Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Densitometry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed2000

Prevention of doxorubicin (adriamycin)-induced cardiomyopathy by simultaneous administration of angiotensin-converting enzyme inhibitor assessed by acoustic densitometry.

The purpose of our study has to determine the myocardial protective effects of the angiotensin-converting enzyme (ACE) inhibitor temocapril (TEM, 7 mg/kg/day) simultaneously administered with doxorubicin (Adriamycin). Twenty male Sprague-Dawley rats were intraperitoneally administered a cumulative dose of 15 mg/kg of doxorubicin (each dose of 1.0 mg/kg x 15) for 3 weeks, and divided into TEM-untreated and -treated rats. Seven control rats were injected with saline intraperitoneally. Body weight, hemodynamics, and echocardiographic measurements including quantitative analysis of ultrasonic integrated backscatter (IB) were obtained for 12 weeks after treatment. Finally, rats were killed for histopathologic study. At 6 weeks, end-diastolic left ventricular diameter (LVD) and percentage fractional shortening (%FS) were similar in TEM-treated and TEM-untreated rats, but cyclic variation of IB (dB) significantly decreased in TEM-untreated rats (7.3 +/- 1.2; control rats, 9.7 +/- 0.9; p < 0.01). At 12 weeks, %FS decreased in TEM-untreated rats (26.1 +/- 6.1%: TEM-treated rats, 34.2 +/- 6.2; p < 0.05), and calibrated IB (dB) in TEM-untreated rats (15.5 +/- 0.5) increased as compared with that in TEM-treated rats (12.1 +/- 0.7; p < 0.01). Interstitial collagen accumulation increased in TEM-untreated rats and was inhibited in treated rats. Simultaneous administration of TEM with doxorubicin was beneficial in preventing doxorubicin-induced myocardial damage, and myocardial tissue characterization was useful for the early detection of myocardial damage and the assessment of therapy.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1993

Radiophosphate imaging and bone densitometry in renal osteodystrophy.

The histologic features of renal osteodystrophy vary from dialysis osteomalacia to osteitis fibrosa cystica. Commensurate with this, the number of osteoblasts and osteoclasts changes with the stage of the disease; the osteoblasts are virtually absent in dialysis osteomalacia and are numerous in osteitis fibrosa. Radiophosphate accretion in bone increases with increasing osteoblastic activity, and the bone mineral status is determined by the net difference in osteoblastic and osteoclastic activity. The application of radionuclide imaging and dual radiographic absorptiometry mineral measurements in patients with renal osteodystrophy, renal transplants, and following parathyroidectomy for secondary hyperparathyroidism is reviewed.

Bone Density↗
PubMed1978

A method for photographic densitometry of scanning electron micrographs.

A method is described for the study of the surface structure of mammalian chromosomes. Densitometric analysis of scanning electron micrographs permits the detection of regularities where overlying material obscures these in directly inspected micrographs. The method has been applied to the study of mammalian chromosomes.

Animals↗
PubMed1993

Video camera calibration for optical densitometry.

An efficient technique for calibrating video cameras to record optical density (OD) from microscopic images is described. The method corrects for variation over the field of the brightfield and darkfield intensities, does not assume a linear response of the camera to the incident intensity and requires a single calibration filter.

Animals↗
PubMed2005

Histomorphometry of tumour cell nuclei in astrocytomas using shape analysis, densitometry and topometric analysis.

