Navigating differences in patient values.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Performing prophylactic or elective modified dissections of the neck in patients with clinically occult lymph nodal metastases from thyroid cancers is controversial since metastases to the lymph nodes are associated with high rates of recurrence. Biopsies of sentinel lymph nodes can be performed successfully in patients with thyroid cancers since they can be identified with dyes or 99mTc. Our preliminary findings indicate that biopsies of sentinel lymph nodes can be useful in the treatment of thyroid cancers, although, the clinical significance of identifying metastases in regional lymph nodes using this technique remains to be determined.
BACKGROUND: Patients with early gastric cancer may be treated by minimally invasive surgery. This study investigated the value of sentinel node (SN) navigation surgery, including detection of micrometastases, in patients with clinical (c) T1 and T2 gastric cancer. METHODS: The day before surgery (99m)Tc-radiolabelled tin colloid was injected submucosally near the tumour. After resecting the stomach, radioisotope uptake in all dissected lymph nodes was measured during and after surgery. Micrometastasis was detected immunohistochemically using an anticytokeratin antibody. RESULTS: SNs were identified in 99 of 104 patients. The rate of identification of SNs in patients with cT1 and cT2 tumours, excluding three technical failures, was 99 and 95 per cent respectively. Lymph node metastases and/or micrometastases were found in 28 patients (15 cT1 and 13 cT2). In the 15 patients with cT1 tumours, at least one SN contained metastasis and/or micrometastasis. For cT1 tumours, the sensitivity and accuracy of detecting SNs were both 100 per cent. Six patients with cT2 tumours had false-negative results. CONCLUSION: SN navigation surgery appears to be clinically useful only for cT1 tumours. Based on SN results, the extent of lymphadenectomy may be reduced in patients with early gastric cancer.
Patient motion can seriously degrade the quality of diffusion-weighted MR images obtained using standard 2DFT imaging procedures. The main source of error arises from an MR signal phase-shift error which is proportional to the magnitude of the motion. A modified pulse sequence is proposed which uses the phase information from an additional spin echo to correct for patient motion. Application of this technique is demonstrated for a human brain study, which greatly improves the quantification of diffusion values from regions of brain tissue.
BACKGROUND: Timely molecular profiling is essential for treatment selection in non-small cell lung cancer (NSCLC), yet delays in biomarker testing remain common. We evaluated the feasibility and early clinical impact of a nurse navigator-driven workflow to initiate liquid biopsy before the initial oncology visit. METHODS: LUNG-FAST (Liquid Biopsy for Urgent Neoplastic Genomic Profiling Focused Accelerated Stratification and Testing) was a 4-month prospective pilot at a tertiary cancer center. Intake nurse navigators identified eligible patients with suspected or newly diagnosed lung cancer and facilitated previsit liquid biopsy ordering. Feasibility, turnaround times, genomic findings, and early clinical outcomes were assessed. RESULTS: Among 64 patients, intake nurse navigators identified 94% (60/64) of eligible cases. Liquid biopsy was ordered in 58 patients, with 62% (36/58) placed before the initial oncology visit. Median turnaround time from blood draw to results was 8.5 days for commercial testing and 12.5 days for institutional testing. FDA-actionable genomic alterations were identified in 34% (22/64) of patients, while an additional 11% (7/64) harbored clinically relevant, non-FDA-actionable alterations. Overall, FDA-actionable or clinically relevant alterations were identified in 45% (29/64), with 22% detected by liquid biopsy and an additional 23% by tissue-only profiling. Median time from new patient visit to systemic therapy was 26 days. CONCLUSIONS: A nurse navigator-driven workflow enabling previsit liquid biopsy is feasible and identifies actionable genomic alterations in a substantial proportion of patients with lung cancer. Plasma and tissue profiling are complementary, and earlier plasma-based testing may expedite treatment decision-making while highlighting opportunities to optimize biomarker testing workflows.
