Cerebral blood flow and cerebrovascular reserve capacity: estimation by dynamic magnetic resonance imaging.

We have developed a new method for estimation of regional CBF (rCBF) and cerebrovascular reserve capacity on a pixel-by-pixel basis by means of dynamic magnetic resonance imaging (MRI). Thirteen healthy volunteers, 8 patients with occlusion and/or high grade stenosis of the internal carotid artery (ICA), and 2 patients with acute stroke underwent dynamic susceptibility-weighted contrast enhanced MRI. Using principles of indicator dilution theory and deconvolution analysis, maps of rCBF, regional cerebral blood volume, and of the mean transit time (MTT) were calculated.

A brain imaging (single photon emission computerized tomography) study of semantic and affective processing in psychopaths.

Psychopaths have been described as human predators who use charm, intimidation, and violence to control others and to satisfy their own needs. Underlying their propensity to violate social norms and expectations is a profound lack of empathy, guilt, or remorse, affective processes that have long resisted scientific investigation. Using brain imaging technology we found that psychopaths differed from nonpsychopaths in the pattern of relative cerebral blood flow during processing of emotional words.

The continuous performance test, identical pairs version (CPT-IP): III. Brain functioning during performance of numbers and shapes subtasks.

The numbers and shapes subtasks of the CPT-IP are difficulty-matched measures of independent aspects of attentional skill that have been used to differentiate the impairments of schizophrenics and major depressives. Previous studies suggest that they tap into lateralized aspects of attentional performance. To investigate this hypothesis, seven subjects free of psychiatric illness were presented with these CPT-IP subtasks during a SPECT procedure.

Postoperative changes on brain SPECT imaging after aneurysmal subarachnoid hemorrhage. A potential pitfall in the evaluation of vasospasm.

Serial brain SPECT imaging was performed on patients after subarachnoid hemorrhage and surgical clipping of intracranial aneurysms. A total of 20 HMPAO scans were performed on 9 patients in whom clinical vasospasm did not develop. Areas of diminished regional cerebral blood flow (rCBF) were found near the operative site in 17 of 20 studies, which did not correlate with the patients' neurologic condition and were suggestive of postoperative edema.

Organ perfusion by dynamic scintigraphy convection-diffusion tracer kinetics in a phantom.

Dynamic scintigraphy is used widely to evaluate qualitatively the perfusion of an organ. Attempts to quantify blood flow to an organ by means of scintigraphic imaging modalities have often employed assumptions that lead to oversimplifying the physiology of the tracer kinetics. We used a mathematical formalism described by W.

The timing of brain morphological changes in schizophrenia and their relationship to clinical outcome.

The present study is an examination of ventricular and temporal lobe size in 50 DSM-III-R first-episode schizophreniform or schizoaffective patients who were ill for less than 6 months. Two-year clinical follow-up and magnetic resonance imaging (MRI) scan analyses are also reported from data collected on an initial group of 30 first-episode schizophrenic patients and controls. Left ventricular enlargement, which was present in our previously published report of first-episode cases of schizophrenia, is not present to the same extent in this larger group of schizophreniform patients closer to the onset of their illness, and no temporal lobe volume reduction was detected.

Anomalous lateral sulcus asymmetry and cognitive function in first-episode schizophrenia.

This study examines the cognitive functioning of first-episode schizophreniform patients within several weeks of hospitalization and at 2 years into the illness. Differences between patients and controls are also reported for measurements of the length of the lateral sulcus, which borders the planum temporal, an area of the brain integral to language function. Neuropsychological test results are also correlated to magnetic resonance imaging structural variables at the time of first hospitalization.

The simultaneous measurement of glomerular filtration rate (GFR) and renal plasma flow (RPF) following renal transplantation by use of functional imaging.

A new method for evaluating renal function using dynamic scintigraphy and deconvolution is described; functional images can be created from the data to quantitate kidney function. Our data are indicating that GFR measurements obtained by this method do not differ from those obtained by classical renal clearance methods. As was expected measurements of renal plasma flow exceed the values of PAH clearance.

Deconvolution using orthogonal polynomials in nuclear medicine: a method for forming quantitative functional images from kinetic studies.

A deconvolution technique is described which utilizes orthogonal polynomials (DOP) and handles inevitable noise in such a way that pixel time activity curves can be deconvolved. This solves the issue of quantitative analysis of serial scintigraphic data in a manner that preserves the high spatial resolution inherent in raw data. In the current work a complete mathematical description of the new deconvolution technique is presented.

Effect of source strength and attenuation on dual photon absorptiometry.

A systematic error in dual photon absorptiometry (DPA) measurements of bone mineral density (BMD) related to source strength has been previously described and attributed to an erroneous algorithm for deadtime correction. Since detected counts (or photon flux) is a product of source strength and attenuation, the effect of various source activities and attenuation depths on BMD calculations were evaluated using a phantom. Ten DPA scans were acquired at two source strengths, 0.

Technetium-99m ECD: a new brain imaging agent: in vivo kinetics and biodistribution studies in normal human subjects.

