Azygos blood flow: phase contrast quantitation in volunteers and patients with portal hypertension pre- and postintrahepatic shunt placement.

Flow volume in the azygos venous system was quantitated with Cine-phase contrast (PC) velocity mapping in volunteers and compared with patients with known portal hypertension, who were referred for transjugular intrahepatic portosystemic shunt (TIPS) placement. Subsequently, the TIPS-induced hemodynamic effects on portal and azygos flow were analyzed. To assess intra- and intersubject variability, flow in the azygos veins was measured in each of 10 normal subjects at three different times. Subsequently, portal and azygos flow was quantitated in 20 patients with portal hypertension, before and after TIPS placement. All imaging was performed on a 1.5-tesla magnetic resonance imaging (MRI) system. Azygos flow was measured transaxially at the midthoracic level. Cine-PC flow measurements of the main portal vein followed morphological evaluation of the portal venous system with axial and coronal breath-held magnet resonance angiogram. Azygos flow in normal subjects was characterized by high inter- and low intrasubject variability. Azygos flow in patients with portal hypertension was significantly higher (P < .001). Following successful TIPS placement in 18 patients, Cine-PC revealed a mean decrease in azygos flow of 46.3% (P < .001) and a 134% (P < .001) increase of portal flow. Reflecting the complexity of portal hemodynamics, there was no correlation between the changes in the portal and azygos systems. In 2 patients with early occlusion of TIPS, documented invasively, portal and azygos flow values remained largely unchanged. Cine-PC enables the noninvasive, quantitative assessment of flow within the azygos venous system. Azygos flow was found to be markedly elevated in patients with portal hypertension. Combined portal and azygos PC flow measurements quantitate the therapeutic effect of TIPS placement.

MR venography of the calf: value of flow-enhanced time-of-flight echoplanar imaging.

OBJECTIVE: Release of a tourniquet on the thigh and termination of Valsalva's maneuver result in a transient increase in venous blood flow in the leg. The purpose of this study was to determine the value of time-of-flight echoplanar imaging performed with these flow-enhancing methods to image the veins of the calf. SUBJECTS AND METHODS: Flow volumes in the femoral veins in eight volunteers were determined with a two-dimensional phase-contrast MR imaging technique before and immediately, 20, 40, and 60 sec after termination of Valsalva's maneuver and thigh vein occlusion. Subsequently, the calf veins of 11 healthy volunteers were imaged with a two-dimensional four-shot echoplanar MR imaging technique. Forty-one 5-mm-thick sections were obtained over 10 sec immediately after termination of venous occlusion. Visibility of the three venous bundles was analyzed in the proximal, middle, and distal portions of the calf on the basis of a four-point scale. Finally, the calf of a single patient with documented DVT was imaged by the same MR imaging technique. RESULTS: Both Valsalva's maneuver and venous occlusion caused significant increases in venous flow (p < .05) only during the first 20 sec after termination of the maneuver and the occlusion. Venous occlusion had a significantly greater effect than did Valsalva's maneuver (p < .05). Flow augmentation by venous occlusion of the thigh improved calf vein visualization with time-of-flight echoplanar MR imaging (p < .0001). Of the 99 calf vein segments examined, 93 were clearly seen. Thrombi were seen in the patient study. CONCLUSION: Multishot time-of-flight echoplanar imaging can exploit the short-lived effect of mechanical flow-enhancing measures, resulting in good visualization of calf veins. The true diagnostic impact of this technique needs to be evaluated in a patient study.

[MRI venous angiography of the abdomen]. / MR-Venenangiographie des Abdomens.

The assessment of abdominal vessels by conventional methods is invasive and frequently does not yield an accurate diagnosis, particularly in evaluation of the portal venous system. MR angiography is non-invasive and is well suited to the examination of abdominal veins. Both vessel morphology and intravascular flow patterns can be characterized with this method. Clinical indications include portal hypertension, portal vein thrombosis, portosystemic shunts as well as assessment of congenital anomalies, thrombus and tumor propagation into the inferior vena cava and the renal veins. In the future MR angiography is likely to evolve into the modality of choice for non-invasive evaluation of abdominal venous structures.

Diffuse idiopathic skeletal hyperostosis (DISH) of the shoulder. A controlled radiological study.

The prevalence of hyperostotic spurs (HS) in different areas of the shoulder was studied in 36 probands with and 58 probands without thoracospinal hyperostosis on lateral chest radiographs. Bilateral shoulder radiographs in three projections were analysed blindly, recording the presence of HS at six separate sites (glenoid, greater tuberculum, acromion, acromioclavicular joint, coracoid and humeral shaft) and applying defined grading criteria. The prevalence of HS ranged from 11.7% of the shoulders at the coracoid to 50.0% at the glenoid. The prevalence of HS was similar on both sides [right, 30.1% of the sites versus left, 27.0%, relative risk (RR) 1.12 (95% confidence interval [Cl] 0.93-1.35)] and was not related to sex and history of work. Classification for the presence of shoulder hyperostosis was identical on both sides with the exception of one individual. In probands with thoracospinal and shoulder hyperostosis all areas analysed contributed to the classification. However, this was particularly prominent at the humeral shaft [RR 5.3 (95% Cl 2.1-13.0)] and the coracoid [RR 8.4 (95% Cl 1.9-36.4)]. These results indicated that the prevalence of HS and the specificity for the presence of diffuse idiopathic skeletal hyperostosis (DISH) vary between different sites. We suggest that future grading criteria for shoulder hyperostosis take into account the localization of HS, in addition to their number and size.

