The hypertransradiant hemithorax: the importance of lateral decentring, and the explanation for its appearance due to rotation

Experimental evidence is presented indicating that 80% of the increase in unilateral film blackening on the chest radiograph resulting from rotation of the patient is due to asymmetrical absorption of the X-ray beam. Scatter contributes 20% to this increase in blackening. The effect on the radiograph of lateral decentring is also described. In the rotated patient, the hypertransradiant hemithorax always occurs on the side to which the patient is rotated, and is independent of the projection. If this rule is broken, then decentring or a thoracic abnormality is present.     

The radiology of external carotid-internal carotid anastomosis.

Surgical anastomosis between branches of the external and internal carotid arteries may be beneficial in selected cases of transient ischaemic attacks and reversible ischaemic neurological deficit. It is the responsibility of the radiologist, at the time of initial angiographic evaluation, to recognise patients who might benefit from this procedure. Postoperatively, angiography is valuable in assessing the surgical results. This report describes the investigations necessary for the adequate evaluation of these patients in both the pre- and post-operative state.     

The role of computed tomography in the staging of bladder cancer.

Computed tomography of the pelvis has been performed in 60 patients with epithelial bladder tumours. The CT findings have been compared with the clinical staging (T-stage), lymphography (N-stage) and wherever possible the surgical staging (P-stage). Although the intraluminal tumour was visualised in a high proportion of examinations, the greatest value of CT is in the accurate delineation of the extravesical extension of the growth. This is likely to be the primary role of CT in the staging of bladder cancer. Difficulties in detecting invasion of contiguous organs, particularly the prostate, and the failure to demonstrate nodal involvement within the pelvis were noted. The technique has clear advantages over more invasive investigations and the additional information provided over and above clinical staging is seen as a major advance in the assessment of these tumours.     

A comparison of nuclear magnetic resonance and intravenous xeroangiography with conventional arteriography in popliteal artery imaging

Twenty-nine patients with peripheral vascular disease had the popliteal artery segment assessed by xeroangiography and nuclear magnetic resonance (NMR) scanning. The result of each test was compared with conventional contrast arteriography. Nuclear magnetic resonance and xeroangiography correctly predicted popliteal artery patency in 97% and 100% of limbs, respectively, and occlusion was correctly predicted in 44% and 63% of limbs. The ability of xeroangiography to define the state of the popliteal artery accurately makes this a useful method in high-risk patients. The potential for NMR imaging appears very promising but more work is required to define its future clinical application.