BACKGROUND: Poor outcome in anterior cruciate ligament reconstruction is often related to tunnel position. HYPOTHESIS: Improving accuracy of the tunnel position will lead to improved outcome. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Sixty patients were randomized to either standard instrumentation or computer-assisted guides to position the tibial and femoral tunnels. The results were evaluated on clinical outcome based on International Knee Documentation Committee form (laxity) and radiologic assessment: radiologic Lachman (Telos at 150 and 200 N) and analysis of the tunnel positions. RESULTS: International Knee Documentation Committee laxity was level A in 22 knees in the conventional group (mean, 1.5 mm at 200 N) compared with 26 navigated knees (mean laxity, 1.3 mm; P = .49). Laxity was less than 2 mm in 96.7% of the navigated group and 83% of the conventional group (P = .292). The variability of laxity in the navigated group was significantly less than in the conventional group, with the standard deviation of the navigated group being smaller than that in the conventional group (P = .0003 at 150 N and .0005 at 200 N Telos). A significant difference (P = .03) was found between the groups in the ATB value (distance between the projection of the Blumensaat line on the tibial plateau and the anterior edge of the tibial tunnel), characterizing the sagittal position of the tibial tunnel (negative ATB values imply graft impingement in extension). In the conventional group, mean ATB was -0.2 (-5 to +4), whereas it was 0.4 (0 to 3) in the navigated patients. There were no negative ATB values in the navigated group. CONCLUSION: This study confirms that the accuracy and consistency of tibial tunnel position can be improved by the use of computer-assisted navigation and that the clinical result in terms of laxity is more reliable.
PURPOSE: To evaluate the clinical value of high-resolution coronary MR angiography (coronary MRA) in a large group of patients with suspected coronary artery disease. METHODS AND MATERIAL: 107 patients with suspected coronary artery disease underwent free-breathing coronary MRA (Intera, 1.5 T, Philips Medical Systems). To compensate for artefacts due to respiratory motion, a right hemidiaphragmatic navigator with real time-time slice correction was used. An ECG-gated, fat-suppressed, 3D segmented-k-space gradient echo sequence (in plane resolution 0.70 x 0.79 mm(2)) was used. Cardiac catheterization with selective coronary angiography was performed in all patients. Visualization of the coronary arteries (CA) was qualitatively assessed using a four-point grading scale. RESULTS: Image quality of grade 1 was achieved in 24 %, grade 2 in 48 %, grade 3 in 24 % and grade in in 4 % of patients. Based on an evaluation of the coronary MRAs of all patients (n = 107) sensitivity and specificity for the detection of stenoses > 60 % in the proximal and middle main coronary arteries were 74 % and 63 %, respectively. In coronary MRAs with good quality [grade 1 and 2, n = 77/107 (72 %)] sensitivity and specificity for the detection of coronary stenoses were 88 % and 91 %, respectively. CONCLUSION: Submillimeter 3D coronary MRA with real-time navigator correction allows high quality imaging of the proximal and middle main coronary arteries with good sensitivity and specificity for detection of stenoses > 50 % in selected patients. However, in about 28 % of patients image quality is severely impaired.
Cavernous angiomas are mostly small intracranial vascular lesions which can be intraoperatively localized by sonography or stereotactic methods. This paper compares the results of cavernous angioma surgery localized by frame-based vs frameless techniques. Thirty-nine patients with cortical or subcortical lobar cavernoma were operated on by a microsurgical trans-sulcal approach. The localization of the lesion was performed in 19 (49%) patients by frame-based technique and in 20 (51%) patients by frameless navigation. In 22 (56%) of the patients, the cavernomas were located in an eloquent cortical area. Ten of 22 of these lesions were localized by frame-based stereotaxy and 12/22 by frameless navigation. The patients demonstrated the following preoperative symptoms: seizures 20 (51%), hemorrhage 18 (46%), focal neurologic deficit 11 (28%), and headache three (7%), and three (7%) were asymptomatic. Thirteen of 19 patients localized with frame-based stereotaxy were postoperatively asymptomatic or their preoperative neurological symptoms improved. Four of 19 had a transitory neurologic deficit and 2/19 a permanent worsening. Seventeen of 20 patients localized by frameless navigation were asymptomatic or neurologically improved. Three out of 20 suffered from a transient neurologic deficit. Regarding the seizures, 14 (70%) patients were postoperatively free of seizures, three (15%) were improved, and three (15%) were unchanged. The frameless navigation was superior regarding the flexibility for approaches along the skull base and midline, and the frame-based method was superior regarding the accuracy for very small lesions (less than 7 mm). In other cases, both methods were equal. Frame-based and frameless stereotactic methods are useful in the localization of small cavernous angiomas. They make it possible to remove cavernous angiomas in eloquent cortical regions with low risk of a permanent neurologic deficit.
