[CT-guided biopsies, drainage and and percutaneous gastrostomies: comparison of punctures with and without CT fluoroscopy]

[Percutaneous abdominopelvic interventional procedures using real-time CT fluoroscopy guidance at 21 mAs: an analysis of 99 consecutive cases]

PURPOSE

The purpose of our study was to retrospectively evaluate the efficacy, the limitations and the complications of real-time CT fluoroscopy (Carevision) as an adjunct to CT guidance for percutaneous abdominopelvic interventional procedures. Materials and methods. During a 28 month period, 99 patients (55 men, 44 women) with a mean age of 59 years had percutaneous abdominopelvic interventional procedure under CT guidance using CT fluoroscopy. Sixty-four patients had a percutaneous drainage of an abdominopelvic fluid collection with a Seldinger technique using an 8.5- to 14-F drainage catheter and 35 patients had a percutaneous biopsy using an 18-G automatic core biopsy needle.

RESULTS

In all cases, the quality of the real-time CT fluoroscopic images allowed to securely monitor needle advancement towards the target lesion and to confirm correct position of the needle tip. The diameters of target lesions ranged from 1.5 to 10 cm, with a mean value of 4.75 cm. No immediate complications were observed. The real-time CT fluoroscopy times ranged from 25 to 242 sec, with a mean time of 117 sec. All percutaneous procedures (100%) were successfully performed.

CONCLUSION

Our initial clinical experience suggests that real-time CT fluoroscopy allows to perform effective and secure percutaneous abdominopelvic interventional procedures. However, because of substantial radiation exposure, its use has to be limited to specific et selected cases.

CT-guided intervention with low radiation dose: feasibility and experience

OBJECTIVE

The purpose of this study was to evaluate the feasibility of performing CT-guided interventional procedures with a very low radiation dose.

MATERIALS AND METHODS

We performed 291 CT-guided interventional procedures using a low dose of radiation. The subjects were 165 men and 126 women 22-89 years old with a mean age of 65 years. CT fluoroscopy was not used. The procedures were 201 percutaneous biopsies and 90 percutaneous aspiration or drainage procedures. Before the procedure, images were obtained with standard mAs of 175-250 mAs. All subsequent CT was performed at a reduced mAs. Technical success of catheter placement and biopsy was calculated, and the results were compared with those of procedures performed over the previous 12 months with standard radiation doses. Patient weight, lesion size, and number of CT acquisitions needed to complete the procedure were recorded.

RESULTS

All but three aspiration or drainage procedures performed at 30 mAs were successful, for a success rate of 96.7%. The technical success rate of biopsy performed at 30 mAs was 93.5%. In the cases of 13 patients undergoing biopsy, the masses were not identified with low-dose technique, and these procedures were completed at a higher dose. Results were independent of patient weight and lesion size. The technical success rate was 98% for percutaneous drainage performed at a standard radiation dose in the 12 months before introduction of the low-dose technique. The technical success rate was 87.5% for biopsy performed at a standard radiation dose in the 12 months before introduction of the low-dose technique. The complication rate of the low-dose technique was comparable to that of the standard-dose technique.

CONCLUSION

Low-dose radiation technique using 30 mAs results in technical success for both catheter placement and percutaneous biopsy comparable to standard radiation dose.

[CT fluoroscopy]

Percutaneous biopsy of pulmonary nodules requires precise needle placement, with the goal of attaining a secure position of the needle for therapeutic or diagnostic purposes as quickly as possible and with minimal tissue damage along the access route. The requirements from the image guidance system during the intervention are, in addition to universal applicability, a quick reaction time and a user-friendly interface. CT fluoroscopy fulfils these requirements, although radiation protection for the patient and radiologist becomes an important issue.

CT arthrography of the glenohumeral joint: CT fluoroscopy versus conventional CT and fluoroscopy--comparison of image-guidance techniques

PURPOSE

To compare examination time with radiologist time and to measure radiation dose of computed tomographic (CT) fluoroscopy, conventional CT, and conventional fluoroscopy as guiding modalities for shoulder CT arthrography.