Lipophilic neutral 99mTc complexes of diaminedithiol (DADT) ligands cross the brain-blood barrier. A new derivative of DADT family, 99mTc ethyl cysteinate dimer (ECD) showed high brain uptake in nonhuman primates. We report here the in vivo kinetics and biodistribution results in 16 normal human subjects.

Constrained least-squares restoration of nuclear medicine images: selecting the coarseness function.

Image restoration using the constrained least-squares (CLS) method theoretically adapts to the image being processed. In addition, it only requires knowing the modulation transfer function of the imaging system when applied to nuclear medicine images. Prompted by these observations, a systematic evaluation of the effects of the form of the "coarseness function" [C(f)] used by the CLS method has been conducted.

[New criteria for scintigraphic follow-up of bone metastases following radiotherapy. Results of functional scintigraphy using 99mTc-MDP].

After radiation therapy regional 99mTc-MDP clearance by 17 metastatic lesions was determined repeatedly in 13 patients. 99mTc-MDP clearance rates decreased within 14 weeks after irradiation of osteoblastic metastases, but were normalized in only one lesion. In osteolytic lesions 99mTc-MDP clearance increased 4 weeks after completion of radiation therapy indicating reossifications evident from X-ray examinations subsequently.

[Function scintigraphy: a uniform method for quantifying organ metabolism and function].

Functional scintigraphy is a quantitative method with which metabolic parameters of an organ can be determined by measuring the time activity course of a radioactive tracer in tissue. Their quantitative value is, however, limited by inherent sources of error, e.g.

[The 4 hr-washout-functional picture: a quantitative visualization of 201Tl myocardial stress kinetics and the significance of paradoxical redistribution].

Between March and August 1983, 62 patients with suspected coronary artery disease were investigated by both 201Tl myocardial scintigraphy and coronary angiography. Functional images of the 4 h-201Tl-washout were compared with conventional scintigrams of the stress and rest phases and with results of coronary angiography. Myocardial scintigraphy with 4 views was performed immediately after exercise and 3-4 h later.

[Bone scintigraphy in assessing the success of chemotherapy in osteosarcoma].

During preoperative chemotherapy regional 99mTc-MDP clearance by tumor and healthy bone as well as tumor blood flow were determined in 13 patients with osteosarcoma. The results were compared to histologic regression grades. After good response (tumor vitality less than 10%) tumor blood flow normalized and regional 99mTc-MDP clearance decreased by 66% (range 56-82%).

Assessment of myocardial necrosis immediately after intracoronary thrombolysis by intracoronary injection of technetium-99m pyrophosphate.

To assess myocardial necrosis immediately after intracoronary thrombolysis, thallium-201 (TL-201) and technetium-99m pyrophosphate (Tc-99m PYP) were injected simultaneously into the coronary artery in 25 patients with acute transmural myocardial infarction. In 17 of the 25 patients, the occluded coronary artery was reopened. Minutes after the intracoronary injection of Tc-99m PYP into the reopened coronary artery a localized accumulation was seen within the area of the Tl-201 defect in all patients.

Quantification of tracer kinetics in intra- and extrahepatic bile ducts and of gallbladder filling rates in hepatobiliary dynamic scintigraphy using 99mTc-IDA derivates.

A method is presented of calculating the flow of 99mTc-labelled IDA derivates in intra- and extrahepatic bile ducts. By computer means the superimposed liver parenchymal activity is subtracted from the original sequence data in each pixel and at each time. In addition to known evaluation methods, the described procedure seems to be helpful for clinical application in order to better display anatomical details of intrahepatic structures like bile ducts and to calculate quantitative parameters like appearance times in intra- and extrahepatic regions.

[Results of radium 224 therapy in ankylosing spondylitis (Strümpell-Marie-Bechterew disease)].

After an average of 5 years following therapy with Ra224, the concentration of Tc99m methyl diphosphonate (MDP) in the region of the sacroiliac joints and lumbar spine was measured in 15 patients with ankylosing spondylitis. The findings were supplemented by those of clinical, pathological, and roentgenological examinations. The concentration of MDP was normal in the sacroiliac joints in almost all the patients, but was raised in the lumbar spine in two-thirds.

Biokinetics of bone tracers by means of deconvolution analysis--comparison of 99mTc MDP, 99mTc DPD and 99mTc EHDP.

Transfer functions of 99mTc methylene diphosphonate (MDP), 99mTc 2,3-dicarboxypropane-1,1-diphosphonate (DPD) and 99mTc ethane-1-hydroxy-1,1-diphosphonate (EHDP) into bone and extravascular fluid of soft tissues were determined in 5 dogs by deconvolution analysis of the time-course of plasma, soft tissue and bone radioactivity. The transfer rates 5 min after injection--indicating the rapid exchange of the tracer between plasma and the extravascular fluid--decrease in the order MDP greater than EHDP greater than DPD (P less than 0.05).

Liver imaging and detection of liver metastases with 99mTc-HIDA.

16 patients with a history or suspicion of malignant disease were investigated scintigraphically for liver metastases. Each patient was studied with 99mTc-HIDA and 99mTc-sulphur- or tin-colloid. In 4 patients liver metastases were suspected and confirmed by ultrasonography and/or computerized tomography.