Ewing sarcoma versus osteomyelitis: differential diagnosis with magnetic resonance imaging.

OBJECTIVE: To find and evaluate characteristic magnetic resonance imaging (MRI) patterns for the differentiation between Ewing sarcoma and osteomyelitis. MATERIALS AND METHODS: We identified 28 consecutive patients referred to our department for MRI (1.5 T) of an unclear bone lesion with clinical symptoms suggestive of Ewing sarcoma or osteomyelitis. MRI scans were re-evaluated by two experienced radiologists, typical MR imaging features were documented and a diagnostic decision between Ewing sarcoma and osteomyelitis was made. Statistical significance of the association between MRI features and the biopsy-based diagnosis was assessed using Fisher's exact test. RESULTS: The most clear-cut pattern for determining the correct diagnosis was the presence of a sharp and defined margin of the bone lesion, which was found in all patients with Ewing sarcoma, but in none of the patients with osteomyelitis (P < 0.0001). Contrast enhancing soft tissue was present in all cases with Ewing sarcoma and absent in 4 patients with osteomyelitis (P = 0.0103). Cortical destruction was found in all patients with Ewing sarcoma, 4 patients with osteomyelitis did not present any cortical reaction (P = 0.0103). Cystic or necrotic areas were identified in 13 patients with Ewing sarcoma and in 1 patient with osteomyelitis (P = 0.004). Interobserver reliability was very good (kappa = 1) in Ewing sarcoma and moderate (kappa = 0.6) in patients with osteomyelitis. CONCLUSIONS: A sharp and defined margin, optimally visualized on T1-weighted images in comparison to short tau inversion recovery (STIR) images, is the most significant feature of Ewing sarcoma in differentiating from osteomyelitis.

Tumor microcirculation evaluated by dynamic magnetic resonance imaging predicts therapy outcome for primary rectal carcinoma.

Contrast enhanced dynamic studies of malignant tumors performed by computed tomography or magnetic resonance imaging (MRI) are increasingly applied to characterize tumor microcirculation for the prediction of therapy outcome. The aim of our study was to correlate perfusion index (PI) values determined in primary rectal carcinoma before chemoradiation with therapy outcome. In 17 patients with clinically staged T3 primary rectal carcinoma, dynamic MRI was performed before the onset of therapy using an ultrafast T1-mapping sequence. On the basis of the acquired data sets, PI values were calculated on a pixel-by-pixel basis. To characterize the heterogeneity of tumor microcirculation, relative cumulative frequency histograms of PI values within the tumors were computed. Subsequent resection of the tumors allowed correlating PI with histopathological classification. In 12 of 17 patients, T-downstaging as a response to therapy was found, whereas in the remaining 5 patients no therapy response was observed after chemoradiation. A statistically significant difference between both groups was found for the mean PI (P < 0.001; 8.5+/-1.7 ml/min/100 g versus 11.4+/-0.7 ml/min/100 g). Analyzing the cumulative frequency histograms for both groups revealed an optimal discrimination for a P1 value of 12.6 ml/min/100 g. The fraction of pixels in the tumor with PI values larger than 12.6 ml/min/100 g was significantly different (P < 0.001) between therapy-responding (3+/-3.6%) and therapy-nonresponding tumors (21+/-4.3%). The results indicate either a reduced supply of nutrients as well as chemotherapeutic agents attributable to increased shunt flow or highly aggressive tumor cell clusters characterized by increased angiogenic activity. Noninvasive PI measurements by dynamic MRI in rectal carcinoma before therapy seem to be of predictive value for therapy outcome in patients scheduled for preoperative chemoradiation.

Calvarial "doughnut lesions": clinical spectrum of the syndrome, report on a case, and review of the literature.

