JOURNAL CLUB: Standardizing CT-Guided Biopsy Procedures: Patient Dose and Image Noise.

OBJECTIVE: The objective of this study was to standardize our image acquisition protocol for CT-guided biopsy procedures. MATERIALS AND METHODS: The records of consecutive patients who underwent CT-guided biopsy 3 months before (n = 598 biopsies) and 3 months after (n = 540 biopsies) standardization of our image acquisition protocol were retrospectively reviewed. CT technical parameters were individualized on the basis of the sum of the anteroposterior and transverse dimensions of the patient. Information on patient demographic characteristics, biopsy site, complications associated with the procedure, and diagnostic yield was collected. The radiation dose metrics that were evaluated included the volume CT dose index, dose-length product, and size-specific dose estimate. Image noise was quantified using the SD of the CT number measured in subcutaneous fat. Fisher exact test and one-way ANOVA were used to evaluate statistical significance. RESULTS: The mean dose-length product decreased by 72.3% (from 699.7 to 193.9 mGy × cm; p < 0.0001), and statistically significant decreases in dose-length product were observed when data were stratified according to biopsy site (i.e., lung, solid organ, lymph node, or bone; for all sites, p < 0.0001). The mean size-specific dose estimate decreased by 58.9% (from 125 to 51.4 mGy), which was statistically significant (p < 0.001). Image noise increased during the study period, but this increase was not statistically significantly different among the four biopsy sites (p = 0.46). CONCLUSION: Standardization of the image acquisition protocol used in CT-guided biopsy procedures significantly reduced patient radiation dose and decreased variability in image noise.

Prevention and management of infectious complications of percutaneous interventions.

Infectious complications following interventional radiology (IR) procedures can cause significant patient morbidity and, potentially, mortality. As the number and breadth of IR procedures grow, it becomes increasingly evident that interventional radiologists must possess a thorough understanding of these potential infectious complications. Furthermore, given the increasing incidence of antibiotic-resistant bacteria, emphasis on cost containment, and attention to quality of care, it is critical to have infection control strategies to maximize patient safety. This article reviews infectious complications associated with percutaneous ablation of liver tumors, transarterial embolization of liver tumors, uterine fibroid embolization, percutaneous nephrostomy, percutaneous biliary interventions, central venous catheters, and intravascular stents. Emphasis is placed on incidence, risk factors, prevention, and management. With the use of these strategies, IR procedures can be performed with reduced risk of infectious complications.

The Effect of Needle Gauge on the Risk of Pneumothorax and Chest Tube Placement After Percutaneous Computed Tomographic (CT)-Guided Lung Biopsy.

BACKGROUND: The aim of this study was to evaluate the effect of coaxial guide needle gauge (18 vs. 19 gauge) on the risk of pneumothorax and chest tube placement after CT-guided lung biopsy. METHODS: Imaging records of all patients who had undergone CT-guided lung biopsies at our institution from March 1, 2006 to December 9, 2010 were retrospectively reviewed. Univariate and multivariate logistic regression analyses were performed to assess the effect of various patient-, lesion-, and procedure-related variables on subsequent pneumothorax and chest tube placement rates. RESULTS: The study included 4262 biopsies (2304 with 18-gauge and 1958 with 19-gauge coaxial guide needles) in 3917 patients. The rates of pneumothorax and chest tube placement were 30.2 and 15%, respectively. Pneumothorax occurred in 35% of procedures performed with 18-gauge needles and in 24.5% of procedures performed with 19-gauge needles (p < 0.0001). Chest tube insertion occurred in 16.7% of procedures performed with 18-gauge needles and in 13.1% of procedures performed with 19-gauge needles (p = 0.0011). Multivariate logistic regression models demonstrated that the use of an 18-gauge needle was associated with a higher rate of pneumothorax (p < 0.0001) and chest tube placement (p = 0.0003). The following factors were also associated with higher rates of pneumothorax and chest tube placement: older age, emphysema, greater number of pleural surfaces crossed, and a longer biopsy needle path length. CONCLUSIONS: The use of a 19-gauge coaxial guide needle significantly decreases the risk of pneumothorax and chest tube placement compared with an 18-guage needle.

A spectrum of nerve injury after thermal ablation: a report of four cases and review of the literature.

Thermal ablation is an accepted alternative for the palliation of pain from bone metastases. Although rare, neurologic complications after thermal ablation have been reported. We present four cases, including two cases of rapid reversal of postcryoablation neurapraxia after the administration of steroid therapy, and review the literature.