Technique For Precise Localization Research Articles

Reliability of High-resolution Gadolinium-enhanced MR Cisternography and Gasket-seal Technique for Management of Anterior Skull Base Defects

PurposePrecise preoperative localization of anterior skull base defects is important to plan surgical access, increase the success rate and reduce complications. A stable closure of the defect is vital to prevent recurrence of cerebrospinal fluid (CSF) rhinorrhea. The purpose of this retrospective case series was to evaluate the reliability of a new high-resolution gadolinium-enhanced compressed-sensing SPACE technique (CS T1 SPACE) for magnetic resonance (MR) cisternography to detect cerebrospinal fluid leaks of the anterior skull base and to assess the long-term success rate of the gasket-seal technique for closure of skull base defects.MethodAll patients with spontaneous or postoperative cerebrospinal fluid rhinorrhea and defects of the anterior skull base presenting to the Departments of Otorhinolaryngology and Neurosurgery between 2019 and 2020, receiving a computed tomography (CT) cisternography and MR cisternography (on a 3T whole-body MR scanner using a 64-channel head and neck coil) with CS T1 SPACE sequence and closure of the defect with the gasket-seal technique, were enrolled in the study. For the cisternography, iodinated contrast agent (15 ml Solutrast 250 M®), saline (4 mL) mixed with a 0.5 mL of gadoteridol was injected into the lumbar subarachnoid space.ResultsA total of four patients were included in the study and MR cisternography with CS T1 SPACE sequence was able to precisely localize CSF leaks in all patients. The imaging results correlated with intraoperative findings. All defects could be successfully closed with the gasket-seal technique. The mean follow-up was 35.25 months (range 33–37 months).ConclusionMR cisternography with CS T1 SPACE sequence could be a promising technique for precise localization of CSF leaks and the gasket-seal technique resulted in good closure of the CSF fistula in this case series.

Ground glass opacity on chest CT scans from screening to treatment: A literature review.

Lung cancer is the most common cause of cancer death in the world. However, recent studies have found that patients with pulmonary ground-glass opacity (GGO) have a better prognosis. Considering its low invasiveness, sublobar resection may be an appropriate treatment of choice. Low-dose computed tomography (CT) is recommended for the high-risk groups of lung cancer. Patients with nonsolid nodule are suggested to take annual low dose CT following-up. For part-solid or solid nodules, the solid component size less or more than 8 mm is the watershed of surgical treatment. Increasing tumor size is a hint of malignancy. Biopsy can be performed for clinically highly suspected malignant nodules. The endobronchial ultrasound biopsy, CT-guide biopsy, or surgical excision are the mainstream for the diagnosis of lung nodules. But for treatment, the sublobar resection is the mainstream of pulmonary GGO. A precise localization technique makes surgeons get enough resection margin and preserve more pulmonary function of the patients. The different localization technique is suitable for different kind nodular position. For patients with pure pulmonary GGO, annual low dose CT checkup is suitable. If the tumor size or solid part of the tumors increased gradually, adequate sublobar resection after tumor localization technique may provide good prognosis and preserve more pulmonary function of the patients.

Intraoperative portable abdominal radiograph for tumor localization: a simple and accurate method for laparoscopic gastrectomy

During laparoscopic gastrectomy, it is impossible to identify early gastric cancer (EGC) lesions; therefore, a precise localization technique is required. In this study, we evaluated a novel method of intraoperative portable abdominal radiograph for localization of EGC lesions after preoperative endoscopic clipping. A retrospective study of 80 patients who had undergone laparoscopic gastrectomies with our intraoperative abdominal radiographic method of tumor localization was performed. During preoperative endoscopy, endoscopic metal clips were applied just proximal to the tumor. A plain abdominal radiograph taken immediately after oral administration of effervescent agents was employed to select candidates for intraoperative localization. Intraoperative vessel clips were laparoscopically applied along the greater and lesser curvatures, and a portable abdominal radiograph was taken to identify the location of endoscopic clips relative to laparoscopic vessel clips. In all patients, endoscopic clips were applied proximal to the lesion without complications. Both intraluminally and extraluminally placed clips were successfully detected by intraoperative portable abdominal radiograph in all patients. Mean±standard deviation (SD) proximal margin length was 34.2±20.2mm. All patients had tumor-free resection margin. Preoperative endoscopic clipping and intraoperative portable abdominal radiograph is an accurate and simple tumor localization method in laparoscopic gastrectomy.

