Jeffrey B. Mendel

Segmentation and registration of three-dimensional rotational angiogram on live fluoroscopy to guide atrial fibrillation ablation: A new online imaging tool

BACKGROUND Three-dimensional rotational atriography (3DATG) was developed to supplement two-dimensional fluoroscopy with 3D volume reconstruction of the left atrium (LA), pulmonary veins (PV), and other structures. Until recently, 3DATG images could only be viewed separately and were not suitable to directly guide atrial fibrillation (AF) ablation. OBJECTIVE The purpose of this study was to evaluate the feasibility and accuracy of intraprocedural 3DATG. METHODS Three-dimensional rotational atriography with right atrial contrast injection was obtained using a Philips Allura Xper FD10 system in 30 patients with symptomatic AF who also underwent preprocedural computed tomographic (CT) scan. RESULTS The majority (93%) of 3DATG image reconstructions were useful for guidance of catheter ablation. Nearly all PVs (94%), LA appendage (89%), and esophagus (100%) were successfully segmented. Measured PV ostial diameters compared using 3DATG and CT showed close concordance. Registration and re-registration of 3DATG overlay image was easily achieved with thoracic landmarks and validated by catheter placement demonstrating minimal discrepancy. Endoscopic views allowed for improved visualization of ostial position, dimensions, and navigation within the antrum. Lesion tagging on 3DATG overlay enhanced ablation guidance. Radiation exposure with 3DATG was significantly reduced compared with preprocedural CT scan (2.1 +/- 0.3 mSv vs 13.8 +/- 2.4 mSv, P <.001). CONCLUSION Intraprocedural 3DATG imaging during AF ablation with online segmentation and superimposition on live fluoroscopy is feasible. Overlay provides valuable and accurate information on 3D surface outline and endoscopic PV location. Three-dimensional rotational atriography overlay is a new imaging method with reduced radiation exposure that may replace preprocedural CT scan for catheter navigation and ablation of AF.

Evaluation of left atrial and posterior mediastinal anatomy by multidetector helical computed tomography imaging: Relevance to ablation

IntroductionIncreasing use of catheter ablation in the left atrium (LA) requires understanding of substrate anatomy, especially with regard to potential damage to adjacent structures.Methods and resultsWe reviewed multidetector helical computed tomography (MDCT) imaging on 42 subjects, 26 imaged before planned LA ablation for atrial fibrillation (AF), and 16 without AF. LA volume and dimensions were larger in patients with AF (p < 0.05) and the spine and aorta (Ao) impressed the LA more frequently in the AF group. The esophagus (Eo) was the predominant feature on the posterior LA wall, contacting it in all patients. The Ao was in contact with the LA body or the left inferior pulmonary vein (PV) in 32 (76%) of 42 cases, and in 10 it ran along an indentation on the posterior aspect of the LA. The coronary sinus was adjacent to LA ablation sites, the azygos vein was rarely adjacent to those sites, and the left bronchus abutted the PV ostium but not the LA. Two patients had findings that directly impacted the ablation procedure: one patient had a dilated fluid filled Eo with esophageal stricture and underwent nasogastric decompression before ablation, and one was discovered to have an anomalous PV and underwent surgical repair.ConclusionsMDCT imaging identifies structures adjacent to the LA, which could be affected by ablation. Posterior LA topography can be influenced by the position of the Ao or by the proximity of the spine. Preprocedural imaging can characterize anatomic structures that could be vulnerable during ablation, and detect unusual pathology that can affect the treatment plan.

CT-Guided Core Needle Biopsy of Breast Lesions Visible Only on MRI

OBJECTIVE As breast MRI has become more widely used, the need to biopsy suspicious lesions visible only on MRI has increased. A small percentage of these lesions are not amenable to MR-guided biopsy. We report our technique of CT-guided core needle biopsy of breast lesions. CONCLUSION CT-guided core needle biopsy is a safe and effective method for sampling breast lesions visible only on MRI when MR-guided biopsy is not feasible.

Percutaneous Excision: A Viable Alternative to Manage Benign Breast Lesions

Objective Benign breast masses, such as fibroadenomas, are common, and their management is variable, depending on symptoms and patient concerns. We undertook this study to determine the safety, efficacy, and patient acceptance of percutaneous excision of benign breast masses by using a hand-held vacuum-assisted device. Methods By using sonographic guidance, percutaneous removal was performed in 40 patients with 42 lesions by using a 9-gauge (n = 13) or 12-gauge (n = 29) probe (ATEC; Suros Surgical). Technical success, procedural complications, and patient experience were recorded at the time of excision and at 48 hours. Clinical, imaging, and/or surgical follow-up was obtained for 39 of 42 lesions (93%). Three of 42 lesions (7%) were lost to follow-up. Results Of 42 lesions, maximal diameters ranged from 0.6–4.0 cm (mean 1.6 cm), with lesion volumes between 0.05 and 11.2 mL (mean [SD] 1.4 ± 2.1 mL, median 7 mL). The procedure was well tolerated by all patients, and no residual mass was visible in any case at the conclusion of the procedure. All the patients preferred this approach to open surgical biopsy. After percutaneous excision, surgery was performed on 3 of 42 lesions (7%) for atypia (n = 2) or malignancy (n = 1), with a residual mass found only for the malignant case. Of the 26 of 42 lesions (62%) with imaging follow-up, 24 (92%) had no lesion recurrence. Overall, the procedure either completely removed the mass and/or relieved the patients symptoms of a mass in 36 of 39 lesions (92%) for which clinical, imaging, and/or surgical follow-up was available. Three lesions were lost to follow-up. Conclusion Ultrasound-guided percutaneous excision of benign breast masses is a safe, effective, and well-tolerated minimally invasive procedure for the diagnosis and removal of benign breast masses. It may serve as an alternative to surgical excision for women with a known benign or probably benign breast mass who desire excision but prefer to avoid surgery or who are poor surgical candidates.

Effect of tamoxifen on breast tissue density in premenopausal breast cancer.

Abstract:  It has been established that hormone replacement therapy (HRT) increases breast tissue density on mammography in up to 30% of women receiving treatment. The effects of selective estrogen receptor modulators (SERMs) on breast tissue have received limited attention, although there have been several reports of tamoxifen decreasing mammographic tissue density in some women undergoing adjuvant or prophylactic breast cancer treatment. We report a case of a premenopausal woman treated with tamoxifen for 5 years whose mammographic density decreased while on tamoxifen and returned to her baseline density following termination of the drug. A regression of breast tissue may be reflective of sensitivity to tamoxifen and possibly, indicative of therapeutic benefit associated with treatment. Furthermore, induction of a more radiolucent pattern by tamoxifen may independently benefit women by enhancing mammographic detection. The clinical significance of resumption of a dense breast pattern following discontinuation of tamoxifen remains to be determined. 

Breast Magnetic Resonance Imaging

The indications for MRI breast imaging and terminology for classifying the report findings. Virtual Mentor is a monthly bioethics journal published by the American Medical Association.