Computed tomography of thymic abnormalities.

Computed tomographic examinations of 38 patients with surgically and histologically proven diagnosis were reviewed. Twenty subjects (52%) had an invasive thymoma and 16% an hyperplasic thymus. Myasthenia gravis was present in 6 cases (16%) of thymic abnormalities, four (10.5%) with invasive thymoma and two (5%) with thymic hyperplasia. Graves' disease was also present in one case of thymic hyperplasia. We emphasize the contribution of CT to the diagnosis and the prognosis.

[Evaluation of pathology of the small intestine by computed tomography. Apropos of 34 cases]. / Evaluation de la pathologie de l'intestin grêle par tomographie numérisée (CT). A propos de 34 cas.

A retrospective study reviewed computed tomography imaging findings in 34 patients with affections of the small intestine. In 68% of cases lesions were demonstrated by the CT scan before any other investigation. Whether the lesions were benign or malignant tumors, inflammatory or infectious disorders or malformations, all images showed segmental or localized parietal thickening of 5 mm or more. In many cases this thickened wall was associated with an extramural mass or an increased attenuation value of adjacent mesenteric fat. Computed tomography is the only available method that provides reliable information on the importance of the intra-and extra-mural components of small intestine affections.

Adjusted versus fixed-dose subcutaneous heparin in the prevention of deep-vein thrombosis after total hip replacement.

Venous thromboembolism after total hip replacement continues to be a serious problem. We conducted a study to determine whether adjustment of the dose of subcutaneous heparin to yield partial thromboplastin times in the high-normal range results in a greater reduction of postoperative deep-vein thrombosis than fixed doses of heparin. Seventy-nine patients undergoing elective hip arthroplasty were randomly divided into two groups two days before surgery. Group 1 (41 patients) received a fixed dose of 3500 IU of heparin subcutaneously ever eight hours; 16 of the 41 (39 per cent) had deep-vein thrombosis diagnosed by venography. Group 2 (38 patients) was started on the same dose, which was then adjusted to keep the activated partial thromboplastin time between 31.5 and 36 seconds. From the day of operation to the eighth postoperative day these patients needed progressively more heparin to maintain the activated partial thromboplastin time in the prescribed range. Only 5 of the 38 (13 per cent) had deep-vein thrombosis (P less than 0.01), and the number of thrombi in proximal veins was also lower in this group (P = 0.003). The number of units of blood transfused, the frequency of postoperative wound hematomas, and the drop in hemoglobin levels were identical in the two groups. Adjusted low-dose heparin prophylaxis appears to be a safe and efficacious method to reduce the frequency of deep-vein thrombosis in patients undergoing total hip replacement.

CT of the thoracic duct.

The ability of computed tomography to demonstrate the normal anatomy of the thoracic duct was investigated after lymphangiography in 20 patients without evidence of chest diseases on the plain films. The entire opacified thoracic duct can be easily imaged from its origin at the thoraco-abdominal level, up to its arch, which enters the venous blood stream, usually at the left subclavian-jugular confluent. Variations of the arch of the duct have been observed in our series. The ability to detect the non-opacified duct with CT was also assessed in 80 patients. Imaging of part or totality of the lower, mid and upper segments of the thoracic duct is possible respectively in 81, 54 and 69 per cent of subjects. The arch of the duct was displayed in 57 per cent. Knowledge of the normal anatomy of the thoracic duct is important since it can be involved in many diseases of the posterior mediastinum and of the thoracic outlet.

CT detection of benign and malignant abnormalities of the small bowel.

The authors analysed the CT findings in 60 normal subjects and 14 patients with small bowel disease to assess the ability of CT to detect wall thickening. The patients all had a small bowel wall thickness larger than 0.5 cm. Benignity could not be distinguished from malignancy solely on the pattern of small bowel thickening. Thus, Crohn's disease could not be differentiated from intestinal Hodgkin's disease or post radiation therapy ileitis. Intra- and extramural masses are also a common but non-specific pattern; they can be associated with small bowel wall thickening and have been encountered in different situations such as duodenal duplication, jejunal haematoma or adenocarcinoma. Knowledge of normal anatomy, optimal endoluminal opacification and careful attention to the appearance of the small bowel are recommended in every CT survey of the abdomen.

[Evaluation of aortic dissection by transverse computerized tomography (CT scan)]. / Evaluation des dissections de l'aorte par tomographie transverse computérisée (CT-scan).

Twenty patients with dissection of the thoracic aorta were studied by CT-scanning. In 9 patients the diagnosis was previously documented by aortography, while in the other 11 patients the diagnosis of aortic dissection was first established by CT-scanning. The latter demonstrated the characteristic signs of aortic dissection and particularly the following features: a) the false channel (95%) and the intimal flap (90%), b) the displacement of aortic wall calcifications (60%), especially when the false channel is partially thrombosed (80%). In 19 patients, a bolus injection of contrast medium was performed. In the majority of cases opacification of the false channel occurred only partially, with some delay and with a non-homogeneous pattern. Six out of the 20 patients underwent one or more follow-up examinations performed between 15 days and 2 years later. CT-scanning clearly demonstrated the late persistence of a patent false channel and particularly the delayed thrombosis, even after surgical treatment of aortic dissection. CT-scanning appears to be a reliable non-invasive method for - establishing the diagnosis of aortic dissection, - delineating the extent of dissection, - follow-up of evolution after surgical or medical therapy.

[Fine needle biopsy guided by computed tomography]. / Ponction-aspiration percutanée à l'aiguille fine sous contrôle de la tomographie transverse assistée par ordinateur.

Percutaneous fine needle biopsy guided by computed tomography is now a well established method in most university radiological departments. Positive results are obtained in some 80% of cases. With this tehcnique most abdominal and pelvic structures can be reached without danger for the patient under local anesthesia, even when the fine needle passes through the gastric or bowel walls. In some instances the technique can also be employed for biopsy of pulmonary and mediastinal lesions.

[New methods of radiologic diagnosis: ultrasonography and tomoradiometry (computer assisted tomography)]. / Les nouvelles méthodes de diagnostic radiologique: ultrasonographie et tomoradiométrie (computer assisted tomography).

The evolution of new and more accurate methods of examination is a welcome complement to current diagnostic resources. However, it is essential to use them intelligently to avoid a further undesirable rise in the cost of health. Now more than ever, the programme of radiologic examinations should be established by common consent between the practising physician and the consultant radiologist.

[Abdominal tomoradiometry: its possibilities]. / La tomoradiométrie de l'abdomen, ses possibilités.

Computer-assisted tomography opens up a new diagnostic chapter in research on abdominal lesions. The display of very faint contrasts, and the possibility of modulating them and of strengthening them by opacifying agents, afford hitherto unknown differentiations. The obtaining of cross-sections is another advantage of this method. Its use for study of the various abdominal organs is reviewed.

Intrathoracic stomach: CT evaluation of two cases.

2 cases of intrathoracic stomach, 1 of them associated with hernia of the splenic flexure of the colon and a right-situated thoracic descending aorta, are evaluated by computed tomography.