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Biomedical subjects

M Vahlensieck

Publications and source records attributed to M Vahlensieck.

At least 19 recordsLinked to original sources
PubMed2006

[Distal clavicle edema].

PURPOSE: Distal clavicle marrow edema: frequency, MRI in the early stage and macroscopic correlation to the bone marrow distribution and to evaluate frequency and diagnostic criteria of a posttraumatic clavicula disorder with an edema pattern on MRI. An additional macroscopic study of the clavicle should elucidate anatomic peculiarities which could explain the reaction of the distal clavicle. MATERIAL AND METHODS: 285 MRI of traumatized patients were analyzed for edema pattern of the distal clavicle. Pattern A edema within the clavicle and the acromion was distinguished from pattern B edema within the clavicle only. Dissection in 20 cadavers should reveal vascular peculiarities and the bone marrow distribution within clavicle and acromion or vascular peculiarities. RESULTS: In 38 patients (13,3%) we found edema within the distal clavicle. Pattern A was found in 28 (9,8%) and pattern B in 10 patients (3,5%). Pattern A was usually associated with swelling of the AC joint (27 out of 28). Other injuries were not evident. 18 cadavers showed hematopoietic marrow within the distal clavicle and fatty marrow within the acromion. CONCLUSION: The distal clavicle can frequently react with edema pattern after trauma without evidence for another injury. Distinguish in cases with and cases without synovitis of the AC joint could have impact on therapy. A peculiar vascular supply of the distal clavicle could not be found.

Adolescent↗
PubMed2006

[Synovial lesions around the knee joint].

This article reviews the anatomy of synovial-lined structures around the knee joint including the joint capsule, plicae, bursae, and tendon sheaths. Pathologic conditions are grouped into either inflammatory, induced by deposition of various substances, or neoplastic. The MRI appearances of the various diseases are discussed.

Humans↗
PubMed2006

[MRI of the wrist: Technical aspects and anatomic variants indicative of disease].

In order to produce high quality MR images of the wrist and hand, it is of major importance to consider the technical aspects of the examination. In this article the basics of patient positioning, MR sequences, acquisition plane, and application of contrast media are discussed. Additional issues such as MR arthrography, MR angiography, and magnetic field strength are addressed as well as anatomical variants, which may result in painful conditions. These include in particular the variability in length of the ulna with possible consecutive impaction or impingement syndromes.

Humans↗
PubMed2005

[CT-guided steroid injection into disc herniation: a causative therapy for lower back pain due to disc herniation].

PURPOSE: To evaluate the therapeutic benefit of CT-guided steroid injection into disc herniations. MATERIALS AND METHODS: In 64 patients, 2.5 mg Dexamethasone was injected into a symptomatic disc herniation under CT-guidance. Conservative treatment 3 to 12 months before injection was unsuccessful. Classified as "complete relief", "strong relief", "mild relief" and "no relief" of pain, the change of discomfort and pain was registered at 14 days, 3 months and 6 months after injection while the conservative regimen continued. RESULTS: At 14 days after injection, 36 patients (56 %) showed complete relief, 5 strong relief (8 %), 12 mild relief (19 %) and 11 no relief (17 %). At 6 months after injection, 25 patients showed complete relief (39 %), 16 strong relief (25 %), and 23 no relief (36 %). One complicating spondylodiscitis was observed. CONCLUSION: CT-guided steroid injection into symptomatic disc herniation represents a therapeutic alternative with good therapeutic results. It can be recommended as an alterative to other minimal invasive therapeutic regimens. The disc material acts as reservoir for the drug with good long term depot effect.

Adult↗
PubMed2004

[Humeroradial plica: frequency and visualization on MRI].

PURPOSE: To determine frequency and size of a humeroradial plica and correlate it with degenerative changes, and to determine frequency of the visualization of a synovial fold on MR-Images (T1-weighted spin-echo and STIR sequences) and correlate it with degenerative changes. MATERIALS AND METHODS: Forty-two elbow specimens were dissected and studied for humeroradial synovial folds (small, medium, large) and degenerative changes (absent, medium, strong), and 88 elbow MR-images were analyzed for a synovial fold (not visible, small, large) and degenerative changes (absent, medium, strong). Comparison was performed using the chi (2) test. RESULTS: Dissections revealed a synovial fold in all cases. The sizes were small in n = 13 (31 %), medium in n = 24 (57 %), and large in n = 5 (12 %). Degenerative changes were absent in n = 9 (21.4 %), medium in n = 29 (69 %), and strong in n = 4 (9.6 %). On MRI the synovial fold was not visible in n = 67 (76 %), small in n = 12 (14 %), and large in n = 9 (10 %). Degenerative changes on MRI were absent in n = 65 (74 %), medium in n = 15 (17 %), and strong in n = 8 (9 %). The size of the fold correlated positively with degenerative changes in the specimen but not with degenerative changes on MRI. The T1-SE sequence was superior to the STIR sequence in revealing the synovial fold. DISCUSSION: A humeroradial plica is a regular finding, but visualized by MRI in only approximately 20 %, probably due to its variable size. Its visualization succeeds best with T1-spin-echo sequences.

