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Biomedical subjects

M F Reiser

Publications and source records attributed to M F Reiser.

At least 19 recordsLinked to original sources

Comparison between high-field-strength MR imaging and CT for screening of hepatic metastases: a receiver operating characteristic analysis.

The diagnostic performance of high-field-strength magnetic resonance (MR) imaging (1.5 T) for detection of liver metastases was compared with that of computed tomography (CT). All patients (n = 52) underwent preoperative screening for metastases by means of MR imaging with T1-weighted, proton-density-weighted, and T2-weighted pulse sequences and CT scanning with unenhanced, incremental dynamic bolus-enhanced, and delayed contrast medium-enhanced techniques. Diagnostic performance was evaluated by means of receiver operating characteristic analysis in which 800 images (400 with and 400 without lesions) and five readers (4,000 observations) were used; images were obtained from patients (n = 39) in whom the same anatomic levels were available for all MR imaging and CT studies. Direct comparison between the best MR imaging technique (T2-weighted spin-echo imaging [repetition time, 2,000 msec; echo time, 70 msec]) and the best CT technique (incremental dynamic bolus CT) showed a strong trend of superiority of T2-weighted MR imaging over incremental dynamic bolus CT. No highly statistically significant difference (P greater than or equal to .01), however, was found between these two techniques.

Esophageal Neoplasms

MRI and MRS of the skeletal muscle.

Magnetic resonance imaging and spectroscopy were performed in several types of muscular disorders. In acute stages, 31P spectra showed remarkable changes compared with normals, and T2-weighted MR images were most sensitive in delineating the pathology. Fatty degeneration of muscle in chronic diseases yielded high contrast in T1-weighted MRI and could be quantified by 1H-MRS including the chemically selective determination of proton T1 values. In order to evaluate true abundance rations of phosphorus metabolites, 31P relaxation times T1 of muscle were measured by localized inversion recovery.

Acute Disease

Cystic pelvic mass in a patient having recurrent carcinoma of the cervix.

The diagnostic difficulties encountered with atypical tumor growth are reported in a 29-year-old female with recurrent carcinoma of the uterine cervix. Following a Wertheim-Meigs procedure and resection of local tumor recurrence eight months later, a second recurrence was detected on CT as a purely cystic lesion in the left pelvic wall. Although the size of the cyst subsequently increased, the patient remained asymptomatic until slight pain developed in the left leg 28 months after initial therapy. One month later, limping was noticed; plain radiography showed a large osteolytic lesion of the left hip and on I.V.U., a dilatation of the left renal collecting system was observed. Pelvic CT showed only minimal solid tissue components within a large cyst. Multiple needle aspirations of the cyst and cytological examinations of the fluid obtained showed no evidence of tumor cells. A definitive histological diagnosis of metastasizing squamous cell carcinoma was only reached after surgery.

Adult

Gadolinium-DTPA in rheumatoid arthritis and related diseases: first results with dynamic magnetic resonance imaging.

Thirty-four joints (19 knees, 15 wrists) of 31 patients suffering from rheumatoid arthritis and related disorders were examined prior to and following intravenous administration of Gadolinium-DTPA (0.1 mmol/kg body weight). T1-weighted spin-echo sequences and the gradient-echo technique FLASH were applied. FLASH scanning was used for the registration of the time-dependent changes of signal intensity following Gd-DTPA. Synovial proliferations exhibited a rapid and marked increase of signal intensity whereas fatty tissue, bone marrow, muscle and synovial effusion demonstrated only minor changes, causing enhanced contrast between synovial pannus and joint effusion or other neighbouring structures. Within the synovial pannus, ratios (absolute signal increase) of 131.3 +/- 53.4% and 122.9 +/- 51.1% were found in T1-weighted spin-echo and in FLASH sequences respectively. The average signal increase gradient of pannus (108.2 +/- 70.6%/min) was significantly (p less than 0.001) different from muscle (13.4 +/- 7.8%/min), fatty tissue (10.2 +/- 8.4%/min), bone marrow (5.5 +/- 7.1%/min), and joint effusion (14.7 +/- 7.8%/min).

Adipose Tissue

Musculoskeletal neoplasms: static and dynamic Gd-DTPA--enhanced MR imaging.

Static and dynamic magnetic resonance imaging studies were performed in 69 patients with bone and soft-tissue tumors. T1-weighted spin-echo (SE) imaging after intravenous administration of gadolinium diethylenetriaminepentaacetic acid (DTPA) improved the differentiation of necrotic from viable areas; the contrast-to-noise ratio (C/N) between tumor and muscle was an average of 44% lower compared with that in T2-weighted SE imaging. The C/N between tumor and bone marrow or fatty tissue was 43% and 37% lower, respectively, compared with that in nonenhanced T1-weighted SE imaging. Dynamic changes of signal intensity (SI) after Gd-DTPA enhancement were assessed with fast low-angle shot imaging. Of malignant tumors, 84.1% exhibited slopes higher than 30% per minute; 72% of benign tumors showed slopes lower than 30% per minute. The dynamic technique enabled assessment of the malignant potential of a tumor with some overlap (accuracy, 79.7%). Necrotic areas and peritumorous edema showed significantly lower and more gradual increases in SI than adjacent neoplastic tissue.

