Discriminatory ability of quantitative ultrasound parameters and bone mineral density in a population-based sample of postmenopausal women with vertebral fractures: results of the Basel Osteoporosis Study.

The discriminatory potential to classify subjects with or without vertebral fractures was tested cross-sectionally with different methods for the measurement of bone status in a population-based sample of postmenopausal women. Quantitative ultrasound (QUS) measurement at the calcaneus (Lunar Achilles, Hologic Sahara), the proximal phalanges (Igea Bone Profiler), and measurement of bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA; Lunar Expert) at several anatomic sites was performed in 500 postmenopausal women (aged 65-75 years) randomly selected from the population. In addition, 50 young female subjects (20-40 years old) had QUS measurements and served as controls to express QUS results as T-score values. Radiographs of the lumbar and thoracic spine were performed in the elderly women. Two independent radiologists reviewed the X-rays for the presence of vertebral fractures. Of 486 eligible study participants, no fracture was seen in 396 participants. Single vertebral fractures were observed in 71 subjects; 19 individuals presented multiple fractures. The overall prevalence of vertebral fractures was 18.5%. Participants without vertebral fractures were compared with subjects with vertebral fractures. Normal statistical distributions were found for all bone measurement results. Risk of vertebral fracture in subjects with no and multiple vertebral fracture was estimated using age adjusted odds ratios (ORs) for QUS and dual-energy X-ray absorptiometry (DXA) values. Each SD decrease in bone measurement increased the risk of multiple vertebral fracture by 3.0 (95% CI, 1.6-5.6) for the Achilles stiffness, by 3.8 (95% CI, 1.8-8.2) for the Sahara QUI, 2.1 (95% CI, 1.3-3.4) for the Bone Profiler amplitude-dependent speed of sound (AD-SOS), and 2.1 (95% CI, 1.2-3.9) and 2.4 (95% CI, 1.3-4.3) for DXA lumbar spine and for DXA total hip, respectively. Results of a discriminant analysis showed sensitivities between 84% and 58% and specificities between 72% and 58% for the respective DXA and QUS parameters. Optimum fracture thresholds for QUS measurements derived from this analysis were calculated also. Optimum T-score threshold values for QUS measurements tended to be higher than those for DXA measurements. However, the performance of QUS measurements is at least comparable with DXA measurements in identifying subjects with multiple vertebral fractures randomly selected from the population.

Mechanism of mosaic attenuation of the lungs on computed tomography in induced bronchospasm.

The purpose of this study was to investigate whether hypoxic pulmonary vasoconstriction is the major determinant of the computed tomography (CT) pattern of mosaic attenuation in asthmatic patients with induced bronchoconstriction. Thin-section CT was performed at suspended full inspiration immediately and 30 min after methacholine bronchoprovocation in 22 asthmatic subjects, who were randomly assigned to breathe room air (group A, n = 8), oxygen via nasal prongs at 5 l/min (group B, n = 8), and oxygen via face mask at 12 l/min (group C, n = 6). CT changes were quantified in terms of global lung density and density in hypodense and hyperdense areas. Lung parenchymal density increases were greatest in group C and greater in group B than in group A, globally (P = 0.03) and in hypodense regions (P = 0.01). On bivariate analysis, the only change in cross-sectional area was related to change in global density. In hypodense regions, density change was related both to reduction in cross-sectional area (P < 0.0005) and to oxygen administration (P = 0.01). After correction for changes in global lung density, only oxygen was independently related to density increase in hypodense areas (P = 0.02). In induced bronchoconstriction, the CT appearance of mosaic attenuation can be largely ascribed to hypoxic vasoconstriction rather than to changes in lung inflation.

Diagnosis of tears in rotator-cuff-injuries.

Pathology of the rotator cuff is the cause of most common problems at the shoulder joint. Acute injuries are not as frequent as chronic cuff disease, but often they aggravate inflammatory or degenerative tendon alterations, even if they are of minor severity. Traumatic rotator cuff tears predominantly affect the supraspinatus tendon or the rotator interval. The subscapularis tendon is involved in anterior dislocations of the glenohumeral joint or in direct trauma. Plain film radiography still remains the base of all further imaging studies. If only full-thickness tears must be ruled out, double-contrast arthrography and ultrasound are acceptable imaging modalities. However, the former has a drawback in being invasive and does not detect partial tears at the bursal site of the cuff or rotator cuff tendinopathy, whereas the latter heavily depends on the experience of the radiologist and is restricted to the rotator cuff. Nowadays the most comprehensive imaging method is magnetic resonance (MR) imaging. MR imaging enables the detection or exclusion of complete rotator cuff tears with a reasonable accuracy and is also suitable to diagnose further pathologies of the shoulder joint. MR arthrography is valuable in the detection of subtle anatomic details and further improves the differentiation of rotator cuff diseases. Although in comparison MR imaging is still the most expensive imaging method, its high negative predictive value for the diagnosis of complete rotator cuff tears and its reliability evaluating different shoulder joint pathologies make it the preferred imaging modality.

