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At least 379 records · Page 21Linked to original sources

A one year experience with the multislice helical CT.

New detector morphology and increased computer power have led to a second leap in CT technology. With multislice helical CT, four slices per rotation are reconstructed resulting in a 3 to 6 times reduction of the examination time. During our one-year experience with the multislice CT, we have learnt that the major advantage of the technique is the possibility to cover a large volume with thin slices. Combination of both makes it possible to scan an entire anatomic region during the optimal enhancement phase (after i.v. contrast injection) with a high spatial resolution. New diagnostic possibilities can be explored by CT together with improved and more detailed post-processing tools.

Contrast Media↗

[Populations of afferent neurons in the sensory ganglia detected using lectin from Laburnum anagyroides].

The purpose of the present research was the study of afferent neuron subpopulations in vagal caudal ganglia and trigeminal ganglion of adult albino rats using a conjugate of fucose-specific Laburnum anagyroides lectin (LAL) with peroxidase. Histochemical preparations obtained were examined using computer videoanalyzer with the determination of dimensions of afferent neurons and integral optical density (IOD) of their cytoplasm. In the ganglia studied LAL was found to bind to the majority (more than 98%) of neurons. Reaction product was demonstrated in the perikaryon either as discrete granules (Nissl body-type), or as a uniform precipitate. Nucleoplasm in most of neurons remained lightly stained. Determination of IOD of neuronal cytoplasm in various ganglia demonstrated significant differences in degree of LAL accumulation. Analysis of interrelation between neuronal size and IOD permitted to establish non-linear correlation of metric and optical parameters and to detect subpopulations of cells in the sensory ganglia, which were stained with LAL most intensely. Functional specialization of these cells remains to be determined. Thus, a combined application of lectin-histochemical method with a computer videoanalysis of morphological slides enabled the identification neuronal populations and subpopulations in rat afferent ganglia, which are not demonstrated with the standard histological methods.

Animals↗

Morphological characteristics of malignant solitary pulmonary nodules.

The solitary pulmonary nodule is a common radiologic abnormality, which is often detected incidentally. It is defined as focal, round or oval areas of increased opacity in the lung which are caused by a variety of disorders, including neoplasm, infection, inflammations, and vascular and congenital abnormalities. Most of the solitary pulmonary nodules are benign, but up to 30%-40% of them are malignant. The main goal of the radiologic evaluation of suspected solitary pulmonary nodules is to differentiate benign from malignant lesions as accurately as possible. The aim of the study was the assessment of the morphological characteristics of the malignant solitary pulmonary nodules. Large nodule size, irregular, spiculated margins, inhomogeneous density of nodule thick walls in cavitary nodules suggest the presence of the malignant lesion. Smooth, well-defined margins, homogeneous density or the presence of diffuse, laminated, central or popcorn-like calcifications suggest the benign nodule. Diffuse, irregular amorphous calcifications suggest the malignant process. Unfortunately there is a kind of overlapping, and some benign nodules may show features typical of malignancy, and some malignant lesions may appear benign. Morphologic characteristics in computed tomography is however helpful in differentiation of benign from malignant nodules.

Calcinosis↗

[Magnetic resonance tomography in preoperative analysis of chronic post-traumatic osteomyelitis].

Chronic osteomyelitis in 8 patients was studied preoperatively by magnetic resonance (MR) imaging and in part of them also by computed tomography (CT). Morphologic information about extraosseous and intraosseous changes was important for surgical planning. In long bones CT generally is superior delineating bone structures (sequestra and fragments of devitalized bone in the intramedullary cavity) and MR may be used as an adjunct for localizing extraosseous and intraosseous abscesses. In trabecular bones as the os calcis MR seems to be equivalent to CT.

Adult↗

Isolated spinous process deviation. A pitfall in the interpretation of AP radiographs of the lumbar spine.