BACKGROUND: Computer navigation systems have increasingly become part of the surgical routine due to the improvements of intraoperative visualization procedures. Because of limited space in the operating room and insufficient workflow, the project of integrated navigation had been started. METHODS: As the first step, the navigation system VectorVision2 and the second-generation fluoroscopic C-arm system Orbic 3D were integrated into one common trolley. In an experimental study the integrated navigation system was used to drill 160 pedicle screws. Afterwards the system was clinically evaluated in 11 surgical procedures. RESULTS: During the whole experimental study the system could be used for all 160 drilling procedures without any technical faults, causing a failure rate of 4.2%. For clinical evaluation the integrated navigation system was used in seven patients with navigated dorsal spine instrumentation, in three cases sacroiliac screws were placed, and in one case supra-acetabular screw osteosynthesis was performed for an acetabular fracture. In all cases the positioning of the screws was correct and no system failure occurred. CONCLUSIONS: The combination of the navigation system and the C-arm system in one common trolley is a major improvement of the surgical workflow. In the experimental study and the clinical trials the system worked extremely reliably and with high precision.
PURPOSE: The purpose of this study is to develop an improved algorithm for measuring the position of the diaphragm using navigator echoes. METHODS: This algorithm was applied to navigator echo data acquired from 14 cardiac patients. For each patient, 160 navigator echo profiles were acquired across the right hemi-diaphragm along the superior-inferior direction. RESULTS: The accuracy of the proposed edge-detection algorithm was evaluated together with that of the least-squares and linear phase-shift algorithms. The estimated measurement error of the proposed algorithm was approximately two times smaller than that of the least-squares algorithm (Magn Reson Med, 1996:36: 117-123), and was approximately four times smaller than that of the linear phase-shift algorithm (Magn Reson Med, 1999;42:548-553). The computational efficiency of this algorithm was 7.5 times higher than that of the least-squares algorithm and was comparable with that of the linear phase-shift algorithm. CONCLUSION: The presented algorithm is accurate, robust, and computationally efficient in the measurement of the diaphragm position.
Real-time magnetic resonance (MR) navigator echo (NE) monitoring of the diaphragm is now possible. Using this technique, temporal changes in diaphragm position can be analyzed in a non-invasive fashion, without x-ray exposure. In this preliminary study, we have optimized three NE parameters (the NE column area, the NE repeat time, and the location of the NE on the diaphragm surface), and demonstrated the clinical application of MR NE diaphragm monitoring in patients with suspected diaphragm paralysis. The NE parameters were defined in 10 healthy volunteers, and diaphragm traces were scored for variance in NE diaphragm position registration. Using the optimal NE column parameters, we investigated four patients with diaphragm paralysis, one of whom required positive pressure ventilation while in the MR scanner, to show the utility of this technique. The NE diaphragm position registration was significantly affected by the area of the NE column, with poor position registration for the smallest column area (2.25 cm2 vs. 4 cm2 vs. 6.25 cm2, variance 6.3 vs. 0.6 vs. 0.3, P = 0.006). Diaphragm position registration was also significantly affected by the NE repeat time, with misregistration for the shortest repeat time (250 msec vs. 500 msec vs. 1000 msec, variance 11.9 vs. 0.6 vs. 1.0, P = 0.02), and data clipping, with loss of end-expiratory and end-inspiratory position registration, for the longest repeat time. Finally, if the NE was positioned too anteriorly, the diaphragm traces were of poor quality (anterior vs. dome vs. posterior, variance 11.8vs. 0.6vs. 3.2, P < 0.001). Application of the technique confirmed diaphragm paralysis in all four patients. The technique can be applied during positive pressure ventilation if necessary. The optimal NE parameters for diaphragm monitoring at 0.5 T were: column area, 400 mm2; NE repeat time; 500 msec; NE column positioned on the diaphragm dome. MR NE diaphragm monitoring provides a safe, non-invasive method of assessing diaphragm motion in patients with suspected diaphragm paralysis and may prove useful for long-term follow-up and monitoring of therapeutic interventions in these subjects.