Many pathologic fractures, lumps on the head, elevated serum alkaline phosphatase (ALP) levels, and dental caries are the main characteristics of the rare autosomal dominantly inherited calvarial "doughnut lesions" (MIM 126550). We report the sporadic case of a 16-year-old patient who has had 10 pathologic fractures between age 6 weeks and 15 years. An elevated serum ALP level was found at age 11 and skull lumps at age 15; radiography showed frontal and parietal round radiolucencies surrounded by sclerotic bone comparable to doughnuts. Magnetic resonance imaging (MRI) showed skull lesions at an early stage. Because the findings are reminiscent of osteogenesis imperfecta (OI), collagen types I, III, and V were analyzed in fibroblasts and shown to be normal in terms of quantities, proportions, electrophoretic mobility, and thermostability. Thus, this rare syndrome can be distinguished from OI by collagen analysis and MRI of the skull at an early stage, even before palpable skull lesions appear.

Effects of exercise on plasma myosin heavy chain fragments and MRI of skeletal muscle.

The effects of a single series of high-force eccentric contractions involving the quadriceps muscle group (single leg) on plasma concentrations of muscle proteins were examined as a function of time, in the context of measurements of torque production and magnetic resonance imaging (MRI) of the involved muscle groups. Plasma concentrations of slow-twitch skeletal (cardiac beta-type) myosin heavy chain (MHC) fragments, myoglobin, creatine kinase (CK), and cardiac troponin T were measured in blood samples of six healthy male volunteers before and 2 h after 70 eccentric contractions of the quadriceps femoris muscle. Screenings were conducted 1, 2, 3, 6, 9, and 13 days later. To visualize muscle injury, MRI of the loaded and unloaded thighs was performed 3, 6, and 9 days after the eccentric exercise bout. Force generation of the knee extensors was monitored on a dynamometer (Cybex II+) parallel to blood sampling. Exercise resulted in a biphasic myoglobin release profile, delayed CK and MHC peaks. Increased MHC fragment concentrations of slow skeletal muscle myosin occurred in late samples of all participants, which indicated a degradation of slow skeletal muscle myosin. Because cardiac troponin T was within the normal range in all samples, which excluded a protein release from the heart (cardiac beta-type MHC), this finding provides evidence for an injury of slow-twitch skeletal muscle fibers in response to eccentric contractions. Muscle action revealed delayed reversible increases in MRI signal intensities on T2-weighted images of the loaded vastus intermedius and deep parts of the vastus lateralis. We attributed MRI signal changes due to edema in part to slow skeletal muscle fiber injury.(ABSTRACT TRUNCATED AT 250 WORDS)

MR imaging of late onset orbital rhabdomyosarcoma with intracranial extension.

Today, patients with alveolar rhabdomyosarcoma have a favorable prognosis with a survival rate of more than 80%, due to modern radiotherapy. However, those patients with secondary meningeal involvement are still afflicted with a mortality rate of 90% unless a different therapeutic approach is taken. We report a case of a young adult with invasion of the tumor into the anterior cranial fossa. MRI aided in the assessment of the intracranial tumor spread and allowed for a direct visualization of the meningeal membranes. The signal characteristics of the tumor and the adjacent tissue in unenhanced and postcontrast MRI is discussed. MRI was clearly superior to CT and indicative for the choice of treatment.

Metallic artifacts in magnetic resonance imaging of patients with spinal fusion. A comparison of implant materials and imaging sequences.

