Biomedical subjects

A Stäbler

Publications and source records attributed to A Stäbler.

At least 73 records · Page 4Linked to original sources

PubMed1996

Degenerative disk vascularization on MRI: correlation with clinical and histopathologic findings.

OBJECTIVE: This prospective study was designed to determine the MRI features, clinical significance, and correlation to histopathologic findings of secondary vascularized degenerative intervertebral disks. MATERIALS AND METHODS: Fifty-three patients with localized painful spine syndrome were investigated prospectively by contrast-enhanced MRI. Pain was not predominantly radiating and there was no clinical evidence of spinal infection. In all patients sagittal SE T1-weighted, fast SE T2-weighted or turbo-STIR, and T1-weighted frequency-selective fat-suppressed images were obtained. RESULTS: We identified 37 vascularized disks in 26 patients. In 18 patients the changes had occurred spontaneously, in 6, the affected disk had been operated on previously, and 2 patients had spondylolisthesis. In 15 patients, vascularization was accompanied by medullary edema adjacent to the vertebral endplates. In one of the vascularized disks, herniation was also found. In seven patients, ventral diskectomy was performed. Histopathologic findings confirmed disk vascularization in six of seven cases. CONCLUSIONS: Degenerative, band-like disk vascularization is a feature which is associated with local pain. It was demonstrated by contrast-enhanced MRI. Degenerative disk vascularization is an important differential diagnosis to bacterial spondylodiskitis. It can be a cause of pain in patients with postdiskectomy syndrome.

Diagnosis, Differential↗

PubMed1996

[Infiltration patterns of plasmacytomas in magnetic resonance tomography].

PURPOSE: To define the different infiltration patterns in the spine in multiple myeloma, in correlation with histological and clinical findings. Quantitative signal evaluation with contrast media (Gd-DTPA). To compare the results in MRI with X-ray films. MATERIAL AND METHODS: 61 patients with proven multiple myeloma and 50 controls were examined (1.0 Tesla, T1-w SE, opposed phase GE images). RESULTS: Five infiltration patterns with different clinical stages were detected: normal bone marrow (11%) in cases of low interstitial marrow infiltration (biopsy), pure diffuse infiltration (25%), focal involvement (33%), combined diffuse/focal infiltration (23%) and a "salt-and pepper" pattern (8%). In diffuse plasmacytoma the 40% signal intensity increase was modification of diffuse infiltration. MRI proved to be more sensitive than radiography. CONCLUSION: MRI is able to show the type and the extension of bone marrow infiltration in multiple myeloma. Diffuse involvement can be objective with gadopentetate dimeglumine.

Adult↗

PubMed1996

Sternoclavicular joint: MR imaging--anatomic correlation.

PURPOSE: To correlate magnetic resonance (MR) images of the sternoclavicular joint with anatomic sections. MATERIALS AND METHODS: MR imaging was performed on 14 sternoclavicular joints in seven specimens from cadavers (three men and four women 64-94 years of age at death; mean, 84 years). MR arthrography was performed in four specimens (eight joints), after injection of gadopentetate dimeglumine. After imaging, the specimens were frozen and cut into 3-mm-thick slices along the MR imaging planes. Images were correlated with the anatomic slices. RESULTS: MR imaging depicted the anatomy of the sternoclavicular joint and surrounding soft tissue. T2-weighted and proton-density-weighted images were superior to T1-weighted images in depiction of the intraarticular disk. MR arthrography depicted best the intraarticular disk and four of five perforations and delineated the joint capsule. All perforations also were depicted on T2-weighted images. CONCLUSION: MR imaging allows delineation of all structures of the sternoclavicular joint. MR arthrography allows delineation of perforations of the intraarticular disk.

Aged↗

PubMed1996

Enlargement of the third intercondylar tubercle of Parsons as a sign of osteoarthritis of the knee: a paleopathologic and radiographic study.

