Feature space analysis of MRI

This paper presents an MRI feature-space image-analysis method and its application to brain tumor studies. The proposed method generates a transformed feature space in which the normal tissues (white matter, gray matter, and CSF) become orthonormal. As such, the method is expected to have site-to-site and patient-to-patient consistency, and is useful for identification of tissue types, segmentation of tissues, and quantitative measurements on tissues. The steps of the work accomplished are as follows: (1) Four T₂-weighted and two T₁-weighted images (before and after injection of gadolinium) were acquired for 10 tumor patients. (2) Images were analyzed by an image analyst according to the proposed algorithm. (3) Biopsy samples were extracted from each patient and were subsequently analyzed by the pathology laboratory. (4) Image-analysis results were compared with the biopsy results. Pre- and postsurgery feature spaces were also compared. The proposed method made it possible to visualize the MRI feature space and to segment the image. In all cases, the operators were able to find clusters for normal and abnorma tissues. Also, clusters for different zones of the tumor were found. The method successfully segmented the image into normal tissues (white matter, gray matter, and CSF) and different zones of the lesion (tumor, cyst, edema, radiation necrosis, necrotic core, and infiltrated tumor). The results agreed with those obtained from the biopsy samples. Comparison of pre- with postsurgery and radiation feature spaces illustrated that the original solid tumor was not present in the second study, but a new tissue component appeared in a different location of the feature space. This tissue could be radiation necrosis generated as a result of radiation.     

Emphysema in the renal allograft

Two diabetic patients in whom emphysematous pyelonephritis developed after renal transplantation are described. Clinical recognition of this unusual and serious infection is masked by the effects of immunosuppression. Abdominal radiographic, ultrasound, and computed tomography findings are discussed. The clinical presentation includes urinary tract infection, sepsis, and acute tubular malfunction of the allograft in insulin-dependent diabetics.     

Levodopa alone and in combination with a peripheral decarboxylase inhibitor benserazide (madopar®) in the treatment of Parkinson's disease

Summary A combination of levodopa and the extracerebrally acting decarboxylase inhibitor benserazide (ratio 4:1) (Madopar^®), was compared with levodopa alone in a controlled double-blind clinical multicenter trial on 94 patients with Parkinson's disease. During 4 months of therapy levodopa + benserazide proved superior to levodopa on several accounts. Nausea and vomiting occurred with statistically significant less severity and frequency. Clinical improvement expressed through improvement in Webster rating occurred sooner and was all together greater.The treatment schedules did not differ with regard to other side effects, in particular involuntary movements and reduction in supine blood pressure. Neither treatment seemed to influence liver function, renal function and hematological parameters.

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Zusammenfassung Levodopa in Kombination mit dem extracerebral wirkenden Dekarboxylasehemmer Benserazid (Dosisverhältnis 4:1) (Madopar^®) wurde mit Levodopa allein in einer kontrollierten, doppelblinden, klinischen Multizenterprüfung an 94 Patienten mit Morbus Parkinson verglichen. Während der viermonatigen Therapie zeigte sich in mehreren Beziehungen Levodopa + Benserazid dem Levodopa überlegen. Übelkeit und Erbrechen waren statistisch signifikant weniger schwerwiegend und traten seltener auf. Klinische Besserung, ausgedrückt durch Reduktion im Webster Rating, trat schneller ein und war im großen und ganzen höher.Andere Nebenerscheinungen, insbesondere unwillkürliche Bewegungen und Reduktion des Blutdruckes im Liegen, verteilen sich gleich über die beiden Gruppen. Bestimmungen von sowohl Leberfunktion und Nierenfunktion als auch hämatologischen Parametern ergaben keine signifikanten Änderungen.