A new type of spinous process deviation is described. This variant may cause confusion in the interpretation of anteroposterior (AP) radiographs of the lumbar spine. In the literature, two types of lumbar spinous process deviation (SPD) have been described: 1) SPD due to rotation of the entire vertebra (as in rotatory scoliosis and degenerative arthritis), and 2) SPD as a consequence of developmental asymmetries of the neural arch. The present study demonstrates that spinous process deviation in the AP radiograph is not a reliable diagnostic guide. The authors' quantitative morphologic analysis of computed tomographic (CT) sections of over 200 lower lumbar vertebrae in vivo revealed a third type of SPD, namely isolated deviation of the spinous process, ie, deviation without any associated rotation or asymmetry of the vertebral body or arch. Since the oval shadow cast by the spinous process in AP radiographs is caused by its tip, rather than by its base (as was demonstrated by in vitro tests), it is concluded that the position of the spinous process shadow in AP radiographs cannot be used as a reliable landmark to differentiate between the three types of SPD. This is only possible by means of a CT examination.

Diagnosis, Differential↗

New method for measuring myocardial blood flow by high resolution scintigraphy in the excised dog heart.

The standard method for measuring myocardial blood flow (MBF) with radioactive microspheres requires processing of selected tissue samples usually from the excised heart, and consequent loss of exact relation to myocardial morphology. A computer-based image processing method was developed by using [99mTc]microspheres (mean particle size 20 microns) for quantitative analysis of MBF in 25 dogs. A computer-controlled gamma camera was used to obtain the images of radioactive microsphere distribution in transaxial slices of the ex vivo heart. Any portion of these slice images could be quantitated by using a computer program based on modification of the formula for determining MBF by the standard microsphere method. Regional myocardial perfusion calculated by this technique correlated well with values obtained with reference microspheres (r = 0.96) over a broad range of MBF. The results show that our new method, accurately and with high resolution, delineated zones of differing MBF and confirmed the increase of MBF in surviving myocardium with healing.

Animals↗

[Basic neurologic syndromes in occlusion of the extracranial portion of the carotid artery and mechanisms of their development].

The author analyzed clinical, angiographic, computer-tomographic and morphological findings obtained in patients with an occluded internal carotid artery. Polymorphism of neurological syndromes is due to a large variety of factors and combinations. The most important of them include characteristics of the pathogenesis of cerebral circulation disorders--mechanical exclusion of the blood flow or hemodynamic changes; different variants of the collateral circulation, combined lesion of extra-and intracranial arteries.

Arterial Occlusive Diseases↗

[Malignant lymphomas of the orbit, facial bones and the parapharyngeal space].

The evaluation of 21 patients with non-Hodgkin-Lymphoma and primary extranodal manifestations involving the orbits, the paranasal sinuses, and the parapharyngeal spaces shows no typical features in malignant lymphoma. The analysis of the morphological features in computed tomography allows no classification of the tumor type. The most important differential diagnoses within the region of the facial skeleton are discussed.

Adolescent↗

Intraoperative sonography through a burr hole: guide for brain biopsy.

Sonographic imaging of the brain was accomplished through a burr hole using a small, real-time, 5 MHz transducer in five patients. Brain tumors were accurately imaged, corresponding closely in morphology to the computed tomographic scan. Intraoperative sonography through a burr hole allows flexibility in technique and greatly facilitates brain biopsy procedures.

Biopsy↗

Frequency, technical aspects, results, and indications of major hepatectomy after prolonged intra-arterial hepatic chemotherapy for initially unresectable hepatic tumors.

