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Biomedical subjects

D Tack

Publications and source records attributed to D Tack.

30 records · Page 2Linked to original sources

[Spiral computed tomography of the renal arteries].

With the recent advent of spiral or helical CT, the ability to acquire large volume of imaging has become possible. Fast scanning of both kidneys, the aorta and the renal vessels can be accomplished during one breathhold. Early reports of CT angiography in the evaluation of renal artery stenosis indicated a sensitivity of 92% utilizing the MIP projection method and 59% utilizing the shaded surface display method. Specificity for both method was approximately 82%. More recent articles reports for hemodynamically relevant renal artery stenosis a sensitivity/sensibility of 96/99%. The introduction of a new multidetector CT technology will probably increase those results and the indication of CT angiography.

Angiography↗

[Placing of a Nitiol Memotherm prosthesis: personal experience].

The authors report their experience in the placement of a new Nitinol stent. Thirty eight stents were placed in 28 iliac arteries, 3 superficial femoral arteries, 1 popliteal artery, 2 subclavian arteries, and 2 veins of hemodialysis fistulae. The primary success rate was 100%, but several angioplasty balloons have been ruptured due to the specific configuration of the stent. The mean follow-up period was 6 months. Memotherm placement is an easy procedure, but the specific structure of the device makes the manipulation of the angioplasty balloons delicate, especially in tortuous vessels.

Aged↗

[Persistent left superior vena cava. Apropos of 2 cases].

Double superior vena cava with persistence of a left superior vena cava is rarely encountered. The prevalence in the general population is 0.3% but may reach 3 to 10% in patients with inborn heart diseases. There are usually no clinical signs and the malformation is usually discovered fortuitiously. We describe the features of two cases observed in our institution and reviewed the literature on the subject.

Adult↗

[NMR evaluation of neoplastic invasion of the pulmonary artery].

Bronchial tumors that invade the mediastinum are not necessarily inoperable. Whether surgery is possible depends, among other things, on the extent of pulmonary artery invasion. The authors have studied the value of cardiac-gated MRI and compared it with CT and venous DSA for staging tumor invasion. CT demonstrated the areas of contact between tumor and mediastinum. The MRI planes were transverse and also in the main axis of the pulmonary arteries. Twenty-one patients were studied and in 16 the findings could be checked during surgery. In all cases the findings on MRI were confirmed. In eight patients MRI provided more information than CT and DSA combined and thereby showed its superiority for evaluating arterial invasion.

Adenocarcinoma↗

[Neoplastic invasion of the pulmonary arteries. Evaluation by MRI. Preliminary experience].

Bronchial tumors invading the mediastinum are no longer systematically regarded as inoperable. Curative surgery has produced a significant survival rate and led to the adaptation of the TNM classification. The degree of invasion of the pulmonary artery is a criterion of operability. The authors are trying to assess the role of MRI with regard to CT and DSA for the measurement of invasion. Their study deals with the prospective assessment of ten patients. The MRI examinations have been carried out with a 0.5 and 1.5 T supraconductive magnet (Philips Gyroscan). Cardiac gating has been used for acquisition. The planes of section are axial, transverse or oblique along the greater axis of the pulmonary arteries. CT examinations in 9-mm thick sections with and IV contrast injection demonstrate the contact of the tumor with the mediastinum. The digital angiograms have been taken with an intravenous injection into a vein of the bend of the elbow or into a femoral vein. Six cases have been verified at surgery. In all cases, the invasion predicted with MRI proved to be correctly assessed. In three cases, MRI provides additional information to the combined findings of CT and DSA. MRI is a good complement for the preoperative assessment of patients with large tumors invading the mediastinum but for which curative surgery is indicated.

Bronchial Neoplasms↗

Radiation dose in computed tomography of the chest.

Since the beginning of the eighties, computed tomography (CT) has been more and more widely used as this technique provides precise anatomical details on the lungs, the mediastinum, and the chest wall. However, CT requires the use of ionizing radiations. The collective radiation from CT is therefore in constant increase. As evaluated on atomic bomb survivors, ionizing radiations increase the mortality by cancer. The risk is proportional to the dose and the dose related to CT is much higher than that related to a chest radiograph, both being in the field "of low-level radiations" a range of radiation dose from which no increase in cancer mortality could be demonstrated. This article outlines the risk estimation in the field of low-level radiations, the various methods to measure and estimate the radiation dose, the CT parameters influencing the radiation dose, dose comparisons between CT and most other imaging techniques of the chest, the newly developed so called "Low-Dose" CT techniques and highlights some of the unresolved questions related to radiation dose in clinical CT practice.

Humans↗