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Biomedical subjects

Roberto Blanco Sequeiros

Publications and source records attributed to Roberto Blanco Sequeiros.

10 recordsLinked to original sources
PubMed2006

MR-guided breast biopsy and hook wire marking using a low-field (0.23 T) scanner with optical instrument tracking.

The purpose of this study was to evaluate the technical feasibility of MR-guided percutaneous breast biopsy (LCNB) and breast hook wire marking in a low-field (0.23 T) MRI system with optical instrument tracking. MR-guided core biopsy and/or hook wire marking was performed on 13 lesions observable at MR imaging only. Seven breast LCNBs and 10 hook wire markings were performed under MR guidance on 11 patients. The diagnosis was confirmed by excision biopsy or mastectomy in 12 lesions and with histopathological and cytological diagnosis and 12-month clinical follow-up in one lesion. All lesions seen in the high-field scanner were also successfully identified and targeted in the low-field scanner. The following procedures were typically technically successful. There were difficulties due to unsatisfactory functioning of some core biopsy guns. Detailed description of low-field MR guidance and optical tracking in breast biopsies is provided. The procedure seems accurate and safe and provides means to obtain a histological diagnosis of a breast lesion only seen with MRI. The low-field biopsy system is comparable to the high-field MRI system. MR-compatible biopsy guns need to be improved.

Adult↗
PubMed2006

Bone augmentation: past, present, and future.

Painful skeletal and vertebral conditions caused by degeneration, fractures, infection, and neoplasm are common and associated with high morbidity and mortality. Since the introduction of modern orthopedic surgery these conditions have been treated with a multitude of techniques. Bone augmentation and grafting have emerged as integral parts of orthopedic reconstructive, reparative, and palliative surgery. As imaging-guided therapy has developed, image-guided procedures to achieve bone augmentation have also emerged. It is important for the radiologist to understand the materials and methods used to achieve bone augmentation. A variety of materials are available for the application of hone augmentation. Methods used to accomplish bone augmentation often are performed under image guidance. Applications in the axial skeleton include vertebroplasty, kyphoplasty (balloon-assisted vertebroplasty), sacroplasty, and acetabuloplasty. This article discusses the development, current trends, and possible future directions of bone augmentation.

Bone Transplantation↗
PubMed2006

Feasibility of MR imaging-guided percutaneous drainage of pancreatic fluid collections.

PURPOSE: To assess the feasibility and safety of magnetic resonance (MR) imaging-guided percutaneous drainage of pancreatic fluid collections in an open configuration low field MR imaging system. MATERIALS AND METHODS: Ten patients with pancreatic fluid collections were examined prospectively. Five of the fluid collections were symptomatic pseudocysts and five were pancreatic abscesses. All percutaneous drainages were performed solely under MR imaging guidance with a 0.23-T open configuration C-arm shaped MR imaging scanner with interventional optical tracking. Every step of the procedure was monitored using balanced fast field echo sequences. In each case, the drainage of the fluid collection was performed with a MR imaging-compatible drainage kit using the Seldinger technique. The kit included an 18-gauge needle, a 0.035-inch stiff guide wire, 6-F and 8-F dilators, and an 8-F pigtail drainage catheter. RESULTS: All drainage catheters could successfully be placed into the pancreatic fluid collections under MR imaging guidance. Visualization of the needle, dilator, and drainage catheter was excellent. However, visualization of the guide wire was suboptimal. The mean time needed for the MR-guided drainage procedure was 44 minutes. No immediate complications occurred. The clinical success rate of the percutaneous drainage was 70%; three patients were subsequently treated surgically. There were no deaths. The average duration of catheterization was 40 days. CONCLUSION: MR imaging-guided percutaneous drainage of pancreatic fluid collections is feasible and safe. The presented technique has limitations--lack of real-time imaging control and small selection of MR imaging-compatible devices--that necessitate further technical developments before the procedure can be recommended for routine clinical use.

