[Optimizing staff radiation protection in radiology by minimizing the effective dose]. / Optimierung des Strahlenschutzes für das Personal in der Radiologie auf Grundlage der effektiven Dosis.

PURPOSE: In the present study the optimization of radiation protection devices is achieved by minimizing the effective dose of the staff members since the stochastic radiation effects correlate to the effective dose. MATERIALS AND METHODS: Radiation exposure dosimetry was performed with TLD measurements using one Alderson Phantom in the patient position and a second phantom in the typical position of the personnel. Various types of protective clothing as well as fixed shields were considered in the calculations. RESULTS: It was shown that the doses of the unshielded organs (thyroid, parts of the active bone marrow) contribute significantly to the effective dose of the staff. Therefore, there is no linear relationship between the shielding factors for protective garments and the effective dose. An additional thyroid protection collar reduces the effective dose by a factor of 1.7 - 3.0. X-ray protective clothing with a 0.35 mm lead equivalent and an additional thyroid protection collar provides better protection against radiation than an apron with a 0.5 mm lead equivalent but no collar. CONCLUSION: The use of thyroid protection collars is an effective preventive measure against exceeding occupational organ dose limits, and a thyroid shield also considerably reduces the effective dose. Therefore, thyroid protection collars should be a required component of anti-X protection.

Acute pancreatitis in obstructive jaundice following combined internal and external percutaneous transhepatic bile duct drainage (PTBD).

Percutaneous transhepatic biliary drainage (PTBD) was performed on 85 patients with obstructive jaundice. Four patients developed an acute pancreatitis after internal drainage of which one died. To our knowledge this serious complication has not yet been described in detail. These four cases are, therefore, reported and the possible causes are discussed.

[A new mathematical method for the radiological determination of total lung capacity]. / Ein neues Rechenverfahren zur radiologischen Ermittlung der totalen Lungenkapazität (TLC).

Various radiological methods for estimating lung volume depend on anatomical correlation with the volume of the thorax. It is not possible to derive general factors for correcting these methods and the accuracy and reliability can be improved only by introducing individual corrections. It must also be remembered that radiometric calculations of gas volume and lung capacity depend on the assumption that there is a fixed relationship between these. This, however, is untrue for a whole series of patho-physiological circumstances. Because of these problems, we describe our own radiometric method.

[Suprapapillary instead of transpapillary bile duct drainage in proximal bile duct obstructions]. / Suprapapilläre anstelle transpapillärer Gallenwegsdrainage bei hochsitzenden Gallenwegsobstruktionen.

The transpapillary passage of a catheter for internal biliary drainage may produce complications due to reflux or acute pancreatitis. A review of 573 biliary obstructions due to malignant tumours showed that in half the obstruction lay in the proximal two-thirds of the biliary passages. Fibrous strictures are nearly always in this region. In these patients, suprapapillary instead of transpapillary internal biliary drainage can be used, thereby maintaining the physiological relationship in the papilla. For this purpose we use a specially designed catheter which meets the requirements of suprapapillary internal drainage.

[The determination of the surface and organ doses in the AMBER system. Advanced Multiple Beam Equalization Radiography]. / Bestimmung von Oberflächen- und Organdosen am AMBER-System.

Surface and organ doses were determined by means of thermoluminescence dosimetry with the Alderson-Rando phantom and the patient, for the AMBER thoracic imaging system, sensitivity class 400, and the conventional grid screen stand, sensitivity class 200. The dose on entering the body, which varied according to object-dependent modulation of x-ray intensity, was 140 microGy for the mediastinum and 96 microGy for the lung in p.a. AMBER takes, and hence was comparable with the entrance dose of 132 microGy with the conventional grid screen stand. In lateral takes the entrance doses were lower with the AMBER system (302 microGy) than with conventional takes (593 microGy). Exposure of the gonads at the AMBER system for p.a. thoracic takes was lower than at the screen grid stand in females (4-6 microGy). More unfavourable values were measured for the gonad exposure in males (2-0.8 micrograms).

[I.v. DSA in the diagnosis and follow-up of thoracic aortic dissection]. / I.v. DSA zur Diagnostik und Verlaufskontrolle der thorakalen Aortendissektion.

