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At least 1,567 records · Page 87Linked to original sources
PubMed2001

Peripheral pulmonary arteries: how far in the lung does multi-detector row spiral CT allow analysis?

PURPOSE: To analyze the influence of multi-detector row spiral computed tomography (CT) on identification of peripheral pulmonary arteries. MATERIALS AND METHODS: Peripheral pulmonary arteries were analyzed on optimally opacified contrast material-enhanced spiral CT angiograms in 30 patients devoid of pleuroparenchymal disease who underwent scanning with multi-detector row CT (collimation, 4 x 1 mm; pitch, 1.7-2.0; scanning time, 0.5 second). Two series of scans were systematically generated from each data set, 1.25-mm-thick (group 1) and 3-mm-thick (group 2) sections, leading to the analysis of 600 segmental (20 arteries per patient), 1,200 subsegmental (40 arteries per patient), 2,400 fifth-order (80 arteries per patient), and 4,800 sixth-order (160 arteries per patient) pulmonary arteries in each group. RESULTS: Multi-detector row CT with reconstructed scans of 1.25-mm-thick sections (group 1) allowed (a) analysis of a significantly higher percentage of subsegmental arteries (94% in group 1 vs 82% in group 2; P <.001) and (b) a significantly higher percentage of fifth- and sixth-order arteries, respectively, identified in 74% and 35% of cases in group 1 and 47% and 16% in group 2 (P <.001). The causes for inadequate depiction of subsegmental branches in group 1 were partial volume effect (43%), anatomic variants (39%), and cardiac (17%) and respiratory (1%) motion artifacts. CONCLUSION: Multi-detector row CT with reconstructed scans of 1.25-mm-thick sections enables accurate analysis of peripheral pulmonary arteries down to the fifth order on spiral CT angiograms.

Angiography↗
PubMed2001

Fluoroscopy-assisted thoracoscopic surgery after computed tomography-guided bronchoscopic barium marking.

BACKGROUND: Small lesions of the peripheral lung have been detected more frequently with the recent prevalence of computed tomography (CT). Identification of these lesions is indispensable for wedge resection performed by video-assisted thoracic surgery. Previous reports of marking techniques showed some failure and complications. We have developed a new marking technique and herein describe the efficacy of this technique: fluoroscopy-assisted thoracoscopic surgery after computed tomography-guided bronchoscopic barium marking. METHODS: Twenty patients underwent this procedure for 21 small peripheral pulmonary lesions approximately 10 mm in size. RESULTS: All the lesions were successfully marked and identified during fluoroscopy-assisted thoracoscopy. They were resected with sufficient margins. There were no complications related to this procedure. The pathologic examination of these 21 lesions revealed primary lung cancer in 14, atypical adenomatous hyperplasia in four, a metastatic tumor in one, and a benign tumor in two. CONCLUSIONS: This procedure is both a reliable and minimally invasive technique in thoracoscopic wedge resection for small peripheral pulmonary lesions.

Adult↗
PubMed2003

Pulmonary cytolytic thrombi: unusual complication of hematopoietic stem cell transplantation.

Pulmonary complications of hematopoietic stem cell transplantation (HSCT), including peripheral blood stem cell transplantation (PBSCT) and bone marrow transplantation, are frequent and often life-threatening. Differentiating acute infectious from noninfectious pulmonary complications is difficult but critical for proper treatment. The authors describe an 11-year-old boy who developed a sudden fever and cough associated with a normal chest radiograph 2 months after successful haploidentical PBSCT for severe aplastic anemia. High-resolution chest computed tomography revealed numerous tiny peripheral pulmonary nodules. Lung biopsy demonstrated an unusual occlusive thrombotic vascular lesion associated with hemorrhagic infarction without evidence of infection. The thrombi were composed of intensely basophilic granular material recently described as "cytolytic" thrombi. Symptoms and chest computed tomography improved rapidly following intravenous corticosteroids and cyclosporin. However, the patient subsequently died of rapidly progressive pulmonary hypertension. Our patient illustrates the importance of considering this noninfectious complication in the acute pulmonary disorders associated with HSCT as this condition may represent a pulmonary manifestation of acute graft-versus-host disease.

