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Biomedical subjects

R F Mattrey

Publications and source records attributed to R F Mattrey.

At least 91 records · Page 5Linked to original sources
PubMed1984

Myocardial infarct size determined by computed transmission tomography in canine infarcts of various ages and in the presence of coronary reperfusion.

Thirty-one dogs underwent in vivo scanning with computed transmission tomography; 15 dogs were studied within 7 days (mean 4) after coronary occlusion, 10 dogs 21 to 25 days (mean 28) after occlusion and 6 dogs 4 days after coronary reperfusion of a 2 to 3 hour coronary ligation. Ungated scans (1 cm in depth) of the left ventricle were obtained from apex to base to determine infarct size. In all animals with documented (postmortem) infarction (n = 26), contrast medium caused delayed enhancement of the entire infarct or the periphery of the infarct. Infarct size was calculated from scans showing contrast enhancement of the infarct. Infarct size was also determined from the postmortem heart using histochemical morphometry (nitroblue tetrazolium) and then compared with infarct size derived from tomography using the outer margin of the contrast-enhanced periphery of the infarct as the border of the infarct. Infarct size calculated by the tomographic technique (excluding the animals without an infarct) correlated well with infarct size determined at autopsy (r = 0.90, p less than 0.001). The tomographic estimate (18.2 +/- 11.3 g) of infarct size was similar to autopsy values (18.6 +/- 11.8 g, p = NS). Thus, ungated computed transmission tomographic imaging of the heart can reliably estimate infarct size in a variety of potential clinical circumstances, particularly when the area of rim enhancement of the infarct is included within the presumed infarct region.

Animals↗
PubMed1984

Perfluoroctylbromide as a blood pool contrast agent for liver, spleen, and vascular imaging in computed tomography.

Perfluoroctylbromide (PFOB) in emulsion form was tested as a blood pool imaging agent for computed tomography (CT) in five animals (three dogs and two pigs). Computed tomography of the kidneys, liver, spleen, and mediastinum was performed in the control state and at various time intervals after the end of PFOB infusion. The attenuation coefficient of the vascular space increased by 117 Hounsfield units (HU) (range 105-128 HU), the liver by 54 HU (range 43-70 HU), and the spleen by 77 HU (range 69-86 HU) 30 to 50 min after the end of PFOB infusion, 5 ml/kg. The vascular space enhanced by 25 HU for every g of PFOB/100 ml of blood and remained at almost a constant level for hours after the end of infusion. In conclusion, PFOB emulsion, in addition to hepatosplenic enhancement, produces prolonged and substantial opacification of the vascular space, allowing CT imaging of the heart and vascular structures minutes to hours after the end of infusion.

Angiography↗
PubMed1984

In vitro magnetic relaxation times of the ischemic and reperfused rabbit kidney: concise communication.

To assess the effects of renal ischemia and reperfusion on in vitro magnetic relaxation times (T1 = magnetization recovery, T2 = spin echo), we evaluated the spectroscopic characteristics of the renal cortex from 25 rabbits. Eight served as controls (Group 1), nine had one renal pedicle ligated for 1 hr (Group 2), and eight (Group 3) were occluded for 1 hr and reperfused for 30 min. For intra-animal comparison purposes, % H2O content, T1 (msec), and T2 (msec) of the ischemic (reperfused) kidney were normalized to the values from the normal kidney within the same animal. Renal ischemia consistently increased water content, which was exaggerated by reperfusion. In association with ischemia, T1 fell, and with reperfusion T1 lengthened. T2 increased with ischemia and declined from the peak ischemic effects with reperfusion.

Animals↗
PubMed1984

Pulmonary edema formation after myocardial infarction and coronary reperfusion: intravascular and extravascular pulmonary fluid volumes. IV.

