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At least 1,009 records · Page 56Linked to original sources
PubMed2000

Telemedicine screening of diabetic retinopathy using a hand-held fundus camera.

The objective was to evaluate digital images of the retina from a handheld fundus camera (Nidek NM-100) for suitability in telemedicine screening of diabetic retinopathy. A handheld fundus camera (Nidek) and a standard fundus camera (Zeiss) were used to photograph 49 eyes from 25 consecutive patients attending our diabetic clinic. One patient had cataracts, making it impossible to get a quality image of one of the eyes (retina). The Nidek images were digitized, compressed, and stored in a Fujix DF-10M digitizer supplied with the camera. The digital images and the photographs were presented separately in a random order to three ophthalmologists. The quality of the images was ranked as good, acceptable or unacceptable for diabetic retinopathy diagnosis. The images were also evaluated for the presence of microaneurysms, blot hemorrhages, exudates, fibrous tissue, previous photocoagulation, and new vessel formation. kappa Values were computed for agreement between the photographs and digital images. Overall agreement between the photographs and digital images was poor (kappa < 0.30). On average, only 24% of the digital images were graded as being good quality and 56% as having an acceptable quality. However, 93% of the photographs were graded as good-quality images for diagnosis. The results indicate that the digital images from the handheld fundus camera may not be suitable for diagnosis of diabetic retinopathy. The images shown on the liquid crystal display (LCD) screen of the camera were of good quality. However, the images produced by the digitizer (Fujix DF-10M) attached to the camera were not as good as the images shown on the LCD screen. A better digitizing system may produce better quality images from the Nidek camera.

Diabetic Retinopathy↗
PubMed1991

Intraoral micro-identification discs.

Intraoral micro-identification discs have recently been utilized to provide a more permanent method of personal identification. A wafer of plastic or metal with a surface area of 2.5 to 5 mm2 and carrying identifying numbers and/or letters (indicia) is bonded to the buccal enamel surface of the posterior teeth. Personal identification can occur after the I.D. disc is identified and the indicia is read. Reading of photoreduced indicia requires the aid of a microscope subsequent to the removal of the microdisc. In situ reading of disc indicia is possible using low power handheld magnifiers if the size of the indicia approximates 0.3 mm. Computerization is an integral part of non-custom alpha/numeric type designs, but a custom disc carries a name, address, and other specific information unique to the manufacturer. The use of a computer improves access to the database and it decreases the amount of data placed on the disc. Microdisc bases may be fabricated using a mylar type plastic or they may be manufactured from a stainless steel blank. Plastic discs are constructed with an internal sandwich containing the photo-reduced indicia. Metal discs are marked with a photochemical etch or engraved with a computer driven YAG laser. Attachment of the disc to the enamel surface is accomplished by conventional etching and bonding techniques and are typically bonded to the buccal surface of the maxillary first permanent molar or the second primary molar. Clear composite bonding material covers the disc so that salivary contamination does not result in degradation of the indicia. Orthodontic style discs with a mesh back carry laser written information that may be cemented with conventional orthodontic bonding cement. Standardization of the indicia and overall design is considered to be an important aspect of patient and professional acceptance.

American Dental Association↗
PubMed2005

Mobile phone use-effects of handheld and handsfree phones on driving performance.

The study was concerned with effects of handsfree and handheld mobile phone dialling and conversation in simulated driving. In the main experiment dealing with conversation, 48 participants drove a distance of about 70 km on a route which led through urban and rural environments. In the dialling experiment, the participants drove a distance of 15 km on a rural two-lane road. The experimental design was mixed with phone mode as a between-subjects factor and phone use (yes/no) as a within-subjects factor. Performance on a peripheral detection task (PDT) while driving was impaired by dialling and conversation for both phone modes, interpreted as an increase in mental workload. Driving performance was impaired by dialling--lateral position deviation increased in a similar way for both phone modes. Conversation had, however, opposite effects--lateral position deviation decreased in a similar way for both phone modes. Driving speed decreased as an effect of dialling with the greatest effect for handsfree phone mode. Conversation also caused reduced speed, but only for handheld phone mode. The effects on speed can be interpreted as a compensatory effort for the increased mental workload. In spite of the compensatory behaviour, mental workload was still markedly increased by phone use. Subjective effects of dialling and conversation were also analysed. Most participants reported a speed decrease but no effect on lateral position deviation as an effect of dialling or conversation. In the conversation experiment, driving performance was rated better for handsfree than for handheld mode. In the dialling experiment, no difference between the two phone modes appeared.