Child↗
PubMedDate not supplied

Computed tomographic analysis of pes cavus.

Patterns of muscle degeneration in patients with peripheral neuropathies exhibiting pes cavus deformity were studied by computed tomography (CT). Twenty-six patients attending the muscle disease clinic at Newington Children's Hospital with hereditary sensory motor neuropathies (HSMN) I, II, or III had clinical and radiographic assessment in addition to CT scans of the feet and legs at designated levels. The pattern of muscle degeneration was analyzed with other variables, including age, sex, tibial torsion, cavus, heel varus, and claw toes. Multiple regression/correlation analysis clearly demonstrated earlier and more severe involvement of the intrinsic muscles of the foot as compared with the extrinsic muscles. The most consistent early degeneration occurred in the pedal lumbricals and interossei, which have the most distal innervation. The order of muscle degeneration is a centripetal pattern, with two types of degeneration occurring in the leg muscles: type P patients had earlier degeneration of the leg muscles innervated by the peroneal nerve, and type T patients showed earlier degeneration of those extrinsics innervated by the posterior tibial nerve.

Adolescent↗
PubMed1991

High definition computed tomography in rheumatoid arthritis associated pulmonary disease.

Eighteen patients with rheumatoid arthritis (American Rheumatism Association definition) were selected consecutively from a rheumatology clinic. All patients were examined with plain chest radiographs, thin slice computed tomography, and pulmonary function tests. Four patients with normal chest radiographs, and normal pulmonary function tests were found to have normal CT scans. In ten patients, abnormalities consistent with rheumatoid associated lung disease were demonstrated, including changes of interstitial fibrosis in seven cases. This fibrosis had a predominantly peripheral pattern on CT scan. Computed tomography was found to be more sensitive than plain radiographs in detecting abnormalities; however, all the patients in this series with CT lung changes had abnormalities on pulmonary function testing.

Adult↗
PubMed1996

Computer-assisted comparative analysis of four-sector and six-sector biopsies of the prostate.

OBJECTIVES: To assess the potential difference in positive biopsy rates between four-sector and six-sector biopsy methods. METHODS: This computer-assisted analysis is based on the records of 156 consecutive patients previously diagnosed with T1c cancer on systematic sextant biopsy of the peripheral zone. For each patient the computer randomly deleted one biopsy result from the left and right prostatic lobes. The deletion process was repeated 1000 times. Based on four randomly chosen biopsy cores, we determined the number of undetected cancers initially diagnosed with sextant biopsy. RESULTS: Based on four-sector biopsy cores of the peripheral zone, between 6 and 30 (3.8% to 19.2% of cases) nonpalpable, isoechoic prostate cancers that were detected with sextant biopsy would have remained undiagnosed. CONCLUSIONS: Our results suggest that the number of biopsy cores used in the early detection of nonpalpable, isoechoic prostate cancer may substantially affect the rate of positive findings.

Aged↗
PubMedDate not supplied

Congenital peripheral facial palsy associated with cerebellopontine angle arachnoid cyst.

OBJECTS: A rare case of cerebellopontine angle arachnoid cyst leading to congenital peripheral facial palsy was presented. CLINICAL PRESENTATION: A 1-year-old girl presented with peripheral facial paralysis since birth. Computed tomography and magnetic resonance imaging revealed left cerebellopontine angle arachnoid cyst causing moderate displacement of the brain stem. INTERVENTION: Retrosigmoid suboccipital craniotomy was performed and microsurgical resection of the cyst wall and fenestration of the cyst to the basal cisterns were achieved. CONCLUSIONS: Cerebellopontine angle arachnoid cyst should be considered as a potential cause of congenital peripheral facial palsy.

Arachnoid Cysts↗
PubMed2004

A low peripheral blood white blood cell count in infants younger than 90 days increases the odds of acute bacterial meningitis relative to bacteremia.

