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PubMed1981

Computer-aided image analysis for the differentiation of mononuclear cells in peripheral blood smears from leukemic patients.

Different leukemias originating from the lymphatic system and from the myeloid tissue of the bone marrow were selected to develop and test algorithms to cytophotometrically define leukemic cells. Two of these cases were of low-grade, one of intermediate-grade and one of high-grade malignancy. The malignant cell types of each leukemic form could be identified and characterized by assessing the chromatin texture of the nucleus in the leukemic cells. With this method, normal peripheral white blood cells could be differentiated from leukemic ones. The results correlate directly with established hematologic parameters as they are described in the literature. The investigation demonstrated the usefulness of computer methods in the differentiation of closely related cell structures.

Blood Cells↗
PubMed1988

Clinical significance of hematic cyst of the orbit.

Hematic cyst is a rarely encountered orbital lesion consisting of encapsulated blood or blood breakdown products. The abnormality may be recognized by identifying the cystic structure by B-scan ultrasonography or computed tomography. Cysts located peripherally in the orbit tend to have histologic features suggesting hematoma formation. More centrally located orbital cysts are sometimes associated with vascular abnormalities. In other cases, the etiology is obscure, as in the case presented here. The visual prognosis is usually good, and associated systemic abnormalities are lacking.

Adult↗
PubMed2004

Computer-assisted detection of subcutaneous melanomas: feasibility assessment.

RATIONALE AND OBJECTIVES: Subcutaneous melanomas may be missed on computed tomography because of their peripheral location or perceived unimportance, yet they can have clinical significance. The use of a novel computer-assisted detection scheme to locate subcutaneous melanoma lesions in body CT images was investigated. MATERIALS AND METHODS: The detection software segments subcutaneous fat from the rest of the body and searches for soft tissue density lesions that match a size and shape constraint. Sensitivity and specificity of the proposed method was analyzed by comparing automated lesion detection results in eight patients with 118 subcutaneous melanomas with ground truth data derived from manual tracings of a trained observer. RESULTS: The sensitivity of subcutaneous melanoma detection was 86%. The false-positive rate was 3.1 per slice. Analysis of the false-positives showed that the most common cause was incorrect classification of muscle as a nodule. CONCLUSION: This study showed the feasibility of a fully automatic subcutaneous melanoma lesion detection system having good sensitivity. The false-positive rate was high, but avenues for further reduction were identified.

Adult↗
PubMed2002

Primary lymphoepithelioma-like carcinoma of lung.

A 57-year-old Caucasian woman presented with nonproductive cough. Computed tomography revealed a peripheral solid mass in the upper lobe of the left lung. She underwent thoracotomy and upper lobectomy. Histology of the excised tumor demonstrated lymphoepithelioma-like carcinoma of the lung, with no associated Epstein-Barr virus activity. Being a rare entity and mostly seen in Asians, very few cases have been described previously.

Carcinoma, Squamous Cell↗
PubMed2001

Peripheral lung adenocarcinoma: correlation of thin-section CT findings with histologic prognostic factors and survival.

PURPOSE: To evaluate the prognostic importance of thin-section computed tomographic (CT) findings of peripheral lung adenocarcinomas. MATERIALS AND METHODS: The subjects were 127 patients with adenocarcinomas smaller than 3 cm in largest diameter who underwent at least a lobectomy with hilar and mediastinal lymphadenectomy. The margin characteristics of nodules and the extent of ground-glass opacity (GGO) within the nodules at preoperative thin-section CT were analyzed retrospectively. Regional lymph node metastasis (LNM) and vessel invasion (VI) were histologically examined in surgical specimens. Survival curves were calculated according to the Kaplan-Meier method. RESULTS: The frequencies of LNM (4% [1 of 24]) and VI (13% [three of 24]) in adenocarcinomas with GGO components of more than 50% were significantly lower than those with GGO components of less than 10% (LNM, P <.05; VI, P <.01). The patients with GGO components of more than 50% showed a significantly better prognosis than those with GGO components less than 50% (P <.05). All 17 adenocarcinomas smaller than 2 cm with GGO components of more than 50% were free of LNM and VI, and all these patients are alive without recurrence. Coarse spiculation and thickening of bronchovascular bundles around the tumors were observed more frequently in tumors with LNM or VI than in those without LNM or VI (P <.01). CONCLUSION: Thin-section CT findings of peripheral lung adenocarcinomas correlate well with histologic prognostic factors.