Adult↗
PubMed2006

Absorbed dose measurements of a handheld 50 kVP X-ray source in water with thermoluminescence dosemeters.

Absorbed dose rate measurements of a 50 kV(p) handheld X-ray probe source in a water phantom are described. The X-ray generator is capable of currents of up to 40 microA, and is designed for cranial brachytherapy and intraoperative applications with applicators. The measurements were performed in a computer-controlled water phantom in which both the source and the detectors are mounted. Two different LiF thermoluminescence dosemeter (TLD) phosphors were employed for the measurements, MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P). Two small ionisation chambers (0.02 and 0.0053 cm(3)) were also employed. The TLDs and chambers were positioned in watertight mounts made of water-equivalent plastic. The chambers were calibrated in terms of air-kerma rate, and conventional protocols were used to convert the measurements to absorbed dose rate. The TLDs were calibrated at National Institute of Standards and Technology (NIST) in terms of absorbed dose rate using a (60)Co teletherapy beam and narrow-spectrum X-ray beams. For the latter, absorbed dose was inferred from air-kerma rate using calculated air-kerma-to-dose conversion factors. The reference points of the various detectors were taken as the center of the TLD volumes and the entrance windows of the ionisation chambers. Measurements were made at distances of 3-45 mm from the detector reference point to the source center. In addition, energy dependence of response measurements of the TLDs used was made using NIST reference narrow spectrum X-ray beams. Measurement results showed reasonable agreement in absorbed dose rate determined from the energy dependence corrected TLD readings and from the ionisation chambers. Volume averaging effects of the TLDs at very close distances to the source were also evident.

Body Burden↗
PubMed2006

Cervical pedicle screw placement: feasibility and accuracy of two new insertion techniques based on morphometric data.

This morphometric and experimental study was designed to assess the dimensions and axes of the subaxial cervical pedicles and to compare the accuracy of two different techniques for subaxial cervical pedicle screw (CPS) placement using newly designed aiming devices. Transpedicular fixation is increasingly used for stabilizing the subaxial cervical spine. Development of the demanding technique is based on morphometric studies of the pedicle anatomy. Several surgical techniques have been developed and evaluated with respect to their feasibility and accuracy. The study was carried out on six conserved human cadavers (average age 85 years). Axes and dimensions of the pedicles C3-C7 (60 pedicles) were measured using multislice computed tomography (CT) images prior to surgery. Two groups consisting of 3 specimens and 30 pedicles each were established according to the screw placement technique. For surgical technique 1 (ST1) a para-articular mini-laminotomy was performed. Guidance of the drill through the pedicle with a handheld aiming device attached onto the medial aspect of the pedicle inside the spinal canal. Screw hole preparation monitored by lateral fluoroscopy. In surgical technique 2 (ST2) a more complex aiming device was used for screw holes drilling. It consists of a frame with a fully adjustable radiolucent arm for carrying the instruments necessary for placing the screws. The arm was angled according to the cervical pedicle axis as determined by the preoperative CT scans. Drilling was monitored by lateral fluoroscopy. In either technique 3.5 mm screws made of carbon fiber polyetheretherketone (CF-PEEK) were inserted. The use of the CF-PEEK screws allowed for precise postoperative CT-assessment since this material does not cause artifacts. Screw placement was qualified from ideal to unacceptable into four grades: I = screw centered in pedicle; IIa = perforation of pedicle wall less than one-fourth of the screw diameter; IIb = perforation more than one-fourth of the screw diameter without contact to neurovascular structures; III = screw more than one-fourth outside the pedicle with contact to neurovascular structures. Fifty-six pedicle screws could be evaluated according to the same CT protocol that was used preoperatively. Accuracy of pedicle screw placement did not reveal significant differences between techniques 1 and 2. A tendency towards less severe misplacements (grade III) was seen in ST2 (15% in ST2 vs. 23% in ST1) as well as a higher rate of screw positions graded IIa (62% in ST2 vs. 43% in ST1). C4 and C5 were identified to be the most critical vertebral levels with three malpositioned screws each. Because of the variability of cervical pedicles preoperative CT evaluation with multiplanar reconstructions of the pedicle anatomy is essential for transpedicular screw placement in the cervical spine. Cadaver studies remain mandatory to develop safer and technically less demanding procedures. A similar study is projected to further develop the technique of CPS fixation with regard to safety and clinical practicability.

