shaped glottic dilation [TSGD]). METHODS: Pressure sensors were affixed at various points on a three-dimensional printed glottic model. The anterior glottis was stented with a triangular stent (18-32F) in combination with balloon dilator (10-20 mm) placed in the posterior glottis (TSGD) in 30 unique combinations. Force applied to the vocal folds (VF) and posterior commissure (PC) during round balloon dilation and TSGD was measured. RESULTS: Dilatory force in the PC ranged from 0.0-3.8 newtons (N) using balloon dilators and 0.0-17.5 N using TSGD. The TSGD technique yielded a superior ratio of force applied to the PC versus VF (P = 0.0296) compared to round balloon dilation alone. Optimal targeting of the PC occurred when the sum of the anteroposterior (AP) dimensions of the stent and balloon dilator approached the AP length of the glottis. CONCLUSION: Use of an anatomically appropriate glottic dilation maximizes expansive force applied to the posterior commissure and decreased force to the vocal folds. This study demonstrates that TSGD minimizes force to the anterior glottis and maximizes dilation of the posterior glottis. This technique may play a role in preventing laryngeal stenosis associated with chronic PGS. LEVEL OF EVIDENCE: NA Laryngoscope, 129:2239-2243, 2019.

Evidence-Based Reporting: A Method to Optimize Prostate MRI Communications With Referring Physicians.

OBJECTIVE: The purpose of this study was to develop an evidence-based method to optimize prostate MRI reports that would improve communication between urologists and radiologists. MATERIALS AND METHODS: This quality improvement initiative was approved by the institutional Quality Improvement Review Committee. A structured report was developed containing essential components defined by local practice norms and Prostate Imaging Reporting and Data System (PI-RADS) lexicon version 2. Two hundred preintervention and 100 postintervention reports were retrospectively reviewed for essential components. Additionally, a sample of 40 reports generated before the intervention and 40 reports generated after the intervention that made use of the structured report were evaluated by a urologist and were scored on a 5-point scale for consistency, completeness, conciseness, clarity, likelihood to contact radiologist, and clinical impact. Variables were compared with ANOVA, chi-square, or Fisher exact test. RESULTS: Essential components of the report were utilization of the PI-RADSv2 lexicon, findings listed by lesion, reporting of pertinent positive and negative findings (extraprostatic extension, seminal vesicle, and neurovascular bundle invasion), and low word count. In postintervention reports, all essential measures were statistically improved except for mean report word count. The urologist indicated statistically improved consistency (before intervention, 2.7; after intervention, 3.5; χ2 < 0.001), completeness (before intervention, 2.8; after intervention, 3.3; χ2 < 0.001), clarity (before intervention, 2.9; after intervention, 3.3; χ2 < 0.05), and clinical impact (before intervention, 2.8; after intervention, 3.8; χ2 < 0.001) of the report with reduced perceived need to contact (before intervention, 3.2; after intervention, 2.1; χ2 < 0.001) the interpreting radiologist for explanation. CONCLUSION: The structured prostate MRI report resulted in improved communication with referring urologists as indicated by the increased perceived clinical impact of the report.

Connecting cancer biology and clinical outcomes to imaging in KRAS mutant and wild-type colorectal cancer liver tumors following selective internal radiation therapy with yttrium-90.

PURPOSE: To determine whether pathologic colorectal tumor KRAS mutation status is correlated with progression-free survival (PFS) by imaging after selective internal radiation therapy with Yttrium-90 (SIRT Y90) for metastatic colorectal cancer in the liver (mCRC). MATERIALS AND METHODS: This was an IRB approved, HIPAA compliant retrospective cohort study. Consecutive patients with unresectable mCRC with documented KRAS mutation status treated at a single center from 2002 to 2013 with SIRT Y90 were investigated. Treatment response was compared between KRAS wild-type (wt) and mutant (mut) using an anatomic tumor response criteria based on RECIST 1.0. Kaplan-Meier estimation and Cox regression analysis were used to measure progression-free survival (PFS) and to assess independent prognostic factors for PFS. RESULTS: 82 of 186 patients met review criteria. 33 (40.2%) patients were identified as KRAS mut. PFS was longer in KRAS wt (median 166 days [95% CI 96-258 days]) vs. mut (median 91 days [95% CI 79-104 days], p = 0.002). KRAS mut patients were 1.48 times more likely to progress at first follow-up imaging than wt (95% CI 1.06-2.08, p = 0.024). Univariate analysis identified high pre-SIRT Y90 INR, KRAS wt, any use of anti-EGFR therapy, and post-SIRT Y90 chemotherapy as prognostic factors for longer PFS. In multivariate analysis, only KRAS wt was an independent prognostic factor for longer PFS (RR: 1.80 [95% CI 1.08-2.99], p = 0.024). CONCLUSION: Longer PFS is associated with KRAS wt vs. mut following SIRT Y90.

