A more cost-effective method of preoperative computerized imaging

Stimulated by the explosive expansion of the computerized desk top publishing industry during the past few years, microcomputer hardware and software are evolving at a staggering rate. Memory is rapidly increasing, and prices are declining. I have found that with the hardware and software described in this paper, I was able to obtain, in a much more cost-effective manner, as useful preoperative information for my practice as I could obtain with more expensive "turnkey" (only one use) computerized imaging systems. This type of microcomputer, of course, is not limited to just the imaging system, but can be used for a variety of other programs as well, such as word processing, slide labeling and production, spreadsheet functions, billing and filing, and numerous business and other applications. The ease of use with readily available 35-mm slides of my patients has greatly enhanced the appeal of this system. Computerized imaging, when used as an educational tool, can be very helpful in preoperative planning, resident teaching, and for illustration and discussion of a patient's proposed surgery. The electronic imaging disclaimer compiled by the American Society of Plastic and Reconstructive Surgeons has been extremely helpful in clarifying the limits of computerized imaging and reducing any false expectations that my patients might have. All of us are experiencing the dawn of a very exciting evolution.     

A new stereotactic instrument for use with computerized tomography and magnetic resonance imaging

The new stereotactic instrument has the advantages of use with computerized tomography (CT) or magnetic resonance imaging (MRI) without special adaptations of instruments, brain targets transferred directly from CT or MRI to apparatus, and use with conventional stereotactic techniques. The apparatus is designed to meet present demands of neurosurgical facilities of good standards and capabilities, encompassing present and future developments towards more efficient and less invasive brain operations.     

Stereotactic system and apparatus for use with magnetic resonance imaging, computerized tomography, and digital subtraction imaging

A light-weight nonmagnetic, nonconductive instrument has been devised for use with magnetic resonance imaging, computerized tomography, and digital subtraction imaging for work in the field of epilepsy, brain tumors and vascular lesions. The apparatus' main characteristic is its ability to use optionally either the lateral orthogonal or the spherical-radial approach.     

Survey radiography and computerized tomography imaging of the thorax in female dogs with mammary tumors

Background  

Accurate early diagnosis of lung metastases is important for establishing therapeutic measures. Therefore, the present study aimed to compare survey thoracic radiographs and computerized tomography (CT) scans to specifically identify lung metastases in female dogs with mammary tumors.     

Arterial elasticity imaging: comparison of finite-element analysis models with high-resolution ultrasound speckle tracking

Background

To resolve the current shortage of donor hearts, we established the Adonhers protocol. An upward shift of the donor age cut-off limit (from the present 55 to 65 years) is acceptable if a stress echo screening on the candidate donor heart is normal. This study aimed to verify feasibility of a "second opinion" of digitally transferred images of stress echo results to minimize technical variability in selection of aged donor hearts for heart transplant.

Methods

The informatics infrastructure was created for a core lab reading with a second opinion from the Pisa stress echo lab. To test the system, simulation standard stress echo cineloops were sent digitally from 5 peripheral labs to the central core lab. Starting January 2009, real marginal donor stress echos were sent via internet to the central core echo lab, Pisa, for a second opinion before heart transplant.

Results

In the simulation protocol, 30 dipyridamole stress echocardiograms were sent from the five peripheral echo labs to the central core lab in Pisa. Both the echo images and reports were correctly uploaded in the web system and sent to the core echo lab; the second opinion evaluation was obtained in all cases (100% feasibility). In the transplant protocol, eight donor cases were sent to the Pisa core lab for the second opinion protocol, and six of them were transplanted in marginal recipients.

Conclusions

Second-Opinion Stress Tele-Echocardiography can effectively be performed in a network aimed to safely expand the heart donor pool for heart transplant.     

Multimodality imaging of borderline left main coronary disease using fluoroscopy, IVUS and CT coronary angiography

A borderline left main narrowing was discovered during coronary angiography in a young asymptomatic man with positive stress test. IVUS demonstrated minimal diameter of 2.9 mm and the cross-sectional area was 11.5 mm(2). CTs were performed, and an eccentric calcific plaque was imaged at the ostium of the left main. Based on all three image modalities after discussing the different therapeutic options with the patient he was referred for bypass surgery.     