STUDY DESIGN: Devices for spinal fusion were compared with respect to their influence on magnetic resonance images. In addition, different magnetic resonance pulse sequences were evaluated to elicit their susceptibility to imaging artifacts. OBJECTIVES: To determine the implants with the least imaging artifacts as a recommendation for the spine surgeon and to assess the best imaging strategy for the radiologist. SUMMARY OF BACKGROUND DATA: For patients who have had surgical spinal fusion with instrumentation, magnetic resonance imaging is the most favorable diagnostic method. Unfortunately, metallic implants lead to severe degradation of image quality. These artifacts depend on the material of the implant and on the choice of the pulse sequence. METHODS: The fusion devices were mounted on a simple plastic phantom in various combinations and were imaged on 1.5-T magnetic resonance units. Frequently used types of plates and screws made of titanium or steel in various alloys were examined on the phantom with routinely used pulse sequences. The results of these examinations were compared with those in patient studies involving the same implants as well as the same pulse sequences. RESULTS: The least imaging artifacts were caused by titanium implants, especially when using shorter screws, wider screw placement, and thinner titanium plates. Nevertheless, there were distinct image distortions that could lead to erroneous image interpretation. The best images were acquired by spin echo (T1), turbo spin echo (T1, T2), and half Fourier single shot turbo spin echo (HASTE) sequences. Sequences containing any gradient echo components (gradient echo or turbo gradient and spin echo sequence or frequency-selective fat saturation techniques) resulted in the highest amount of image degradation. CONCLUSION: By choosing appropriate spinal fusion devices as well as pulse sequences, postoperative magnetic resonance imaging examinations can give acceptable results, in spite of the presence of metallic implants.

[Sonographic determination of the position of the carotid bifurcation as a diagnostic aid in cerebral catheter angiography]. / Sonographische Lagebestimmung der Karotisgabel als diagnostische Hilfe bei zerebralen Katheter-angiographien.

A simple sonographic method is described for demonstrating the position of the carotid bifurcation in the sagittal plane. As a result, it is possible to demonstrate the bifurcation by angiography without overlay, thereby improving the diagnosis of vascular abnormalities. Since non-invasive sonography of the carotid arteries should be carried out before cerebral angiography in any case, the present procedure does not involve any additional effort.

[The value of sonography in the therapeutic supervision of induratio penis plastica (Peyronie's disease)]. / Die Wertigkeit der Sonographie in der Therapieüberwachung der Induratio penis plastica (Peyronies Disease).

The article reports on 18 sonographically examined patients with clinically verified Peyronie's disease (induratio penis plastica) who underwent a basic sonographical classification according to the system of Kelami. Four weeds after the initial sonography a control study was carried out in 17 patients. 10 of these received a treatment by local instillation with Ontosein, whereas seven patients remained without treatment. In one patient an operation (Nesbit) had been performed in the meantime. 10 of the 17 examined patients presented a change of the initial findings. Seven patients out of the number of the patients who had received treatment presented a change, whereas three patients showed no change of their basic findings. The untreated group of seven patients demonstrated in three cases a change of the sonographic pattern, and four cases were unchanged. The most significant change of the sonographic appearance (treated or untreated) was an increased echogenicity of the corpora cavernosa. In some cases no plaques could be found, in one cases a new plaque developed. In two cases the initial hypoechogenic rings sign disappeared. Sonography, however, cannot prove the success of a specific therapeutic regimen, because 50% of all patients recover without treatment.

[The value of CT and MRT in assessing aortocoronary venous bypasses in comparison with coronary angiography]. / Die Wertigkeit von CT und MRT bei der Erfassung von aortokoronaren Venenbrücken im Vergleich zur Koronarangiographie.

In a follow-up study of 20 patients with a total of 52 aortocoronary venous bypass grafts (ACVB) three months after surgery, the patency of the grafts was assessed by magnetic resonance tomography (MR) followed by contrast enhanced CT-scan and selective coronary angiography on the following day. Each examination was interpreted independently and immediately after the procedure for the visibility and patency of the grafts. The statistical figures for the non-occluded grafts showed a sensitivity of 90.24% and a specificity of 54.54% for the CT scans and a sensitivity of 73.17% with a specificity of 72.72% for the MR. Although the sensitivity of the CT is somewhat higher than that of MR, neither procedure offers a clear advantage over each other and neither of both methods alone is adequate for the assessment of ACVB's. They are therefore only valuable as an adjunct to clinical data and as a screening procedure for selective coronary angiography.

[The role of sonography and MR tomography in the diagnosis and therapeutic control of the carpal tunnel syndrome]. / Der Stellenwert von Sonographie und MR-Tomographie in Diagnose und Therapiekontrolle des Karpaltunnelsyndroms.