Adenocarcinoma↗
PubMed2001

Recanalization 24 months after endovascular repair of a large internal iliac artery aneurysm with use of stent-graft.

An 83-year-old man with a large internal iliac artery aneurysm (IIAA) was treated with the use of stent-graft, suggesting successful results at 3, 6, and 12 months after treatment. However, 24-month follow-up computed tomography showed minor peripheral opacification of the IIAA. The patient underwent surgical endoaneurysmorrhaphy. No previous report of long-term recanalization of a satisfactorily thrombosed iliac artery aneurysm at 2 years or more after stent-grafting has been previously reported. Further follow-up studies need to be performed on the present procedure before anyone can confidently recommend it in regard to its long-term safety.

Aged↗
PubMed1993

Direct digital dental x-ray imaging with visualix/VIXA.

Visualix (VIXA in North America) is a new commercial system for direct dental x-ray imaging. It is based on a special charged-coupled device sensor and a personal computer platform with dedicated peripherals. Application software is installed that manages the operation of the sensor and provides a user interface specifically conceived for real time imaging. Given the high sensitivity of the sensor and the corresponding low dosage required, the performance of the system in terms of signal-to-noise ratio is essentially determined and limited by the quantized nature of the original radiologic information in the x-ray beam. At full scale range, the dose requirements are approximately six times less than those for a D-speed film.

Artifacts↗
PubMed2004

A case of systemic lupus erythematosus with giant hepatic cavernous hemangioma.

A 39-year old woman with antiphospholipid antibody positive systemic lupus erythematosus (SLE) was admitted to our department because of high fever, liver dysfunction and high level of C-reactive protein. At hospitalization, there was no anemia or jaundice. A tumor was palpable in the epigastric region, and there was tenderness in this region, but no muscular defense. There were no findings which indicated disease activity of SLE. The result of abdominal ultrasonography showed that there was a giant tumor, which occupied the majority of the left lobule of the liver, and a nonuniform ultrasound image was observed inside the tumor. The result of dynamic computed tomography (CT) showed peripheral globular enhancement, and enhancement then extended to the tumor center with time. Consequently, the patient was diagnosed with multiple hepatic hemangiomas. After admission, anemia rapidly deteriorated, and platelet count tended to decline. Therefore, intratumor hemorrhage was suspected, and emergent angiography was performed. For hemostatic purposes, transcatheter arterial embolization (TAE) and extended left hepatic lobectomy were performed. In patients with autoimmune diseases such as SLE and antiphospholipid syndromes, when thrombocytopenia is observed, care should be paid to identifying its cause, considering thrombocytopenia may be induced by hemangioma, although these cases are extremely rare.

Adult↗
PubMed2006

Virtual histology and color flow intravascular ultrasound in peripheral interventions.

The quality and interpretation of intravascular ultrasound (IVUS) imaging has been revolutionized in recent years by two new and major advances: virtual histology and color flow IVUS. Virtual histology intravascular ultrasound (VHIVUS) is a catheter-based technology where IVUS is generated from the transducer on the catheter tip and the reflected signals from the artery wall produce a color-coded map of the arterial disease. Different histological constituents of the plaque produce different reflected signals and these are assigned different colors (dark green, fibrous; yellow/green, fibrofatty; white, calcified; red, necrotic lipid core plaque). This color-coded map assists the interventionalist in understanding more fully how the lesion will behave at the moment of treatment, whether it will resist complete stent deployment or be liable to embolization. Originally introduced for coronary interventions, VHIVUS is now being applied to peripheral situations. Because it provides a detailed and close-proximity view of plaque, its potential to improve the safety and efficacy of carotid endoluminal repair is stimulating substantial interest. Similarly, color flow IVUS provides greater understanding for the operator of blood flow, and the interface between the vessel wall and the blood stream, lumen size, and success of treatment. Color flow IVUS does not use the Doppler effect, but creates real-time images that resemble color flow Doppler ultrasound. These two technological advances in IVUS have greatly improved the ability of the endovascular specialist to understand the arterial disease they are treating and to assess the completion of treatment.

