Radiologia clinica最新文献

The application of fast neutrons, negative pions or heavy ions will only provide an advantage for the radiotherapy of cancer if, in comparison with conventional radiation, e.g., X-rays, gamma rays and electrons, better depth-dose and collimation characteristics or specific radiobiological dose-response relationships result in greater local control probabilities for tumours without increased frequencies of severe normal tissue damage. Differences in intrinsic radiosensitivity and the presence of hypoxic cells are considered to be the main factors which can cause values of the relative biological effectiveness (RBE) for responses of tumours to be larger than RBE values for normal tissue tolerance. Clinical studies on lung metastases irradiated with single doses of 15 MeV neutrons indicate that RBE values for tumour growth delay can vary between 1.2 and 4.0, while RBE values for damage to several normal tissues are estimated from data on a few animal tissues to be approximately 2.5.

Three patients with different stages of renal scleroderma are presented, and the angiographic diagnosis of this disease is dicussed. No one pattern is specific, but the combination of findings is considered diagnostic of this disease. Pharmacoangiography is proposed for differential of renal scleroderma, and selective renal artery infusion of vasodilators is suggested as a potential means of therapy.

The authors describe a rare 'pseudo-tumour' in the right heart, discovered after a cerebrovascular accident (paradoxal embolus probably). The mass occupied the anterior leaflet of the tricuspid valve. Its mobility and numerous calcifications facilitated diagnosis, determination of its exact position, and evaluation of haemodynamic consequences. The histopathologic features are reported, and its aetiology is discussed.

The case of a patient in whom an allergic reaction developed after injecting 99Tcm sulfur colloid for a routine liver scan is herein presented. Since this reaction did not appear when injecting the same patient 99Tcm polyphosphate for a bone scan, it can be assumed that the allergic reaction was due to the stabilizer.

A few cases of scimitar syndrome and intralobar pulmonary sequestration are presented. The characteristic features of the two syndromes are discussed with reference to similarities and differences. Emphasis is placed on the persistent embryonic communications between the pulmonary and the systemic circulation in both syndromes.

Interstitial implants are either removable or permanent (and occasionally a combination of both). Permanent implants are generally utilized where tumors are not accessible enough to permit easy removal of sources or where accurate source distribution is less critical. They are useful for cancers of the lung, pancreas, prostate, bladder, lymph nodes, etc. Radon and gold-198 have been largely replaced by iodine-125. Our major interests are in the removable after-loading iridium-192 implant techniques. Template (steel guide) and non-template (plastic tube) techniques are utilized. Templates are preferred where the tumor volume can only be approached from one side and where accurate positioning of sources would otherwise be difficult. They are useful for cancers of the cervix, vagina, urethra, and rectum. Non-template (plastic tube) techniques are preferred where the tumor volume can be approached from at least two sides and where templates are either not feasible or not essential for accurate positioning of sources. The single needle non-template approach is useful for cancers of lip, nodes, and breast (plastic button) and for cancers of the oral cavity and oropharynx (gold button). The paired needle non-template approach is useful for cancers of the gum, retromolar trigone, and base of tongue (loop technique) and for cancers of the palate (arch technique). Procedures for each technique are described in detail.

To aid in the differential diagnosis of upper abdominal tumors, pancreatic scintigraphy was performed in 62 cases. The findings were rather characteristic for pancreatic cysts; namely, pancreatic displacement and, adjacently, an oval-shaped activity area whose count was lower than background. Pancreatic displacement was observed with comparatively large retroperitoneal masses. Low activity areas were observed in cystic lesions. Both findings were noted in 7 (54%) of 13 pancreatic cyst cases. Among the 12 cases with these findings, 7 (58%) had pancreatic cysts.

18 cases of total occlusion of the lumbar aorta of one common iliac artery are discussed. The collateral patterns, described in the literature, were classified into eight groups, according the localization of the occlusion. Also a new collateral plexus of paravertebral arteries was observed. A survey of the scattered information in the literature of the last five years, about the incidence and the causes and consequences of total lumbar aortic occlusion, is given.

This report describes one case in which bone scintigraphy was helpful in establishing the diagnosis of osteoid osteoma and presents three other cases in which increased accumulation of 99mmTc-EHDP was found at the side of the osteoid osteoma. The study contributes to the observation by others that the osteoid osteoma occurs as a scintigraphic 'hotspot'. It is concluded that the diagnostic delay of the osteoid osteoma can be shortened when bone scintigraphy is performed more often and at an earlier stage in patients with unexplained bone pain or with a clinical history that leads to the suspicion of the presence of an osteoid osteoma.