The Effect of Bridging Locoregional Therapy and Sociodemographics on Survival in Hepatocellular Carcinoma Patients Undergoing Orthotopic Liver Transplantation: A United Network for Organ Sharing Population Study.

PURPOSE: To investigate socioeconomic and demographic factors associated with transplantation outcomes in patients with hepatocellular carcinoma (HCC) treated with bridging locoregional therapy (LRT) before orthotopic liver transplantation (OLT). MATERIALS AND METHODS: The United Network for Organ Sharing (UNOS) database was used to identify all patients in the United States with HCC who were listed for OLT between 2002 and 2013. Mean overall survival (OS) after OLT was stratified based on age, sex, ethnicity, transplant year, region, and insurance status. Kaplan-Meier estimation was used for survival analysis with log-rank test and Cox proportional hazards model to assess independent prognostic factors for OS. RESULTS: Of the 17,291 listed patients with HCC, 14,511 underwent OLT. Mean age was 57.4 years (76.8% male). Favorable sociodemographic factors were associated with increased rates of bridging LRT before OLT and longer wait time on the transplant list and were shown to be independent prognostic factors for prolonged OS after OLT using multivariate analysis. Favorable demographic factors included patient age < 60 years, donor age < 45 years, year of diagnosis between 2008 and 2013, UNOS regions 4 and 5, Asian ethnicity, high functional status, postgraduate education, private payer insurance, and employment at the time of OLT. CONCLUSIONS: Patients with favorable sociodemographics had higher rates of LRT before OLT performed for HCC cure. These patients had longer transplant wait times and longer OS after OLT.

KRAS Status as an Independent Prognostic Factor for Survival after Yttrium-90 Radioembolization Therapy for Unresectable Colorectal Cancer Liver Metastases.

PURPOSE: To evaluate Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation status as a prognostic factor for survival after yttrium-90 ((90)Y) radioembolization for colorectal cancer (CRC) liver metastases. MATERIALS AND METHODS: Consecutive patients with unresectable CRC liver metastases and documented KRAS mutation status who were treated with (90)Y radioembolization during the period 2007-2014 were investigated. Patient demographics, disease characteristics, therapy regimens, and overall survival (OS) from first (90)Y radioembolization were compared between patients with KRAS wild-type (wt) and mutant status. Kaplan-Meier estimation and Cox regression were used for survival analysis and to assess independent prognostic factors for OS. RESULTS: Of 186 patients, 104 underwent KRAS mutation analysis before (90)Y radioembolization, with 45 (43.3%) identified as mutant. The wt and mutant groups were similar in demographics, liver status, overall performance status, and tumor characteristics (all P > .05). Mean time from liver metastasis to (90)Y radioembolization was greater in patients with KRAS wt status (P = .033). A greater percentage of wt patients received anti-epidermal growth factor receptor therapies before (90)Y radioembolization (66.1% vs 8.9%; P < .001). Median OS from first (90)Y radioembolization was significantly greater in KRAS wt patients (9.5 mo vs 4.8 mo; P = .041). Univariate analysis identified Child-Pugh class, carcinoembryonic antigen (CEA), chemotherapy after (90)Y radioembolization, KRAS status, and treatment-induced toxicity as prognostic factors for OS. Multivariate Cox regression analysis demonstrated Child-Pugh class, CEA, and KRAS status to be independent prognostic factors for OS, even when correcting for the effect of chemotherapy after (90)Y radioembolization. CONCLUSIONS: Patients with CRC and KRAS wt may derive greater survival benefit from (90)Y radioembolization therapy than patients with KRAS mutant.

Biocompatibility and preclinical feasibility tests of a temperature-sensitive hydrogel for the purpose of surgical wound pain control and cartilage repair.