Adipose Tissue

Magnetic resonance in cartilaginous lesions of the knee joint with three-dimensional gradient-echo imaging.

Diagnosis of chondromalacia of the patellofemoral joint using three-dimensional gradient-echo sequences was investigated in 41 patients, with arthroscopic verification in 25 patients. In vitro examinations in human cadaveric patellae were performed in order to determine optimal imaging parameters. FLASH (TR = 40 ms, TE = 10 ms, flip angle = 30 degrees) and FISP (TR = 40 ms, TE = 10 ms, flip angle = 40 degrees) were used in clinical studies. Advanced stages of chrondromalacia could be visualized with high sensitivity. In less advanced disease, overstaging was observed. The therapeutically relevant differentiation of major and minor degrees of chondromalacia seems to be possible. 30 degrees FLASH-images in the axial plane proved to be the most efficacious technique for the diagnosis of chondromalacia.

Arthroscopy

Are psychiatric educators "losing the mind"?

Psychiatry is part of medicine, and developing competence to deal with the mental life of patients is an essential part of general medical as well as psychiatric subspecialty education. As psychiatry's neurobiological data base, therapeutic armamentarium, scope of interest, and philosophical views expand and competitive pressures for time in residency training are intensified, teaching in the mental sciences and opportunities for residents to develop solid psychodynamic diagnostic and therapeutic skills are rapidly disappearing. However, brain science does not yet, and probably never will, fully explain the mind. The author urges psychiatric educators not to give up the mind or, worse yet, lose it by default.

Attitude of Health Personnel

Comparison of theoretically oriented and patient-oriented behavioral science courses.

Effective teaching of medical behavioral science is an important challenge for psychiatrists. Two behavioral science courses taught at different times at the Yale University School of Medicine are described: a theoretically oriented course emphasizing symbolic function, primary source reading, and conceptual thinking and a patient-oriented course emphasizing the relevance of behavioral science to the practice of medicine, taught primarily by consultation-liaison psychiatrists. Students' evaluations of the two courses during the fifth year each course was taught were compared. The students' acceptance of the patient-oriented course was dramatically greater than that of the theoretically oriented course. The class mean scores on the behavioral science subtest of the Part I examination of the National Board of Medical Examiners during the last four years that the courses were taught were compared. The mean scores of the classes that had taken the patient-oriented course were significantly higher than those of the classes that had taken the theoretically oriented course. The mean score for the class that took the fifth year of the patient-oriented course was 52 points higher than the mean score for the class that took the fifth year of the theoretically oriented course. The authors concluded that the skills that consultation-liaison psychiatrists use every day in their work may be exactly those that are useful in teaching a successful behavioral science course for medical students.

Behavioral Sciences

Spontaneous ejaculation associated with anxiety: psychophysiological considerations.

The association of anxiety with sexual excitement has been noted since the early part of this century. The authors present case reports of a schizophrenic and a neurotic patient in whom no direct sexual precipitants of spontaneous ejaculation could be identified but in whom severe anxiety was evident. The central noradrenergic neurophysiology that anxiety may share with sexual excitement could provide a basis for spontaneous ejaculation during anxiety. The pharmacology of spontaneous ejaculation during opiate withdrawal is used to elaborate this central noradrenergic model.

Adult

A general systems taxonomy for psychological defence mechanisms.

A taxonomy of psychological defence mechanisms based on general systems concepts is proposed. The personality system consists of the subsystems concerned with input, internal processing, and output of information. Psychological defence mechanisms can be classified according to the subsystem whose function is mainly altered. Defence mechanisms primarily altering the input apparatus function through changes in the perceptual process. These include diminution of perception (denial), distortion of the origin of the percepts (projection and introjection), and distortion of subjectively perceived direction of the feelings and thoughts (displacement). Defence mechanisms that primarily alter the functions of the internal processing apparatus include repression, rationalization, intellectualization, isolation, and fantasy/day-dreaming. These mechanisms alter associative and cognitive processes either directly (repression) or indirectly. In reaction formation, there may by a selective distortion to produce an opposite affect. Defence mechanisms that primarily affect the output apparatus include acting out, counterphobic activity, undoing, sublimation, and non-specific activity. Regression and identification are defence mechanisms that affect all the subsystems, input, internal processing and output, more or less uniformly producing effects throughout the personality system. The advantage of this classification scheme is that it relates primarily to directly observable phenomena that can be readily classified. Another advantage is that it may generate researchable neuropsychological hypotheses concerning possible neural substrates of defence mechanisms.

Defense Mechanisms

Goals of education in psychosomatic medicine.

The modern concept of psychosomatic medicine is based on a multifactorial, interactional systems model for all diseases in which the behavioral and social dimensions play important roles in the pathogenesis, manifestation, course, and outcome. This psychosomatic approach forms the philosophical underpinning of a modern educational program. A general goal of education for all physicians is understanding the behavioral and psychosocial factors in all illness. Specific goals for the primary physician and the psychiatrist are the instillation of a holistic attitude in patient care through systematic training, and the attainment of skills and knowledge to integrate behavioral and biomedical sciences, respectively. This includes specific diagnostic, treatment, and educational skills. Yale's multilevel educational program in psychosomatic medicine is described.

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