Aged, 80 and over↗
PubMed1994

Relation between coronary artery stenosis assessed by visual, caliper, and computer methods and exercise capacity in patients with single-vessel coronary artery disease. The Veterans Affairs ACME Investigators.

BACKGROUND: Practitioners often assume a close relation between angiographic coronary artery stenosis and patient functional capacity. To test this unproven hypothesis, we analyzed the relation between coronary artery stenosis measured by different methods and maximal treadmill exercise tolerance in patients with single-vessel disease before and after intervention by percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: Coronary angiography and maximal exercise testing off anti-ischemic medication were performed before random assignment of 227 patients with single-vessel coronary artery disease to PTCA or drug therapy. Six months later, angiography and exercise testing were repeated with patients assigned to PTCA off anti-ischemic therapy so that the altered coronary stenosis was the only consistent variable. Patients assigned to drug therapy were exercised on drug therapy. Coronary stenosis was assessed visually by the local investigator and quantitatively by blinded caliper and computer methods in central laboratories. Variabilities of caliper and computer measurements were established in a subset read twice. Visually estimated stenosis > or = 90% at baseline was associated with shorter exercise duration (7.9 versus 9.2 minutes, P < .04). Similar segregation at baseline was not observed with caliper or computer methods. Regardless of the method of measurement used, correlation between changes of lesion severity and exercise duration from baseline to follow-up was poor. Patients were angiographically classified as "better," "unchanged," or "worse" if follow-up stenosis was below, within, or above 2 SD of mean technical variability from baseline (+/- 18.8%, caliper, +/- 14.6%, computer). Exercise duration for PTCA patients improved among those with better lesions (+2.4 minutes, n = 50, P = .001) but also among those with unchanged lesions (+1.9 minutes, n = 41, P < or = .001). Unchanged medically treated patients improved less (+0.5 minutes, n = 86, P = .04). Results were similar when patients were angiographically classified by minimum lumen diameter. CONCLUSIONS: Handheld calipers and quantitative coronary angiography are equivalent techniques for making anatomic measurements. Neither method identified patients having reduced exercise capacity at baseline as well as visual estimation. The relation between changes of coronary stenosis and exercise duration is highly variable, at least in part because of the insensitivity of angiographic methods for detecting small but potentially important changes. Minimal anatomic improvement 6 months after PTCA does not preclude a good functional outcome. Contrary to common belief, angiographic stenosis does not correlate well with functional capacity, even in patients with single-vessel disease.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Bar codes in the clinical laboratory.

A basic overview of bar code technology is presented with a focus on applications in the clinical laboratory. Bar codes operate based on symbology, a pattern of bars and white spaces that define alphanumeric characters. The codes are read by scanners, which may be stationary or handheld. Bar codes may be printed using any of several available methods. Bar codes are currently being implemented in several areas of health care, including materials management, clinical laboratory, pharmacy, medical records, and asset management. Planning for implementation of a bar code system is very much like computer installation, in terms of systems analysis and design, procedures, and training. Clinical laboratories should consider use of bar code systems, as they often are faster, better, and more cost-effective than available alternatives.