120 wrists of 105 patients with carpal tunnel syndrome were studied preoperatively by high-resolution sonography. Follow-up examinations after carpal tunnel release were performed in 72 wrists. In addition, 40 wrists were examined preoperatively, and 20 wrists were examined postoperatively by MR imaging. Based on quantitative analysis of the cross-sectional area and shape of the median nerve and of the palmar bowing of the flexor retinaculum, sonography established the diagnosis in 95% of cases. MR was superior in the evaluation of mild degrees of median nerve compression, and in the detection of possible causes of the carpal tunnel syndrome, such as synovitis of the flexor tendon sheaths or ganglionic cysts. In postoperative follow-up, sonographic demonstration of a normally flattened median nerve was an excellent indicator of the successful carpal tunnel release. In 10 patients with persistent or recurrent symptoms after carpal tunnel release, the underlying pathology could be exactly demonstrated by MR.

[Magnetic resonance tomography in spinal trauma]. / Magnetresonanztomographie beim spinalen Trauma.

PURPOSE: To assess the value of MR imaging in the acute and chronic stages of spinal trauma. METHODS: 126 MR examinations of 120 patients were evaluated retrospectively. In 15 cases of acute spinal cord injury, correlation of MR findings with the degree of neurological deficit and eventual recovery was undertaken. RESULTS: Cord anomalies in the acute stage were seen in 16 patients. Intramedullary haemorrhage (n = 6) and cord transection (n = 2) were associated with complete injuries and poor prognosis, whereas patients with cord oedema (n = 7) had incomplete injuries and recovered significant neurological function. In the chronic stage, MR findings included persistent cord compression in 8 patients, syringomyelia or post-traumatic cyst in 12, myelomalacia in 6, cord atrophy in 9, and cord transection in 7 patients. CONCLUSION: In acute spinal trauma, MR proved useful in assessing spinal cord compression and instability. In addition, direct visualisation and characterisation of post-traumatic changes within the spinal cord may offer new possibilities in establishing the prognosis for neurological recovery. In the later stages, potentially remediable causes of persistent or progressive symptoms, such as chronic spinal cord compression or syringomyelia can be distinguished from other sequelae of spinal trauma, such as myelomalacia, cord transection or atrophy.

[Diffusion-weighted MRI--a new parameter for advanced rectal carcinoma?]. / Diffusionsgewichtete Magnetresonanztomographie--Ein neuer Prognoseparameter beim fortgeschrittenen Rektumkarzinom?

PURPOSE: To evaluate the predictive value of apparent diffusion coefficient (ADC) on therapy outcome of combined chemoradiation in patients with primary carcinoma of the rectum. MATERIALS AND METHOD: Prior to standardized, combined, neoadjuvant chemoradiation, 16 patients with primary carcinoma of the rectum (cT3) were examined with magnetic resonance imaging (MRI). Diffusion-weighted spin echo echo-planar images (SE-EPI) and contrast-enhanced T 1 -weighted spin echo (SE) images at 1.5 Tesla were obtained. The mean ADC of the tumor region was calculated and correlated with the therapy outcome substantiated by postsurgical histopathologic staging. RESULTS: Tumor down-staging (pT0-2) occurred in 9 patients (therapy responders) and no down-staging (pT3) in 7 patients (therapy non-responders). The mean ADC measured 0.476 +/- 0.114 x 10(-3) mm 2/s in the responder group and 0.703 +/- 0.085 x 10(-3) mm 2/s in the non-responder group. Comparison of the mean ADC between the groups reached statistical significance (p = 0.001). CONCLUSION: The mean ADC might be a new quantitative parameter to predict therapy outcome of combined preoperative chemoradiation in patients with primary carcinoma of the rectum.

The role of dynamic magnetic resonance imaging in the detection of lesions of the ulnocarpal complex.

