In order to understand and evaluate fully the composition of the radiologic report, an experiment was performed in which eight readers each read the same 100 chest radiographs. The reports were dissected into individual statements, each of which was analyzed for accuracy, statement type (descriptive or etiologic), confidence, and specificity. In addition, each report was evaluated for stylistic factors of succinctness, orderliness, and the use of supplemental comments. Detailed analysis showed the radiologic report to be a series of largely descriptive statements in which confidence level, specificity, and orderliness were associated with the presence of errors in film interpretation. These factors can serve as important markers for identifying error-laden films. The use of specific, etiologic diagnoses in these film readings was limited. The composition of the report was not related to the length of radiologic training beyond the first year of residency. The implications of these findings concerning report composition in light of present day radiologic practice and new, automated radiologic reporting systems were discussed.
Preformed arterial collaterals are critical to renal parenchymal survival after acute total renal artery occlusion. This study was designed to delineate and quantify preformed collaterals and assess their response to vasodilators. A Swan-Ganz catheter induced a sudden, total occlusion of a renal artery sufficient to reduce distal arterial pressure to near zero and prevent perfusion through the renal artery. Arteriography assessed the effectiveness of the occlusion and delineated the collateral arterial pathways. Strontium, cerium, and chromium-labeled microspheres measured renal blood flow and cardiac output 1, 60, and 120 minutes after occlusion. In two additional series of experiments either contralateral nephrectomy was performed 5 to 8 days before the study, or dibenzylene, dopamine, or glucagon were administered in an attempt to increase blood flow through the collaterals. Collateral renal blood flow was demonstrated in all dogs. Mean blood flow to the occluded kidneys ranged from 0.13 ± 0.05 cm3/minute/g to 0.22 ± 0.08 cm3/minute/g, about 5% of control values. Neither prior contralateral nephrectomy nor vasodilator agents increased the flow to the obstructed kidneys. In the dogs with intact contralateral kidneys, however, there was a progressive decrease in cardiac output during the experiment, which was not found in uninephrectomized animals. We concluded that preformed arterial channels are available to maintain a small, but probably critical level of perfusion following sudden total occlusion of the renal artery. Neither hypertrophy due to prior contralateral nephrectomy nor active vasodilators modify flow through the preformed channels. It is likely that total renal ischemia provides a maximal stimulus for vasodilatation. The pattern of hind limb collaterals differed strikingly from those of the kidney, with maintenance of a greater portion of a normal flow and rapid increase in flow within 1 hour after femoral artery occlusion. Thus, data concerning collateral circulation cannot be generalized from one vascular bed to another even in the same species.
In almost any branch of medicine, one may sometimes overlook the total needs of the patient. This is especially true in radiology in which clinical contact with patients is necessarily limited. Clearly, radiologists must expand their role as diagnostic consultants rather than confining themselves to championing a particular approach to disease evaluation.
The capacity of electrostatic imaging for edge enhancement and wide latitude recording can improve visualization in neuroradiologic studies using low differential absorption contrast agents. Gas myelography and pneumoencephalography show the most satisfactory improvement in visualization. Tomography combined with xerography enhances definition further, but with gas myelography, especially in the thoracic region, plain xeroradiographic definition is frequently diagnostic.
The angiograms and clinical records of 42 patients with arteriosclerosis obliterans who underwent repeat angiography were analyzed in order to correlate the effects of surgery with progression of the occlusive process in native vessels. Occlusive disease progressed significantly faster in operated limbs (77%) than in nonoperated limbs (44%). When progression occurred, it was more likely to take the form of occlusion in operated limbs (85 %) than in nonoperated limbs (61 %). Graft closure was associated with a 93% incidence of disease progression, but even limbs with patent grafts had a more rapid progression than the nonoperated limbs (62% vs. 44%). There was a good correlation between the presence of symptoms and the angiographic progression.
