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Biomedical subjects

B Kramann

Publications and source records attributed to B Kramann.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Radiation exposure in abdominal radiography with digital luminescence radiography and conventional screen-film system: an experimental animal study].

PURPOSE: To determine and compare the minimum required radiation exposure for a.-p. abdominal radiographs with digital luminescence radiography (DLR) and a screen-film system (SFS) providing adequate image quality in clinical routine. MATERIAL AND METHOD: Abdominal radiographs a.-p. of a pig were produced with DLR and SFS systematically varying the tube current-time product. The image quality was assessed by eight experienced radiologists according to the criteria of visual resolution, mean optical density, perceptibility of the lateral edge of the psoas, the caudal edge of the liver, bone structures and intestinal wall. RESULTS: The image quality of the digital radiographs was better for each criterion except visual resolution if the same current-time product was used for both techniques. From the minimum tube current-time products providing an adequate image quality it follows that a dose reduction of 57% can be achieved by applying DLR instead of speed class 200 SFS. CONCLUSION: The recently published guide-lines for quality assurance in x-ray diagnostics issued by the German Federal Board of Physicians recommend using speed class 400 SFS. Since in that case an approximately halved radiation dose is necessary, dose reduction is hardly to be expected with DLR.

Animals↗
PubMed1996

A study of dose reduction using digital luminescence radiography for lateral skull radiography.

For lateral skull radiography the minimum required radiation patient exposure to ensure adequate image quality was determined for digital luminescence radiography (DLR) in comparison with a screen-film system (speed class 200). Radiographs were produced with a grid technique on conventional X-ray equipment. A real prepared female head including a true fracture above the pars petrosa ossis temporalis was imaged. The tube current-time product (mAs), and thus the surface entrance dose, was varied systematically. Surface entrance dose was measured with TLD-100 rods. Image quality was judged by experienced radiologists according to the criteria: visual resolution, mean optical density, contrast and perceptibility of specific bone structures. Surface entrance dose was reduced from 0.46 to 0.20 mGy by application of DLR instead of speed class 200 screen-film system without loss of diagnostic information in clinical routine. This corresponds to a dose reduction potential of 57% showing a good agreement with the dose reduction potential of 52% obtained in a previous study using the Alderson head phantom.

Female↗
PubMed1996

[Endovascular therapy of visceral aneurysms].

Sixteen cases of endovascular treatment of aneurysms and pseudoaneurysms were reported; five patients had true aneurysms, 11 presented pseudoaneurysms of splanchnic arteries. In all cases embolization was performed with coils; in one case we used coils in combination with Ethibloc. In 14 of 16 patients definite occlusion of the aneurysms was achieved without further surgical intervention.

Adult↗
PubMed1995

[Proton spin tomography of the orbit in post-traumatic motility disorders].

AIM: To analyse the value of MRI for the assessment of posttraumatic disturbances of eye motility. MATERIAL AND METHODS: We analysed retrospectively the results of 38 MR examinations of the orbit in 31 patients with posttraumatic motility impairment with preserved visus. 18 patients underwent MRI preoperatively. From this group 5 patients were additionally examined postoperatively. Another 5 patients who had not been examined prior to surgery were controlled postoperatively. Hence, a total of 10 patients with persisting disturbances was examined postoperatively. 8 patients who underwent MRI were not treated by surgery because of only minor disturbances. In all patients conventional radiography of the orbit was performed prior to MRI. Additional CT imaging was carried out in 12 patients. RESULTS: In 18 patients examined preoperatively we found displacement of orbital fat tissue, displacement and entrapment of orbital muscles, swelling of muscles and oedema in retrobulbar fat tissue. 10 patients from the postoperative group exhibited remaining prolapsed fat tissue, oedema in fat tissue and/or swelling of muscles. 8 patients had only small soft tissue changes which did not require surgery. CONCLUSION: Since it can image soft tissue precisely, MRI provides the decisive information in the assessment of motility impairment of the eye. In case of isolated orbital fracture with motility impairment, CT is not absolutely necessary for surgical therapy.

