Paul R. Morrison

585 nm for the Treatment of Port-Wine Stains

Although the flashlamp-pulsed-dye laser has been successfully used for the treatment of port-wine stains (PWS) at 577 nm, a number of adult patients had incomplete clearance of their birthmarks with this treatment modality because of residual vessels lying beyond the 0.75-mm penetration depth of 577-nm irradiation. Fifteen adult patients, of whom nine were previously treated with limited success at 577 nm (group A), and six untreated patients (group B) were included in the study. For the group A patients, treatment with 585 nm produced successful clearance of the birthmark. For the six patients in group B, parallel treatment of different sites of the same lesion coupled with skin biopsies and histologic examination revealed that a change in the wavelength from 577 to 585 nm allowed the laser light to penetrate from the midreticular dermis into the subcutaneous fat. This explained the clearance achieved at 585 nm and not at 577 nm.

MRI-guided percutaneous cryotherapy for soft-tissue and bone metastases: initial experience.

OBJECTIVE We sought to determine the safety and feasibility of percutaneous MRI-guided cryotherapy in the care of patients with refractory or painful metastatic lesions of soft tissue and bone adjacent to critical structures. MATERIALS AND METHODS Twenty-seven biopsy-proven metastatic lesions of soft tissue (n = 17) and bone (n = 10) in 22 patients (15 men, seven women; age range, 24-85 years) were managed with MRI-guided percutaneous cryotherapy. The mean lesion diameter was 5.2 cm. Each lesion was adjacent to or encasing one or more critical structures, including bowel, bladder, and major blood vessels. A 0.5-T open interventional MRI system was used for cryoprobe placement and ice-ball monitoring. Complications were assessed for all treatments. CT or MRI was used to determine local control of 21 tumors. Pain palliation was assessed clinically in 19 cases. The mean follow-up period was 19.5 weeks. RESULTS Twenty-two (81%) of 27 tumors were managed without injury to adjacent critical structures. Two patients had transient lower extremity numbness, and two had both urinary retention and transient lower extremity paresthesia. One patient had chronic serous vaginal discharge, and one sustained a femoral neck fracture at the ablation site 6 weeks after treatment. Thirteen (62%) of the 21 tumors for which follow-up information was available either remained the same size as before treatment or regressed. Eight tumors progressed (mean local progression-free interval, 5.6 months; range, 3-18 months). Pain was palliated in 17 of 19 patients; six of the 17 experienced complete relief, and 11 had partial relief. CONCLUSION MRI-guided percutaneous cryotherapy for metastatic lesions of soft tissue and bone adjacent to critical structures is safe and can provide local tumor control and pain relief in most patients.

MRI-guided cryotherapy

Over the last decade the focus of published research on MRI‐guided cryotherapy has switched from the study of experimental models to the clinical treatment of patients. The latter reports attest to the safety and feasibility of treating lesions in the liver, kidney, and other sites throughout the body. Further, the published images and initial results speak to the utility of MRI for the task of monitoring this specific procedure. This clinical utility is a realization of the promise of the earlier experimental work that showed the clarity with which interstitial ice is seen under MRI under various pulse sequence parameters. Early adopters have taken advantage of access to the patient that is provided by low and mid‐field open scanners; the near future will test the suitability of higher field systems. It has been critical that an FDA‐approved cryotherapy system and suitably thin probes were customized for the MRI environment a decade ago by which percutaneous cryotherapy could be performed. There is still work to be done to expand the role of percutaneous cryotherapy, to understand various tissue responses, and to optimize visualization of therapeutic isotherms. Also, long‐term outcomes need to be assessed. Overall, in a worldwide environment in which the practice of ablation is growing and an appreciation for such therapies is on the rise, the work of these recent years provides sound footing for the advances that lay ahead for clinical MRI‐guided cryotherapy. J. Magn. Reson. Imaging 2008;27:410–420.