Although tumour cell nuclei are important histological structures for grading of astrocytomas according to the WHO-classification of brain tumours, there is no reported morphometric study of astrocytomas which describes quantitatively the four main morphologic criteria of tumour cell nuclei: size, shape, texture (densitometric characteristics) and spatial relationships between the nuclei (topometric analysis). Using a set of morphometric parameters describing these criteria as well as the Ki67-proliferation index, 74 astrocytomas from 74 patients were studied by means of a digital image analysis system. The objective of the study was to test, if these morphometric parameters were sufficient for statistical discrimination between pilocytic astrocytomas WHO-grade I, astrocytomas grade II and anaplastic astrocytomas grade III. Our results showed a correct reclassification of 97.3% (72/74) of the cases with respect to the tumour grade by means of cross-validated discriminant analysis. Morphometric parameters characterizing nuclear shape (shape factors, Fourier-amplitudes) showed the most prominent differences between the three groups of cases, followed by topometric parameters (number of neighbours per nucleus, distances between the nuclei). Less pronounced differences between the tumour grades were found for parameters characterizing nuclear size, nuclear texture and the Ki67-proliferation index. In conclusion, the present morphometric procedure provided good discrimination between the tumour grades, supporting the view that histomorphometry of tumour cell nuclei could be a valuable tool for grading of astrocytomas.

Algorithms↗
PubMed1995

Densitometry of Pautrier's microabscess cells in cutaneous T cell lymphoma.

BACKGROUND: Epidermotropic lymphoid T cell infiltrates are part of a continuous spectrum of lesions ranging from "benign" parapsoriasis to frank cutaneous T cell lymphoma (CTCL, mycosis fungoides). Either the clinical or histologic differentiation between these entities prove often difficult and the prognosis may be difficult to assess. PATIENTS AND METHODS: We studied 15 patients, men aged 50 to 81 years, mean +/- SD 68 +/- 12 years, with patch-plague CTCL. Sections from punch biopsies from active lesions were stained with Feulgen reagent, coupled with a "twin" adjacent hematoxylin and eosin (H&E)-stained section and analyzed with a VIDAS Zeiss-Kontron Image Analyzer. At least 50 dermal infiltrating cells and 50 epidermotropic Pautrierian cells per specimen were counted and the biopsies were repeated periodically. RESULTS: Nine patients with aneuploid Pautrierian cell DNA patterns dis well after conventional phototherapy (dermal cell ploidy was irrelevant), whereas six patients with euploid Pautrierian cell DNA patterns had to be treated aggressively (IFN + retinoids, COP). Clinical and histopathologic aspects of the first group were comparable to those of the second group. CONCLUSIONS: The classical cytophotometric aphorism seems to be reversed in this sample: "The more abnormal the ploidy of epidermotropic Pautrierian cells, the better the prognosis." Euploid epidermotropic cell prove more efficient in invading the skin and other areas and this efficiency may be reflected in more aggressive trends in the evolution of the lymphoma. Thus, DSM analysis of epidermotropic cells could prove very useful as an inexpensive tool for routine CTCL grading.

Abscess↗
PubMed2004

Pulsed dye densitometry with two different sensor types for cardiac output measurement after cardiac surgery: a comparison with the thermodilution technique.

BACKGROUND: Assessment of cardiac output (CO) by the indocyanine green (ICG) dye dilution technique (IDD) with transcutaneous signal detection may be a less invasive alternative to the pulmonary artery catheter (PAC). The aim of this study was to determine the accuracy and reliability of the DDG2001 analyzer (Nihon Kohden Corp, Tokyo, Japan) using a finger (IDDf) and a nose (IDDn) sensor as compared with the thermodilution technique by PAC. METHODS: In 31 consecutive patients after routine cardiac surgery, CO measurements were performed by IDD compared with the thermodilution technique following postoperative haemodynamic stabilization in the intensive care unit. Repeated measurements were made at 30-min intervals. CO was determined by iced water bolus (IWB: mean of three repeated injections) and IDDf or IDDn, respectively (mean of three repeated ICG injections). RESULTS: Thirty-three per cent of all measurements for IDDf and 9% for IDDn failed due to a missing signal detection. Mean bias for IDDf to IWB was -0.5 l min(-1).m(-2) (limits of agreement: -1.8/0.8 l min(-1).m(-2)) and for IDDn to IWB was -0.1 l min(-1).m(-2) (limits of agreement: -1.6/1.5 l min(-1).m(-2)). Correlation between IDDf and IWB (r = 0.2) was found to be inferior to the correlation between IDDn and IWB (r = 0.5). CONCLUSION: The IDD showed a systematic bias compared with the IWB and its performance was limited due to signal detection failure. Therefore, the DDG2001 analyzer cannot be recommended as a substitute for the PAC in routine monitoring of cardiac output after cardiac surgery.