A prospective study of 32 patients was carried out to investigate the significance of dynamic magnetic resonance imaging (MRI) in diagnosis of triangular fibrocartilage (TFC) lesions. Tears of the TFC can be diagnosed well by means of static MRI and arthroscopy. Dynamic MRI examination has an advantage in evaluating the stability of the TFC and ulnocarpal impingement. By means of dynamic MRI it was possible to make a preoperative diagnosis of an ulnocarpal impingement in five patients, a diagnosis which was confirmed through arthroscopy in all cases. In three further patients, dynamic MRI showed ulnocarpal impingement caused by instability of the ulnar attachment of the TFC. This kind of impingement could not be ascertained arthroscopically. Dynamic MRI extends the possibilities of evaluating obscure ulnar wrist pain. Its significance lies in the non-invasive examination of ulnocarpal impingement as well as the evaluation of TFC stability.

[Diagnosis of the ulnocarpal complex in MRI cineradiography]. / Diagnostik des ulnokarpalen Komplexes im MR-Movie.

73 patients with persistent ulnar wrist pain of undetermined origin were examined by Magnetic Resonance Imaging (MRI). A series of 15 coronal slices was acquired using a T2* weighted gradient echo sequence. With repetitive measurement of those three slices that showed the triangular fibrocartilage complex (TFCC) best, the carpus was imaged 12 times during radial-ulnar deviation in increments of five degrees. The single images were combined according to their slice positions and continuously displayed on an image workstation, allowing for kinematic evaluation. Three different types of impingement of the TFCC were identified.

[Isolated injuries of the pulley of the finger flexor tendon sheath--injuries in extreme climbing sports]. / Isolierte Ringbandverletzungen im Fingerbereich--Verletzungen des extremen Klettersportes.

Injuries of pulleys are quite common in mountain climbing. The clinically diagnosed rupture of a pulley can now be verified by MRI. Partial ruptures, which in MRI always showed as scars, can frequently lead to intrinsic bow-stringing. The injuries were primarily treated non-surgically. With regard to chronic, recurring cases or large ruptures, however, annular ligament plastics have to be considered. As a prophylaxis we recommend special training exercises for climbers on wide ledges with changing exertion patterns and a tape-bandage for the fingers. During climbing, the PIP-joint should best not be strained in an obtuse angle. Warming-up and stretching exercises before climbing are absolutely necessary.

[(Neuro)muscular changes in the knee stabilizing muscles after rupture of the anterior cruciate ligament]. / (Neuro)Muskuläre Veränderungen der kniegelenksstabilisierenden Muskulatur nach Ruptur des vorderen Kreuzbandes.

Recent data indicate that the function of the knee joint may be the result of a complex synergy between bones, ligaments, muscles and proprioceptive receptors in these structures. Therefore, it was the aim of this study to investigate if muscular changes could be found more than 5 years following ACL-injury and if there are therapy-dependent differences. 35 patients with ACL-reconstruction and 25 conservatively treated patients were studied. The thigh circumference was measured and in 5 randomly selected patients of each group additionally MRI cross-sections of both limbs were made. Using an isokinetic dynamometer and an EMG device the relation of strength, electrical activity and muscle size were analyzed. Only minimal differences in thigh circumference as well as in muscular cross sections were found between the uninjured and injured limb of both groups; however, the isokinetic torque and iEMG values showed significant differences. It may be assumed that the major reason for these results is a modified muscle fiber utilization in the ACL-injured limb, caused by a changed joint receptor afferent inflow or a compensation of the central nervous system to primary alterations of the muscle fibers.

Isolated right-sided varicocele as a salvage pathway for portal hypertension.

Retrograde blood flow can occur in the testicular veins and in the pampiniformis plexus in the absence of valves or if the valves are incompetent, resulting in tortuosity and dilatation of the veins. These abnormal alterations in the anatomy of the veins, termed varicoceles, are associated with infertility in the male. Most varicoceles occur on the left. We report the case of a rare isolated right-sided varicocele in a male evaluated for infertility in whom extensive work-up revealed venous anomalies and a spontaneous porto-systemic shunt. In such cases, standard approaches to infertility treatment are fruitless.