Magnetic resonance imaging of skeletal muscles in idiopathic inflammatory myopathies of adults.

The purpose of the study was to describe typical MRI findings in various types of idiopathic inflammatory myopathies in adulthood and to correlate the MRI with histopathological and electromyographic findings, and the serum creatine kinase (CK) activity. A third goal was to assess the diagnostic value of the use of gadolinium-DTPA (Gd-DTPA). Fifty-eight patients (35 women, 23 men), aged 21-83 years (median age 59 years), suffering from idiopathic myositides (13 with acute and 45 chronic diseases; 25 with polymyositis, 14 with dermatomyositis, 8 with granulomatous and 11 with inclusion body myositides) were examined with MRI. Seventeen of them received an intravenous infusion of Gd-DTPA. Histopathological and MRI findings of 21 muscles of 18 patients were compared. MRI of skeletal muscles showed abnormal signal intensities in 56 (96.6%) of the 58 patients. MRI abnormalities were found more often than elevated CK activity (P < 0.001). The hyperintensity of T2-weighted images was more conspicuous than on T1-weighted images in 26 (44.8%) patients, indicating oedema-like abnormalities. MRI of 50 (86.2%) patients showed fat replacement. In acute myositides, oedema-like abnormalities were more often visible and in muscle lipomatosis less often visible than in chronic diseases (P < 0.05 each). In dermatomyositis oedema-like abnormalities were more and lipomatosis less frequent than in the other types of myositis (P < 0.005) and correlated with the acuteness of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

31P-spectroscopy of head and neck tumors--surface coil technique.

Comparative phosphorus-31 magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) of 15 patients with superficial masses such as sarcoma, carcinoma, lymphoma, adenoma, and tuberculosis revealed significant increased concentrations of phosphomonoester, phosphodiester, and inorganic phosphorus in the lesion, whereas the concentration of the phosphocreatine was lower in comparison to muscle tissue. In nearly all masses, pH showed a slight alkaline shift. Existence of necrotic regions detected by MRI was marked by an increase of inorganic phosphorous in the spectra. Tumor growth was characterized by raised concentrations of phosphomonoester. Follow-up studies in a case of lymphoma showed a six-fold decrease of the tumor, while the spectra indicated a gradual transition of tumor values to muscle values. A follow-up study during irradiation of a squamous cell carcinoma revealed a considerable decrease of inorganic phosphate and a subsequent increase of phosphodiester.

Imaging techniques in myotonic dystrophy. A comparative study of ultrasound, computed tomography and magnetic resonance imaging of skeletal muscles.

Limb and trunk muscles of 57 patients with the juvenile or adult form of myotonic dystrophy were studied by imaging techniques (ultrasound, computed tomography, magnetic resonance imaging). Typical findings were atrophy of the tibialis anterior and triceps brachii muscles and fatty degeneration of the vastus intermedius, sartorius, tibialis anterior and soleus muscles as well as of medial head of the gastrocnemius muscle. Magnetic resonance imaging was the most sensitive technique in depicting mesenchymal muscle alterations, followed by computed tomography and ultrasound. The data support that imaging is more sensitive in detecting the myopathy than measurement of the creatine kinase activity.

[Diffuse liver parenchymal diseases: the value of MRI compared to sonography and CT]. / Diffuse Leberparenchymerkrankungen: Wertigkeit der KST im Vergleich mit Sonographie und CT.

29 patients with diffuse liver disease were examined by ultrasound, CT and MRI. MRI imaging was performed using T1-and t2-weighted spin-echo-sequences and fast gradient-echo-sequences. The paramagnetic contrast agent Gd-DTPA was applied intravenously (0.1 mmol/kg). In all patients with hepatitis MRI enabled exact liver biopsy by delineation of inflammatory changes in cases of chronic or focal hepatitis. CT and ultrasound were superior to MRI in the detection of focal or diffuse fatty degeneration. However, MRI enabled an exact differentiation of fatty changes from neoplasm. In cases of fibrotic changes the most accurate findings could be shown by MRI. In patients suffering from hemochromatosis MRI supplied additional information compared to CT and ultrasound revealing significant reduction of signal intensity due to reinforced enhancement of iron. Concerning Wilson's disease MRI showed a characteristic pattern of parenchymal changes. The application of Gd-DTPA in cases of diffuse liver disease adds supplementary information about perfusion of liver parenchyma, but its value for diagnostic accuracy is only secondary.

[The efficacy of lead shielding in patient dosage reduction in computed tomography]. / Effektivität der Bleiabdeckung zur Dosisreduktion beim Patienten in der Computertomographie.