Adolescent↗
PubMed1995

[Experiences with the endovascular embolization therapy of aneurysms of the splanchnic arteries--a report on 13 cases].

PURPOSE: The authors report on their experience in endovascular embolization therapy in 13 cases with splanchnic artery aneurysms or pseudoaneurysms. PATIENTS AND METHODS: Three patients suffered from true aneurysms, ten patients presented pseudoaneurysms of different origin. Eight patients were transferred to our department for life-threatening intestinal bleeding. Five patients showed transpapillary bleeding, four of whom presented with haemobilia and one patient had intermittent bleeding into the pancreatic duct due to a true aneurysm of the splenic artery. Embolization was performed using a coaxial microcatheter coil delivery system. In 4 patients the aneurysm-bearing vessel was temporarily blocked during the intervention. RESULTS: In 11 patients definite occlusion of the aneurysm was obtained without surgical intervention. In one patient, suffering from a splenic aneurysm, we observed a partial inadvertent embolisation of the spleen which did not require further treatment. In one case, rupture of an hepatic aneurysm during embolization occurred. One patient with pseudoaneurysm due to displacement of a port catheter showed severe rebleeding one day after embolisation. CONCLUSION: Transcatheter embolization is an effective method for treatment of aneurysms of the splanchnic arteries. To avoid life-threatening bleeding due to rupture of the aneurysm, the feeding vessel should be temporarily blocked during embolization therapy.

Adult↗
PubMed1993

[Pseudoaneurysms of the femoral artery--noninvasive diagnosis and compression therapy].

In 8 patients with pseudoaneurysms of the femoral artery, diagnosis and possible nonsurgical treatment is presented: After primary clinical diagnosis and color-Doppler or angiographic confirmation, aneurysms of less than 5 cm in diameter are treated by manual or color Doppler-supported compression. Within 9 to 36 min the lumen is occluded, remaining closed even in controls up to 12 months.

Aneurysm, False↗
PubMed1993

Oncogenic osteomalacia: imaging studies.

X-ray und NMR imaging studies of a 34-year-old patient with tumor-induced hypophosphatemic osteomalacia (OM) are presented. Besides typical features of OM, periosteal new bone formation was noticed initially. After 17 months of conservative treatment with supplements of inorganic phosphorus and 1,25-dihydroxyvitamin D, bone density had increased but Looser's zones were still present, while periosteal new bone formation was strikingly less evident. At this time a tumor in the first left metatarsal space became palpable, was surgically excised and proved to be a low-grade synovial sarcoma with hypervascular and partially calcified structures. Six months later an X-ray survey showed no more signs of metabolic osteopathy. Preoperatively, the pronounced vascularity of the tumor could be demonstrated by angiography and NMR scanning.

Adult↗
PubMed1992

[Intra-arterial calcium provocation for the preoperative diagnosis of the location of an occult insulinoma].

Blood-sugar levels below 40 mg/dl were measured during syncope in two female patients (aged 59 and 73 years). Suspected organic hyperinsulinism was confirmed by a fasting test. Ultrasound examination and computed tomography failed to demonstrate an insulinoma. Coeliacomesentericography was then undertaken together with a selective intra-arterial calcium provocation test of the pancreas (0.4 or 0.5 mmol calcium in physiological saline was injected into the pancreas-supplying arteries--proximal and distal splenic, superior mesenteric and gastroduodenal). The insulin level was determined in simultaneously obtained hepatic venous blood. In case 1, the insulin level rose tenfold after calcium injection into the proximal splenic artery, indicating a process in the body of the pancreas. In case 2, a steep rise in insulin occurred after injection into the truncus coeliacus and the proximal and distal splenic artery, suggesting an insulinoma in the tail of the pancreas. The site of the insulinoma was confirmed in both cases at surgery. The adenoma was enucleated in case 1, removed by partial resection of the tail of the pancreas in case 2.--These observations show that occult insulinomas can be localized preoperatively by intraarterial calcium injection with measurement of insulin concentration in simultaneously obtained hepatic venous blood.