Intravenous DSA was performed in 53 patients with suspected dissection of the thoracic aorta and in 13 patients following surgery for aortic dissection. In 36 patients, the suspected diagnosis could be excluded definitely and, in 14 cases out of 17, a dissection was correctly diagnosed. All 11 type B dissections were correctly diagnosed. Of six type A dissections, only three were adequately demonstrated by IV DSA. In type B dissections, IV DSA is reliable, but in type A dissection with massive aortic insufficiency or pericardial tamponade the findings are not reliable. In all 13 patients who had surgery for dissection, IV DSA proved suitable for showing the anastomosis and progress of the disease.

[Percutaneous transluminal irradiation of biliary tract cancer using iridium]. / Perkutan transluminale Bestrahlung von Gallenwegskarzinomen mit Iridium.

In ten patients with biliary carcinomas, percutaneous biliary drainage was instituted and intracavitary irradiation performed, using 192iridium with a dose of 40 to 80 Gy. Eight of these patients had been found to be inoperable at laparotomy and two had had a recurrence. In half the patients there was a reduction in the degree of stenosis due to the tumour, but in only one patient was it possible to remove the draining catheter. Survival time in eight patients was between one and eight months, average 5 months. Two patients survived for eleven and twelve months respectively. The relatively poor results are due to extensive metastases. On the other hand, there can be no doubt about the effectiveness of this treatment on locally confined tumours, in view of the reduction in the obstruction caused by the tumour.

[Peripheral venous DSA of the calf arteries in arterial obstructive disease patients. A comparison with conventional angiography]. / Periphervenöse DSA der Unterschenkelarterien bei AVK-Patienten. Vergleich mit der konventionellen Angiographie.

The ability of venous DSA to demonstrate the calf vessels distal to the trifurcation in patients with proximal blocks was compared with conventional angiography in 33 patients (44 limbs) in a study carried out by four observers. In 11.1% cases, the vessels were demonstrated better by DSA and in 2.5% by conventional angiography. In 86.4% the quality was the same. The reasons for this are analysed.

[Peripheral venous digital subtraction angiography in the follow-up of aortocoronary venous bypass grafts]. / Peripher venöse digitale Subtraktionsangiographie (DSA) zur Kontrolle von aortokoronaren Venenbypassgrafts (ACVB).

36 patients with 68 aorto-coronary venous bypass grafts (45 of which were angiographically patent) were examined via DSA (DV12V, serial mode, Philips) and angiography. Imaging was triggered via R waves, and effected in RAO 30 degrees, LAO 60 degrees, and AP projection. 63 of the 68 grafts were correctly detected (92.7%). Two anterior interventricular branch grafts (RIVA = ramus interventricularis anterior) were not visualised via DSA (95.6% sensitivity). One graft each to the RIVA, to the right coronary artery (RCA), and to the posterior branch of the lateral cutaneous branches of intercostal arteries (PLA), were falsely found to be patent (87% specificity). Grafts were visualised in full length. In some cases morphological changes of the walls were also visible.

[Clinical experience with mammography using grids (author's transl)]. / Klinische Erfahrungen mit der Raster-Mammographie.

Duplicate examinations were carried out on 122 patients in order to compare the results of mammography using a grid technique (Diagnost U. Müller) with a film-screen systemadn also a conventional set without screens (Mamma-Diagnost, Müller). The results were compared with reference to film quality and dose. The new technique was superior to the conventional method in all respects, independent of the size of the gland. Another advantage of the grid technique was the larger available film size. Dose requirements for grid mammography with a film-screen system was less than for conventional techniques by a factor of about 1.8. The results speak for increased use of the grid technique in clinical practice.

[Mesenteric vein thrombosis following percutaneous transhepatic portal vein catheterization for the localization of an insulinoma]. / Mesenterialvenenthrombose nach perkutantranshepatischer Pfortadersondierung (PTP) bei der Lokalisationsdiagnostik eines Insulinoms.

The authors report on a fatal mesenteric vein thrombosis following an uncomplicated percutaneous transhepatic portal vein catheterisation for the localisation of an insulinoma. Several hours after the procedure the patient developed an acute abdomen. An emergency laparotomy revealed a haemorrhagic infarct of the ileum. The resected specimen showed an acute phlebitis with fresh thrombus. The cause of the phlebothrombosis was thought to be intimal damage from high osmolar contrast medium. There was no evidence of damage due to the catheter, either on the phlebogram or pathologically.