UNLABELLED: In relying on the peripheral blood white blood cell (WBC) count to identify infants at high risk for acute bacterial meningitis and bacteremia, to the best of the authors' knowledge, it has not been reported previously whether high and low values of the test have similar implications for predicting these separate infections. OBJECTIVE: To analyze the relationship between the peripheral WBC count and the odds of acute bacterial meningitis relative to bacteremia among sick infants aged 3 to 89 days. METHODS: Areas under the receiver operating characteristic curve (AUCs) and likelihood ratios at various intervals of the total peripheral blood WBC count were computed. RESULTS: A pathogen was isolated from blood or cerebrospinal fluid (CSF) from 72 infants aged 3 to 89 days. Fifty-two infants had growth of a pathogen from the blood only, and 20 had growth from the CSF. The most common bacteria isolated were Escherichia coli (32) and group B streptococci (32). The AUC for the peripheral WBC count when differentiating between acute bacterial meningitis and bacteremia was 0.75 (95% CI = 0.63 to 0.88). The odds of acute bacterial meningitis relative to bacteremia were sevenfold higher for a peripheral WBC cutoff below 5,000 cells/mm(3) and threefold lower for a peripheral WBC cutoff at or above 15,000 cells/mm(3). CONCLUSIONS: In young infants, the peripheral blood WBC count is useful for estimating the odds of acute bacterial meningitis relative to isolated bacteremia. A low peripheral blood WBC count should be considered a much more worrisome laboratory finding because it is associated with a relatively high risk for acute bacterial meningitis relative to the potential for bacteremia.

Age Distribution↗
PubMed2002

Measurement of localized ground-glass attenuation on thin-section computed tomography images: correlation with the progression of bronchioloalveolar carcinoma of the lung.

RATIONALE AND OBJECTIVE: This study was to measure localized ground-glass attenuation (GGA) in the peripheral lung on thin-section computed tomography (CT) and to assess any relationship between the attenuation and lesion. MATERIALS AND METHODS: Twenty-eight surgically resected tumors with localized GGA at thin-section CT were studied. The tumors were histologically diagnosed as 8 atypical adenomatous hyperplasia (AAH), 11 bronchioloalveolar carcinoma (BAC), and 9 BAC with fibrosis. We assumed three concentric circles, which were 0.8, 1.0, and 1.2 times the diameter of each tumor and measured the average CT values corresponding to inside each circle. We calculated a difference in CT value between 0.8 and 1.2 times the diameter of the tumor and defined as the contrast index. RESULTS: The contrast index for tumors with AAH, BAC, and BAC with fibrosis were 19.8 +/- 8.3, 42.5 +/- 16.0 (P < 0.05 vs. group with AAH), and 111.4 +/- 32.6 (P < 0.0001 vs. Group with BAC), respectively. The contrast index became greater in the stepwise progression from AAH to BAC and from BAC to BAC with fibrosis. CONCLUSION: The contrast index correlated histologic findings of the tumor growth in BAC. The contrast index may be a useful and objective measurement for determining surgical treatment for localized GGA in preoperative diagnosis.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1997

Variable tip angle slab selection pulses for carotid and cerebral time-of-flight MR angiography. Theory and experimental analysis.