We recently introduced a novel pluronic F127 and hyaluronic acid-based hydrogel (HG) designed to deliver a broad range of therapeutics. The reverse-thermal responsive HG exhibits physical properties that seem to be ideal for the local delivery of drug- and cell-based therapies to specific anatomic sites through percutaneous injection. However, questions related to the HG's safety and efficacy must first be addressed. To address these issues, we performed standard in vitro cytotoxicity and drug release tests and in vivo biocompatibility tests in a rat model. In addition, we determined whether the HG was an effective stem cell carrier in a rat cartilage defect model. We found that the HG showed viability and biocompatibility levels similar to those reported for F127 or hyaluronic acid alone. In vitro drug release studies with bupivacaine, a drug used clinically for local pain relief, revealed that after an initial burst bupivacaine was released continuously for 10 days. Stem cells loaded in the HG were retained in situ and stimulated cartilage regeneration in experimental defects. Taken as a whole, these findings support further efforts to develop the HG as a versatile system for the delivery of a wide range of therapeutic agents in humans. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.

Biocompatibility and preclinical feasibility tests of a temperature-sensitive hydrogel for the purpose of surgical wound pain control and cartilage repair.

We recently introduced a novel pluronic F127 and hyaluronic acid-based hydrogel (HG) designed to deliver a broad range of therapeutics. The reverse-thermal responsive HG exhibits physical properties that seem to be ideal for the local delivery of drug- and cell-based therapies to specific anatomic sites through percutaneous injection. However, questions related to the HG's safety and efficacy must first be addressed. To address these issues, we performed standard in vitro cytotoxicity and drug release tests and in vivo biocompatibility tests in a rat model. In addition, we determined whether the HG was an effective stem cell carrier in a rat cartilage defect model. We found that the HG showed viability and biocompatibility levels similar to those reported for F127 or hyaluronic acid alone. In vitro drug release studies with bupivacaine, a drug used clinically for local pain relief, revealed that after an initial burst bupivacaine was released continuously for 10 days. Stem cells loaded in the HG were retained in situ and stimulated cartilage regeneration in experimental defects. Taken as a whole, these findings support further efforts to develop the HG as a versatile system for the delivery of a wide range of therapeutic agents in humans.

Biomechanical comparison of anterior, posterior, and circumferential fixation after one-level anterior cervical corpectomy in the human cadaveric spine.

STUDY DESIGN: In vitro biomechanical study of cadaveric cervical spine. OBJECTIVE: To compare the rigidity of the cervical spine after anterior, posterior, and circumferential fixation after 1-level corpectomy, and evaluate the effects of the integrity of the facet capsules and posterior ligaments (PL). SUMMARY OF BACKGROUND DATA: Anterior cervical corpectomy is commonly used for decompression of the spinal canal in the treatment of different pathologic conditions. The effect of the integrity of the facet capsules and PLs on the biomechanical stability provided by anterior, posterior, or circumferential fixation following 1-level corpectomy has not been investigated. METHODS: Nine cadaveric cervical spines were potted rostrally at C2, and caudally at T1-T2, and were tested in 6 directions with pure moment application, in 5 conditions: In the intact spine, after a C5 corpectomy and anterior fixation, after anterior fixation and disruption of the C4-C5 and C5-C6 facet capsules and PL, after circumferential fixation, and after posterior fixation alone without anterior cage. Angular motion of C4 relative to C6 was measured. RESULTS: Despite C5 corpectomy, anterior grafting and plate fixation was more rigid than the intact spine with all loads in flexion, at loads of 0.5 Nm and 1.0 Nm in right axial rotation and right lateral bending, and at all loads in left lateral bending. Posterior ligamentous disruption increased motion in the coronal and axial planes, but not in the sagittal plane. Circumferential instrumentation resulted in a significant reduction in motion of the spine compared with anterior instrumentation in both the coronal and axial planes but not in the sagittal plane. Posterior fixation without anterior cage failed to limit cervical spine motion in the sagittal plane, but was restrictive in axial rotation and lateral bending when compared with circumferential fixation. CONCLUSION: After C5 corpectomy, with intact PLs and facet capsules, anterior instrumentation is sufficient for spinal stabilization as the resultant construct is more rigid than the intact state. In the presence of C5 corpectomy with PL and bilateral facet capsule disruption, anterior plus posterior instrumentation is more rigid than anterior instrumentation alone in the axial and coronal planes and more rigid than posterior instrumentation without anterior cage in the sagittal plane.