Two studies were performed to assess the importance of coronary reperfusion on pulmonary capillary endothelial permeability in 34 anesthetized dogs. The response of intravascular pulmonary blood volume (PBV) and extravascular lung water (EVLW) was examined using indicator-dilution and postmortem (wet weight/dry weight) techniques. In the first study, six dogs served as sham controls, seven were occluded (LAD) for 45 min, and seven occluded for 45 min and reperfused for 15 min. While PBV was similar in each group, EVLW was greater in the reperfused than nonreperfused dogs (9.5 +/- 0.7 cc/kg vs 8.1 +/- 0.8 cc/kg; P less than .05), and both occluded groups were greater (P less than .01) than the control animals (7.0 +/- 1.0 cc/kg). Similar trends in postmortem wet weight/dry weight data were observed when compared with the in vivo EVLW data. In a second study of 14 open-chest dogs, an LAD ligation was held for 45 min in 14 dogs. In seven dogs, reperfusion was allowed for 15 min. A left atrial (LA) balloon was then inflated in all 14 dogs, increasing left atrial pressure to 25 mmHg in each dog for 90 min. Once again, PBV was similar in both groups, but EVLW was greater at the matched level of LA pressure elevation (14.6 +/- 3.2 cc/kg nonreperfused vs 18.7 +/- 4.1 cc/kg reperfused dogs; P less than .01). Again, postmortem data confirmed these data. Thus, we conclude coronary occlusion accelerates EVLW formation independent of LA pressure. Edema formation is worsened by coronary reperfusion, suggesting that the washout of myocardial toxins from the ischemic myocardium alters endothelial permeability.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Computer technique for monitoring time dependent changes from sequential CT images.

The sequential computed tomography (CT) images used in this manuscript are electrocardiogram-gated images of the same cross section of the heart (10 in this study) depicting one cardiac cycle from end-diastole to the next end-diastole. Each of these 10 reconstructions corresponds to 10% intervals extending from one R wave to the next R wave. When each image of the series of 10 images is assigned a consecutive table position, using the program for sagittal reconstructions a chronogram along any line through the X-Y plane of the left ventricular (LV) wall can be produced. The chronograms display changes in wall thickness and wall motion in relation to time throughout the cardiac cycle at a preselected site in the LV and can be used to demonstrate the LV myocardial response to perturbations. This technique adds the dimension of time to spatial information in the CT images and can be used to monitor cardiac physiology in a quantitative fashion.

Animals↗
PubMed1983

CT localization and aspiration of postoperative pericardial fluid collection.

The authors report a case in which computed tomography (CT) was used to guide percutaneous needle aspiration of postoperative pericardial and paracardiac fluid collection. This application of CT has particular importance in postsurgical cardiac patients because of the loculated nature and occasional atypical location of fluid collections.

Female↗
PubMed1983

Percutaneous biopsy of difficult mediastinal, hilar, and pulmonary lesions by computed tomographic guidance and a modified coaxial technique.

A technique for biopsy of small or inaccessible mediastinal, hilar, or pulmonary lesions with computed-tomographic (CT) guidance is described. A modified coaxial system was used in order to make multiple passes possible without multiple punctures. The size of the original puncture needle (23 gauge) provided the inherent safety associated with a fine needle. All repositioning was done using this needle and CT until the lesion was engaged. The hub of the needle was then cut, and a 19-gauge needle was inserted coaxially over the larger needle. After removal of the 23-gauge needle, multiple biopsy specimens were then obtained coaxially with a 22-gauge needle through the 19-gauge needle. One small pneumothorax and no bleeding occurred in 10 instances. Results suggest that the combined use of CT guidance and this modified coaxial system may offer an extra margin of safety for difficult cases.

Adult↗
PubMed1983

In vivo assessment of left ventricular wall and chamber dynamics during transient myocardial ischemia using prospectively ECG-gated computerized transmission tomography.