Blood Vessel Prosthesis Implantation↗
PubMed1991

Peripheral nerve function in sepsis and multiple organ failure.

Forty-three patients who had sepsis and multiple organ failure (critical illness) were studied prospectively to determine the incidence and severity of peripheral nerve function and to correlate such function with a number of variables. Electrophysiologic studies indicated a primary axonal degeneration of motor and sensory fibers in 30 (70 percent). Fifteen (30 percent) had the clinical signs of difficulty in weaning from assisted ventilation, weakness of limb muscles, and reduced or absent deep tendon reflexes. Full recovery from the polyneuropathy occurred among the 23 (53 percent) who survived, except three who had a very severe polyneuropathy. A peripheral nerve function index, computed from electrophysiologic measurements, showed statistically significant (p less than 0.01) negative correlations with the time in the critical care unit, and the serum glucose value; the serum albumin level showed a positive correlation. Multiple regression analyses indicated all three factors accounted for 47 percent (r2 = 0.4678) of all potential variables. In a separate analysis, the nerve function index correlated with the amplitude of the diaphragm compound muscle action potential (p less than 0.01). The results were consistent with the polyneuropathy being due to the same mechanisms that are currently postulated to cause dysfunction in this syndrome of other organ systems (including the neuromuscular respiratory system).

Bacterial Infections↗
PubMed2006

Transdermal glyceryl trinitrate lowers blood pressure and maintains cerebral blood flow in recent stroke.

High blood pressure (BP) is common in acute stroke and is independently associated with a poor outcome. Lowering BP might improve outcome if it did not adversely affect cerebral blood flow (CBF) or cerebral perfusion pressure. We investigated the effect of glyceryl trinitrate ([GTN] an NO donor) on quantitative CBF, BP, and cerebral perfusion pressure in patients with recent stroke. Eighteen patients with recent (<5 days) ischemic (n=16) or hemorrhagic (n=2) stroke were randomly assigned (2:1) to transdermal GTN (5 mg) or control. CBF (global, hemispheric, arterial territory, and lesion, using xenon computed tomography) and BP (peripheral and central) were measured before and 1 hour after treatment with GTN. The effects of GTN on CBF and BP were adjusted for baseline measurements (ANCOVA). GTN lowered peripheral systolic BP by (mean) 23 mm Hg (95% CI, 2 to 45; P=0.03) and central systolic BP by 22 mm Hg (95% CI, 0 to 44; P=0.048). In contrast, GTN did not alter CBF (mL/min per 100 g): global -1.2 (95% CI, -6.5 to 4.2; P=0.66) and ipsilateral hemisphere -1.4 (95% CI, -7.6 to 4.9; P=0.65) or area of stroke oligemia, penumbra, or core (as defined by critical CBF limits). Contralateral CBF did not change: hemisphere 0 (95% CI, -7 to 6; P=0.96). GTN did not alter cerebral perfusion pressure or zero-filling pressure. Significant reductions in BP after transdermal GTN are not associated with changes in CBF or cerebral perfusion pressure or cerebral steal in patients with recent stroke. Trials need to assess the effect of lowering BP on functional outcome.

Aged↗
PubMed2006

Practical nerve morphometry.

Histopathological examination of peripheral nerves is often complemented by morphometric analysis in both clinical and research settings. However, existing manual or semi-automated methods are highly tedious, labour intensive and time-consuming, whereas fully automated morphometry is prone to error from the conversion of maldetected particles to spurious data. Both fully and interactive-automated morphometry have significant hardware requirements and may be difficult to implement. A new method for nerve morphometry is described aiming to combine the speed of automated morphometry with the accuracy of manual or semi-automated methods, and requiring only a digital image of the nerve section and two widely available software packages. Comparison with a standard digitizer pen method of nerve morphometry without sampling yielded statistically similar axon counts, mean area assessments and axonal area frequency distribution histograms, with assessment times of the new method between 35% and 45% of those of the standard method. This has widespread potential experimental and clinical applications and offers a means of relieving much of the tedium currently associated with nerve morphometry.