Electronic Data Processing↗
PubMed1995

Preferred viewing distances for handheld and structurally fixed displays.

This research was conducted to define viewing distance characteristics of individuals engaged in ordinary reading tasks. Specific attention was directed to assessing the potential relationship between observed distance and individual resting point accommodation. Consistent, statistically significant differences were observed across variable handheld and structurally-fixed hardcopy display configuration conditions. Relationships between observed viewing distance and resting point accommodation were not apparent. These findings suggest that simple eye-to-display viewing distance is fundamentally different for handheld text presentations and for the same text presented in a configuration similar to that of a video display terminal.

Accommodation, Ocular↗
PubMed2005

Preoperative technetium Tc 99m sestamibi SPECT imaging in the management of primary hyperparathyroidism in patients with concomitant multinodular goiter.

HYPOTHESIS: Preoperative parathyroid and thyroid imaging using technetium Tc 99m sestamibi scintigraphy-single-photon emission computed tomography (Tc 99m MIBI SPECT) and technetium Tc 99m sodium pertechnetate, respectively, in patients with parathyroid adenomas and concomitant multinodular goiters enables the selection of those suitable for minimally invasive radio-guided surgery. DESIGN: One hundred thirty patients with primary hyperparathyroidism were treated surgically during a 30-month period. Forty-one of these 130 patients had an associated multinodular goiter. All patients underwent planar and SPECT parathyroid scintigraphy using Tc 99m MIBI, and thyroid scintigraphy with technetium Tc 99m pertechnetate 2 to 5 days before surgery. On the morning of surgery each patient was reinjected with Tc 99m MIBI for intraoperative localization and validation. Minimally invasive radio-guided parathyroidectomy was performed using a handheld gamma-detection device with a thyroid probe. Removed glands were submitted for histopathologic examination for comparison with the scintigraphic results. Quantitative analysis of parathyroid activity was performed. RESULTS: Minimally invasive, radioguided parathyroidectomy was successfully performed in 21 (51%) of 41 patients who had a concomitant multinodular goiter. The remaining 20 patients underwent standard neck exploratory surgery because of associated thyroid disease; 5 of them had malignant thyroid disease. Among the 41 patients planar scintigraphy correctly identified 28 adenomas (68%). Single-photon emission computed tomographic imaging identified an additional 11 adenomas for a sensitivity of 95% and a specificity of 100%. Moreover, SPECT imaging correctly identified malignant thyroid nodules in 4 of 5 patients. Technetium Tc 99m MIBI retention was noted in only 25 adenomas (61%) while the remaining adenomas demonstrated a rapid washout. The average uptake ratio of parathyroid counts to maximum thyroid activity was significantly correlated with parathyroid hormone levels before surgery (P = .04). CONCLUSIONS: Our data encourage the use of preoperative SPECT imaging of parathyroid adenomas in patients who have multinodular goiters to select those suitable for minimally invasive radioguided surgery. This technique also offers important information regarding thyroid nodules that are suspicious for malignancy. The intraoperative gamma-probe technique enables the surgeon to focus his or her search, provides instant feedback regarding the progress of the operation, reduces surgical trauma and complications, and yields better cosmetic results. Patients with higher presurgical parathyroid hormone levels may especially benefit from radioguided surgery.

Adult↗
PubMed2003

Intraoperative radioguided sentinel lymph node biopsy in non-small cell lung cancer.