OBJECTIVE: To determine the optimal parameters of variable tip angle slab selection (tilted optimized nonsaturating excitation, TONE) pulses in time-of-flight MR angiography, in order to produce the best visualization of vessels distal to the entry partition. MATERIAL AND METHODS: The influences of the mean flip angle (MFA) and the profile tilt of the TONE pulse in three-dimensional (3D) time-of-flight MR angiography were evaluated with a mathematical modeling of the flow signal amplitude. We compared the calculated flow signals with the signals from flow-phantom models and with those from 6 normal volunteers. 3D gradient echo images (TR/TE 30/7) were acquired with a single variable of the MFA and the profile tilt. The flow velocity of the phantom was maintained at 15 cm/s. Regions of interest were measured on the source images. We also evaluated the visualization of the cerebral vessels on maximum intensity projection images obtained with and without TONE pulses in 5 other healthy volunteers. RESULTS: The changes of flow signals in the phantom and in the volunteers were in good accord with those of the signals mathematically predicted and plotted by a computer, as each parameter was varied. The peripheral saturation was weaker at smaller MFA than at larger MFA. A greater profile tilt produced a more pronounced TONE effect than a lower one. The visualization of the peripheral cerebral vessels was markedly improved by the addition of the TONE pulse. CONCLUSION: Computer simulation is useful for examining the optimal TONE parameters. The TONE pulse markedly improves the visualization of the distal branches of the cerebral vessels.

Adult↗
PubMed2005

[Measurement of otoacoustic emissions by sound card].

A new method in OAE's measurement by computer sound card is introduced. It is a measurement system using SF-1 detector. We designed the appropriate analog filter amplifier peripheral, utilized the mature technology of computer sound card, and recorded the OAE signal using Windows' API function programming by VB. The recorded signals can be analyzed by Matlab, such as digital filtering and Coherence average. The system is, in the main, cost-effective. The statistical results of the experiments proved the reliability of the method.

Acoustic Stimulation↗
PubMed1987

A mathematical simulation of oxygen delivery in rat peripheral nerve.

We have performed a mathematical simulation on a CYBER computer of the release, diffusion, and consumption of oxygen in the capillaries and surrounding tissue of peripheral nerve under steady-state conditions. The Krogh-Erlang equation was used to calculate oxygen tension in tissue, while numerical solution of the differential equation governing oxygen release from hemoglobin and diffusion was used to calculate oxygen tension in the capillary. Using average measured values for the parameters of oxygen solubility, diffusion coefficient, capillary diameter, capillary density, nerve blood flow, oxygen consumption rate, and arterial oxygen tension in rat peripheral nerve, we calculated the endoneurial oxygen tension as a function of distance from the nearest capillary and distance along the capillary from the arterial end to the venous end. The range of calculated values agreed with experimental measurements obtained from the sciatic nerves of rats. Alterations in these parameters produced changes in the calculated oxygen tension distributions. Conditions which adversely affected oxygen delivery include reduced capillary diameter, increased intercapillary distance, reduced blood flow, and reduced arterial oxygen tension. The lower experimentally obtained oxygen tensions in sciatic nerves of diabetic rats could be accounted for reasonably by this model on the basis of a 33% reduction in nerve blood flow (consistent with previously measured flow reduction). However, the measured reduction in oxygen tensions in sciatic nerves of rats with experimental galactose neuropathy were not as marked as those predicted on the basis of a 22% increase in tissue cylinder radius in the model (consistent with experimental observations). This may be due to the fact that the oxygen consumption rate is reduced in hypoxic regions of tissue.

Animals↗
PubMed2006

An inexpensive sub-millisecond system for walking measurements of small animals based on optical computer mouse technology.

Stimuli from a broad spectrum of sensory modalities, including visual, auditory, thermal, and chemical, can elicit walking responses in animals, reflecting neural activity in sensorimotor pathways. We have developed an integrated walking measurement system with sub-millisecond temporal accuracy capable of detecting position changes on the order of 100 microm. This tracking system provides the experimenter with a means by which to map out the response spectrum of a tethered animal to any number of sensory inputs on time scales relevant to propagation in the nervous system. The data acquisition system consists of a modified optical computer mouse, a microcontroller with peripheral support circuitry, a binary stimulus sync line, and a serial (RS-232) data transfer interface. The entire system is constructed of relatively inexpensive components mostly converted from commercially available peripheral devices. We have acquired walking data synchronized with auditory stimuli at rates in excess of 2100 samples per second while applying this system to the walking phonotactic response of the parasitic fly Ormia ochracea.

Acoustic Stimulation↗
PubMed1981

[Computed tomography and densitometric pattern of pulmonary lesions (author's transl)].