[Digital subtraction angiography for the follow-up control of percutaneous transluminal angioplasty using a scoring system]. / Digitale Subtraktionsangiographie (DSA) zur Verlaufskontrolle der perkutan-transluminalen Angioplastie (PTA) unter Verwendung eines Scoresystems.

Seventy-two patients were examined by venous DSA following angioplasty, 28 of these within three weeks and 44 six months to three years after the procedure. The resolution of the DVI 2 V is adequate for showing reparative changes after dissection in the short-term follow-up. Demonstration was sufficient to enable one to use a coding system which classified the type and severity of the vascular changes. Clinical and angiographic follow-up showed good agreement regarding the amount of improvement obtained; in these patients, clinical follow-up alone is adequate. Where there has been no change in the clinical state or if there has been deterioration, a DSA examination should be carried out in order to ascertain the reason for the lack of improvement.

[A comparison of radiology and endoscopy in the diagnosis of gastric and duodenal ulcers(author's transl)]. / Vergleichende röntgenologische und endoskopische Diagnostik des Ulces ventriculi und duodeni

The results of endoscopy and radiology were compared in 455 patients, 250 with gastric ulcers and 205 with duodenal ulcers. Accuracy of endo- scopy for gastric ulcers was 95% and for duodenal ulcers 92%. Findings were judged on the results of endoscopy. The radiological findings were related to the endoscopic diagnosis and radiological examinations were carried out on out-patients as well as in-patients. 20% of gastric ulcers in out-patients were missed, and 10% of those in in-patients. Of duodenal ulcers, 27% of out-patients and 8% of in-patients were missed. Gastric ulcers missed radiologically were usually small or superficial and situated predominantly in the upper third of the stomach or in the antrum. Duodenal ulcers tended to escape radiological diagnoSIS if they were linear in shape. Improved technique and greater experience of the examiner increased the radiological accuracy significantly.

[The radiological diagnosis of non-calculous biliary duct obstruction (author's transl)]. / Röntgenologische Kriterien nicht steinbedingter Gallengangsobstruktionen

A diagnosis of obstructive biliary duct disease was achieved in 80% of 63 patients using endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous trans-jugular cholangiography (PTJC) alone or in combination, and taking account of the clinical features. In obstructions of themajor intrahepatic ducts and of the hepatic ducts (type I) a smooth occlusion indicated a carcinoma. Narrow forms of stenoses could not be differentiated, but with a history of previous operation, fibrous strictures were most likely. Obstructions at the point of confluence (type II) showed smooth narrowing if due to fibrous strictures, whereas carcinomas produced an irregular termination. Obstructions of the common bile ducts (type III) resembled those of type II. A smooth termination within the pancreas indicates a pancreatic carcinoma. Inflammatory disease in the head of the pancreas usually produces a tubular stenosis, while cysts of the pancreas result in smooth impressions and displacement.

[Computer tomography (CT) in the choice of treatment and the planning of percutaneous transhepatic biliary drainage in obstructive jaundice due to tumour (author's transl)]. / Computertomographie (CT) beim tumorbedingten Verschlussikterus zur Therapieentscheidung und zur Planung der perkutantranshepatischen Gallenwegsdrainage (PTCD).

We have performed percutaneous transhepatic biliary drainage on 27 patients; of these, thirteen were examined by CT before and after the procedure. Our experience suggests that CT or sonography is indicated every case of obstruction due to tumour in order to: 1. Decide on treatment by a non-invasive method thereby saving the patient an unnecessary laparotomy and 2. Plan the biliary drainage accurately, leading to the lowest possible number of complications.

[Percutaneous transhepatic portal vein catheterisation in the diagnosis of hormone-producing tumours in the splanchnic area (author's transl)]. / Perkutan-transhepatische Pfortadersondierung (PTP) zur Diagnostik hormonproduzierender Tumoren im Splanchnikusgebiet.

During 1980, percutaneous transhepatic portal vein catheterisation was carried out in eight patients with suspected hormone-producing tumours in an attempt to localise these. Seven patients with hyperinsulinism were suspected of having an insulinoma and one a gastrinoma. There were no complications following the catheterisation, and difficulties were reduced by the use of a special catheter. The blood samples were examined by radio-immunological methods for insulin or gastrin. On the basis of localised rise in hormone level, it was possible to diagnose three insulinomas and one gastrinoma in the pancreas. The beta-cell tumours were removed by enucleation or segmental resection, the gastrinoma by a Whipple's operation. Three patients showed an insulin gradient and sub-total pancreatectomies were performed. In one patient there was no definite abnormality in the insulin level and an operation has so far not been performed. Our experience indicates that this technique is difficult, bu is nevertheless a reliable method for localising hormone-producing tumours and surgery should not be carried out without it.