OBJECTIVES: The aim of this study was to determine the accuracy and the role of the sentinel lymph node (SLN) technique in patients with early non-small cell lung cancer (NSCLC). METHODS: This study was carried out on 29 consecutive patients (M/F = 24:5, mean age 65.9 +/- 7.1 years) with resectable NSCLC (Stage IA-IB). Intraoperative injection with a (99m)Tc-nanocolloid suspension was performed in the first ten patients; the following patients were injected under computed tomography scan guidance. A total dose of 37 MBq (1 ml) was administered in two to four divided aliquots (depending on the size), injected in the periphery of the tumour. Intraoperative radioactivity counting started a mean of 1 h (range 50-70 min) after the injection. The SLN was defined as the node with the highest count rate using a handheld gamma probe counter. Resection with mediastinal node dissection was performed and findings were correlated with histologic and immunohistochemistry (IHC) examination. RESULTS: Three of the 29 patients did not have NSCLC (two benign lesions, and one metastatic breast tumour) and were excluded. The SLN was identified in 25/26 (96.1%) patients (a total of 31 SLNs); 7/31 (22.5%) of the SLNs were positive for metastatic involvement after histologic and IHC examination. One inaccurately identified SLN was encountered (3.8%). CONCLUSIONS: These preliminary results demonstrate the feasibility of this procedure in identifying the first site of potential nodal metastases of NSCLC. The actual clinical impact of this procedure remains to be elucidated by further investigation in larger groups of patients.

Aged↗
PubMed2004

Ultra-high-throughput microarray generation and liquid dispensing using multiple disposable piezoelectric ejectors.

The authors have constructed an array of 12 piezoelectric ejectors for printing biological materials. A single-ejector footprint is 8 mm in diameter, standing 4 mm high with 2 reservoirs totaling 76 micro L. These ejectors have been tested by dispensing various fluids in several environmental conditions. Reliable drop ejection can be expected in both humidity-controlled and ambient environments over extended periods of time and in hot and cold room temperatures. In a prototype system, 12 ejectors are arranged in a rack, together with an X - Y stage, to allow printing any pattern desired. Printed arrays of features are created with a biological solution containing bovine serum albumin conjugated oligonucleotides, dye, and salty buffer. This ejector system is designed for the ultra-high-throughput generation of arrays on a variety of surfaces. These single or racked ejectors could be used as long-term storage vessels for materials such as small molecules, nucleic acids, proteins, or cell libraries, which would allow for efficient preprogrammed selection of individual clones and greatly reduce the chance of cross-contamination and loss due to transfer. A new generation of design ideas includes plastic injection molded ejectors that are inexpensive and disposable and handheld personal pipettes for liquid transfer in the nanoliter regime.

Cell Line↗
PubMed1998

Remotely pollable Geiger-Müller detector for continuous monitoring of iodine-131 therapy patients.

UNLABELLED: In many countries, patients treated with therapeutic amounts of (131)I are hospitalized because of radiation safety considerations. To determine when they can return home, radiation levels are intermittently monitored at bedside using a handheld Geiger-MIller (GM) counter, although this procedure can be cumbersome and inexact. METHODS: We have developed and tested a remotely pollable system for continuous radiation monitoring of (131)I therapy inpatients, using readily available hardware and standard telephone lines. The remote detector system, consisting of a palmtop IBM-compatible personal computer, specialized software, PCMCIA modem and miniature serial port-based GM detector, is placed opposite the patient's bed at a fixed distance, and continuous 1-min acquisitions are started. Initially and at least twice daily, the remote palmtop is contacted by modem, and all interval data are uploaded onto the operator's base computer over the telephone line, including measurements taken with the patient in a predetermined standardized position. Continuous minute-to-minute data may be viewed in native form or can be imported into graphing and spreadsheet programs. Points acquired with the patient in standardized position are specially marked to highlight the constant geometry used. The ratio of initial counting rate to administered dose is used to estimate residual (131)I body burden by proportionality. Display of data as a semilogarithmic plot facilitates extrapolation of the activity curves and prediction of the patient's earliest time of discharge. RESULTS: We have characterized the remote GM detector system to confirm accuracy, counting rate linearity and reliability of data transfer. We describe examples that illustrate the applicability and usefulness of this method for remote monitoring of inpatient (131)I therapy levels. CONCLUSION: Monitoring patients with the described remotely pollable GM detector is an accurate and easy-to-implement technique that could conceivably lead to shortened hospital stays for (131)I therapy inpatients. Continuous quantitative data obtained are useful for kinetic and dosimetric analyses, which may be applied to study other gamma-emitting radiopharmaceuticals as well. The flexibility of the technique may permit its use in the monitoring of therapy on an outpatient basis, where allowed.