Elbow Joint↗
PubMed2003

[Performance of an open low-field MR unit in routine examination of knee lesions and comparison with high field systems].

The purpose of this study was to analyze the diagnostic value of a low-field open MR system in the diagnosis of knee lesions and to compare it with that of high-field MR systems. In 139 knees,arthroscopic investigations were used as the gold standard to calculate sensitivity, specificity, predictive values and accuracy of the low-field open MR system. Figures for high field systems were taken from the literature. The values for the open MR system relative to arthroscopy were as follows: sensitivity 66%,specificity 95%,positive predictive value 64%,negative predictive value 92%, and accuracy 82%. The corresponding values taken from 10 relevant publications for highfield systems were: sensitivity 81%, specificity 90%, accuracy 90%. A lower diagnostic performance has to be expected using open low field MR units for knee lesions in comparison to high field units. Sedative drugs can make it possible for claustrophobic patients to be investigated in high-field units. The use of open low-field scanners may still be indicated in very adipose patients who do not fit into closed units.

Adolescent↗
PubMed2002

[Magnetic Resonance Imaging (MRI) of the TMJ: Influence on therapy and inter-observer agreement of two radiologists].

AIM: To evaluate the influence of MRI of the temporomandibular joint on the therapeutic strategy in patients with craniomandibular disorders (internal derangement) and, furthermore, to analyze interobserver agreement for defined MRI criteria. MATERIALS AND METHODS: Fifty-one unilateral and bilateral MRI examinations of 32 patients were enrolled. Therapeutic strategies before and after performance of the MRI were compared. Retrospectively, two radiologists independently analyzed the MR images for position of the disk, position of the condyle, signal intensity of the disk and bilaminar zone, osseous changes and several additional findings, using a check list. Agreement was tested by kappa statistics. RESULTS: In 56% of the cases, changes of the therapeutic regimen were registered after MRI. Statistically significant agreement of the two observers was found for anterior position of the disk (kappa = 0.44), transverse position of the disk (kappa = 0.46) and position of the condyle (kappa = 0.45). No significant agreement was found for signal intensity of the disk (kappa = 0.14) or bilaminar zone (kappa = 0.24), osseous changes (kappa = 0.13) and the additional findings (kappa = 0.29). DISCUSSION: MRI has a measurable impact on the therapeutic approach to the internal derangement of the TMJ. The position of the disk and condyle can be reproducibly judged, while the signal intensity of the disk and bilaminar zone and the osseous changes are subject to wide observer variations.

Adolescent↗
PubMed2001

Hoffa's recess: incidence, morphology and differential diagnosis of the globular-shaped cleft in the infrapatellar fat pad of the knee on MRI and cadaver dissections.

We frequently observed a fluid-like indentation at the inferior posterior margin of Hoffa's fat pad of the knee and sought to establish the incidence and differential diagnostic criteria of this cleft. In total, 133 MRI studies and 35 cadaver specimens were analyzed for the location, size, and shape of clefts at the inferior posterior margin of Hoffa's fat pad. The incidence of a fluid-like ovoid cleft on MR images was 13.5% and in cadavers 14.3%. The cleft was located just below the insertion of the infrapatellar synovial fold (plica synovialis infrapatellaris, ligamentum mucosum). More linear-shaped indentations at the posterior margin were visible in all patients and cadavers due to the horizontal course of the alar folds. A fluid-filled indentation within the inferior posterior margin of Hoffa's fat pad has to be expected in more than 10% of knee studies and should not be confused with tumors like ganglion cysts. We term this cleft the infrahoffatic recess. One hypothesis of its origin concerns the embryological regression process of the infrapatellar membrane into the infrapatellar synovial fold. It should not be confused with linear clefts due to the alar folds.