BACKGROUND: Major hepatectomy after prolonged intra-arterial hepatic chemotherapy (IAHC) is extremely rare, because IAHC usually fails to reduce the tumor volume sufficiently or obtain a long duration of response, or both, and because it impairs hepatic function. The present report was done to study the frequency, feasibility, and results of hepatectomy following IAHC. STUDY DESIGN: This retrospective study consisted of 14 patients treated with at least six courses of IAHC (mean of 17.6, median of 13, range of six to 48 courses) for hepatic tumors: colorectal metastases (n = 9), apudoma metastases (n = 4), and hepatoblastoma (n = 1). Systemic chemotherapy was associated in eight cases during (n = 5) or after (n = 3) IAHC. Initially, multiple hepatic tumors were unresectable in ten cases. They eventually became resectable, but were associated with extensive extrahepatic sites of involvement in four cases. All patients underwent curative major hepatectomy after a careful and specific morphologic and functional hepatic assessment. Right portal vein embolization was performed preoperatively upon three patients, resulting in 38, 44, and 77 percent hypertrophy of the left lobe before hepatectomy. Hepatectomy was also performed upon three patients with hepatic arterial thrombosis induced by IAHC, after a careful workup of the neoarteriovascularization of the liver. RESULTS: These 14 cases only represented 5.8 percent of the 239 patients in whom a catheter was inserted for IAHC, and 4.2 percent of the 335 patients who had hepatectomy for carcinoma. Postoperatively, there was no mortality and no clinical hepatic insufficiency. However, ten complications occurred in eight patients (three of them resulted in reoperation). Histologic examination revealed substantial modifications of the hepatic parenchyma because of IAHC. Results concerning survival were very encouraging: five of the nine patients with metastases of the colon and rectum are free of disease, with a mean follow-up period of 36 months after the beginning of IAHC. CONCLUSIONS: The decision to perform a major hepatectomy after prolonged IAHC is difficult and must be based on an output morphologic assessment with computed tomographic portography and a careful evaluation of functional liver impairment because of IAHC (the therapeutic strategy proposed by Makuuchi for hepatectomy in patients with cirrhosis, based on indocyanine green clearance and volume to resect, is very useful for this purpose). Hepatectomy is technically difficult to perform following IAHC because of a flabby parenchyma and unusually high pressure in the small central hepatic veins. This drawback is circumvented by using techniques, such as preoperative hypertrophy of the future remaining liver, a transparenchymatous approach of vasculobiliary structures, and intermittent clamping of the hepatic pedicle or vascular isolation of the liver. Postoperative complications occurred more frequently than after major hepatectomy in other clinical settings (p < 0.05). However, as this therapeutic approach greatly increases survival, it should not be neglected by clinicians, although indications for its use are very rare.

Adult↗

[Major hepatectomy after intra-arterial chemotherapy for initially unresectable liver tumors. Frequency, technical problems, results and indications].

BACKGROUND: Major hepatectomy after prolonged intra-arterial hepatic chemotherapy (IAHC) is extremely rare, because IAHC usually fails to reduce the tumor volume sufficiently or obtain a long duration of response, or both, and because it impairs hepatic function. The present report was done to study the frequency, feasibility and the results of hepatectomy following IAHC. STUDY DESIGN: This retrospective study consisted of 14 patients treated with at least six courses of IAHC (mean of 17.6, median of 13, range of six to 48 courses) for hepatic tumors: colorectal metastases (n = 9), apudoma metastases (n = 4), and hepatoblastoma (n = 1). Systemic chemotherapy was associated in eight cases during (n = 5), or after (n = 3) IAHC. Initially, multiple hepatic tumors were unresectable in ten cases. They eventually became resecable, but were associated with extensive extrahepatic sites of involvement in four cases. All patients underwent curative major hepatectomy after a careful and specific morphologic and functional hepatic assessment. Right portal vein embolization was performed preoperatively upon three patients, resulting in 38, 44 and 77 percent hypertrophy of the left lobe before hepatectomy. Hepatectomy was also performed upon three patients with hepatic arterial thrombosis induced by IAHC, after a careful workup of the neoarteriovascularization of the liver. RESULTS: These 14 cases only represented 5.8 percent of the 239 patients in whom a catheter was inserted for IAHC, and 4.2 percent of the 335 patients who had hepatectomy for carcinoma. Postoperatively, there was no mortality and no clinical hepatic insufficiency. However, ten complications occurred in eight patients (three of them resulted in reoperation). Histologic examination revealed substantial modifications of the hepatic parenchyma because of IAHC. Results concerning survival were very encouraging: five of the nine patients with metastases of the colon and rectum are free of disease, with a mean follow-up period of 36 months after the beginning of IAHC. CONCLUSIONS: The decision to perform a major hepatectomy after prolonged IAHC is difficult and must be based on an output morphologic assessment with computed tomographic portography and a careful evaluation of functional liver impairment because of IAHC (the therapeutic strategy proposed by Makuuchi for hepatectomy in patients with cirrhosis, based on indocyanine green clearance and volume to resect, is very useful for this purpose). Hepatectomy is technically difficult to perform following IAHC because of a flabby parenchyma and unusually high pressure in the small central hepatic veins. This draw-back is circumvented by using techniques: such as preoperative hypertrophy of the future remaining liver, a transparenchymatous approach of vasculobiliary structures, and intermittent clamping of the hepatic pedicle or vascular isolation of the liver. Postoperative complications occurred more frequently than after major, hepatectomy in other clinical settings (p < 0.05). However, as this therapeutic approach greatly increases survival, it should not be neglected by clinicians, although indications for its use are very rare.