Endoscopic sinus surgery with magnetic resonance imaging guidance: Initial patient experience:

We report the first endoscopic surgeries performed with patients under general anesthesia using intraoperative guidance with MRI. The procedures were experimental and intended to test (1) the unusual working environment of a unique new “open-configuration” MRI unit for head and neck surgery, and (2) real-time image guidance. Twelve patients underwent endoscopic sinus surgery while under general anesthesia in a new open MRI unit that provides the surgeon with access to the patient while imaging is performed. Eleven patients had chronic sinusitis (eight of them had bilateral disease), and one had a right nasoethmoid and antral tumor. All 12 surgeries were performed without complications. Both the endoscopic view and the MRI scans were available at the surgical field. The image plane was surgeon controlled, and the MRI updated images in as little as 14 seconds. MRI provided adequate visualization of both the disease and the related anatomy and allowed the surgeon to navigate during the procedure. The intraoperative data reflect the tissue changes during surgery and provide optimum feedback for surgical guidance. Although the operating environment poses some limitations, it has become apparent that intraoperative MRI has a role in the treatment of head and neck disorders and warrants further study.

Inflammatory nodules mimic applicator track seeding after percutaneous ablation of renal tumors.

OBJECTIVE The objective of our study was to report the occurrence of benign inflammatory nodules that develop in or near applicator tracks after percutaneous radiofrequency ablation and cryoablation of renal tumors. CONCLUSION Benign inflammatory nodules occur rarely after percutaneous ablation of renal tumors and may mimic tumor seeding of the applicator track.

Percutaneous cryoablation techniques and clinical applications.

Once requiring surgery, cryoablation now can be performed percutaneously under image guidance, thanks to the development of small probes. Sonography was used to guide cryoablation performed surgically; now, computed tomography and magnetic resonance images are typically used to guide percutaneous cryoablation. Intraprocedural monitoring helps those performing the procedure to treat the tumor completely, while avoiding complications. Percutaneous cryoablation has been shown to be safe and effective for many clinical applications including kidney, liver, prostate, breast, and musculoskeletal cancers. In this article, we briefly review percutaneous cryoablation techniques and clinical applications.

Percutaneous CT–guided Radiofrequency Ablation of Symptomatic Bilateral Adrenal Metastases in a Single Session

Percutaneous computed tomography (CT)-guided radiofrequency (RF) ablation has been used in the palliative treatment of symptomatic bilateral adrenal tumors, often with each tumor addressed separately over the course of multiple treatment sessions. In the present case, a 71-year-old man with a diagnosis of lung cancer and painful bilateral metastases to the adrenal glands underwent percutaneous CT-guided RF thermal ablation of both adrenal masses in a single session (left adrenal mass, 4.7 cm; right adrenal mass, 4.3 cm), without occurrence of blood pressure instability or other acute complications. Measurement of plasma levels of cortisol, adrenocorticotropic hormone (ACTH), and glucose before and after RF ablation revealed transient changes that suggested preservation of endocrine feedback mechanisms. The patient experienced marked relief in pain bilaterally. By 5 days after the procedure, cortisol, ACTH, and glucose levels returned to preprocedural levels. On further follow-up at 6 months, the patient noted a lack of endocrine sequelae and continued pain relief.

Image-guided neurosurgery at Brigham and Women's Hospital

In this article, we report efforts to integrate a number of state-of-the-art technologies for MRI-guided neurosurgery at the Brigham and Womens Hospital (BWH) in Boston. These include advanced intraoperative imaging, image registration, visualization, navigation, minimally invasive ablative therapies, and robotics. This is part of a multidisciplinary Image-Guided Therapy Program that comprises several key research thrusts, including the surgical planning laboratory, magnetic resonance therapy (MRT), focused ultrasound surgery, thermal ablation, and neurosurgery

Dynamic T1-weighted magnetic resonance imaging of interstitial laser photocoagulation in the liver: Observations on in vivo temperature sensitivity

Magnetic resonance imagings (MRI) potential to monitor interstitial laser photocoagulation (ILP) has been previously demonstrated and is further tested here with improved spatial and temporal resolution.

Intraoperative Image Guidance during Endoscopic Sinus Surgery

Endoscopic sinus surgery (ESS) is one of the most commonly performed procedures in otorhinolaryngology and is associated with a definite risk for both intraoperative and postoperative complications. Intraoperative image guidance is expected to have a major effect on procedures such as ESS by allowing the clinician to more efficiently remove pathology and by improving surgeon confidence and knowledge of anatomy, particularly in revision procedures or in patients with altered anatomy. As a consequence, complications during these pro-’ cedures will decrease and patient safety will increase. Several guidance modalities are available including computed tomography (CT), magnetic resonance imaging (MRI), and fluoroscopy. This article will describe current applications of each of these three techniques with respect to ESS while focusing on innovative techniques that use MRI and CT to provide intraoperative guidance with unmatched convenience, reliability, and utility.