BACKGROUND AND PURPOSE: We evaluated an advanced concept for patient-based navigation during minimally invasive neurosurgical procedures. METHODS: An infrared-based, off-line neuro-navigation system (LOCALITE, Bonn, Germany) was applied during operations within a 0.5 T intraoperative MRI scanner (iMRI) (Signa SF, GE Medical Systems, Milwaukee, WI, USA) in addition to the conventional real-time system. The three-dimensional (3D) data set was acquired intraoperatively and up-dated when brain-shift was suspected. Twenty-three patients with subcortical lesions were operated upon with the aim to minimise the operative trauma. RESULTS: Small craniotomies (median diameter 30 mm, mean diameter 27 mm) could be placed exactly. In all cases, the primary goal of the operation (total resection or biopsy) was achieved in a straightforward procedure without permanent morbidity. The navigation system could be easily used without technical problems. In contrast to the real-time navigation mode of the MR system, the higher quality as well as the real-time display of the MR images reconstructed from the 3D reference data provided sufficient visual-manual coordination. CONCLUSION: The system combines the advantages of conventional neuro-navigation with the ability to adapt intraoperatively to the continuously changing anatomy. Thus, small and/or deep lesions can be operated upon in straightforward minimally invasive operations.
PURPOSE: To present a corneal topography screening device for the detection of corneal ectasias and various refractive procedures based on corneal topography patterns. METHODS: A database of corneal topography patterns were analyzed and used to "train" a neural network on nine different corneal topography patterns using nineteen corneal topography indices of corneal shape and power. RESULTS: Sample normal and corneal topographies were recognized correctly. CONCLUSIONS: The use of the corneal navigator to screen various corneal topographies aids clinical diagnosis.
LifeLines provide a general visualization environment for personal histories. We explore its use for clinical patient records. A Java user interface is described, which presents a one-screen overview of a computerized patient record using timelines. Problems, diagnoses, test results or medications can be represented as dots or horizontal lines. Zooming provides more details; line color and thickness illustrate relationships or significance. The visual display acts as a giant menu, giving direct access to the data.
In slipped capital femoral epiphysis (SCFE), cannulated screw fixation is a standard procedure. The aim of this study was to investigate the feasibility of a fluoroscopy-supported navigation system for screw fixation in SCFE. Using a fluoroscopy-enhanced navigation system, a cannulated screw fixation was performed in seven hips of four patients. The navigation system showed a high feasibility in instrument visualization and implant placing. The mean x-ray time was 6.2 seconds. Initial experiences are very promising and show advantages of the fluoroscopy-supported navigation. Considerably reduced x-ray exposure for patients and surgeons is possible. In the future, further efforts will be necessary to develop navigation-specific instruments to enhance the precision of screw positioning.
PURPOSE: To present an advanced concept for patient-based navigation and to report on our first clinical experience with interventions in the cranium, of soft-tissue structures (breast, liver) and in the musculoskeletal system. MATERIALS AND METHODS: A PC-based navigation system was integrated into an existing interventional MRI environment. Intraoperatively acquired 3D data were used for interventional planning. The information content of these reference data was increased by integration of additional image modalities (e. g., fMRI, CT) and by color display of areas with early contrast media enhancement. Within 18 months, the system was used in 123 patients undergoing interventions in different anatomic regions (brain: 64, paranasal sinus: 9, breast: 20, liver: 17, bone: 9, muscle: 4). The mean duration of 64 brain interventions was compared with that of 36 procedures using the scanner's standard navigation. RESULTS: In contrast with the continuous scanning mode of the MR system (0.25 fps), the higher quality as well as the real time display (4 fps) of the MR images reconstructed from the 3D reference data allowed adequate hand-eye coordination. With our system, patient movement and tissue shifts could be immediately detected intraoperatively, and, in contrast to the standard procedure, navigation safely resumed after updating the reference data. The navigation system was characterized by good stability, efficient system integration and easy usability. Despite additional working steps still to be optimized, the duration of the image-guided brain tumor resections was not significantly longer. CONCLUSION: The presented system combines the advantage of intraoperative MRI with established visualization, planning, and real time capabilities of neuronavigation and can be efficiently applied in a broad range of non-neurosurgical interventions.