Equipment Design↗
PubMed1983

Use of the handheld programmable calculator in the preparation of TPN solutions.

A handheld programmable calculator was used to increase speed and decrease errors when calculating and labeling total parenteral nutrition formulations for pediatric patients. A program was developed and tested and an evaluation of the calculator vs. the manual method was performed. The time required to calculate total parenteral nutrition formulations decreased 50% and errors decreased from 3% to 0. Use of a handheld programmable calculator saves time and increases the accuracy of calculations and labels when preparing total parenteral nutrition formulations. The approximate total cost of the calculator, printer, and card reader is $1000.

Child, Preschool↗
PubMedDate not supplied

Design of remote control units for seniors.

HumRRO International, Inc. conducted a project to improve the human factors aspects of remote control unit (RCU) design. Although the research was oriented toward RCUs for future telerobots that older adults may use, the RCUs examined were currently available models. An observational study found that a sample of 18 persons aged 65-88 years made errors in performing a simple arithmetic task with four different handheld calculators and that 13 participants made errors operating 11 VCR remotes. Better human-machine designs in RCUs appear to be needed to reduce errors that might cause accidents in the future use of mobile telerobots and their manipulators. In addition, manufacturers of RCUs, gerontologists, and members of SeniorNet, a network of older adults interested in computers, were queried regarding the design of RCUs. The responses of these individuals and the participants in the observational study, together with human factors engineering analyses, suggested numerous design improvements that may be systematically examined.

Aged↗
PubMed2003

Cardiovascular effects at multi-detector row CT colonography compared with those at conventional endoscopy of the colon.

PURPOSE: To compare the cardiovascular effects of computed tomographic (CT) colonography and conventional endoscopy in a group of patients undergoing both procedures. MATERIALS AND METHODS: A total of 144 patients underwent CT colonography followed by flexible sigmoidoscopy (40 patients) or colonoscopy (104 patients). Pulse, blood pressure, and oxygen saturation were measured before, during, and after the procedures. Forty patients also underwent continuous Holter electrocardiographic (ECG) monitoring. Periprocedural pain was assessed by using a handheld counting device. Outcome variables were assessed by using a combination of paired t testing and multilevel linear regression. RESULTS: When a spasmolytic was not used, CT colonography was associated with only a small increase in oxygen saturation (P =.03), while use of a spasmolytic caused an increase in pulse (mean increase, 19.9 beats per minute; P <.001) and diastolic blood pressure (mean increase, 5 mm Hg; P <.001). Compared with that at CT, oxygen saturation decreased significantly during and after colonoscopy and sigmoidoscopy (mean decrease after colonoscopy with sedation, 1.0%; P <.001). Systolic and diastolic blood pressure also decreased during and after colonoscopy (mean systolic decrease after colonoscopy with sedation, 16.6 mm Hg, P <.001; mean diastolic decrease after colonoscopy with sedation, 7.5 mm Hg, P <.001). Patients were 30.3 times more likely to develop bradycardia after endoscopy (95% CI: 2.65, 346; P =.006). Ventricular couplets were significantly higher at endoscopy than at CT in patients with a history of cardiac disease (odds ratio: 72.5 and 95% CI: 4.56, 1,153 at CT vs odds ratio: 14.6 and 95% CI: 0.96, 222 at endoscopy; P =.002). Patients were 1.89 times more likely to register pain during colonoscopy than during CT (95% CI: 1.06, 3.38; P =.03). CONCLUSION: CT colonography had no significant cardiovascular effect other than spasmolytic-induced tachycardia. Endoscopy-and colonoscopy in particular-causes cardiovascular effects that are largely related to sedation. CT colonography is less painful than colonoscopy and is comparable to flexible sigmoidoscopy.

Adult↗
PubMed2002

Desktop and mobile software development for surgical practice.