Seven dogs were evaluated with prospective ECG-gated computerized transmission tomography (CTT) to analyze left ventricular (LV) wall thickness and cross-sectional chamber area after acute occlusion of the left anterior descending coronary artery (LAD). ECG-gated CTT scanning during i.v. administration of contrast material was performed over the mid-left ventricle at rest, after acute occlusion of the LAD and 30 minutes after release. The extent of systolic wall thickening (EWTh) of the anterior (potentially ischemic) segment was 39.8 +/- 8.8% (SEM) in the control state and -26.0 +/- 4.7% during LAD occlusion (p less than 0.01). The nonischemic septum demonstrated a compensatory increase in EWTh, from 28.6 +/- 3.5% to 46.4 +/- 6.1% during LAD occlusion (p less than 0.05). The end-diastolic LV luminal area (LVA) increased from 17.4 +/- 0.8 cm2 in the control state to 21.0 +/- 1.1 cm2 during LAD occlusion (p less than 0.01). End-systolic LVA also increased, from 11.0 +/- 0.9 to 15.2 +/- 1.1 cm2 (p less than 0.01). In addition, the percent change in LVA from end-diastole to end-systole declined from 37.4 +/- 3.8% during control to 28.0 +/- 2.6% during LAD occlusion (p less than 0.02). In conclusion, gated CTT demonstrates that the alterations in acute ischemia are characterized by changes in regional wall thickening dynamics, consisting of wall thinning during systole in the jeopardized segment and compensatory increase in the extent of systolic thickening in the normal segment, and changes in global LV function, consisting of an increase in the LVA and a decrease in the percent change of LVA during systole. Gated CTT may be useful for monitoring regional and global effects of ischemia when subjects can be studied in the supine position and with respiration suspended for 45 seconds.

Animals↗
PubMed1983

Perfluorochemicals as liver- and spleen-seeking ultrasound contrast agents.

In this study, Fluosol-DA, 20 per cent (composed of perfluorodecalin and perfluorotripropylamine) was tested as a liver-specific ultrasound contrast agent. Twelve normal rabbits were scanned, utilizing the Picker Microview (10 MHz), prior to and two days following the intravenous administration of 24 ml/kg of Fluosol (or 4.8 g/kg of perfluorochemicals) emulsion to ten of the rabbits and 24 ml/kg of Ringer's solution to two rabbits as control. In all ten rabbits given Fluosol, liver echogenicity increased relative to that of the kidney, whereas the liver remained less echogenic than the kidney in the two rabbits given Ringer's solution. Four independent reviewers correctly identified all rabbits that received Fluosol and both rabbits that received Ringer's solution. It is demonstrated that, similar to PFOB, Fluosol serves as an echogenic contrast material for ultrasound and opacifies the normal rabbit liver.

Animals↗
PubMed1982

Evaluation of the hemodynamic effects of intravenous administration of ionic and nonionic contrast materials. Implications for deriving physiologic measurements from computed tomography and digital cardiovascular imaging.

The effects of intravenous injection of an ionic contrast material (Renografin-76 [meglumine sodium diatrizoate]) on left ventricular pressure, internal diameter, and wall thickness, and on coronary and femoral hemodynamics were compared with those of a hydrolytically stable nonionic contrast material (iohexol). Renografin-76 caused drastic biphasic changes in left ventricular pressure and dp/dt (rate of change of left ventricular pressure), and moderate changes in end systolic dimension. Iohexol caused little or no change in left ventricular pressure and dimensions. In addition, Renografin-76 caused marked arterial hypotension and large increases in coronary and femoral blood flows, while iohexol caused no significant change in arterial pressure and coronary blood flow, and a mild increase in femoral blood flow. Based on these findings, it is concluded that iohexol is preferable to standard ionic contrast material for deriving basal physiologic information from computed tomographic and digital vascular studies.

Animals↗
PubMed1982

Perfluoroctylbromide: a reticuloendothelial-specific and tumor-imaging agent for computed tomography.

Perfluoroctylbromide (PFOB) was evaluated as a liver/spleen-specific and tumor imaging agent in 30 rabbits implanted with VX2 tumors. Computed tomographic (CT) scanning of all rabbits was performed after sacrifice. Half of the animals were given 5 ml/kg of PFOB emulsion intravenously 48 hours prior to sacrifice. Twenty rabbits were used for anatomic correlation and ten for histologic analysis. PFOB concentration was measured in normal liver and spleen in eight rabbits at two days, in six rabbits at seven days, and in six rabbits at 14 days after PFOB administration (5 ml/kg, intravenously). PFOB increased the CT numbers of the liver by 49 HU and the spleen by 250 HU. More important for diagnostic purposes, PFOB produced dense enhancement of the rim of the tumor. The density of the rim of the tumor was increased by 102 HU as a result of accumulation of PFOB in macrophages at the periphery of the tumor. The half-life of PFOB in the liver and the spleen was approximately five days.