PURPOSE: Investigation of the efficacy of lead apron, testis capsule and thyroid collar for dose reduction in uterus, ovaries, testes and thyroid gland in computed tomography examinations. METHODS: At an Alderson-Rando phantom dose of uterus, ovaries, testes and thyroid gland was measured with thermoluminescent dose meters. CT of the upper abdomen, the whole abdomen and the skull were simulated without and with lead shielding. As lead shielding, a lead apron was attached around the pelvis of the phantom in case of CT of the upper abdomen, a testis capsule was used in CT of the whole abdomen and a thyroid collar in CT of the skull. RESULTS: In CT of the upper abdomen the lead apron did not lead to any recognisable dose reduction in uterus and ovaries. In CT of the whole abdomen the testis capsule led to a dose reduction in testes of 95% (1.39 mSv) and in CT of the skull the thyroid collar to a dose reduction in thyroid gland of 23% (0.19 mSv). CONCLUSIONS: In abdominal CT examinations the testis capsule is an important instrument to reduce the dose of the testes whereas the lead apron is not appropriate for a dose reduction in the uterus and ovaries. In CT of the skull the thyroid collar can remarkably reduce the scattered radiation exposure of the thyroid gland and should be recommended.

[Color-coded duplex sonography in the differential diagnosis of cervical lymph node enlargements]. / Farbkodierte Duplexsonographie in der Differentialdiagnostik zervikaler Lymphknotenvergrösserungen.

55 patients with cervical lymph node enlargement were studied prospectively by colour coded duplex sonography. The aim was to demonstrate the perfusion of individual lymph nodes and to determine whether the resistance and pulsatile index are able to show the cause of the enlargement. The lymph nodes were subsequently examined histologically. Useful perfusion measurements were obtained in 177 lymph nodes out of 216. Perfusion index < 1.6 and resistance index < 0.8 distinguishes between reactive lymph node enlargement and lymph node metastases with an accuracy of 91%. Reliable differentiation between lymphoma and metastases was not possible. Tuberculous lymph nodes and cysts showed significantly reduced resistance and pulsatile index when compared with metastases. Further information on the type of disease was obtained from the perfusion patterns. Reactive lymph nodes showed increased central perfusion of the hilum, whereas metastases tended to show increased peripheral perfusion.

[The MRT of scaphoid pseudarthrosis with Gd-DTPA. Its staging and clinical correlation]. / MRT der Skaphoidpseudarthrose mit Gd-DTPA. Stadieneinteilung und klinische Korrelation.

During a period of two years, 134 patients with pseudo-arthrosis of the scaphoid were examined by conventional radiography and by MRI in the course of a prospective study. The aim of the study was to define radiological staging using contrast enhanced MRI in order to improve the prognostic criteria. All MRI examinations were carried out with a 1.5 tesla scanner (SP63) using a surface coil and T1 weighted spin echo sequences in sagittal and frontal projection and frontal FLASH T2 sequences and axial spin echo T2 sequences. The T1 weighted SE sequences in frontal projection were carried out before and after iv contrast (0.1 mmol Gd-DTPA/kg KG). All sequences were compared with conventional radiographs and the operative findings. Eight patients in stage 0 showed high signal intensity of both fragments in T1 weighted SE sequences and at surgery there was good vascularisation. In 22 cases there was reduced signal intensity in at least one fragment (stage I). 45 patients with scaphoid pseudo-arthrosis showed complete signal loss but marked contrast uptake with still vital nuclei at surgery (stage II). In 22 patients, there was no increase in signal intensity after contrast and complete loss of vitality of the fragments at surgery. Staging was not possible in 37 patients because of previous operative intervention. The use of contrast enhanced MRI provides additional information compared with conventional radiography or plain MRI.

[Spiral CT of the pancreas. A clinical comparison with conventional CT and dynamic CT]. / Spiral-CT des Pankreas. Klinischer Vergleich mit der konventionellen CT und der dynamischen CT.

PURPOSE: Spiral CT is compared with the dynamic CT and the conventional CT with regard to the enhancement of the pancreas and peripancreatic vessels and the visualisation of anatomic details. METHODS: In 15 patients spiral CT of the pancreatic region was performed in the arterial phase followed by spiral CT of the upper abdomen in the arterial-venous phase. In 30 patients dynamic CT (n = 15) and spiral CT (n = 15) of the pancreatic region was performed in the arterial phase followed by conventional CT of the upper abdomen. RESULTS: Compared with dynamic CT, spiral CT of the pancreatic region in the arterial phase (flow 4 ml/s, delay 15-18 s) leads to a stronger contrast of the peripancreatic vessels (p < 0.001) and the pancreas (108 vs. 86 HU) (p < 0.05). In the following spiral CT of the upper abdomen (flow 1 ml/s, delay 70 s), a high enhancement of both arteries and veins could be achieved. Intrapancreatic structures and peripancreatic vessels were better seen in the spiral CT than in the conventional CT (p < 0.05) and p < 0.005, respectively). CONCLUSION: The combination of spiral CT of the pancreatic region in the arterial perfusion phase and spiral CT of the upper abdomen in the arterial-venous phase enables an optimal enhancement of the pancreas and the abdominal vessels and a reliable visualisation of anatomic details.