Imaging the long head of biceps tendon--a pictorial essay emphasizing magnetic resonance.

Lesions of the long head of the bicepstendon (BT) are seen in association with tears of the rotator-cuff, particularly lesions of the subscapularis tendon and the rotator-interval. The frequency of positive MR-findings at the BT is approximately 25%. The pathologic alterations include complete medial luxation, subluxation and entrapment by the subscapularis tendon, tendinitis or tendovaginitis and lesions at the origin of the tendon at the superior labrum (superior labrum anterior to posterior (SLAP)--lesions). The imaging signs of BT pathology on MR include an abnormal course and position of the tendon, alterations in shape and changes in signal-intensity (SI), obliteration and thickening of the tendon-sheath. In long standing intra-articular BT rupture, neo-insertion of the tendon in the bicipital sulcus may ensue. The long BT needs to be visualized in transaxial, coronal oblique and sagittal oblique projections. Besides serving as stabilizer of the long head of biceps muscle, the BT is also an important stabilizer of the anterior joint capsule.

Spin-echo and 3D gradient-echo imaging of the knee joint: a clinical and histopathological comparison.

OBJECTIVE: A clinical and histopathological comparison of 2D spin-echo (SE) and 3D gradient-echo (3DGE) sequences was undertaken for the knee joint. The purpose of the study was to evaluate the clinical results and to explain the different appearances of meniscal abnormalities on both 2DSE and 3DGE images. PATIENTS, MATERIALS AND METHODS: The clinical study comprised 45 patients with arthroscopically correlated MR imaging results. For the histopathological correlation, seven cadaveric knee joints were examined with the same 2DSE and 3DGE (FISP) imaging protocol and sliced in sagittal sections according to the MR images. Different stainings were used. RESULTS: For the detection of meniscal tears, accuracy (82.2%) and positive predictive value (70.7%) of the 3DGE sequence were limited due to a high number of false positive findings. Cartilaginous lesions were more easily visible on 3DGE than on 2DSE images (sensitivity: 63.1% vs. 52.6%, respectively). As in the clinical study, the meniscal signal abnormalities of the cadaveric knee joints were much more extensive on the 3DGE images than on the 2DSE images. The 3DGE findings correlated better with degenerative meniscal changes which were visible microscopically. CONCLUSION: The high sensitivity of the 3DGE sequence for degenerative meniscal changes explains the lack of specificity for the differentiation between meniscal degeneration and tears with this sequence. The MR grading system for meniscal lesions is of limited value for the evaluation of 3D FISP images.

[Magnetic resonance tomographic diagnosis of periarticular cystic space-occupying lesions in the knee joint]. / Magnetresonanztomographische Diagnostik periartikulärer, zystischer Raumforderungen am Kniegelenk.

The MR images of the knee joint of 100 successively examined patients were evaluated in retrospect with regard to periarticular cystic lesions. There were 18 popliteal cysts, 8 meniscal cysts and 4 ganglion cysts. Localisation and internal structure of the lesions were of main importance in respect of differential diagnosis. All meniscal cysts were associated with horizontal meniscal tears. Spin-echo and 3D gradient-echo images did not enable differentiation because of signal intensity values. A spin-echo sequence with long repetition time in double-echo technique was best suited to assess the periarticular cystic lesions as well as the intraarticular pathological changes which were often concomitant.

[Duplex sonography and magnetic resonance tomography in the clarification of nephrologic complications following kidney transplantation]. / Duplexsonographie und Kernspintomographie bei der Abklärung nephrologischer Komplikationen nach Nierentransplantation.

A prospective study compared duplex sonography and magnetic resonance imaging in evaluating renal transplants. One hundred and two duplex sonographic and 24 MR examinations were performed and correlated with clinical course or biopsy. All normal renal allografts, 6 transplants with acute tubular necrosis and 2 cases of cyclosporin toxicity had normal Doppler waveforms, whereas 9 renal transplants with evidence of interstitial rejection by biopsy showed an obliteration or reversal of diastolic flow. MR imaging was less specific in identifying allograft rejection. There were false positive results in normal renal transplants, allografts with acute tubular necrosis and after rejection therapy. With regard to cost, accessibility and specificity, duplex sonography is the method of choice for the evaluation of renal allografts.

[Nephrocalcinosis in childhood. Sonographic findings and differential diagnosis]. / Die Nephrokalzinose im Kindesalter. Sonographische Befunde und Differentialdiagnostik.