Adult↗

[Total pancreatectomy for diffuse and malignant mucinous ductal ectasia of the pancreas. Apropos of 2 cases].

Two cases of mucinous duct ectasia are reported. Epithelial changes were spread along the pancreatic duct and ductal ectasia was diffuse. Multi focal infiltrating carcinoma was observed in one case, microinvasive carcinoma located in the head of the pancreas was observed. Morphologic features by computed tomography, endoscopic ultrasonography pancreatography were useful for preoperative diagnosis of mucinous pancreatic duct ectasia. In one case, malignancy was suggested by measurement of tumor markers in cystic fluid aspirated during percutaneous pancreatography. Total duodenopancreatectomy was performed in both cases. The two patients were alive and disease-free with a follow-up in both cases of 18 and 36 months.

Aged↗

[CT aspects of brain metastases in bronchial carcinoma].

Twenty patients of 210 with the brain metastases with diagnosed bronchogenic carcinoma were analysed, according to existing morphological criteria of computed tomography (CT), in correlation with pathohistologically findings (PHD) of primary tumor. Multiple lesions and perifocal edema as the main CT features of metastatic disease of the brain were confirmed. Some details like increased frequence of the solitary forms and uncharacteristic perifocal edema were emphasized. Also, some differential diagnostic possibilities with the brain metastases were considered.

Brain Neoplasms↗

Simulation and analysis of flow patterns around the scleractinian coral Madracis mirabilis (Duchassaing and Michelotti).

Three-dimensional morphologies of Madracis mirabilis were obtained using X-ray computed tomography scanning techniques. The morphologies were used to simulate the flow patterns around the colony. In the simulations, the thin-branching low-flow morph with a relatively larger branch-spacing was compared with the more compact high-flow morph of M. mirabilis. For both morphologies, the inside-colony flow velocities were computed for Reynolds numbers ranging from 154 to 3840. In the high-flow morph, it was found that in the range of investigated Reynolds numbers a stagnant region develops within the colony, whereas in the low-flow morph the stagnant region disappeared. Experiments done under natural conditions suggest that a morph is adapted to a certain external flow velocity and develops a stagnant region below a particular threshold for the external flow velocity. When the external flow velocity exceeds a certain threshold, which is characteristic for the growth form, the core velocity becomes equal to the external velocity. A potential application of a profile of core velocities for a range of Reynolds numbers for a certain morph is the prediction of the optimal external flow velocity for a certain morph, and this can be used to assess the state of the physical (palaeo-) environment.

Animals↗

[Computer morphometry in the differential diagnosis of thyroid neoplasms].

The quantitative studies of follicular thyroid tumors were applied for their morphological differentiation. The computer-aided analysis of the images permits objective and prompt estimation of the quantitative parameters of the structural components of a tumor in the histological sections. The comparison of the values obtained in the tissue samples could identify the most typical differentially diagnostic criteria that could help to define the type of a tumor, by replacing a routine morphological study based on the analysis of qualitative morphological signs. Its effectiveness is largely determined by the skill of a physician and the subjectivity of assessments of observed phenomena.

Adenoma↗

Structural transitions of chromatin in isolated Xenopus erythrocyte nuclei. II. Computer-based image analysis.

