Conventional Hepatic Volumetry May Lead to Inaccurate Segmental Yttrium-90 Radiation Dosimetry.

OBJECTIVE: To compare radioembolization treatment zone volumes from mapping cone beam CT (CBCT) versus planning CT/MRI and to model their impact on dosimetry. METHODS: Y90 cases were retrospectively identified in which intra-procedural CBCT angiograms were performed. Segmental and lobar treatment zone volumes were calculated with semi-automated contouring using Couinaud venous anatomy (planning CT/MRI) or tumor angiosome enhancement (CBCT). Differences were compared with a Wilcoxon signed-rank test. Treatment zone-specific differences in segmental volumes by volumetric method were also calculated and used to model differences in delivered dose using medical internal radiation dosimetry (MIRD) at 200 and 120 Gy targets. Anatomic, pathologic, and technical factors likely affecting segmental volumes by volumetric method were evaluated. RESULTS: Forty segmental and 48 lobar CBCT angiograms and corresponding planning CT/MRI scans were included. Median Couinaud- and CBCT-derived segmental volumes were 281 and 243 mL, respectively (p = 0.005). Differences between Couinaud and CBCT lobar volumes (right, left) were not significant (p = 0.24, p = 0.07). Couinaud overestimated segmental volumes in 28 cases by a median of 98 mL (83%) and underestimated in 12 cases by median 69 mL (20%). At a 200 Gy dose target, Couinaud estimates produced median delivered doses of 367 and 160 Gy in these 28 and 12 cases. At a 120 Gy target, Couinaud produced doses of 220 and 96 Gy. Proximal vs. distal microcatheter positioning, variant arterial anatomy, and tumor location on or near segmental watersheds were leading factors linked to volumetric differences. CONCLUSION: Use of CBCT-based volumetry may allow more accurate, personalized dosimetry for segmental Y90 radioembolization.

The economics of quality and safety in radiology: Accreditation programs and landmark legislation.

Quality and patient safety are essential to the practice of radiology. "Quality is our image" is the slogan for the American College of Radiology (ACR), which has embraced the quality and safety movement as a central tenet. The impact of advances in radiology on diagnosis and management of complex medical disorders cannot be understated. Nevertheless, these revolutionary technologies do come at a cost. Increasing utilization of advanced imaging in emergency departments throughout the country poses challenges both in terms of appropriate use and management of radiation dose. The indispensable place advanced imaging plays in diagnosis has necessitated guidelines and accountability to protect patients and radiology staff. In this series, we have created a concise discourse on what we have determined to be the essentials of the economics of quality and safety as it pertains to radiology. In this first article, we summarize the accreditation programs in radiology, their legislative background, and the associated financial and market responses that have subsequently resulted. We discuss the progression from historical predecessors to the passage of the Mammography Quality and Safety Act (MQSA), which served as a model for subsequent laws governing the quality and safety of other imaging modalities. These laws have had real economic implications for radiology practices seeking to meet new increasingly stringent guidelines. We also break down the costs of participation in the ACR accreditation and center of excellence programs.

Interventional radiology's role in the diagnosis and management of patients with gallbladder carcinoma.

Gallbladder carcinoma is a rare, aggressive biliary tract malignancy, with a 5-year survival of less than 5%. It is the 6th most common gastrointestinal malignancy in the United States and more commonly found in women. While some risk factors include gallstones, porcelain gallbladder, and smoking, gallbladder carcinoma is often found incidentally following cholecystectomy or percutaneous image guided biopsy. Patients frequently present in a late disease state when they are no longer surgical candidates and minimally invasive image guided-interventions therefore play a critical role in the management and treatment of these patients. This review will discuss some of the key procedures and roles interventional radiologists play in the diagnosis and management of patients suffering from gallbladder carcinoma including tissue sampling, placement of intra-arterial infusion pumps, preoperative portal vein embolization (PVE), biliary drainage, management of post-operative complications such as bile leaks or biliary obstruction, and management of chronic pain.

Are chargemaster rates for imaging studies lower in States that cap noneconomic damages (tort reform)?

PURPOSE: To determine whether chargemaster (a list of prices for common services and procedures set by individual hospitals) rates for diagnostic imaging were lower in states that cap awards for noneconomic damages (NED) than states with unlimited awards for medical negligence. METHODS: We analyzed 2011 chargemaster data from the Centers for Medicare & Medicaid, pertaining to 6 ambulatory patient classifications specific to imaging. The dataset includes outpatient imaging facilities and hospitals in 49 states and the District of Columbia. The association between caps on NED and chargemaster rates for imaging in a sample of 15,218 data points was analyzed using linear regression and two-sample t tests assuming unequal variances. RESULTS: In states that cap NED, the chargemaster rates were higher for the following modalities: Level II Echocardiogram without Contrast (mean charges: $2,015.60 versus $1,884.81, P = .0018); Level II Cardiac Imaging ($4,670.25 versus $4,398.58, P = .002); MRI & Magnetic Resonance Angiography without Contrast ($2,654.31 versus $2,526.74, P = .002); and Level III Diagnostic and Screening Ultrasound ($1,073.31 versus $1,027.32, P = .037). High charge-to-payment ratios were associated with states with the highest charges. There was a positive correlation between number of outpatient centers in the state and the average chargemaster rates for the state (mean chargemaster rate = 1727 + 0.79*Number of Outpatient Centers; R-squared = 0.23, P = .0004). CONCLUSIONS: Chargemaster rates for select imaging services are not lower in states that have capped NED.