Animals↗
PubMed1986

Changes in systemic vascular resistance detected by the arterial resistometer: preliminary report of a new method tested during percutaneous transluminal coronary angioplasty.

A recently developed apparatus provides on-line continuous monitoring of systemic vascular resistance (SVR) by means of simple computer analysis of the peripheral arterial waveform. The fundamental equation of this method is Ri = P'/(dP/dt), where dP/dt is the peak dP/dt of the peripheral arterial waveform, P' is the pressure at time of peak dP/dt, and Ri is a resistance index that bears a direct relation to SVR. Eleven patients undergoing percutaneous transluminal coronary angioplasty (PTCA) were studied to evaluate the changes in SVR associated with myocardial ischemia (angina detection). There were 49 balloon inflations, all of which were associated with an increase in Ri (from 38.4 +/- 12 to 81.2 +/- 36 X 10(-3) sec; p less than .01) and a decrease in dP/dt (from 2076 +/- 257 to 1327 +/- 326 mm Hg/sec; p less than .01). In 42 of the balloon inflations these changes were associated with electrocardiographic ST-T changes and in 23 it was also associated with anginal pain. When angina was present, a further increase in Ri (to 97.5 +/- 43 X 10(-3) sec; p less than .01) and a decrease in dP/dt (to 1218 +/- 338 mm Hg/sec; p less than .01) was observed. It was found that myocardial ischemia is associated with an increase in the resistance index and a decrease in dP/dt and can be detected by the resistometer.

Angioplasty, Balloon↗
PubMed1987

Beat-to-beat estimation of peripheral resistance and arterial compliance during pressure transients.

We have used a computer-based parameter estimation method to obtain peripheral resistance, total arterial compliance, and characteristic resistance from the measurement of aortic pressure and flow in the open-thorax cat, assuming the three-element windkessel as a model of the systemic arterial tree. The method can be applied on a beat-to-beat basis in the steady state and in transients. We have validated this method by analyzing nonsteady-state data obtained from an electrical analog with fixed values of the resistances and compliance and by showing that the values obtained by this procedure were within 5% of the fixed values of the circuit. Changes in total peripheral resistance and arterial compliance were studied before, during, and after acute heart rate changes in five open-thorax cats with blocked autonomous nervous system. As expected, the peripheral resistance, estimated during the heart rate transient [3.93 +/- 0.94 (SE) kPa X ml-1 X s] was the same as before the transient (3.53 +/- 0.83 kPa X ml-1 X s); total arterial compliances were also identical (0.28 +/- 0.04 vs. 0.27 +/- 0.03 ml/kPa). In six cats without nervous blockade we obtained similar results. Calculation of peripheral resistance during transients from the mean pressure-to-mean flow ratio, i.e., without correction for arterial compliance, suggested changes in resistance values of less than or equal to 57%, which shows that correction is necessary. The findings indicate that peripheral resistance and total arterial compliance can be estimated in vivo on a beat-to-beat basis, even during hemodynamic transients.

Animals↗
PubMed1984

Subpleural pulmonary hamartoma: demonstration by computed tomography.

A case of a subpleural pulmonary hamartoma demonstrated by computed tomography is presented. The literature on subpleural pulmonary lesions demonstrated by computed tomography is reviewed. Although peripheral pulmonary hamartomas have been well documented, we believe this is the first demonstration of a subpleural location by computed tomography scanning. In the appropriate clinical setting, pulmonary hamartoma should be included in the differential diagnosis of subpleural lesions identified on computed tomography scanning of the chest.

Aged↗
PubMed1996

Morphometric analysis of noninvasively assessed bone biopsies: comparison of high-resolution computed tomography and histologic sections.