Ultrasonography is the method of choice for the detection of medullary or cortical nephrocalcinosis in infancy and childhood. Compared with abdominal radiographs and computed tomography even smallest calcifications are detected more accurately. Using furosemide, ACTH, steroids or high doses of vitamin D, early forms of medullary nephrocalcinosis associated with a faint hyperechogenic rim at the margins of the renal pyramids can be diagnosed by ultrasound. Idiopathic hypercalciuria, Bartter's syndrome and renal tubular acidosis cause medullary nephrocalcinosis, whereas cortical nephrocalcinosis is the result of renal vein thrombosis; primary hyperoxaluria is associated with cortico-medullary calcifications. Due to the localisation of the nephrocalcinosis and the age distribution of the diseases, sonography merely enables us to narrow down differential diagnosis.

[The findings and value of computed tomography in pleural empyema]. / Befunde und Stellenwert der Computertomographie beim Pleuraempyem.

Chest radiographs and CT images of 25 patients with pleural empyemas were compared retrospectively with those of 20 patients with pleural exudates and transudates in order to determine criteria for differential diagnosis and to define the place of CT in the diagnosis of pleural empyemas. The sign which was most suggestive of an empyema on a chest radiograph was an encapsulated effusion in an atypical position (18/25); this was found in only 4 out of 20 exudates and in none of the transudates. On CT, changes in the pleura, the subcostal tissues and the configuration and position of the fluid were suggestive of an empyema. In nearly all patients with a pleural empyema there was thickening and increased contrast uptake of the parietal pleura (22/25) and thickening and increased density oft the subcostal tissues (23/25). Usually, empyemas were encapsulated and biconvex (20/25). None of the patients with pleural transudates showed any of these changes. In the presence of some pleural exudates, pleural (14/20) or thoracic (11/20) changes were noted. In part, these changes were due to previous treatment (sclerotherapy) or tumour infiltration (7/20). An attempt to correlate the CT findings with changes in the pleura and subcostal tissues with the clinical empyema stages I-III, according to Light, showed that CT was unable to distinguish between early and late empyemas. Consequently, diagnostic aspiration remains necessary for correct treatment.

[Nuclear magnetic resonance tomographic diagnosis of brain tumors in children and adolescents. A comparison with computed tomography]. / Kernspintomographische Hirntumordiagnostik im Kindes- und Jugendalter. Vergleich mit der Computertomographie.

Thirty-one pediatric patients with brain tumors--25 primarily diagnosed, 6 recurrences--underwent MR and CT examinations before and after application of contrast media. Tumor detection, delineation of the tumor extent and definition of the tumor type were compared. Gd-DTPA-enhanced MR was superior in delineating the extent of primarily diagnosed tumors, which showed enhancement (n = 22). The tumor detection (1/6) and the identification of the tumor margins (5/6) were improved by Gd-DTPA in the 6 recurrences. Tumors without enhancement (n = 3) were judged by T2-weighted images better than by CT. The results suggest that Gd-DTPA is indicated for the evaluation of brain tumors in pediatric patients as well, especially since it offers advantages distinguishing between tumor types. Only the detection of tumor calcifications, which is rarely specific, is not possible by MR.

[A comparative study of the imaging quality and picture dosage of a new conventional film-screen system for skeletal x-ray diagnosis]. / Vergleichende Untersuchung der Abbildungsqualität und Aufnahmedosis eines neuen konventionellen Film-Folien-Systems für die skelettal Röntgendiagnostik.

PURPOSE: This paper compares a new film-screen system (FSS) called INSIGHT Skeletal Imaging System with the previously used Lanex/T-MAT G FSS. MATERIAL AND METHODS: Using a Bronder phantom, measurements were made of dose, resolution and contrast. 135 skeletal phantom images were assessed in order of quality by six observers. RESULTS: Comparable high resolution film-screen combinations (FSC) showed similar geometric resolution. Comparing high intensifying screens, the new INSIGHT Skeletal Regular FSS showed better resolution than the Lanex medium FSC. Dose reduction for the INSIGHT Skeletal Imaging FSS was 29-56%. The new FSS showed image quality similar to high resolution screens but was significantly better when using high intensifying screens. CONCLUSION: The new INSIGHT Skeletal Imaging System can replace the Lanex/T-MAT G FFS by retaining quality but reducing radiation dose by 29-56%. Using the new high intensifying FSC, images showed in addition improved film quality.

[NMR tomography in plasmacytoma]. / Kernspintomographie beim Plasmozytom.

In 20 patients with multiple myeloma, the results of MR, x-ray, bone scintigraphy, bone marrow scintigraphy and bone marrow biopsy were compared. MR proved the most sensitive imaging method for the detection of bone marrow infiltration followed by x-ray examinations. Bone marrow scintigraphy and especially bone scintigraphy revealed false-negative results more often. These findings were more impressive by the direct comparison of several investigated regions showing different findings of each imaging method. False-positive results were not found. In 4 patients false-negative results of bone marrow biopsy had to be assumed because of definitely pathological findings by x-ray and MRI.