PURPOSE: To correlate presence and size of the third intercondylar tubercle of Parsons (TITP) with occurrence and severity of osteoarthritis of the knee. MATERIALS AND METHODS: In 100 paleopathologic tibial specimens and on 160 clinical knee radiographs, size of the TITP was correlated with osteoarthritis of medical and lateral femorotibial joints (FTJ) and with prominence of tibial spines. RESULTS: TITP size correlated significantly with osteoarthritis of the tibial plateau in the paleopathologic specimens (P<.0001). TITP size correlated significantly with osteoarthritis of medial FTJ and tibial spines on radiographs (P<.0001). Of 85 patients without osteoarthritis of the medial FTJ, 49 (58%) had no TITP, 33 (39%) had small TITPs, and three (4%) had medium or large TITPs. TITPs were found in 15 (88%) of 17 patients with pronounced osteoarthritis. CONCLUSION: Frequency and prominence of TITPs are increased in patients with osteoarthritis of the medial FTJ and prominent tibial spines. Prominent TITP is a secondary sign of osteoarthritis. At histologic examination, increasing size of TITPs represents osteophytosis or enthesopathy of the TITP.

Adolescent↗

PubMed1996

Contrast enhancement and quantitative signal analysis in MR imaging of multiple myeloma: assessment of focal and diffuse growth patterns in marrow correlated with biopsies and survival rates.

OBJECTIVE: This study describes infiltration patterns of multiple myeloma in spinal MR imaging and correlates the findings with biopsies, survival rates, and signal intensity measurements in unenhanced and enhanced studies. MATERIALS AND METHODS: Fifty-three patients with multiple myeloma and 53 age-matched controls underwent MR imaging of the spine. Twenty-nine patients underwent sagittal T1-weighted spin-echo enhanced imaging and all patients underwent sagittal T1-weighted spin-echo unenhanced and opposed-phase gradient-recalled echo images, and signal intensity measurements were taken. MR imaging was correlated to marrow specimens (n = 40) and a clinical staging system. The probability of survival was also calculated. Finally, we performed qualitative visual evaluation (infiltration pattern, degree of tumor involvement) and a quantitative evaluation (marrow signal intensity ratios, contrast enhancement). RESULTS: Five infiltration patterns were found: normal-appearing marrow with low-grade interstitial infiltration (n = 5), focal (n = 18), diffuse (n = 12), focal and diffuse (n = 13), and salt-and-pepper (n = 5). Infiltration pattern correlated with clinical staging; all patients with normal-appearing and salt-and-pepper patterns were clinically stage I. Diffuse marrow infiltration was assessed by marrow ratios: low-grade infiltration, greater than 2.0; intermediate, 1.0-2.0; highgrade, less than 1.0. Contrast enhancement with a signal intensity increase greater than 40% indicated diffuse infiltration. In the control group, all of whom had no marrow disease, enhancement varied (mean +/- SD, 16% +/- 8.9%) but did not exceed 40%. Marrow involvement on MR images correlated significantly with clinical staging and survival (p < or = .001). CONCLUSION: MR imaging with opposed gradient-recalled echo sequences and contrast enhancement provided data that allowed us to classify infiltration patterns and to quantify diffuse marrow involvement in multiple myeloma, both of which correlated to clinical staging and biopsy. Also, the MR data was of prognostic value. Therefore, like laboratory parameters, biopsies, and radiographs, MR imaging can be a supporting pillar in staging and planning treatment of patients with multiple myeloma.

Adult↗

PubMed1995

Diagnostic accuracy of ultrasound and computed tomography in the staging of Hodgkin's disease. Verification by laparotomy in 100 cases.

BACKGROUND: A staging laparotomy still is considered the gold standard to detect occult abdominal involvement in Hodgkin's disease. Computed tomography and ultrasound are routinely available for diagnostic imaging. To the authors' knowledge, the exact contribution of ultrasound for the staging of Hodgkin's disease has not been reported in a large series of patients before this study. METHODS: The diagnostic accuracy of abdominal ultrasound was compared with that of computed tomography and laparotomy in 100 patients with biopsy-proven Hodgkin's disease. Liver, spleen, paraaortic, and iliac lymph nodes were evaluated separately. RESULTS: Seventeen patients had a higher disease stage after surgery (17%). Considering only patients without known abdominal disease (supradiaphragmatic involvement), 14/79 (18%) had a positive staging laparotomy. Ultrasound had superior sensitivity for detecting splenic involvement with Hodgkin's disease (sensitivity, 63% compared with 37% for computed tomography). The specificity of both methods for detecting splenic disease was identical (99% vs. 96%). Inhomogeneities of structure or small nodular infiltrates were detected preferentially by ultrasound. Hepatic involvement also was visualized better by ultrasound than by computed tomography. Lymph nodes at the splenic hilus were recognized by both methods with identical sensitivity (64% vs. 62%). Paraaortic and iliac lymph nodes were recognized with greater sensitivity by computed tomography than by ultrasound (sensitivity, 93% and 100% vs. 77% and 67%, respectively). CONCLUSIONS: These results indicate that ultrasound and computed tomography each have their weaknesses and strengths and therefore should be combined, if possible. Ultrasound is the fastest and least invasive method and has particular accuracy for detecting splenic involvement, whereas computed tomography is more accurate in detecting involvement of paraaortic or iliac lymph node. If cost is important in the staging of Hodgkin's disease and if computed tomography is considered the standard, patients whose results are negative by computed tomography should be examined by ultrasound, focusing on splenic texture and size. Even in the era of combined modality treatment, surgical staging may be necessary to detect occult abdominal disease in a certain number of cases.