The morphology of isolated Xenopus erythrocyte nuclei is largely determined by the ionic constitution of the isolation medium. Electron microscopy of thin sections of nuclei isolated under varying ionic conditions has revealed four different morphological types with characteristic chromatin configurations. These nuclei have been used to study the condensation of chromatin within the confines of the nucleus. Electron micrographs of thin nuclear sections have been analysed by computer on the basis of their intensity of staining with lead citrate/uranyl acetate. The staining pattern (image analysis scan) is characteristic for each nuclear morphology and can be explained by a model which assumes that there are only four higher-order conformations that chromatin can adopt within the nucleus. These are present in varying amounts in the different nuclear types and an attempt has been made to equate the peaks identified by image analysis with previously-described chromatin structures. The results of this study serve to emphasize the potential of computer-based image analysis in the study of chromatin structure.

Animals↗

Lone cryptogenic fibrosing alveolitis: a functional-morphologic correlation based on extent of disease on thin-section computed tomography.

In most clinical series of patients with cryptogenic fibrosing alveolitis (CFA), disease severity is staged using lung function indices. However, many physiologic indices are measured in routine clinical practice; the choice of variable to evaluate functional severity is contentious. Computed tomography (CT) provides a reproducible means of quantifying the morphologic extent of disease. The aim of this study was to evaluate the functional consequences of smoking-related lung damage in CFA and to identify functional measures best reflecting the extent of fibrosing alveolitis on CT. Sixty-eight patients with CFA were studied. Fourteen patients with emphysema on CT were characterized by relative preservation of FVC and TLC (p < 0.005) and relative depression of DLCO (p < 0.05) and KCO (p < 0.00005). On multivariate analysis, the extent of fibrosing alveolitis and the presence of emphysema were independent determinants of functional impairment; there was no independent relationship between smoking history and functional abnormalities. In patients without emphysema on CT, percent predicted DLCO (r = -0.68), oxygen desaturation on exercise (r = 0.64), and the physiologic component of the clinical-radiographic-physiologic (CRP) score (r = 0.62) correlated much better with the extent of disease on CT than spirometric and plethysmographic volumes. A composite functional index was generated against the extent of disease on CT, using multivariate analysis; comparison with the CRP score suggested that the relationship between morphologic disease extent and the CRP score would be improved by the inclusion of DLCO and by the use of negative weighting for depression of FEV1. These findings indicate that in CFA, the presence of concurrent emphysema on CT has a more profound influence upon functional measures than the smoking history, and underline the importance of both the measurements of DLCO and exercise testing in the assessment of the severity of CFA.

Case-Control Studies↗

Quantitative enzymatic histophotometry of morphologic alterations caused by urologically relevant tubular kidney damages using computed image analysis device technique.

The tissue concentration of tubular marker enzymes were evaluated in sections of kidneys from 86 patients with various underlying diseases such as hydronephrosis, interstitial nephropathies, ischemia due to renal arterial stenosis and chronic allograft rejection. In addition, as an experimental model, kidney tissue sections of 166 Wistar rats were analyzed due to hydronephrosis caused by ureteral obstruction, ischemia and obstruction of the renal vein. The tissue concentration of indicator enzymes, such as alkaline phosphatase (AP) and alanine-aminopeptidase (AAP), was considered as a parameter describing the extent of kidney tubule damage. Quantitative evaluation of enzymatic activity was performed by histophotometry using a computed image analysis device technique. As compared to normal human kidney (enzyme activity 100%), the concentrations of brush border enzymes were significantly (p less than 0.001) lower under pathological conditions (AP less than 15%, AAP less than 55%). In similar manner investigations of kidneys in animal experiments with rats exhibited lower enzyme concentrations following kidney injury caused by ureteral obstruction for 10 and 21 days (AP less than 12%, AAP less than 65%; 2p less than 0.01). Kidneys after an ischemic period of 2 h and a subsequent 14-day recirculation period displayed a significant (2p less than 0.01) decrease of normally present indicator enzyme concentrations (AP less than 22%, AAP less than 77%) as compared to normal renal organs (100%). Computed image analysis of kidney tissue sections might be a useful aid in evaluating morphologic and enzymatic patterns of human and animal kidney alterations.

Alkaline Phosphatase↗