Animals↗
PubMed1982

Perfluoroctylbromide: a liver/spleen-specific and tumor-imaging ultrasound contrast material.

The effect of perfluoroctylbromide (PFOB) on liver and tumor echogenicity was evaluated in rabbits. The echogenicity of the kidney, which is not affected by PFOB, was used as the basis for comparison in the liver studies. For the liver echogenicity study, sonography was performed on four rabbits, two with PFOB and two without PFOB, and four rabbits prior to and following the intravenous administration of 5 ml/kg PFOB. All livers were equal to or less echogenic than kidney in the control animals. All livers became more echogenic than kidney two days after administration of PFOB. The effect of PFOB on tumor echogenicity was evaluated in 18 rabbits with VX2 tumor implanted in the liver. Ultrasound studies of all rabbits were performed by the same physician before and two days after half the rabbits had received PFOB (5 ml/kg intravenously). The reviewers correctly identified all rabbits that received PFOB by visualization of an echogenic rim around the hepatic tumors.

Animals↗
PubMedDate not supplied

MR imaging of disorders of the brachial plexus.

The authors evaluated 64 consecutive patients with suspected brachial plexus (BP) abnormalities of diverse cause with magnetic resonance (MR) imaging, using the body coil and a standardized protocol. Of the 43 patients for whom follow-up was available, 25 were suspected of having neoplastic involvement of the BP, nine had sustained injuries, and nine presented with BP symptoms of uncertain cause. MR imaging was 63% sensitive, 100% specific, and 77% accurate in demonstrating the abnormality in this diverse patient population. When patients with neoplastic and traumatic disorders were considered separately, sensitivity increased to 81%, accuracy to 88%, and specificity remained unchanged. In the patients with a clinical diagnosis of idiopathic or viral plexitis, the MR imaging findings were normal, serving to exclude other structural abnormalities. It is concluded that MR imaging is valuable in the assessment of a wide range of BP disorders.

Brachial Plexus↗
PubMedDate not supplied

MR imaging assessment of experimental hepatic dysfunction with Mn-DPDP.

Manganese (II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate 5,5'-bis(phosphate) (DPDP) is a paramagnetic magnetic resonance (MR) contrast agent that enhances the liver and is predominantly excreted through the biliary tree. The authors evaluated its utility in diffuse liver disease by assessing liver and gallbladder enhancement in 24 rabbits. Total (n = 6) or segmental (n = 6) biliary occlusion or galactosamine-induced hepatitis (n = 6) was induced 3 days before imaging. Six rabbits served as normal controls. T1- and T2-weighted axial MR images were acquired at baseline, followed by T1-weighted images every 10 minutes for 1 hour after the intravenous administration of 20 mumol/kg Mn-DPDP. Except for the segmental occlusion group, the baseline study did not allow distinction between normal and abnormal livers. The temporal hepatic enhancement pattern was statistically different for each group. The normal, segmental occlusion, and hepatitis groups showed patterns similar to one another but markedly higher signal intensity than the total-occlusion group throughout the observation period. In contrast, the gallbladder showed a greater difference in both degree of enhancement and time to peak enhancement among the four groups. Mn-DPDP produces a temporal hepatic enhancement pattern that allows recognition of markedly impaired livers, and gallbladder enhancement patterns that allow distinction of more subtly impaired livers.

Animals↗
PubMedDate not supplied

MRI of pelvic neurofibromatosis.

Pelvic neurofibromatosis is a rare disease and rarely involves the prostate. A 19-year-old male presented with irritative and obstructive voiding symptoms. Magnetic resonance imaging showed a large mass extending from the sacral promontory to the perirectal and perivesical spaces and to the proximal root of the penis. The mass also involved the prostate. The characteristics of the mass were highly suggestive for neurofibroma. Prostate biopsy showed neurofibroma, and the immunohistochemistry stain for S-100 protein was positive.

Adult↗