Abdominal Neoplasms↗

PubMed1995

Vacuum phenomena in insufficiency fractures of the sacrum.

OBJECTIVE: Insufficiency fractures of the sacrum are found in women who have undergone radiation therapy to the lower abdomen as well as those suffering from osteoporosis of postmenopausal, steroid-induced, or primary biliary cirrhosis-related origin. Increased uptake in bone scintigraphy and osteolytic changes in these fractures can be misinterpreted as bone metastases, leading to unnecessary biopsies and other procedures in the ensuing search for non-existent primary tumor. PATIENTS: In eight female patients averaging 69.4 years of age, insufficiency fracture of the sacrum was diagnosed by computed tomography (CT) and bone scintigraphy. Three underwent a total of five MRI examinations. Malignancy was excluded by histology in two patients and follow-up of at least 6 months in the remainder. Retrospective analysis of CT scans of 13 patients with metastases in the sacrum revealed no vacuum phenomena. RESULTS: In seven of eight patients with insufficiency fracture of the sacrum, vacuum phenomena were shown on CT examination. The gas was localized centrally within the ventral part of the fracture in three patients; gas was located in ten adjacent sacro-iliac joints of six patients. CONCLUSIONS: The vacuum phenomenon may be an incidental finding in osteoarthritis of the sacro-iliac joint, but it has not been previously recognized in IFS. The presence of intra-articular vacuum phenomena in the sacro-iliac joints in combination with a sacral fracture and vacuum phenomena located within the sacral fracture supports a diagnosis of insufficiency fracture or may indeed be the clue by which this diagnosis is established.

Aged↗

PubMed1995

[The percutaneous treatment of surgical and catheter-angiographic vascular complications].

PURPOSE: Technical innovations of angioplasty have introduced new therapeutic options in the treatment of symptomatic arteriosclerotic disease. Atherectomy devices, aspiration catheters and vascular endoprostheses can be used not only for angioplasty purpose but also for correction of iatrogenic dissections and thromboembolic complications. MATERIAL AND METHODS: 54 patients with vascular complications after surgical (n = 7) and percutaneous (n = 47) interventions were observed in a 5 years period. The complications included acute dissections in 34 cases, acute thrombosis in 4 cases, distal embolism after angioplasty in 14 cases, and two cases with arterial rupture after balloon dilatation. RESULTS: 34 patients with dissections and 18 patients with acute thrombosis were treated. Stent implantation for repair of vessel dissection was successful in 33 of 34 cases. Percutaneous catheter aspiration in combination with local thrombolysis was successful in 4 cases with local thrombosis. Distal emboli after angioplasty were successfully removed using aspiration catheters in 13 of 14 patients. Vessel rupture after angioplasty was closed with prolonged balloon dilatation in two patients avoiding emergency surgery. CONCLUSION: Using newly developed intravascular technologies such as atherectomy, stents, and catheter aspiration, many iatrogenic complications after vascular surgery or vascular interventions can be treated. These technologies should be available in every radiology department performing angioplasty.

Acute Disease↗

PubMed1995

Diagnostic approach in acute pulmonary embolism: perfusion scintigraphy versus spiral computed tomography.