PURPOSE: The aim of this study was to develop a mobile software solution that will merge patient data with a centralized patient database, aid surgical decision making, and document clinical services. METHODS: iIncise is a computerized, menu-driven database that was developed for real-time entry of historical, clinical, and laboratory data. Within the process, examination data, testing rationale, and test results are captured. AAST staging criteria are presented during data entry to describe and classify organ injuries accurately. A legible, time-stamped, conclusive report can be generated for printed or electronic entry into the medical record. The handheld version of the database runs on a Compaq iPAQ Pocket PC in either stand-alone mode or via LAN or WAN through the Internet. Microsoft Information Internet Server 5.0 provides data transaction services to Microsoft SQL Server 2000 to merge multiuser replicate data between the back ends stored on the desktop and handheld devices. RESULTS: The printed report provides superior documentation for comprehensive evaluation and management services, including history and physical examination, documentation of medical decision making, appropriateness of diagnostic/or therapeutic services, and coordination of care in accordance with Health Care Financing Administration (HCFA) regulations. CONCLUSIONS: Rapid data entry, ease of use, and appropriate documentation of detailed and legible patient visits and procedural notes are early benefits. Wireless data transmission between handheld devices and the desktop database provides the required speed, flexibility, and multitasking environment necessary for the mobile surgeon.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed2000

Can preoperative spiral CT scans alone determine the feasibility of endovascular AAA repair? A comparison to angiographic measurements.

PURPOSE: To determine whether computed tomography (CT) alone can be used for excluding patients from endovascular repair for abdominal aortic aneurysms (AAA). METHODS: Among 71 patients evaluated for endovascular AAA repair using spiral CT imaging and angiography, 31 were selected who had both studies performed within 6 months of each other using a graduated measuring catheter or guidewire. Measurements of aneurysm neck diameter, neck length, and infrarenal aortic length were made from the CT and angiographic images using handheld calipers with calibration markers as guides. Infrarenal aortic length and neck length were determined from CT images by multiplying the width of the cuts by the number of slices between the lowest renal artery and the aortic bifurcation or the top of the aneurysm, respectively. RESULTS: CT neck diameter measurements differed significantly from the angiographic dimensions (6.3 +/- 5.1-mm mean difference, p < 0.001). In the majority of patients (25, 81%), CT neck diameters were larger (mean 7.3 +/- 3.8 mm). The mean difference in neck length measurements was 0.5 +/- 15.9 mm (p = NS). Twenty-two (71%) patients had aortic length measurements that were longer on the angiogram (mean 15.4 +/- 17.2 mm, p = NS). Five patients who would have been excluded as candidates based on overestimated CT neck diameter measurements subsequently underwent successful endovascular aneurysm repair. CONCLUSIONS: Considerable discrepancies exist between preoperative neck diameter and infrarenal aortic length measurements obtained from CT scans and angiograms used to evaluate candidates for endovascular aortic aneurysm repair. CT alone may not be adequate for predicting the feasibility of endovascular AAA repair.

Angiography↗
PubMed2004

A preliminary study on sentinel lymph node biopsy: feasibility and predictive ability in oral cavity cancer.

The main factor that affects the prognosis of patients with head and neck cancer (HNC) is regional lymph node metastases. For this reason, the accurate evaluation of neck metastases is required for neck management. This study investigates the sentinel lymph node identification and the accuracy of the histopathology of the sentinel lymph node in patients with HNC. Eleven patients with histologically proven oral squamous cell carcinoma accessible to radiocolloid injection were enrolled in this study. Using both lymphoscintigraphy and a handheld gamma probe, the sentinel lymph node could be identified in all 11 patients. Subsequently, the sentinel lymph nodes and the neck dissection specimen were examined for lymph node involvement due to tumor. The histopathology of sentinel lymph nodes was consistent with the pathological N classification in all 11 patients. Furthermore, the histopathology of sentinel lymph nodes was superior to physical examination, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) scan. The results of this study indicate that sentinel lymph node identification is technically feasible and predicts cervical metastases in patients with oral cavity cancer. This may be a useful diagnostic technique for identifying lymph node disease in staging lymph node dissection.

Adult↗