A small decrease in cerebral blood flow (approximately 10%) in response to 100% oxygen (O2) administration is well recognized. This observation was based on human volunteer studies, which employed a nitrous oxide washout method for the measurement of cerebral blood flow. Because this method is now appreciated to be subject to potential errors we have examined the cerebral blood flow response to 100% oxygen using a magnetic resonance imaging technique to quantify changes in carotid and basilar artery flow. The study, was performed in 12 normal male subjects aged 23-42 years. We report decreases in cerebral blood flow ranging from 9 to 31% with a mean value of over 20%. The decrease in cerebral blood flow was greater in seven young subjects (aged 23-26 years) with decreases in cerebral blood flow of 19.3-31.4% (mean 26.8%). In five older subjects (aged 32-42 years), decreases in CBF were smaller (mean 16. 2%). The administration of 100% O2 was accompanied by a small decrease in end-tidal CO2 (3.7-7.1%), insufficient to explain the changes in cerebral blood flow. We conclude that the decrease in cerebral blood flow in response to O2 administration is greater than previously described and appears to be greater in young adults.

This study examined the effects of a recently developed automated intensity non-uniformity correction on surface coil images using the orbit as an exemplar. Images were obtained using a standard head coil and a range of surface coils. Slices through the optic nerve head and cavernous sinus were subjected to the correction algorithm. Blind forced-choice rankings of the subjective image quality were performed. Quantitative measurements were taken of the similarity between vitreous humor at two depths from the coil, and of the conspicuity between orbital fat and temporalis muscle intensities. The combined qualitative ranks for corrected surface coil images were higher than for the equivalent uncorrected images in all cases. Intensity non-uniformity correction produced statistically significant improvements in orbital surface coil images, bringing their intensity uniformity in homogeneous tissue to the level of head coil images. The subjective quality of the corrected surface coil images was superior to head coil images, due to increased spatial resolution combined with improved signal to noise ratio across the image. J. Magn. Reson. Imaging 2001;14:540 -546.

Non-operative management has frequently been adopted for closed injuries of the infraclavicular brachial plexus and its branches in the belief that spontaneous recovery is likely to occur, and surgical exploration is performed only if recovery has not occurred in the expected time. This paper correlates the clinical and electrophysiological features with the operative findings in six patients with such injuries. The axillary nerve was ruptured in all six patients, the musculocutaneous nerve in two and the radial nerve in two. When the muscles supplied by a branch of the plexus were denervated, the differentiation between rupture of that branch and a lesion in continuity could only be made by surgical exploration, which should be performed as soon as other injuries permit.

In spite of new drugs, lung cancer is associated with a very poor prognosis. While targeted therapies are improving outcomes, it is not uncommon for many patients to have only a partial response, and relapse during follow-up. Thus, new drugs or re-evaluation of existing therapies used to treat other non-malignant diseases (drug repurposing) are still needed. While this research both in vitro and in vivo is being carried out, it is important to be attentive to patients where the disease responds to treatments not considered standard in clinical practice. We report here a patient with adenocarcinoma of the lung who, after declining chemotherapy and radiotherapy, presented with tumour response following self-administration of cannabidiol, a non-psychoactive compound present in Cannabis sativa . Prior work has shown that cannabidiol may have anti-neoplastic properties and enhance the immune response to cancer. The data presented here indicate that cannabidiol might have led to a striking response in a patient with lung cancer.

A case is described of bilateral ischaemic contracture of the intrinsic muscles of the hands, presenting in a mentally-disturbed patient one year after a reported period of immobilisation in a physical restraint device. Involvement of the deep thenar muscles and the interossei on the radial side of the hand can be explained by consideration of the anatomy of the deep palmar arch. Division of the tendons of the contracted interosseous muscles proximal to the metacarpophalangeal joints and release of the left first web improved hand function. Those who supervise the use of physical restraint devices should be aware of the risk of intrinsic muscle ischaemia and of the need for prompt diagnosis and treatment.

Chronic joint pain in rheumatoid arthritis may mask that from other causes. Stress fractures, particularly in osteoporotic lower limb bones of such patients, are well described but can still cause diagnostic difficulty. These difficulties were highlighted by a case in which an unusual fracture occurred through a geode in the proximal ulna mimicking an exacerbation of synovitis in the elbow joint.

We describe the case of an asymptomatic 24-year-old man with hypertension who was investigated for aortic coarctation but found on MR scanning to have narrowing of the distal thoracic aorta. Stenosis of the thoracolumbar aorta--the Middle Aorta Syndrome--is rare and is usually found below the diaphragm. The MRI and angiographic findings are presented.

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