[CT angiography in carotid stenosis. Diagnostic value compared to color-coded duplex ultrasonography and MR angiography]. / CT-Angiographie bei Karotisstenosen. Diagnostischer Wert im Vergleich zur farbkodierten Duplexsonographie und MR-Angiographie.

PURPOSE: To evaluate the accuracy of different diagnostic methods for the visualization of the carotid arteries and their pathological changes in order to avoid invasive angiography whenever surgery was considered. MATERIAL AND METHODS: 24 patients with clinically suspected stenosis or occlusion of the carotid arteries were prospectively examined via CT angiography. MR angiography and colour-coded duplex sonography (ccds) to evaluate the degree of stenosis and the extent of calcification. RESULTS: In 36 cases stenoses of different extent could be documented with CT angiography, 33 cases were found using colour-coded duplex sonography and MRA. Sonography could not prove mild stenoses (< 30%), and in two patients with sonographically suspected total occlusion vessel perfusion was documented via CT angiography. MR angiography led to a overestimation in patients with high-grade stenosis compared to the degree of stenosis obtained via ccds and CTA. With regard to the diagnosis of calcification MIP, reconstructions after CT examination showed best correlation to the plain CT slices referring to length (94.6%) and thickness (89.2%). CONCLUSION: CTA with MIP reconstructions is an excellent screening method and, in combination with ccds, CT angiography may replace DSA before surgery or intervention.

[Magnetic resonance tomographic studies of paragangliomas of the glomus caroticum and glomus jugulare using Gd-DTPA]. / Kernspintomographische Untersuchungen von Paragangliomen des Glomus caroticum und Glomus jugulare mit Gd-DTPA.

The value of magnetic resonance tomography in the diagnosis of paragangliomas in the head and neck has been studied and compared with CT and angiography. Magnetic resonance tomography on its own equals the accuracy of CT, but the use of Gd-DTPA improves diagnostic accuracy. In 19 patients with a glomus jugulare tumour, MR tomography with Gd-DTPA accurately diagnosed all tumours larger than 5 mm. In seven patients with a carotid body tumour, it was possible to arrive at an exact differential diagnosis. Sensitivity was better than that of CT or of sonography. Where there is clinical suspicion of a glomus tumour, magnetic resonance tomography with Gd-DTPA should be the first investigation; if there is a positive finding, angiography should be carried out to demonstrate the circle of Willis.

[Dynamic computerized tomography of the bone marrow of normal and pathologic vertebrae]. / Dynamische Computertomographie des Knochenmarks gesunder und pathologisch veränderter Wirbelkörper.

PURPOSE: The contrast medium dynamics of normal and abnormal bone marrow was examined by CT. MATERIAL AND METHOD: Standardised sections of lumbar vertebrae were obtained after intravenous injection of 80 ml Ultravist 370 and time-density curves of the marrow spaces were calculated in 38 patients. RESULTS: Time-density curves of patients with normal bone marrow differed significantly from those with proliferative bone marrow diseases in respect of maximal density and uptake at 120 and 240 seconds. Patients treated by radiation showed reduced uptake. CONCLUSION: Variations in the time-density curves between normal and abnormal bone marrow provided evidence of different perfusion and uptake of the contrast medium in the extracellular space of the bone marrow. Further investigation will be necessary to determine whether dynamic CT is able to document the effect of radiotherapy or chemotherapy on malignant bone marrow infiltration.

[MRI of the nasopharynx with Gd-DTPA: its value and differential diagnostic criteria]. / KST des Nasopharynx mit Gd-DTPA: Wertigkeit und differentialdiagnostische Kriterien.

81 patients with masses in the nasopharynx were examined by MRI and CT. In cases of primary lesions of the nasopharynx (such as carcinomas and fibromas), MRI with Gd-DTPA was superior to CT. Secondary tumors involving the nasopharynx were visualized equally well with MRI with Gd-DTPA and CT. The results show that MRI should be the primary method of examination in lesions of the nasopharynx. CT is a secondary procedure useful for showing small areas of bone erosion. MRI with the paramagnetic contrast medium Gd-DTPA permits differentiation between inflammatory, cystic and neoplastic masses.

