[Multiplanar imaging in the retroperitoneum: noninvasive diagnosis with a new spiral CT technique--anatomy and pathology]. / Multiplanare Bildgebung im Retroperitoneum: Nichtinvasive Diagnostik mit einer neuen Spiral-CT-Technik--Anatomie und Pathologie.

Both anatomic and pathologic structures are often not documented in sufficient detail to provide overall information in axial scans, and magnetic resonance imaging does not always provide the required spatial resolution. The spiral CT technique, in contrast, with use of the secondary image reconstruction is capable of clearly documenting these interrelations. We have examined 45 patients with pathologic changes in the retroperitoneum by means of a spiral CT scanner and used the secondary image reconstruction in the coronary and sagittal plane in all cases. The scan times ranged between 45 and 60 seconds at a selected slice thickness of 3 mm and a table feed of 4.5 mm. Up to 30 cm of the crania-caudal length of the patients could thus be documented. From the basic data, up to 170 overlapping images were calculated for a multiplanar image reconstruction, and every third axial scan was photographed. The post-processing time was 10 to 15 minutes. The patients received 120 ml of a non-ionic contrast medium, intravenous at a flow rate of 2.5 ml per second. The spiral CT examination was started 40 seconds after the injection had been begun. It could be performed in all patients under inspiration, without problems. The chosen scan times did not lead to significant overshadowing due to motion artefacts. The vascular structures of the aorta and its main branches as well as the vena cava and the portal vein could be identified in their whole lengths. The peritoneal duplications and the renal fascia could be clearly documented. The lymph nodes could be identified in all of them. In cases of tumours with metastases, the extent of the tumor was excellently visible in the multiplanar reconstructions and a thickened peritoneum could be differentiated in such cases. This standardized examination procedure offers a uniform and reproducible diagnostic basis with short examination times. The early detection even of small recurrences in the axial slices and the identification of pathologic changes of the lymph nodes enable a timely tumor treatment for curative purposes.

Electron beam computed tomography in the evaluation of cardiac calcification in chronic dialysis patients.

The purpose of this study was to assess the value of electron beam computed tomography in the detection of cardiac calcifications in coronaries and valves of dialysis patients and to determine the rate at which calcification progresses. Forty-nine chronic hemodialysis patients aged 28 to 74 years were compared with 102 non-dialysis patients aged 32 to 73 years with documented or suspected coronary artery disease, all of whom underwent coronary angiography. We used high-resolution electron beam computed tomography scanning to make 30 axial slices with a distance of 3 mm between each slice. The number of calcifications, the surface area, and the average and highest density values were measured. We calculated a quantitative coronary artery calcium score and assessed calcification of mitral and aortic valves. In dialysis patients, the measurements were repeated after 12 months. The coronary artery calcium score was from 2.5-fold to fivefold higher in the dialysis patients than in the non-dialysis patients. Hypertensive dialysis patients had higher calcium scores than non-hypertensive dialysis patients (P < 0.05). A stepwise, multiple regression analysis confirmed the importance of age and hypertension. No correlation between calcium, phosphate, or parathyroid hormone values and the coronary calcium score was identified; however, the calcium score was inversely correlated with bone mass in the dialysis patients (r = 0.47, P < 0.05). The mitral valve was calcified in 59% of dialysis patients, while the aortic valve was calcified in 55%. The coronary artery calcium score was correlated with aortic valvular, but not mitral valvular calcification. A repeat examination of the dialysis patients at an interval of 1 year showed a disturbing tendency for progression. Our data under-score the frequency and severity of coronary and valvular calcifications in dialysis patients, and illustrate the rapid progression of this calcification. Finally, they draw attention to hypertension as an important risk factor in this process.

[Computer program for contrast medium administration in computerized tomography diagnosis]. / Computerprogramme zur Kontrastmittelapplikation in der Computertomographie-Diagnostik.

Contrast medium administration with the contrast medium injector system XD 5500 has proved to be an ideal supplement to the Somatom Plus. The specially developed programs for specific organ regions and differential diagnosis allow an optimization of the diagnosis. The contrast medium administration is thereby standardized and reproducible at any time. Contrast medium enhancement is constant and homogenous with density values of the aorta definitely over 60 Hounsfield units and in most cases over 100 HU. Operation is simple for the proficient investigator and is performed from outside the examination room. The function of a particle filter and an air bubble detector were convincing and certainly ensure the safety of the patient. As a disadvantage, it must be mentioned that the injector carries out program selected even in the event of a perivascular injection. This only occurred three times during our examinations on a total of approximately 5600 patients, without any lasting harm to the patient.

[Results of percutaneous transluminal angioplasty]. / Ergebnisse der perkutanen transluminalen Angioplastie.

Percutaneous transluminal angioplasty (PTA) can be subdivided into three epochs: 1. from its inception by Dotter and Judkins up to the first coronary artery stenosis dilatation with the Grüntzig balloon catheter system; 2. from the introduction of coronary stenosis dilatation by Grüntzig up to its unequivocal acceptance; 3. the period of influence of low-risk coronary dilatation on peripheral angioplasty and the search for techniques to compliment or obviate the need for balloon dilatation. The Grüntzig double-lumen balloon catheter system contributed to the lower rate of complications and higher success rate. The clinical acceptance appeared greater for the coronary arteries since, in contrast to the peripheral vascular system, the indication for treatment is established by the physician performing the dilatation. PTA implies percutaneous puncture of a vessel with Seldinger technique and introduction of devices such as guidewires, Dotter or Grüntzig catheters among others, catheters with fiberglass for laser conduction and instruments for fractionating, drilling and cutting. The goal of PTA is to completely or partially eliminate, without surgery, intraluminal vascular narrowing in the presence of peripheral arterial disease in stage II, III or IV. Prerequisite to the use of PTA are: 1. adequate fluoroscopic and angiographic facilities; 2. adequate instrumentation; 3. experience with at least 200 procedures; 4. knowledge of the pathophysiology and adjunctive treatment; 5. knowledge of the treatment of complications; 6. cooperation with a vascular surgery service. A number of factors may influence the results of treatment. Adjunctive medical treatment: the use of platelet aggregation inhibitors and heparin influences the rate of early rethrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)