Intraoperative tumor localization using laparoscopic ultrasonography in laparoscopic–assisted gastrectomy

During laparoscopic-assisted gastrectomy, it is impossible to identify early gastric cancer (EGC) lesions; therefore, a precise localization technique is needed. In this study, we used laparoscopic ultrasonography (LUS) after endoscopic clipping as a method of localizing EGC and evaluated the effectiveness of this method. A prospective study of 17 patients who had undergone laparoscopic-assisted gastrectomy was performed. Three endoscopic clips were applied just proximal to the tumor during the preoperative endoscopy. The applied clips were detected from the serosal side of the stomach using LUS. The serosal surface of the lesion was marked with dye. In all patients, endoscopic clips were applied proximal to the lesion without complications, and the applied clips were confirmed by plain abdominal radiography. The clips were successfully detected by LUS in all patients. In the resected specimen, the serosal surface, marked with dye, was always just above the clips in the anterior wall or on the anterior wall opposite the clips applied in the posterior wall. The mean detection time was 4.7 min (range, 2-8). With this procedure, two patients underwent total gastrectomy and 15 patients underwent distal subtotal gastrectomy with gastroduodenostomy or gastrojejunostomy. Histological examination confirmed that the resection margins were tumor free in all patients. There was no operative morbidity related to the LUS procedure. Using LUS to detect endoscopic clips is an easy, safe, and accurate method to localize EGC lesions in laparoscopic-assisted gastrectomy.

Clinical nuclear magnetic resonance spectroscopy: Insight into metabolism

Nuclear magnetic resonance (NMR) spectroscopy can nondestructively evaluate changes in metabolites with different disease states, as well as with therapeutic interventions. Animal studies have provided the basis for understanding changes in high-energy phosphates with myocardial ischemia. Studies of graded ischemia due to partial coronary stenosis have shown the sensitivity of the ratio of phosphocreatinine to inorganic phosphate to small reductions in myocardial blood flow and its relation to myocardial function. The application of NMR spectroscopy to humans requires precise localization techniques to avoid acquiring contaminating information from structures around the heart, such as the chest wall and diaphragm. With these localization techniques, metabolic evidence of ischemia has been demonstrated in patients with myocardial infarction and patients with known coronary disease, although the sensitivity of this technique for the diagnosis of inducible ischemia is unknown. At rest, patients with dilated and hypertrophic cardiomyopathies often have an elevated phosphodiester resonance, possibly signifying abnormal breakdown of membrane phospholipids. Increasing oxygen demand in these patients does not usually alter high-energy phosphates, suggesting that oxidative energy metabolism is preserved under these conditions. NMR spectroscopy is a powerful tool to increase understanding of metabolic changes in a variety of pathologic conditions.

A computerized tomography-computer graphics approach to stereotaxic localization

This paper describes the use of three-dimensional computer graphics to display structures visible in computerized tomography (CT) scans and to accurately determine optimum stereotaxic probe placement relative to those structures. A prototype Lucite stereotaxic frame designed for use in CT body scanners was fitted with a phantom consisting of small Lucite spheres representing intracranial tumors with diameters of 6 to 19 mm. A series of CT scans was obtained of the frame and phantom together. Edge outlines of the spheres were extracted from each scan in the series. A three-dimensional visual representation of the spheres was obtained by displaying their outlines from all CT scans. A superimposed visual simulation of the stereotaxic frame was adjusted interactively using several analog dials in order to simulate trajectory choice and probe depth before actual surgery. The frame settings and probe depth calculated by the graphical computer were then applied to the actual prototype frame in order to assess the accuracy of this combined CT-computer graphics approach to stereotaxic localization. The results of 22 such experiments and the implications for future clinical use of this new and precise localization technique are discussed.

Vasovagal Pseudohemorrhage Complication of Percutaneous Renal Biopsy

PERCUTANEOUS renal biopsy is associated with a low risk of morbidity and mortality when precise localization techniques are used.1,2Nonetheless, a small number of patients will have complications from percutaneous renal biopsy.2,3One of the most serious complications is biopsyrelated bleeding requiring surgical intervention. The present report describes a patient who was initially considered to have hemorrhagic complications from a percutaneous biopsy but probably presented this clinical picture through the circumstantial interaction of diverse events. Report of a Case A 22-year-old woman with systemic lupus erythematosus was admitted to the University of Virginia Hospital for a percutaneous renal biopsy. The physical examination was essentially unremarkable. Her weight was 46.3 kg; blood pressure, 130/90 mm Hg; and pulse, 73 beats per minute. The creatinine clearance was 80 ml/min; quantitative urinary protein level, 6 gm/24 hr; hematocrit reading, 29%; platelet count, 197,000/cu mm; fibrinogen, 500 mg/100 ml; prothrombin time, 12.0/

Vasovagal pseudohemorrhage. Complication of percutaneous renal biopsy.

PERCUTANEOUS renal biopsy is associated with a low risk of morbidity and mortality when precise localization techniques are used.1,2Nonetheless, a small number of patients will have complications from percutaneous renal biopsy.2,3One of the most serious complications is biopsyrelated bleeding requiring surgical intervention. The present report describes a patient who was initially considered to have hemorrhagic complications from a percutaneous biopsy but probably presented this clinical picture through the circumstantial interaction of diverse events. Report of a Case A 22-year-old woman with systemic lupus erythematosus was admitted to the University of Virginia Hospital for a percutaneous renal biopsy. The physical examination was essentially unremarkable. Her weight was 46.3 kg; blood pressure, 130/90 mm Hg; and pulse, 73 beats per minute. The creatinine clearance was 80 ml/min; quantitative urinary protein level, 6 gm/24 hr; hematocrit reading, 29%; platelet count, 197,000/cu mm; fibrinogen, 500 mg/100 ml; prothrombin time, 12.0/