Use of CO2 to move structures as an aid to percutaneous procedures

By injecting small amounts of CO2 through a needle, one can move bowel or bladder from the intended path of instruments during interventional procedures. The technique worked well in six of seven cases in the pelvis and retroperitoneum; it was not effective in the mediastinum or midabdomen (n = 6).     

CT guided interstitial therapy of pancreatic carcinoma

We describe the use of percutaneous CT guidance for localization and placement of 192Ir sources into a patient with pancreatic carcinoma. We have shown the feasibility of this procedure and the lack of complications which are probably due to minimal damage to tissue involved. Computed tomography is ideally suited for percutaneous implantation because it provides the most accurate method for needle placement within the abdomen.     

The positive automatic thoughts questionnaire (ATQ-P) and the automatic thoughts questionnaire—Revised (ATQ-RP): Equivalent measures of positive thinking?

We examined two recently developed measures of positive automatic thought, the Positive Automatic Thoughts Questionnaire (ATQ-P) and the Automatic Thoughts Questionnaire—Revised (ATQ-RP). Internal consistency, concurrent validity, and convergent and discriminant validity were addressed. Two hundred one undergraduates completed self-report measures of positive automatic thoughts, negative automatic thoughts, depressive symptoms, anxiety symptoms, and positive affectivity. The ATQ-P and ATQ-RP both showed high internal consistency, strong negative associations with depressive symptoms, specificity to depressive symptoms rather than anxiety symptoms, an average state-of-mind (SOM) ratio in the positive dialogue range, and a stronger relation with each other than with a measure of positive affectivity. The only notable difference between the measures was a significantly lower mean score (correcting for number of items) on the ATQ-RP. This paper is based on a thesis completed by the first author, under the supervision of the second author, in partial fulfillment of the requirements for the Master of Arts degree at American University. We are grateful to thesis committee members Lorah Dorn and Jim Gray for feedback on this material.     

MR monitoring of MR-guided radiofrequency thermal ablation of normal liver in an animal model

The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r² value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease.     

Magnetic resonance imaging of the liver

In this article, the author discusses his experience with a 0.30-T superconducting magnet for evaluation of the liver. This discussion includes evaluation of malignant and benign disease and comparison of MRI with CT scanning.     

Percutaneous nephrostomy in neonates and infants

A total of 8 patients between 2 days and 2 years old underwent 13 percutaneous nephrostomies for treatment of hydronephrosis. No significant complications were encountered.     

Interventional CT: 30 years' experience

CT-guided procedures remain an important tool for diagnosis and tissue acquisition for primary diagnosis and molecular/tissue correlation. New imaging devices such as MDCT and PET/CT will improve diagnosis but percutaneous procedures will be needed to confirm and support new molecular and DNA treatments. Coagulopathic patients can be treated with LIBE a new method to prevent bleeding. Vasoactive drugs can be used to improve differentiation of malignant and benign diseases.