The purpose of this article is to introduce a technique for transrectal drainage of deep pelvic abscesses performed under interactive MRI guidance.
A new method for triorthogonal image plane MRI ...guidance was developed and used to interactively monitor the puncture needle on continuously updated sets of adjustable three-plane images. The merits and limitations of the technique are highlighted and the patient population that is likely to benefit from this approach is suggested.
Laser interstitial thermal therapy has been used as an ablative treatment for glioma; however, its development was limited due to technical issues. The NeuroBlate System incorporates several ...technological advances to overcome these drawbacks. The authors report a Phase I, thermal dose-escalation trial assessing the safety and efficacy of NeuroBlate in recurrent glioblastoma multiforme (rGBM).
Adults with suspected supratentorial rGBM of 15- to 40-mm dimension and a Karnofsky Performance Status score of ≥ 60 were eligible. After confirmatory biopsy, treatment was delivered using a rigid, gas-cooled, side-firing laser probe. Treatment was monitored using real-time MRI thermometry, and proprietary software providing predictive thermal damage feedback was used by the surgeon, along with control of probe rotation and depth, to tailor tissue coagulation. An external data safety monitoring board determined if toxicity at lower levels justified dose escalation.
Ten patients were treated at the Case Comprehensive Cancer Center (Cleveland Clinic and University Hospitals-Case Medical Center). Their average age was 55 years (range 34-69 years) and the median preoperative Karnofsky Performance Status score was 80 (range 70-90). The mean tumor volume was 6.8 ± 5 cm(3) (range 2.6-19 cm(3)), the percentage of tumor treated was 78% ± 12% (range 57%-90%), and the conformality index was 1.21 ± 0.33 (range 1.00-2.04). Treatment-related necrosis was evident on MRI studies at 24 and 48 hours. The median survival was 316 days (range 62-767 days). Three patients improved neurologically, 6 remained stable, and 1 worsened. Steroid-responsive treatment-related edema occurred in all patients but one. Three had Grade 3 adverse events at the highest dose.
NeuroBlate represents new technology for delivering laser interstitial thermal therapy, allowing controlled thermal ablation of deep hemispheric rGBM. CLINICAL TRIAL REGISTRATION NO.: NCT00747253 ( ClinicalTrials.gov ).
Real-time MRI-guided percutaneous sclerotherapy is a novel and evolving treatment for congenital lymphatic malformations in the head and neck. We elaborate on the specific steps necessary to perform ...an MRI-guided percutaneous sclerotherapy of lymphatic malformations including pre-procedure patient work-up and preparation, stepwise intraprocedural interventional techniques and post-procedure management. Based on our institutional experience, MRI-guided sclerotherapy with a doxycycline-gadolinium-based mixture as a sclerosant for lymphatic malformations of the head and neck region in children is well tolerated and effective.
This clinical trial was performed to evaluate the safety and feasibility of interactive MR-guided radiofrequency (RF) interstitial thermal ablation (ITA) performed entirely within the MR imager. ...RF-ITA was performed on 11 intra-abdominal metastatic tumors during 13 sessions. The RF electrode was placed under MR guidance on a .2-T system using rapid fast imaging with steady state precession (FISP) and true FISP images. A custom 17-gauge electrode was used and was modified in four sessions to allow circulation of iced saline for cooling during ablation. Tissue necrosis monitoring and electrode repositioning were based on rapid T2-weighted and short-inversion-time inversion recovery (STIR) sequences. Morbidity and toxicity were assessed by clinical and imaging criteria. The region of tissue destruction was visible in all 11 tumors treated, as confirmed on subsequent contrast-enhanced images. No significant morbidity was noted, and patient discomfort was minimal. In conclusion, interactive MR-guided RF-ITA is feasible on a clinical .2-T C-arm system with supplemental interventional accessories with only minor patient morbidity. The ability to completely ablate tumors with RF-ITA depends on tumor size and vascularity.
This investigation was performed to test the hypotheses that interactive guidance of MR image acquisition during needle-directed procedures using a clinical 0.2-T C-arm open MR imaging system ...integrated with a frameless optically linked stereotaxy system is feasible, and that procedure times can be sufficiently short to be well tolerated by the patient.
One hundred six MR-guided procedures were performed in 86 patients (ranging in age from 5 months to 88 years) using a clinical C-arm imaging system supplemented with an in-room RF-shielded liquid crystal display monitor, a frameless stereotaxy system, rapid gradient-echo sequences for needle guidance, and MR-compatible monitoring and surgical lighting equipment. We performed 50 biopsies and aspirations of the head and neck in 37 patients, 23 biopsies of musculoskeletal lesions in 22 patients, 16 biopsies of abdominal sites in 10 patients, six biopsies of the thoracolumbar spine or sacrum in six patients, and 11 shoulder joint injections for MR arthrography in 11 patients, in addition to 38 MR arthrographic injections on the same imaging system described in a previous report. Tissue sampling included fine-needle aspiration (n = 90) and cutting needle core biopsy (n = 41). Thirty-five patients underwent both procedures. Procedures were evaluated for success of needle placement, procedure time, and complications.
Needle placement was successful in all cases, and no complications occurred. Tissue was sufficient for pathologic diagnosis for all but eight patients. Passes per patient averaged 2.1. For fine-needle aspiration, instrument time averaged 7 min 42 sec per pass, cutting needle core biopsy averaged 6 min 24 sec, and shoulder injection averaged 8 min.
MR imaging guidance for needle procedures on a clinical 0.2-T C-arm system with supplemental interventional accessories is feasible, with relatively rapid needle placement.
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.
This clinical trial was performed to evaluate the safety and feasibility of interactive MR‐guided radiofrequency (RF) interstitial thermal ablation (ITA) performed entirely within the MR imager. ...RF‐ITA was performed on 11 intra‐abdominal metastatic tumors during 13 sessions. The RF electrode was placed under MR guidance on a .2‐T system using rapid fast imaging with steady state precession (FISP) and true FISP images. A custom 17‐gauge electrode was used and was modified in four sessions to allow circulation of iced saline for cooling during ablation. Tissue necrosis monitoring and electrode repositioning were based on rapid T2‐weighted and short‐inversion‐time inversion recovery (STIR) sequences. Morbidity and toxicity were assessed by clinical and imaging criteria. The region of tissue destruction was visible in all 11 tumors treated, as confirmed on subsequent contrast‐enhanced images. No significant morbidity was noted, and patient discomfort was minimal. In conclusion, interactive MR‐guided RF‐ITA is feasible on a clinical .2‐T C‐arm system with supplemental interventional accessories with only minor patient morbidity. The ability to completely ablate tumors with RF‐ITA depends on tumor size and vascularity.
To overcome problems associated with poor contrast between vessels and background tissue in time-of-flight magnetic resonance angiography, the role of intravenous gadopentetate dimeglumine in ...conjunction with a postprocessing adaptive vessel tracking scheme was studied. Vessel tracking makes it possible to discriminate arteries from veins, to prevent problems associated with other bright tissues on maximum-intensity projections, and to increase the signal-to-noise ratio. Short, asymmetric, velocity-compensated field echoes were used in conjunction with high-resolution imaging techniques to spatially discriminate between adjacent vessels and stationary background tissue. Gadopentetate dimeglumine was shown to be useful for visualization of small vessels, aneurysms, and regions of slow flow, when used with this post-processing scheme.
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