Cardiac Output↗
PubMedDate not supplied

Computed tomographic densitometry of normal feline thyroid glands.

We studied the computed tomographic (CT) appearance and determined Hounsfield units (HU) for normal thyroid tissue in eight cats. Helical CT images (2 mm collimation) were acquired from cranial aspect of the second cervical vertebra (C2) through caudal aspect of the fourth cervical vertebra (C4). Data were acquired before contrast medium administration (n = 7), after delayed contrast medium enhancement (n = 8), and immediately after contrast medium enhancement after a second dose of contrast medium (n = 8). Attenuation of thyroid tissue was compared with surrounding tissues. Before contrast medium enhancement, thyroid tissue was hyperattenuating to the surrounding soft tissues. After delayed contrast medium enhancement, thyroid tissue was hyperattenuating to surrounding soft tissues and isoattenuating to contrast medium-laden blood vessels. Immediately after contrast medium enhancement, thyroid tissue was hyperattenuating to surrounding soft tissues and hypoattenuating to contrast medium-laden blood vessels. The thyroid glands were dorsolateral to the trachea, ovoid, and displayed homogenous contrast medium enhancement. Circular regions of interest were drawn on the right and left thyroid lobes. Densitometric data of thyroid tissue were as follows: precontrast medium enhancement, 123.2 HU (95% CI: 119.4-127.1 HU); delayed contrast medium enhancement, 132.1 HU (95% CI: 127.4-136.8 HU); immediate postcontrast medium enhancement, 168.5 HU (95% CI: 163-173.9 HU). Normal feline thyroid tissue is easily detected using CT without contrast medium enhancement. This information may be useful for CT evaluation of abnormal feline thyroid glands.

Animals↗
PubMed1999

Quantitative optical densitometry with scanning-laser film digitizers.

A new process for eliminating two types of artifacts inherent in commercially available transmission scanning-laser film digitizers is presented. The first kind of artifact results in nonreproducible interference-pattern fluctuations as large as 7%. The second kind results in spreading of transmitted light from low-to-high optical density (OD) in regions with rapidly varying ODs, producing errors as large as 50%. These OD artifacts cause the loss of precision for films with low-OD regions (first type) and the loss of accuracy for films with regions of high-OD near high-OD gradients (second type). Test radiochromic films, produced by uniform exposure to a 6 MV photon beam and a high dose rate 192Ir brachytherapy source, along with test radiographic films were used to characterize the artifacts of a commercially available scanning-laser film digitizer. The interference-pattern artifact was eliminated by digitizing the films on a masked diffusing ground-glass scanning bed. The light-transmission artifact was eliminated through discrete-fast-Fourier-transform (DFFT) deconvolution of transmission profiles with measured digitizer line-spread functions. Obtaining precise OD distributions after the DFFT deconvolution required prior removal of the interference-pattern artifact and application of a low-pass Wiener noise filter. Light-transmission artifacts are particularly significant for applications requiring measurement of high-gradient OD distributions, such as brachytherapy or conformal photon-beam film dosimetry and quantitation of two-dimensional electrophoresis gels. Errors as large as 15%-35% occur in OD distributions representative of these applications. The data collection and correction process developed in this study successfully removes these artifacts.

Biophysical Phenomena↗
PubMed1965

Bone density measurements in vivo: improvement of x-ray densitometry.

An X-ray bone densitometer has been developed which makes direct tracings of absorption curves on a nearly linear scale. Speed and precision are increased by elimination of x-ray film. Results are reproducible to within 3 percent with a phantom finger, and within 6 percent with human subjects.

Animals↗