[Possible computed tomographic and magnetic resonance tomographic detection of wood foreign bodies following perforating eye injuries]. / Computertomographische und kernspintomographische Nachweismöglichkeit hölzerner Fremdkörper nach perforierender Augenverletzung.

After perforating eye injury the retention of a foreign body in the orbits has to be excluded. Wooden foreign bodies mostly have negative density on CT, which increases later as a result of granulomatous changes. On MRI, pieces of wood appear with low signal intensity, and only in some cases is a collar-shaped structure recognizable, allowing differentiation from gas. Soon after orbital trauma with splinters of wood, therefore CT allows better differentiation of pieces of wood from intraorbital gas by measurement of their density, whereas MRI, makes it possible to demonstrate wooden foreign bodies in older injuries in spite of granulomatous changes.

The rope ladder: an uncommon artifact and potential pitfall in MR arthrography of the shoulder.

OBJECTIVE: MR arthrograms were retrospectively reviewed for susceptibility artifacts induced by accidental injection of a small amount of gas when paramagnetic contrast solution was injected. A pitfall to interpretation, an unusual distribution of intraarticular gas into the sheath of the long biceps tendon that resembled a rope ladder, was observed and compared with findings of bicipital tenosynovitis. CONCLUSION: Intraarticular gas contamination during MR arthrography must be differentiated from intraarticular loose bodies and findings of bicipital tenosynovitis. Most reliable for the differential diagnosis are the different shapes and sizes of the gas-induced susceptibility artifacts on spin-echo and gradient-recalled echo images.

Arterial pseudoaneurysm as a complication of percutaneous transhepatic biliary drainage: treatment by embolization.

We observed a serious arterial hemorrhage as a complication of percutaneous transhepatic biliary drainage (PTBD). The hemorrhage appeared during catheter placement for implantation of an endobiliary stent as a two-step procedure. It was caused by an arterial pseudoaneurysm and could be successfully treated by superselective embolization. Although there was a preexisting cavernous transformation of the portal vein no signs of liver cell necrosis appeared after embolotherapy. Vascular complications of PTBD will be discussed with regard to their frequency, possible etiology, ways to avoid them and their interventional therapy.

MR arthrographic findings in tenosynovitis of the long bicipital tendon of the shoulder.

PURPOSE: To assess the MR arthrographic findings of bicipital tenosynovitis in correlation with arthroscopy. DESIGN AND PATIENTS: The shoulder MR arthrographies of 500 consecutive patients were retrospectively analyzed for signs of bicipital tenosynovitis and associated pathologies. Forty patients (8%) had MR evidence of bicipital tenosynovitis, but only 17 (3%) with arthroscopic confirmation were included in the study. The MR findings in these patients were compared with those of 10 patients with rotator cuff lesions but arthroscopically normal long biceps tendons. MR arthrography was performed with 10-15 ml of a 250 mmol/l gadoterate meglumine (Gd-DOTA) solution injected under fluoroscopic guidance, and transaxial, oblique coronal and sagittal MR sequences were obtained. RESULTS: All 17 patients showed one or more abnormal findings: signal increase in the tendon with or without fusiform distension was seen in 12, surface irregularities in six, adhesions in 11 and noncommunicating effusions of the tendon sheath in six. Associated abnormalities of the rotator cuff were present in 16 while the seventeenth patient had glenohumeral synovitis without rotator cuff pathology. MR arthrograms correlated with arthroscopic findings in the joint but comparison was not possible in the intertubercular groove portion of the biceps tendon. None of the 10 patients with an arthroscopically normal biceps tendon showed any of the MR findings of bicipital tenosynovitis. CONCLUSION: Bicipital tenosynovitis is detectable by MR arthrography. In most cases it is an associated finding of rotator cuff abnormalities and likely to have a similar etiology. When lesions of the anterior rotator cuff are recognized, the biceps tendon should be scrutinized for inflammatory changes.

[Duplex sonographic findings following kidney transplantation-- possible value in the diagnosis of graft rejection]. / Duplexsonographische Befunde nach Nierentransplantation--Aussagemöglichkeiten bei der Abstossungsdiagnostik.

59 prospective duplex ultrasound studies have been performed on 30 patients after renal transplant to assess the feasibility of detection of acute rejection. The results were compared with clinical, biochemical and histopathologic findings. Real time ultrasound was not a reliable method in predicting acute rejection. Doppler sonography, however, characteristically showed a diminished diastolic blood flow in all cases of acute rejection. Acute tubular necrosis and cyclosporine toxicity were not provable, neither by real time ultrasound nor by doppler sonography. Duplex ultrasound combines the advantages of both methods in detecting perirenal fluid collections, hydronephrosis and acute transplant rejection.