Cadaver validation of skeletal muscle measurement by magnetic resonance imaging and computerized tomography

Magnetic resonance imaging (MRI) and computerizedtomography (CT) are promising reference methods for quantifying wholebody and regional skeletal muscle mass. Earlier MRI and CTvalidation studies used data-acquisition techniques and data-analysisprocedures now outdated, evaluated anatomic rather than adiposetissue-free skeletal muscle (ATFSM), studied only the relatively largethigh, or found unduly large estimation errors. The aim ofthe present study was to compare arm and leg ATFSM cross-sectional areaestimates (cm²) by usingstandard MRI and CT acquisition and image-analysis methods withcorresponding cadaver estimates. A second objective was to validate MRIand CT measurements of adipose tissue embedded within muscle(interstitial adipose tissue) and surrounding muscle (subcutaneousadipose tissue). ATFSM area (n = 119)by MRI [38.9 ± 22.3 (SD)cm²], CT (39.7 ± 22.8 cm²), and cadaver (39.5 ± 23.0 cm²) were not different(P > 0.001), and both MRI and CTestimates of ATFSM were highly correlated with corresponding cadavervalues [MRI: r = 0.99, SE of estimate (SEE) 3.9 cm²,P < 0.001; and CT:r = 0.99, SEE = 3.8 cm²,P < 0.001].Similarly good results were observed between MRI- and CT-measured vs.cadaver-measured interstitial and subcutaneous adipose tissue. ForMRI-ATFSM the intraobserver correlation for duplicate measurements invivo was 0.99 [SEE = 8.7 cm²(2.9%), P < 0.001]. Thesefindings strongly support the use of MRI and CT as reference methodsfor appendicular skeletal muscle, interstitial and subcutaneous adiposetissue measurement in vivo.

     

Adipose tissue volume measured by magnetic resonance imaging and computerized tomography in rats

The primary purpose of this study was to investigate the viability of magnetic resonance imaging (MRI) as a means of measuring the body composition of rodents. To do so we compared adipose tissue (AT) volumes measured by MRI with those obtained by X-ray computerized tomography (CT) in a group of rats (n = 17) varying in weight (465-815 g) and percent body fat (5.4-31.1%), with the latter determined by chemical analysis. For both MRI and CT, AT volumes (cm3) per transverse slice (3-mm thickness, 21-mm centers) were determined using a computer-based image analysis system that permitted detailed comparisons of both visceral and subcutaneous AT depots. Total AT volumes were calculated using a linear interpolation of AT areas obtained on consecutive slices. Correlation coefficients between MRI and CT for visceral [r = 0.98, standard error of estimate (SEE) = 6.8 cm3], subcutaneous (r = 0.98, SEE = 6.5 cm3), and total AT volumes (r = 0.99, SEE = 9.0 cm3) were highly significant (P less than 0.001). Both MRI- and CT-predicted AT mass (assuming fat density = 0.90 g/ml) correlated strongly with chemically extracted lipid (grams) values (r = 0.98, SEE 9.6 g and r = 0.99, SEE = 6.9 g, respectively). Post hoc Scheffé contrasts demonstrated that the mean AT and lipid mass values derived by the three methods were not significantly different (P = 0.01). No systematic differences were observed because the regression lines derived for either MRI or CT vs. chemical analysis were not significantly different from the identity line.(ABSTRACT TRUNCATED AT 250 WORDS)     

Arterial spin labeling blood flow magnetic resonance imaging for evaluation of renal injury