This article describes a new method to analyze the structural behavior of trabecular bone structure by means of noninvasive measurements of the three-dimensional cancellous bone architecture. For the noninvasive data acquisition, a high-resolution quantitative computed tomography system for peripheral measuring sites (pQCT) was used. With this system and the help of a multiple thin-slice measuring technique, it became possible to examine three-dimensional bone structure with a resolution of 0.25 mm. Using a special three-dimensional segmentation algorithm, mineralized bone was separated from bone marrow and muscle tissue within the three-dimensional stack of CT slices. These segmented data sets can then be processed nondestructively and, even more important, repetitively in either two or three dimensions. In order to validate this noninvasive procedure, a two-dimensional comparative morphometric study was performed including CT slices and corresponding histologic sections prepared after CT measurement. Three representative sections from the three-dimensional stack of CT slices were selected and the morphometric indices of the segmented CT slices were compared with the indices stemming from the corresponding histologic sections prepared after CT measurement. Although the presented approach can only give an example of the method, the results from the morphometric analysis support the assumption that cancellous bone structures based on noninvasive high-resolution CT measurements are representative for trabecular microstructures assessed from histologic bone sections. The study demonstrates the potential of high-resolution CT imaging for in vivo applications of quantitative bone morphometry. This is especially true for repetitive follow-up measurements, which cannot be performed using histologic sections. Additionally, the method offers an easy access to the three-dimensional structure of trabecular bone, which is mandatory for the analyses of the anisotropic mechanical behavior of cancellous bone.

Algorithms↗
PubMed2003

Design and testing of a virtual environment to train stroke patients with unilateral spatial neglect to cross a street safely.

Virtual reality (VR) entails the use of advanced technologies, including computers and various multimedia peripherals, to produce a simulated (that is, virtual) environment that users perceive as comparable to real world objects and events. In recent years, virtual reality technologies have begun to be used as an assessment and treatment tool in occupational therapy, in part because of the ability to create environments that provide patients with opportunities to engage in meaningful, purposeful tasks that are related to real-life interests and activities. The objective of this study was to determine the suitability and feasibility of using a PC-based, non-immersive, VR system (that is, a system in which the user has a reduced sense of actual presence in and control over the simulated environment) for training individuals with unilateral spatial neglect to cross streets in a safe and vigilant manner. A virtual environment, consisting of a typical city street, was programmed using Superscape's 3D-Webmaster, a 3D web-authoring tool. Twelve subjects, aged 55 to 75 years, participated in the initial feasibility study and, to date, a further eight subjects have participated in the intervention study. Six of the initial subjects and all eight of the intervention subjects had sustained a right hemispheric stroke at least 6 weeks prior to the study. The remaining subjects were healthy age-matched adults who were independently mobile and had no difficulty in crossing streets. The results show that this virtual environment was suitable in both its cognitive and motor demands for the targeted population and indicate that the virtual reality training is likely to prove beneficial to people who have difficulty with crossing streets. The generalizability of these results, and recommendations regarding the use of virtual reality as an occupational therapy intervention, must be substantiated by further studies using a range of VR platforms with people with different cognitive and motor disabilities.

Accidents, Traffic↗
PubMedDate not supplied

CT findings of cystic duct carcinoma two years before obstructive jaundice.

We describe a case of cystic duct carcinoma, the computed tomography findings of which had been incidentally obtained several times over the preceding three years before obstructive jaundice appeared. Under the diagnosis of extrahepatic bile duct carcinoma, a 75-year-old man underwent surgery. Two years before obstructive jaundice appeared, the arterio-portal phase of enhanced computed tomography demonstrated an ovoid mass with peripheral rim enhancement, measuring 1.5 cm in diameter, beside the extrahepatic bile duct. One year later, a repeat enhanced computed tomography consistently showed the ovoid mass with peripheral rim enhancement, and the lower slice of the contiguous computed tomography scan revealed a uniformly enhanced mass compressing the neck of the gallbladder. Four months before obstructive jaundice, the uniformly enhanced mass beside the extrahepatic bile duct markedly infiltrated the surrounding tissues with spicula-formation. At laparotomy, a solid and hard tumor was localized on the right side of the extrahepatic bile duct, in the cholecystic duct and the neck of the gallbladder. Of 29 reported cases fulfilling Farrar's criteria in the English literature other than autopsy cases, computed tomography imaging was only performed in two cases, and the computed tomography findings of cystic duct carcinoma in its early stages, have never been fully described.

Aged↗