[Pre- and postoperative NMR tomographic studies in avascular femur head necrosis]. / Prä- und postoperative kernspintomographische Untersuchungen bei avaskulären Hüftkopfnekrosen.

46 patients with avascular necrosis of the femoral head were examined by T2- and T1-weighted MR before and after infusion of Gd-DTPA. Both sides were involved in 12 cases. The classification was done according to Ficat. In early stages and in postoperative studies a correlation of signal intensity after infusion of Gd-DTPA and clinical symptoms was found. Hyperintensity of the avascular area or of the implanted material was assumed to be vascularised or vital components in 4 cases of Ficat I and in 15 postoperative studies. Contrariwise, we found in 5 patients with severe postoperative symptoms, low signal intensity areas due to avascular regions.

[MR angiography in neuropediatric problems: the technic and the clinical results]. / MR-Angiographie bei neuropädiatrischen Fragestellungen: Technik und klinische Ergebnisse.

31 children aged between 6 months and 14 years with various neurovascular abnormalities were examined by MR angiography in a prospective study. In order to test the sensitivity and specificity of the MR results, these were compared in 8 cases with the findings of digital subtraction angiography or conventional angiography. In 24 patients arterial MR angiography was performed; in 17 these showed anomalies or abnormalities of the intracranial vascular system. In 7 patients venous MR angiography was performed and demonstrated the presence of sinus thrombosis in 6 of these. Comparison between MR angiography and DSA showed agreement in 7 cases; in one patient the degree of a stenosis was exaggerated by MR. The results of this study indicate that arterial and venous MR is of great value as an additional study in paediatric neurovascular problems.

Thoracic computed tomography of patients infected with the human immunodeficiency virus: relevance for the course of disease.

To determine the diagnostic accuracy and prognostic implications of thoracic computed tomography (CT) in patients with human immunodeficiency virus infection (HIV), CT scans of 154 HIV-infected patients (mean age, 41 years; range 23-65 years; 18 female) with suspicion of pulmonary disease were retrospectively reviewed for signs of disease by two investigators blinded to clinical data other than positive HIV serology. Abnormal CT features were correlated with CD4-T lymphocyte count, histologic or microbiologic diagnosis, and survival. Computed tomography detected features of pulmonary disease in 133 patients. A recent chest film was available in 96 patients, and it was normal in 16. In 17 of 99 patients (17%) with histologic or microbiologic correlation, pathologic CT features could be demonstrated, though histologic and microbiological studies were unrevealing. Median survival was 649 days. Confluent pulmonary infiltrates and bilateral masses on CT indicated advanced disease with a median survival of 115 days (n = 11, p = 0.0005) and 174 days (n = 15, p < 0.0001), respectively. The authors concluded that thoracic CT detects pulmonary lesions in an appreciable portion of HIV-infected patients in whom chest radiographs, microbiologic methods, or histology failed to establish a diagnosis, and that CT findings allow for an estimation of patient survival in acquired immunodeficiency syndrome.

[Dynamic magnetic resonance tomography (MRI): a follow-up study after femur core decompression and instillation of recombinant human bone morphogenetic protein-2 (rhBMP-2) in avascular femur head necrosis]. / Dynamische Magnetresonanztomographie (MRT): Verlaufsbeobchtung nach Femurkerndekompression und Auffüllung mit rekombinantem, humanem Bone morphogenetic Protein-2 (rhBMP-2) bei avaskulärer Femurkopfnekrose.

OBJECT: The aim of the study was to test the use of dynamic magnetic resonance imaging study with Gd-DTPA-application and the dynamic changes of signal intensity at patients with avascular femoral head necrosis after having installed rhBMP-2 and/or decompressed the core. MATERIAL AND METHODS: Six patients with avascular necrosis of the femoral head ARCO-stage I- or II-lesions were treated surgically by femoral head core decompression. Three of these patients were additionally treated with rhBMP-2-instillation. The progression or regression could be confirmed by T1- and T2-weighted spinecho-sequences (zero, four, ten, sixteen weeks and 24 months follow up). RESULTS: Corresponding ARCO-classification with partly more sensitive measurement of vitality signs in comparison to the optical x-ray classification. The objective, quantitative measurement of signal intensity post contrast medium reduces the influence of experience and level of education. The dynamic sequences results are reproducible. CONCLUSION: The dynamic magnetic resonance imaging study after Gd-DTPA-application and the dynamic changes of signal intensity after Gd-DTPA enhancement in the necrotic areas of the femoral head were the important subject of our study and it seems, that these sequencies and the ascertainment of signal intensity changes will be an efficient method for judgement of vitality, vascularisation and perfusion after therapeutical intervention. Combination of femoral head core decompression and rhBMP-2-instillation for the purpose of osseous regeneration seems to stabilize the affection.