A multitude of evidence suggests that iodinated contrast material causes nephrotoxicity; however, there have been no previous studies that use arterial spin labeling (ASL) blood flow functional magnetic resonance imaging (fMRI) to investigate the alterations in effective renal plasma flow between normointensive and hypertensive rats following injection of contrast media. We hypothesized that FAIR-SSFSE arterial spin labeling MRI may enable noninvasive and quantitative assessment of regional renal blood flow abnormalities and correlate with disease severity as assessed by histological methods. Renal blood flow (RBF) values of the cortex and medulla of rat kidneys were obtained from ASL images postprocessed at ADW4.3 workstation 0.3, 24, 48, and 72 h before and after injection of iodinated contrast media (6 ml/kg). The H&E method for morphometric measurements was used to confirm the MRI findings. The RBF values of the outer medulla were lower than those of the cortex and the inner medulla as reported previously. Iodinated contrast media treatment resulted in decreases in RBF in the outer medulla and cortex in spontaneously hypertensive rats (SHR), but only in the outer medulla in normotensive rats. The iodinated contrast agent significantly decreased the RBF value in the outer medulla and the cortex in SHR compared with normotensive rats after injection of the iodinated contrast media. Histological observations of kidney morphology were also consistent with ASL perfusion changes. These results demonstrate that the RBF value can reflect changes of renal perfusion in the cortex and medulla. ASL-MRI is a feasible and accurate method for evaluating nephrotoxic drugs-induced kidney damage.     

Mechanics informed fluoroscopy of esophageal transport

Biomechanics and Modeling in Mechanobiology - Fluoroscopy is a radiographic procedure for evaluating esophageal disorders such as achalasia, dysphasia and gastroesophageal reflux disease. It...     

Synthesis and radiolabeling of 111In-core-cross linked polymeric micelle-octreotide for near-infrared fluoroscopy and single photon emission computed tomography imaging

The objective of this study was the development of a dual-modality imaging device, namely ¹¹¹In-core-cross-linked polymeric micelle (CCPM)-octreotide, for neuroendocrine tumor detection, using near-infrared fluoroscopy (NIRF) and single photon emission computed tomography (SPECT). The tumor targeting ability of the ¹¹¹In-labeled CCPM-octreotide was evaluated in a tumor mouse model. SPECT/CT, NIRF and gamma imaging results showed high tumor uptake of ¹¹¹In-labeled CCPM-octreotide. In contrast, there was a much lower signal in the same mouse model injected with ¹¹¹In-labeled CCPM. The high accumulation of ¹¹¹In-labeled CCPM-octreotide in U87 tumor was reduced after co-injection with an excess amount of CCPM-octreotide. These results suggested CCPM-octreotide’s potential applications in tumor diagnosis, drug delivery and molecular imaging.     

Computer graphics with computerized tomography for functional neurosurgery

A computer graphics technique for computer-assisted stereotactic surgery is presented. The program is designed to aid the surgeon by presenting an on-line graphics display of stereotactic probes and electrodes superimposed on cross sections of the human brain stem. This technique simulates an otherwise blind surgical procedure on a graphics screen for use during surgery. An earlier system based around the DEC MINC-11 BA computer system has been used by the authors for the performance of stereotactic surgery with conventional ventriculography. This system has been upgraded and is now configured about an even more compact microprocessor-based hardware system with expanded graphics capabilities, which also allows its use with computerized tomography.     

Torsional tests of long bones with computerized equipment

An experimental method using a computerized torsion machine to study the mechanics of entire diaphyseal bones is described. Besides controlling continuous torsion to ultimate fracture of the bone, the computer is able to use non-linearity of the torque-twist curve as a criterion for reversal of the direction of torsion and to control repeated loadings and unloadings with a graduated increase of deformation until final fracture. It permits determination of a small residual deformation, and several other parameters charcterizing the load-deformation curve. The linearity of the equipment is shown to be good and precision is high, with a method error of 2.3% when determining stiffness. Repeated loadings and unloadings of entire dog femora revealed a minor residual deformation before ultimate fracture.     

Measurement of cardiac mechanical function in isolated ventricular myocytes from rats and mice by computerized video-based imaging

Isolated adult cardiac ventricular myocytes have been a useful model for cardiovascular research for more than 20 years. With the recent advances in cellular physiology and transgenic techniques, direct measurement of isolated ventricular myocyte mechanics is becoming an increasingly important technique in cardiac physiology that provides fundamental information on excitation-contraction coupling of the heart, either in drug intervention or pathological states. The goal of this article is to describe the isolation of ventricular myocytes from both rats and mice, and the use of real-time beat-to-beat simultaneous recording of both myocyte contraction and intracellular Ca²⁺ transients. Published: December 11, 2001