Aged↗
PubMed1992

[The diagnosis of bone marrow lesions in the MR tomogram in children with diseases of the hematopoietic system with special reference to post-therapy changes].

119 MR-examinations of both tibiae, knees and the lower part of both femur were performed in 41 children suffering from bone marrow disease (27 ALL, 4 AML, 3 NHL, 1 agranulocytosis, 6 anaemia). T1- and T2-spin-echo sequences and a T2-gradient-echo sequence were used. Bone marrow changes in leukaemia were diffuse before therapy and patchy after therapy. Due to their different signal in T2-weighted images, differentiation of the post-therapeutic patchy findings into infiltrations, fibrosis, necrosis and siderosis seems to be possible. In future, MRI will be the method of choice for screening and controlling bone marrow disease if the examination time is shortened by using only a T1-spin-echo sequence and a T2-gradient-echo sequence.

Adolescent↗
PubMed1992

[MR tomography of the lower limbs of children with diseases of the hematopoietic system].

In 41 children with disorders of the hematopoetic system 119 MR examinations of both tibiae and knees were performed (T1 and T2 spin-echo sequences and a T2 gradient-echo sequence). Before therapy bone marrow changes in leukemia were diffuse, and patchy during and after therapy. Signals in T2-weighted images were different for infiltrations, fibrosis, necrosis and siderosis. In 3 children suspected of suffering from osteomyelitis, Ewing-sarcoma or coxitis, MR examination was the first to show the correct diagnosis. Therefore in children indications for MR tomography should be handled more generously to win time for therapy. Using only a T1 spin-echo sequence and a T2 gradient-echo sequence screening of more than one region is capable of controlling bone marrow diseases.

Acute Disease↗
PubMed1992

[Radioimmunoscintigraphy and magnetic resonance tomography in the diagnosis of urinary bladder cancer].

Magnetic resonance tomography is a method which is sufficiently precise to demonstrate morphological changes for tumor staging of carcinoma of the urinary bladder. The stage of the tumor was correct in 68 resp. 86% of the patients. The RIS shows organ and lymph node metastases and has the capability to differentiating between scar and tumor after transurethral resection. The local spread, especially the infiltration depth of the tumor, is not visible. In 90% of the patients a primary tumor was detected, only in 5 cases a false-negative and in 2 cases a false-positive finding was made.

Adult↗
PubMed1990

[The multicentric glioblastoma multiforme].

The authors report on two cases of multicentric glioblastoma multiforme, one of them being a trilocular glioblastoma, whereas in the second case a second focus developed contralaterally. Both patients received whole skull radiation of 40 Gy. The patient who suffered from the primarily unilocal tumour was given a tumour boost. The article reports on the imaging via CT and MR.

Brain Neoplasms↗
PubMed1990

[Early and late results of PTA in relation to the patient's age].

506 cases of percutaneous transluminal angioplasty performed between 1983 and 1988 in the iliac, femoropopliteal and crural segments were analyzed with special consideration of the patients' age. The early results were significantly worse only in the age group over 70. The late results were evaluated by the life table method. Relapses within the first 6 months occurred in 13.8% of the patients over 60 and in 8.2% of the younger age group (under 60). After 12 months, however, no significant difference was observed between the two age groups. The rate of complications (overall value 7.9%) was twice as high in the geriatric age group than among the younger patients. Type and extent of the occlusion, clinical stage and run-off conditions determine the early and late results.

Age Factors↗
PubMed1989

[Diagnosis of postpartum complications using CT and MRT].

Severe puerperal infections, iliacal and ovarian vein thrombosis are post-partum complications which are potentially life-threatening. They require prompt medical treatment. CT and MR enable diagnosis by noninvasive methods.

Female↗