For diagnosing acute pulmonary embolism, perfusion scintigraphy in combination with ventilation studies is a well-established and sensitive method. Recently, computed tomography (CT) incorporating an angiographic technique was introduced for evaluating the pulmonary arterial system without breathing artefacts. The present study compared lung scans with spiral CT data to establish the diagnostic value of the latter approach. Twenty-five patients with a clinical suspicion of acute pulmonary embolism were examined using both methods. Perfusion and ventilation lung scans were done and spiral volumetric CT studies were performed. In 18 patients, pulmonary embolism was diagnosed using both methods. However, the results were interpreted differently. Particularly when centrally localized emboli were present in both pulmonary arteries, assessment of the more affected side was difficult on CT and depended on the experience of the physicians interpreting the scans. Small, (sub-)segmental emboli could not be demonstrated on CT. This may explain the false-positive and false-negative results, respectively. Spiral CT enables an exact demonstration of thrombosis in severe, centrally localized emboli. In incompletely occluded vessels, estimation of the degree and the location of perfusion defects is better with scintigraphy. Based on the present results and the technical equipment necessary for spiral CT, it is concluded that perfusion scintigraphy remains the method of choice for diagnosing acute pulmonary emboli.

Acute Disease↗

PubMed1995

Reproducibility of quantitative, spirometrically controlled CT.

Quantitative spirometrically controlled computed tomography (with 1-mm-thick sections) was performed twice (with a 5-minute break) in 24 adult patients with pulmonary disease to objectively evaluate parenchymal changes in the lung. Twelve measurements of attenuation were made on apical, carinal, and basal scans (right, left, total of each level, total right, total left, total of all three scans), obtained at 50% vital capacity. Since differences in measurements between the first and second examination were not significant, the method provides highly reproducible results.

Adult↗

PubMed1995

[Fatigue fractures of the sacrum in primary biliary liver cirrhosis].

Insufficiency fractures of the sacrum are found in women after radiation therapy of the pelvis and those suffering from postmenopausal and steroid-induced osteoporosis. We report two female patients with insufficiency fractures of the sacrum occurring on the basis of a primary biliary cirrhosis. Both patients had simultaneous Tarlow cysts of the sacrum. The fractures were diagnosed by computed tomography. The findings were sclerotic bone changes, running from the ventral and lateral parts of the lateral mass of the sacrum parallel to the adjacent sacro-iliac joints. These fractures exhibited increased uptake in bone scintigraphy and were responsible for local pain. In one of the patients, the bilateral fractures healed four months after transplantation of the liver was performed.

Female↗

PubMed1995

[Percutaneous transluminal angioplasty of arterial stenoses after kidney transplantation].

Over a period of 11 years, percutaneous transluminal angioplasty (PTA) was performed in 47 patients with post-transplantation renal artery stenosis. In 42 of 47 patients (89%) PTA was technically successful. Complications or technical failure (n = 5) were observed in the beginning of the series and were due to technical problems. Within a five-year follow-up period in 33 patients, blood pressure (BP) remained constant in 18% and mean pressure was improved in 48%. In 33%, normal BP was reached without any need for medication. Systolic and diastolic BP were reduced from 175.9/105.7 (mean values) before PTA to 146.9/91.0 six months after PTA. Depending upon the initial value, serum creatinine was reduced after PTA by from 0.0 to 1.0 mg/dl with noticeable difference between individual values. An account of this effect, renal function was of reduced value for controlling the effectiveness of PTA. The morphology of the stenoses corresponded only partially with the clinical results: in five patients mean BP after successful PTA remained constant, while two patients with reduced therapeutic result (remaining stenosis > 30%) had either markedly improved BP (n = 1) or normal BP (n = 1). The technical improvement of PTA instrumentation has broadened the spectrum of indications and improved the safety of the procedure.

Adolescent↗

PubMed1994

Rotatory palmar subluxation of the lunate in post-traumatic ulnar carpal translocation.

Post-traumatic ulnar carpal translocation is a rare, severe ligamentous injury to the wrist. Radiologic findings include widening of the radiocarpal joint space at the radial styloid process and ulnar displacement of the carpus. Less than 50% of the lunate articulates with the radius in the neutral position; the lunate is tilted dorsally with palmar subluxation due to a ruptured radio-scapholunate (RSL) ligament. This malposition should be called rotatory palmar subluxation of the lunate (RPSL), by analogy to rotatory subluxation of the scaphoid (RSS). In contrast to dorsiflexed intercalated segment instability (DISI), in RPSL the RSL ligament is ruptured and, in the majority of cases, the scapholunate ligament remains intact. A prompt diagnosis should lead to successful treatment.

Adolescent↗

PubMed1994

[The nuclear magnetic tomographic diagnosis of focal lesions of the red bone marrow. The optimization of the acquisition parameters for GE and SE sequences].