Abscess↗
PubMed2005

Musculoskeletal interventional MR imaging.

MR imaging guidance has great potential to direct the management of diagnostic and therapeutic procedures performed in the musculoskeletal region. To take full advantage of this excellent diagnostic tool, radiologists should also embrace the minimally invasive techniques available for MR imaging. This can be achieved by cooperation with clinical colleagues, multidisciplinary integration, and the development of efficient techniques for MR-guided procedures. By combining the excellent ability to recognize pathologic findings and the feasibility of performing interventional procedures, MR imaging is emerging as a powerful tool in diagnosing and treating musculoskeletal neoplasms and in performing minimally invasive procedures, such as spine injections.

Biopsy, Needle↗
PubMed2003

MR imaging-guided laser ablation of osteoid osteomas with use of optical instrument guidance at 0.23 T.

The purpose of this study was to determine the feasibility and features of low-field MR imaging in performing interstitial laser ablation of osteoid osteomas. Between September 2001 and April 2002, five consecutive patients with clinical and imaging findings suggesting osteoid osteoma and referred for removal of osteoid osteoma were treated with interstitial laser treatment. A low-field open-configuration MRI scanner (0.23 T, Outlook Proview, Philips Medical Systems, Finland) with optical instrument guidance hardware and software was used. Laser device used was of ND-Yag type (Fibertom medilas, Dornier Medizin Technik, Germany). A bare laser fiber (Dornier Medizin Technik, Germany) with a diameter of 400 microm was used. Completely balanced steady-state (CBASS; true fast imaging with steady precession) imaging was used for lesion localization, instrument guidance, and thermal monitoring. A 14-G (Cook Medical, USA) bone biopsy drill was used for initial approach. Laser treatment was conducted through the biopsy canal. All the lesions were successfully localized, targeted, and treated under MRI guidance. All the patients were symptom free 3 weeks and 3 months after the treatment. There was one recurrence reported during follow-up (6 months). The MRI-guided percutaneous interstitial laser ablation of osteoid osteomas seems to be a feasible treatment mode.

Adolescent↗
PubMed2003

Percutaneous MR-guided discography in a low-field system using optical instrument tracking: a feasibility study.

PURPOSE: To evaluate the feasibility of MRI-guided discography with optical tracking. MATERIAL AND METHODS: 12 consecutive patients who had a clinical suspicion of lumbar discogenic pain and/or suggestive finding of disc degeneration in imaging studies (MRI, CT, plain radiography) underwent MRI-guided discography in order to determine possible pain provocation during puncture and contrast injection. An 0.23 T open configuration MRI device with interventional tools (Outlook Proview, Philips Medical Systems, MR Technologies, Finland) was used in procedural imaging and instrument guidance. An optical guidance tool was attached to the MRI compatible needle (Chiba-type MReye, Cook, Bloomington, IN). After initial disc puncture, 1-2 mL of gadolinium contrast (Magnevist, 469 mg/mL, Schering AG, Germany) saline mixture (1:8) was injected into the disc. Immediately after injection, sagittal FE T1 weighted images were obtained to verify the final position of the needle and formation of the MRI discogram. On nine patients, additional noncontrast sagittal fast spin echo (FSE) T1, FSE T2, and axial 3D T1 gradient echo imaging was performed before and after contrast media injection to obtain MRI discograms. RESULTS: Overall, 35 disc punctures were initialized and 34 MRI discograms were obtained. In all punctures, a positive or negative pain response was obtained. The average time for performing a procedure for three discs was 1 hour 25 minutes (minimum 45 minutes, maximum 2 hours, 15 minutes), and the average number of imaging sequences used for a puncturing one disc was 12. On one disc, the puncture failed and a discogram was not acquired. There was one complication (disc collapse) reported during follow-up. CONCLUSION: Our results show that MRI guidance in performing discography is accurate and relatively safe. It is a technically comparable method to CT-guidance or fluoroscopy.