OBJECTIVE: To explore the role of diffusion tensor imaging (DTI) in neuronavigation surgery of brain tumors involving pyramidal tracts. METHODS: Forty-nine patients with brain tumors involving pyramidal tracts were randomly divided into trial group (DTI navigation) and control group (traditional navigation). The patients in trial group underwent DTI and T1 weighted 3D navigational magnetic resonance imaging (MRI) studies. The main white matter tracts were constructed by the DTI datasets, and merged to the anatomical structure, which was delineated by the T1-weighted three-dimensional fast spoiled gradient recalled sequence (3D/FSPGR). The relationship between the tumors and adjacent pyramidal tracts were segmented and reconstructed for three-dimensional visualization. RESULTS: In 25 patients of trial group and 24 patients of control group, the statistic analysis confirmed well balance of main variations. The tumors were completely resected in 12 patients (50.0%) of control group and in 20 patients (80.0%) of trial group (P < 0.05). Postoperative aggravated contralateral extremities weakness or hemiplegia due to pyramidal tract injury occurring in 75.0% cases of control group whereas only 20.0% patients in trial group (P < 0.01). The mean Karnofsky scale were 69.58 +/- 23.49 and 84.80 +/- 23.49 respectively in control and trial groups (P < 0.05). The excellent outcome ratio (Karnofsky scale = 90 - 100) was 37.5% in control group and 72.0% in trial group respectively (P < 0.05). CONCLUSIONS: DTI allows individual estimation of large fiber tracts of brain. Furthermore, to integrate spatial three-dimensional information concerning the white matter tracts into traditional neuronavigation images during surgery, was valuable in presenting topographical character of involving (shift or erosive) pyramidal tracts and relationship with the margins of neighboring tumors. The mapping of large fiber tracts was a safe, efficient, reliable technique. DTI should be routinely used in neuronavigation surgery of brain tumor involving pyramidal tracts to plan the optimal trajectory and ensure total resection of the lesions during operation, as well as to decrease potential disability after operation and to shorten the length of hospitalization.
Five patients with chronic sinus pathology and an indication for sinus surgery were selected. For intraoperative navigation, we used Surgical Planning and Orientation Computer Systems (SPOCS) Aesculap navigation software (ISG Technologies, Mississauga, Ontario, Canada) and surgical instruments fitted with light-emitting diodes. Navigation procedures are described in detail in the article. The system's precision was measured by pointing at anatomical landmarks. The accuracy was measured as the distance in millimeters between the bony structures of the computed tomographic (CT) scan on screen and the cross-hair of the pointer tip displayed on the screen. Another parameter of the system's accuracy was calculated by the system itself as the root mean square error in millimeters between the markers' position as registered and their position in the CT data set. Axial 3/3/1-mm spiral CT provided sufficient resolution, and data transfer via optical disk was practicable. Positioning of the navigation equipment required some experience, and the registration of the patient's head position also needed attention, as the markers have to be pointed at precisely. During the operation, the position of the head-tracking system on the patient's head must remain unchanged to ensure a correct navigation display. The main advantage of the computed navigation system was the constant orientation provided during the sinus surgical procedure. Borders and critical anatomical structures could be identified in the corresponding CT data set, thus enabling the surgeon to decide on subsequent procedures. Use of the navigation system was found to increase the operation time by about 1 h, resulting in additional time under anesthesia. We found the SPOCS Aesculap computed navigation system to be an established technical aid, ready for use in ENT sinus surgery. In the cases reported here, a precision between 1 and 3 mm was obtained.