Fifty-five peripheral pulmonary lesions in 46 patients were examined by computed tomography. The results were correlated with histologic diagnoses. The series comprised 26 bronchial carcinomas, 17 metastases, 4 chondromas, 5 tuberculomas and 3 echinacoccal cysts. The high resolution capacity of CT in the evaluation of macro pathologic pattern specially with the electronic image processing, with densitometry in regional interest is emphasised. Therefore cysts, fatty and other solid masses in the lung can be distinguished. Further more one can gain information of the underlying tissue on the basis of absorption profile.

Absorptiometry, Photon↗
PubMed1988

[Ultrasonography and x-ray computed tomography in the diagnosis of intra-abdominal textiloma. Apropos of 12 cases].

Feared by every surgeon, retained surgical sponges (or gossypiboma) are rare iatrogenic entities. Ultrasonography and computed tomography are very valuable, providing an immediate answer in the majority of cases. We report 12 cases of intra-abdominal retained surgical swabs. The ultrasonic pattern was made whether of a large poorly echogenic mass with a hyper-echogenic center and sharply delineated posterior acoustic shadow (7 cases) or of a large acoustic shadow posterior to a solitary highly echogenic area (4 cases). Computed tomography demonstrated whether large peripherally enhanced cystic mass associated with serpiginous or spongiform central area (5 cases) or heterogeneous abscess-like fluid mass.

Abdomen↗
PubMed2006

Long-term follow-up in patients with lost coronary stents during interventional procedures.

The aim of this retrospective study was to determine the incidence of stent loss during interventional procedures and to identify the associated immediate and long-term consequences of such loss. We evaluated 36 cases in which the stents were prematurely displaced from the stent delivery device. Five stents were completely removed from the vascular system successfully. Five stents could not be retrieved from the coronary circulation and led to significant adverse events in 3 patients, in whom the lost stents were not excluded by the placement of another stent. In 26 patients, peripheral embolism below the renal arteries occurred after successful stent retrieval from the coronary arteries. Of these 26 patients, 1 patient died during hospital stay, unrelated to the peripheral stent loss. Additional follow-up examinations were performed for 20 of the remaining 25 patients. Clinical patient status and the ankle-brachial index were evaluated 59 +/- 30 months after stent loss. All patients were free of any stent-related peripheral ischemic symptoms. We also attempted to determine the exact physical locations of the lost stents using computed tomography during follow-up. In 15 patients, we were able to detect the stent in the peripheral arteries using computed tomography. In conclusion, if stents cannot be retrieved from the coronary system, severe problems may occur. Stent loss with peripheral embolization is asymptomatic in long-term follow-up.

Aged↗
PubMedDate not supplied

Designing a medical Web site.

BACKGROUND: A web site is a valuable shop window for any medical unit with something to sell or something to say. AIMS: The aim of this report is to outline the basic steps of web page design for the individual or unit with limited financial resources. METHODS: There are two ways of designing a web site. A reputable web design company can be employed, but this is usually expensive. Alternatively, a web site can be designed in-house using commercial software, following a few simple steps. The basic requirements are a personal computer, software that is available on most computers and access to a few peripheral items of hardware. An outline of the page design should first be put down on paper. This can be transferred to a computer file using a web page design program. This file is then sent to a server for publication on the World Wide Web (WWW). CONCLUSION: Designing and publishing a web page can take time and effort, but the rewards can be great and the results will reflect the message and motto of the unit.

Humans↗
PubMed1978

Measurements in microscopic images: an inexpensive device for semi-automatic analysis of microscopic images.

Measurement of histological and cytological parameters can be performed much faster and more accurate by means of a semi-automatic device that is described in detail. The system consists mainly of a medium-sized computer and one or more peripheral terminals. Each terminal incorporates a special measurement table for data acquisition, a keyboard for manual data input, and an interface. The software program for the evaluation and storage of the digital data is simple to write and offers a high degree of flexibility to the user. The system can be operated in real time.

Computers↗