[Thoracic radiography in intensive care units. Comparison of an asymmetric film-screen-grid combination with an L-film]. / Thoraxaufnahmen auf der Intensivstation. Vergleich einer asymmetrischen Film-Folien-Raster-Kombination mit einem L-Film.

PURPOSE: Using an asymmetrical screen-film-grid combination with an ITC-VHC special grid (Kodak), the effect of the individual components was evaluated with regard to detail in the lungs and mediastinum as well as patient dose. MATERIALS AND METHODS: The system was compared with the Curix Ortho screen film system (Agfa L-film) using phantoms and 62 patients in an intensive care unit. The results were analysed by three independent observers. Dose measurements on phantoms were carried out with a WD 10 (Wellhoefer) dosimeter and with a thermoluminescence dosimeter for patients. RESULTS: Both phantom and patient images showed improved demonstration of mediastinal structures with similar details of lung structure. Details in the peripheral lungs are significantly better shown with the ITC-VHC system with the special grid than they are without the grid. However, there is an increase about three to four times in radiation dose when using the grid. CONCLUSION: Our trial shows that the use of the ITC-VHC grid system is to be recommended for routine clinical use because of the better demonstration of details, but one must be aware of the increased radiation dose to the patient.

[Transjugular puncture of the portal vein. Portography and selective phlebography of abdominal organs. An experimental study in dogs (author's transl)]. / Transjugulare Pfortaderpunktion, Portographie und selektive Phlebographie viszeraler Organe. Eine experimentelle Studie am Hund

Transjugular transhepatic portography is a new method for catheterising the portal vein and its tributaries. In order to gather experience of the method before applying it clinically, the transvenous approach was studied in six dogs. Transjugular portography has the following advantages as compared with umbilical vein catheterization and percutaneous, transhepatic portal vein catherterisation: 1. Because of the relative positions of the jugular veins, vena cava and portal vein, manipulation of the catheter for selective phlebography is simpler. 2. There is no risk of a haemoperitoneum or bile peritonitis if a correct technique is used since the liver capsule remains intact. 3. In the presence of portal hypertension, it may be possible in future to create an intrahepatic portocaval shunt by the transjugular approach without a major operation. Sclerosis of oesophageal varices is possible, as it is with the other procedures.

[The accuracy of radiological and endoscopic examinations in the diagnosis of carcinoma of the stomach (author's transl)]. / Aussagewert röntgenologischer und endoskopischer Untersuchungen beim Magenkarzinom

The accuracy of radiology in the diagnosis of gastric carcinomas was checked on 232 cases, including 24 early examples. Accuracy depends most of all on the experience of the radiologist. Amongst 146 patients, using a satisfactory technique, a carcinoma was diagnosed in 131 patients (90%) and suspected in eight (6%). In five (3%) the changes were misinterpreted as being benign and the lesion was missed in two (1%). Of 120 gastric carcinomas submitted to operation a correct diagnosis had been made radiologically in 88% and suspected in 4%; endoscopically, the diagnosis was made in 92% and suspected in 2%. Of the 24 early carcinomas, both methods suggested the presence of a malignant lesion in 80%. The combination of radiology, endoscopy, hitology and cytology increases accuracy to 95%. These results indicated that localised changes in the gastric mucosa and the wall of the stomach can be demonstrated only by using refined radiological techniques; each lesion should be confirmed by endoscopy and histology.

[Phantom measurements of blood flow using color-coded Doppler sonography (Quantum Angiodynograph): accuracy and sources of error]. / Phantommessung des Blutflusses mit der farbkodierten Doppler-Sonographie (Quantum Angiodynograph): Genauigkeit und Fehlerquellen.

Flow measurements were carried out on a phantom simulating tissue, using systematic variations of various parameters and of relevant geometric factors. The effect of imaging and flow parameters on the accuracy of the measurements is described and the conditions are defined which are necessary for obtaining a high degree of accuracy. Large errors are introduced by measurements carried out with large Doppler angles or if the delimiters used for automatic vessel measurements have not been set up accurately.