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Objective: Colorectal liver metastases (CLM) have a variable response to radioembolization. This may be due at least partly to differences in tumor arterial perfusion. The present study examines whether quantitative measurements of enhancement on preprocedure triphasic CT can be used to predict the response of CLM to radioembolization., Materials and Methods: We retrospectively reviewed patients with CLM treated with radioembolization who underwent pretreatment PET/CT and triphasic CT examinations and posttreatment PET/CT examinations. A total of 31 consecutive patients with 60 target tumors were included in the present study. For each tumor, we calculated the hepatic artery coefficient (HAC), portal vein coefficient (PVC), and arterial enhancement fraction (AEF) based on enhancement measurements on pretreatment triphasic CT. HAC and PVC are estimates of the hepatic artery and portal vein blood supply. AEF, which is the arterial phase enhancement divided by the portal phase enhancement, provides an estimate of the hepatic artery blood supply as a fraction of the total blood supply. For each tumor, the metabolic response to radioembolization was based on findings from the initial follow-up PET/CT scan obtained at 4-8 weeks after treatment., Results: A total of 55% of CLM had a complete or partial metabolic response. Arterial phase enhancement, the HAC, and the PVC did not predict which tumors responded to radioembolization. However, the AEF was statistically significantly greater in tumors with a complete or partial metabolic response than in tumors with no metabolic response (i.e., those with stable disease or disease progression) (p = 0.038). An AEF of less than 0.4 was associated with a 40% response rate, whereas an AEF greater than 0.75 was associated with a 78% response rate., Conclusion: Response to radioembolization can be predicted using the AEF calculated from the preprocedure triphasic CT.

Objective: The purpose of this article is to describe a new method for coding trainee participation in vascular interventional radiology procedures., Materials and Methods: From July 2008 through June 2009, all interventional radiology fellows maintained an enhanced case log at our institution; 748 unique cases were logged by procedure type, supervising physician, and level of participation in the case. Level of participation was classified on a 5-point scale that included designations for observation, first assistant, performance of basic techniques, performance of advanced techniques, and primary operation. Descriptive statistics of participation scores were calculated for each quarter and were analyzed by procedure type and by teaching faculty member., Results: As expected, analysis by procedure type showed that average participation scores increased from one quarter to the next in most cases. By the fourth quarter, the modal participation score was 5, indicating primary operation or performance of multiple critical steps. Analysis by teaching faculty member revealed three patterns: those attending physicians facilitating increasing levels of participation in every quarter, those facilitating maximal growth within the first 6 months, and those with irregular trainee participation profiles., Conclusion: Data from a 5-point participation scale add information to the procedure case log that could be used to quantitatively track the technical progress of trainees while providing education quality feedback to both teaching physicians and program directors.

Objective: The purpose of this study is to describe a method for the evaluation and prioritization of near-miss events in a radiology department., Materials and Methods: Sixty-two consecutive near-miss events occurring between 2007 and 2009 were retrospectively evaluated, classified by error type, and scored for five elements associated with risk. The worst outcome potentially associated with each event was predicted by consensus and scored on a standardized 5-point complications grading scale. Scores were then assigned for event frequency, method of detection, barrier number, and quality. The product of individual scores, ranging from 1 to 180, was termed the hazard score. Events were analyzed by error type, element scores, and hazard score., Results: Electronic order entry errors were the most common error type, and 90% of these errors originated outside the radiology department. More than half (65%) of the events were assigned maximal severity scores, and 68% of the errors had been encountered three or more times previously. Twenty-five events (40%) were detected by good fortune rather than by plan. No barrier to the projected worst outcome was identified in nearly half (47%) of cases. In most instances (73%), strong barriers were absent. Nine events (15%) had maximal hazard scores of 180, whereas 21 events (34%) had hazard scores of 30 or less., Conclusion: This method was constructed from standardized definitions of outcome severity, the ability of current systems to detect or mitigate an adverse event or outcome, and event frequency and offers a tool for systematic evaluation and stratification of near-miss adverse events.

Objective: The objective of our article is to describe the technique, complications, and long-term results of transileal conduit retrograde nephroureteral stents placed for ureteral obstruction after radical cystectomy., Materials and Methods: Patients with urinary diversion who presented for retrograde nephroureteral stent placement for the management of ureteral obstruction from June 1997 to August 2007 were identified via retrospective review of PACS and medical records. The procedure was performed in three stages: placement of an antegrade percutaneous nephrostomy or nephroureterostomy catheter, subsequent conversion to a transileal conduit retrograde nephroureteral stent with replacement of the antegrade nephrostomy catheter, and removal of the antegrade nephrostomy catheter after the first successful exchange of the retrograde catheter via the conduit. Medical records were reviewed to determine resolution of the signs and symptoms prompting the procedure and procedure-related complications., Results: Forty-nine patients with ureteral obstruction underwent image-guided placement of 61 antegrade nephrostomy or nephroureterostomy catheters (37 unilateral, 12 bilateral) followed by attempted conversion to transileal conduit retrograde nephroureteral stents. Technical success was achieved in 56 of 61 renal units (91.8%). Clinical success, which was defined as resolution of creatinine elevation, urosepsis, and pain associated with hydronephrosis, occurred in 44 of 49 patients (89.8%) with a mean clinical follow-up of 22 months. Minor complications included tube dislodgement resulting in pericatheter leakage in two patients. No major complications occurred. Delayed complications including catheter dislodgement, recurrent urosepsis, and inability to exchange the retrograde nephroureteral stents were seen in four patients (8.2%) and were mostly due to catheter encrustation., Conclusion: Transileal conduit retrograde nephroureteral stent placement is safe and effective and may serve as definitive treatment for the management of postsurgical ureteral obstruction after noncontinent urinary diversion procedures.

Objective: The objective of our study was to evaluate the safety and efficacy of transhepatic lobar portal vein embolization (PVE) using polyvinyl alcohol (PVA) particles to induce contralateral lobar hypertrophy in patients with liver-only metastases and normal underlying liver function., Materials and Methods: Fifty-eight consecutive patients with small predicted future liver remnants (FLRs) underwent PVE with PVA particles to induce hypertrophy of the contralateral hemi-liver before surgical resection of liver metastases. Total liver, right hemi-liver, and left hemi-liver volumes were calculated before and after embolization using a 3D workstation., Results: Eight patients underwent left PVE; 47, right PVE; and three, right and segment IV PVE. There were no major complications of the procedure. The mean increases in the ratio of the FLR to the total estimated liver volume after right, right and segment IV, and left PVE were 9%, 10%, and 3%, respectively; the corresponding mean hypertrophy ratios were 24.3%, 31.9%, and 1.5%, respectively., Conclusion: Right PVE using PVA particles alone as the embolic agent is safe and effective in achieving left hemi-liver hypertrophy. In contrast, left PVE did not induce significant right hemi-liver hypertrophy in this patient population.

Objective: The purpose of this study was to determine the incidence of variant intrahepatic portal vein anatomy detected on CT portography and to discuss surgical implications., Conclusion: Variant portal vein anatomy is nearly as common as variant hepatic artery anatomy. The complexity of hepatic interventions now performed by interventional radiologists and surgeons, including portal vein embolization, anatomic resection, and transplantation, make recognition and understanding of normal and variant portal vein anatomy increasingly important.