Gradient-echo (GE) imaging with repetition times equivalent to those of T1-weighted spin-echo (SE) sequences and echo times for antiphase (opposed) transverse magnetisation have proved to be sensitive for high contrast imaging of focal lesions of red bone marrow. The sensitivity of antiphase GE sequences is due to the chemical shift between water-bound and fat-bound protons which introduces a tissue parameter that is not accessible by SE sequences. Main advantage of these GE sequences is the low signal intensity of intact red marrow and the high signal intensity of tumours and inflammatory lesions which allows, similar to T2-weighted SE sequences, for positive contrast imaging of lesions. In order to evaluate and to optimise the contrast-to-noise ratio (CNR) for red bone marrow and tumour 200 GE and 40 SE sequences with repetition times (TR) between 100 and 900 ms, echo times (TE) between 14 and 21 ms and flip angles (alpha) between 10 and 90 degrees were studied. CNR was measured and optimized regarding TR, TE, and alpha. The results indicate that opposed GE sequences, relatively independent from TR and alpha, are characterized by a high contrast-to-noise ratio. According to their high sensitivity for lesion detection they are suited to replace T2-weighted SE sequences.

Artifacts↗

PubMed1994

[MRI in orthopedics: diagnosis of joint disorders].

For the visualization of joint structures, magnetic resonance imaging (MRI) has definite advantages over other imaging modalities. High soft tissue contrast and multiplanar capabilities contribute to adequate representation of the joints. With surface and special coils as well as high gradient field strengths, superior spatial resolution can be achieved, thus allowing for depiction of fine anatomical details. Newly developed pulse sequences, especially with fat suppression techniques and utilization of paramagnetic contrast agents (gadolinium complexes) have improved image contrast. Examination techniques, results and diagnostic value of MRI in various joints are discussed. Close cooperation between orthopaedic surgeons and radiologists is mandatory for effective and economically acceptable use of MRI in the diagnosis of joint disorders.

Ankle Joint↗

PubMed1994

[Ct-portography in diffuse liver steatosis. Potential for a false-negative assessment].

CT portography is the most sensitive technique currently available for the preoperative diagnosis of liver metastases. We report on a patient with liver steatosis in whom ultrasound examination revealed two liver metastases in the follow up after resection of a papillary carcinoma. The liver metastases could be clearly identified both on plain CT and on enhanced CT with dynamic bolus contrast medium injection. Because of the small difference in attenuation values between liver parenchyma and metastases the two liver metastases had not been recognized on CT portography. When severe and diffuse liver steatosis is present CT portography may fail to detect metastases or small hepatocellular carcinoma.

Adult↗

PubMed1993

Reversible hyperkinesia in a patient with autoimmune polyglandular syndrome type I.

Autoimmune polyglandular syndrome is characterized by a failure of multiple endocrine organs and the presence of circulating organ-specific autoantibodies targeted against the failing organs. Here we describe a patient with autoimmune polyglandular syndrome type I with the endocrine manifestations of hypoparathyroidism, adrenocortical insufficiency, and insulin-dependent diabetes mellitus. Long-standing hypoparathyroidism led to extensive calcification of the basal ganglia which resulted in the clinical presentation of an extrapyramidal movement disorder (choreoathetotic and hemiballistic hyperkinesia of the left extremities). Interestingly, parallel to rehydration and the initiation of cortisol replacement therapy a complete reversion of the hyperkinetic signs was achieved. This case shows a rare multiendocrine organ failure with complex metabolic interactions resulting in marked neurological signs. Furthermore, this case demonstrates for the first time that a hyperkinetic syndrome--most likely due to hypoparathyroidism-induced basal ganglia calcification--can be reversed solely by adequate treatment of the concomitant endocrine failures.

Adrenal Cortex Diseases↗

PubMed1993

["Inflammatory" disk degeneration. Magnetic resonance tomographic clinical picture].

Disc degeneration, if it appears relatively early, progresses rapidly with inadequate bone compensation for stabilisation of the area, or in the presence of anatomic variation of the vertebrae with short sagittal diameters, there may be tissue proliferation and edema in the bone marrow and vascular granulations within the disc. We demonstrated these changes in 17 patients by means of MRT which shows edema of the bone marrow and contrast enhancement within the disc. All these patients had severe symptoms. There were no significant neurological findings since in general there was no disc prolapse. The MRT characteristics of this condition are described and correlated with the clinical and radiological features. The use of Gd-DTPA and subtractive spin-echo and gradient-echo sequences in the differential diagnosis from infective discitis is discussed.

Adult↗