Adult↗
PubMed2002

MRI-guided periradicular nerve root infiltration therapy in low-field (0.23-T) MRI system using optical instrument tracking.

The purpose of this study was to evaluate the feasibility of the MRI-guided periradicular nerve root infiltration therapy. Sixty-seven nerve root infiltrations under MRI guidance were done for 61 patients suffering from lumbosacral radicular pain. Informed consent was acquired from all patients. A 0.23-T open-MRI scanner with interventional tools (Outlook Proview, Philips Medical Systems, MR Technologies, Finland) was used. A surface coil was used in all cases. Nerve root infiltration was performed with MRI-compatible 20-G needle (Chiba type MReye, Cook, Bloomington, Ind.; or Manan type, MD Tech, Florida). The evaluation of clinical outcome was achieved with 6 months of clinical follow-up and questionnaire. The effect of nerve root infiltration to the radicular pain was graded: 1=good to excellent, i.e., no pain or not disturbing pain allowing normal physical activity at 3 months from the procedure; 2=temporary, i.e., temporary relief of pain; 3=no relief of pain; and 4=worsening of pain. As an adjunct to MRI-guided positioning of the needle the correct needle localization by the nerve root was confirmed with saline injection to nerve root channel and single-shot fast spin echo (SSFSE) imaging. The MRI guidance allowed adequate needle positioning in all but 1 case (98.5%). This failure was caused by degeneration-induced changes in anatomy. Of patients, 51.5% had good to excellent effect with regard to radicular pain from the procedure, 22.7% had temporary relief, 21.2% had no effect, and in 4.5% the pain worsened. Our results show that MRI guidance is accurate and safe in performing nerve root infiltration at lumbosacral area. The results of radicular pain relief from nerve root infiltration are comparable to CT or fluoroscopy studies on the subject.

Adult↗
PubMed2002

MR-guided bone biopsy: preliminary report of a new guiding method.

PURPOSE: To evaluate the feasibility of a new MR compatible optical tracking guided bone biopsy system. MATERIALS AND METHODS: Wireless optical tracker elements were connected to a bone biopsy set. Biopsies of five different anatomic areas and lesions varying from 9 mm to 40 mm (mean 25 mm) in size, were performed. RESULTS: We were able to perform the biopsies in all cases, and the samples allowed for a pathologic diagnosis. The procedure time was limited to less than 40 minutes, and no complications occurred. CONCLUSION: MR-guided bone biopsy with this new guiding system was a feasible and fast procedure that did not compromise the usability of the bone biopsy set.

Biopsy↗
PubMed2001

MRI-guided trephine biopsy and fine-needle aspiration in the diagnosis of bone lesions in low-field (0.23 T) MRI system using optical instrument tracking.

The purpose of this study was to evaluate the feasibility of MRI-guided bone biopsy with optical instrument tracking and evaluate advantage of combined fine-needle aspiration (FNA) with trephine biopsy. Twenty trephine bone biopsies and 13 FNAs were performed under MRI and CT guidance in 14 patients. Informed consent was obtained from all patients. The evaluation of diagnostic accuracy was achieved by comparing the histopathological and cytological diagnosis with current or final diagnosis made during 6-month clinical follow-up. A 0.23-T open MRI scanner with interventional tools (Outlook Proview, Marconi Medical Systems, Cleveland, Ohio) was used. A surface coil was used. For trephine biopsy MRI-compatible bone biopsy set (Daum medical, Schwerin, Germany) was used. The FNA was performed with MRI compatible 20-G needle (Cook, Bloomington, Ind.). The diagnostic accuracy of MRI-guided trephine biopsy was 95%. The FNA sample diagnosis concurred with the histological in 54%. Our results show that MRI guidance in bone biopsies is accurate and safe. It is comparable to CT-guided or open biopsy. The role of combined FNA with bone biopsies remains controversial.

Biopsy↗