Adult↗
PubMed2001

[Magnetic resonance imaging (MRI) of the bursa around the knee joint].

INTRODUCTION: Since fluid filled bursae lead to visible structures on MR images it is important to establish criteria to recognize them and to differentiate them from tumorous fluid-like structures. With this study the bursae around the knee joint were analyzed for potential differential diagnostic criteria such as localisation, size and shape. MATERIAL AND METHODS: In a retrospective study of 133 MR exams the frequency, localization and morphology were registered. The frequency of occurrence was correlated with the frequency of an effusion by means of the chi 2 test. RESULTS: The most frequently recognized bursae were bursa subtendinea musculi gastrocnemii medialis (54.9%), bursa musculi semimembranosi (21%), and bursa infrapatellaris profunda (18.8%). 8 different bursae were identified in complete. Size roanged from 2 to 18 mm. The shape was round and ovoid. The bursa subtendinea musculi gastrocnemii medialis and bursa musculi semimembranosi correlated with the occureance of an effusion. CONCLUSION: Bursae around the knee are frequently visualized as asymptomatic fluid like structures. Knowledge of the typical localization, size and contour is important for identification and differentiation diagnosis against ganglia, cysts or joint recesses.

Adolescent↗
PubMed2000

[The nutritive vascular canals. The magnetic resonance differential diagnosis of carpal cystic lesions?].

PURPOSE: To find and describe potential MRI criteria of nutrient vessel canals of carpal bones. METHODS AND MATERIAL: 16 wrists of 13 patients with pain and radiographic depiction of cystic changes within the lunate were examined. The MRI protocol included coronal and sagittal T1- and T2-weighted SE sequences (4 mm slices, 120 FOV, 256 x 256 matrix) as well as coronal STIR images. Final diagnosis was confirmed by surgery (n = 5) and follow up. 10 cadaveric ossa lunata were studied to describe size, number, location and shape of nutrient vessel canals. RESULTS: Ganglion cysts (n = 6) showed characteristic signs. In ulnar impaction syndrome (n = 1) small cystic lesions in the lunate were surrounded by a sclerotic rim and located near the proximal ulnar surface. In Kienböck's disease (n = 3) cystic components were irregular and surrounded by bone marrow edema. Nutrient vessel canals (n = 7) imaged as 1 to 3 small cystic lesions within the palmar or dorsal subchondral region. CONCLUSION: MRI can aid in differential diagnosis of cystic carpal lesions. Nutrient vessel canals may not be mistaken for pathologic cystic lesions. Carpal ganglion cysts show distinct diagnostic pattern.

Adolescent↗
PubMed2000

[The normal bone marrow and its variations in MRT].

Physiology and age-dependent changes of human bone marrow are described. The resulting normal distribution patterns of active and inactive bone marrow including the various contrasts on different MR sequences are discussed.

Aging↗
PubMed2000

[The diagnostic problems in magnetic resonance tomography of the bone marrow in patients with malignomas under G-CSF therapy].

AIM: To study the effect of G-CSF therapy directly by MRI and 1H MRS in the lumbar and femoral bone marrow and differentiate between malignant bone marrow infiltration (MBMI) and reconversion of red marrow. METHODS: Thirteen patients could be examined twice, before and during G-CSF medication and another six only during treatment. T1 weighted spin-echo and opposed-phase gradient-echo images as well as the spectroscopic data (T2 values, water content) were analysed. RESULTS: After G-CSF a pathologic bone marrow signal intensity was seen in 8/13 (lumbar) and 11/13 (femoral) patients respectively. The majority of the signal alterations were diffuse (6 and 8), the minority focal (2 and 3). If a patient was successfully stimulated, a significant increase in water content occurred (21% lumbar, 34% femoral). T2 values did not change significantly, nor did they correlate with the stimulation success. CONCLUSIONS: MR tomography and -spectroscopy are suitable to detect lumbar and femoral bone marrow stimulation by G-CSF quantitatively and qualitatively. The changes may simulate MBMI. The adequate judgement of G-CSF treated bone marrow without pretherapeutic images is not possible.

Adult↗
PubMed2000

[Radiological diagnosis of the skeletal system].

Diagnostic strategies, radiological signs on conventional techniques and MRI as well as problems in skeletal radiology are discussed. Emphasis is given on inflammatory conditions, bone metastasis and traumatology. Particularly common aspects of diagnostic radiology and nuclear medicine are considered.

Acute Disease↗