MATERIALS AND METHODS

Glenohumeral injection of contrast material for CT arthrography was performed in 64 consecutive patients (mean age, 32 years; age range, 16-74 years) and was guided with CT fluoroscopy (n = 28), conventional CT (n = 14), or conventional fluoroscopy (n = 22). Room times (arthrography, room change, CT, and total examination times) and radiologist times (time the radiologist spent in the fluoroscopy or CT room) were measured. One-way analysis of variance and Bonferroni-Dunn posthoc tests were performed for comparison of mean times. Mean effective radiation dose was calculated for each method with examination data, phantom measurements, and standard software.

RESULTS

Mean total examination time was 28.0 minutes for CT fluoroscopy, 28.6 minutes for conventional CT, and 29.4 minutes for conventional fluoroscopy; mean radiologist time was 9.9 minutes, 10.5 minutes, and 9.0 minutes, respectively. These differences were not statistically significant. Mean effective radiation dose was 0.0015 mSv for conventional fluoroscopy (mean, nine sections), 0.22 mSv for CT fluoroscopy (120 kV; 50 mA; mean, 15 sections), and 0.96 mSv for conventional CT (140 kV; 240 mA; mean, six sections). Effective radiation dose can be reduced to 0.18 mSv for conventional CT by changing imaging parameters to 120 kV and 100 mA. Mean effective radiation dose of the diagnostic CT arthrographic examination (140 kV; 240 mA; mean, 25 sections) was 2.4 mSv.

CONCLUSION

CT fluoroscopy and conventional CT are valuable alternative modalities for glenohumeral CT arthrography, as examination and radiologist times are not significantly different. CT guidance requires a greater radiation dose than does conventional fluoroscopy, but with adequate parameters CT guidance constitutes approximately 8% of the radiation dose.

Pulse-inversion harmonic imaging improves lesion conspicuity during US-guided biopsy

PURPOSE

To assess the feasibility of percutaneous biopsy of low-conspicuity focal liver lesions with use of pulse-inversion harmonic imaging (PIHI) guidance in the late phase after injection of microbubble contrast agent.

MATERIALS AND METHODS

Twelve patients referred for ultrasound (US)-guided biopsy had liver lesions lacking adequate conspicuity to undergo biopsy under conventional ultrasound (US) guidance. They underwent biopsy procedures performed with the use of PIHI guidance in the late phase after injection of Levovist. The conspicuity of lesions, procedure time, number of passes, and success and complication rates were documented and compared to a control group. The control group consisted of retrospective analysis of 19 patients who had undergone conventional US-guided biopsy procedures performed by the same radiologist.

RESULTS

After contrast material injection, all lesions had sufficient increases in conspicuity to be targeted under PIHI guidance. Procedure time was prolonged in the PIHI group (66 minutes; range, 30-120 min; vs control, 33 min; range, 15-77 min; P <.01, Wilcoxon signed-rank test). The number of passes was greater in the PIHI group (1.9 +/- 0.3; vs control, 1.4 +/- 0.6; P <.01, chi(2) test). No statistically significant difference was observed when comparing success and complication rates.

CONCLUSION

PIHI in the late phase after injection of Levovist generated clear delineation of focal liver lesions in all cases, allowing an accurate and safe sampling. This technique broadens the scope of US-guided biopsy to lesions lacking adequate conspicuity on conventional US.

Technical note: CT-guided biopsy: A new diagnostic method for paleopathological research

The aim of this paper was to demonstrate the application of computerized tomographic (CT)-guided biopsy in a paleopathological examination. Researchers dealing with such special tasks should be aware of this method. We performed a CT-guided percutaneous biopsy of an ancient Egyptian child mummy, which allowed us to revise its initial diagnosis. Based on this experience, extended preinterventional planning and the choice of equipment (needle type) preferred by performing radiologists are strongly recommended, since they will influence diagnostic outcome. Easy documentation, suitable approaches according to the object's condition, and a reliable anatomical orientation without superposition effects during the procedure are some of the advantages of this method. It its already widely established in clinical practice. This technique is recommended for future tissue-sampling of human paleopathologic remains like mummies that are still wrapped within their original bandages, or any small bone lesion of unclear etiology.