Shortcomings of chest radiography in detecting Pneumocystis carinii pneumonia.

The radiographic presentation of Pneumocystis carinii pneumonia (PCP) was studied in 93 consecutive patients to determine the frequency of normal findings on chest roentgenograms and possible correlations with clinical or laboratory findings. The roentgenograms were reviewed by two radiologists in an independent, blinded way and judged with a score distinguishing between none, interstitial, and acinar infiltrates. Discordance mainly between absent versus interstitial and interstitial versus acinar infiltrates occurred in 23% of roentgenograms and was settled by consensus. The majority of patients presented with moderate-to-mild symptoms; the combination of dyspnea, cough, and fever was present in 53%. Lactate dehydrogenase (LDH) was elevated in 63%, hypoxemia (PaO2 < 75 mm Hg) was present in 57%. Findings on chest roentgenograms were normal in 39%, whereas 36% showed interstitial and 25% acinar infiltrates. These three radiographic groups represented an increasingly severe PCP, indicated by higher LDH levels and hypoxemia (both p < 0.05). In a multivariate logistic regression, normal roentgenograms were predicted by low LDH and low peripheral blood granulocytes (p < 0.005). Mortality within 3 weeks was only 4% and correlated with the severity of infiltrates (p < 0.05). Normal roentgenograms thus corresponded to an oligosymptomatic, less severe PCP. In immunodeficient HIV-infected patients, a normal chest roentgenogram does not exclude PCP and should not distract from attaining a definite diagnosis by examination of induced sputum or bronchoalveolar lavage.

[Three-dimensional imaging of the pelvic veins using magnetic resonance angiography]. / Dreidimensionale Darstellung der Beckenvenen mit Magnetresonanz-Angiographie.

The veins in the pelvis and lower limbs have been demonstrated by means of magnetic resonance angiography (MRA) in 11 normals and in 20 patients, using a "time-of-flight" technique (TOF). Using normals, changes in the measurement parameters were used in order to optimise the examination protocol; consequently, the internal and external iliac veins and the superior and inferior gluteal veins could be identified in all cases and the internal pudendal veins in 6 out of 11 cases. This examination protocol was then used in patients with clinical suspicion of lower limb or pelvic vein thrombosis. Comparison of the MRA findings with those of phlebography (7 cases), duplex sonography (6 cases) and colour Doppler examinations (11 cases) showed that MRA was better for diagnosing thrombosis of the internal iliac veins (10 cases) than the other methods. In two patients thromboses of the common iliac veins and the inferior vena cava were demonstrated which were missed by colour Doppler examination. On the basis of our present experiences, MRA, using a two-dimensional TOF technique, appears to be a reliable non-invasive technique for demonstrating the veins of the pelvis and thigh.

[Magnetic resonance imaging. Sequences, options, indications]. / Magnetresonanz-bildgebung. Sequenzen, Optionen, Indikationen.

In the last few years several new MR sequences have been developed an even more imaging options have become available. In this paper, the properties of all the important MR sequences and their possible variations are discussed and their use in different clinical settings is addressed.

[Reduction of MRT time in the female pelvis using T2-weighted Fast-Spinecho(FSE)-technique. A quantitative and qualitative comparison of conventional spinecho(SE) and Fast-Spinecho(FSE)-sequence]. / Verkürzung der MRT-Messzeiten im weiblichen Becken mit Hilfe der T2-gewichteten Fast-Spinecho(FSE)-Technik. Quantitativer und qualitativer Vergleich der konventionellen Spinecho(SE)- und Fast-Spinecho(FSE)-Sequenz.

The fast spin echo (FSE) technique leads to time saving by individual phase coding of several spin echoes within one repetition interval. The new sequencing was compared quantitatively and qualitatively with conventional spin echo sequences in 30 patients with gynaecological pelvic disease. The signal-to-noise ratio was higher on FSE images in all tissues but to a variable degree. This led to an increased contrast-to-noise ratio, particularly between fat and solid structures, and to a reduction in the contrast between fat and fluid. Artifacts were reduced in FSE sequences leading to improved image quality in 83% and increased diagnostic information in 10%. This is of particular advantage when using time consuming T2-weighted sequences, which are necessary for the examination of the female pelvis.

The prevalence of palpable finger joint nodules in diffuse idiopathic skeletal hyperostosis (DISH). A controlled study.

The presence of clinically palpable finger joint nodules (Heberden's and Bouchard's nodes) was documented in 123 consecutive cases with diffuse idiopathic skeletal hyperostosis (DISH) of the thoracic spine and 191 matched DISH negative controls. The prevalence of palpable finger joint nodules was almost twice as frequent in cases with spinal DISH compared to controls (46% versus 31%, chi 2 = 7.67, P less than 0.01; multivariate adjusted odds ratio OR = 1.84; 95% CI: 1.14-2.98). This increase was most marked at the proximal interphalangeal joint, in males and in patients up to the age of 65 years. In addition and independent of other variables such as hyperostotic features, age and sex, the prevalence of palpable finger joint nodules was about twice as high in probands with a history of physically heavy work compared to those without (43% versus 26%, chi = 9.18, P less than 0.005; multivariate adjusted odds ratio OR = 2.10; 95% CI: 1.26-3.52). From these results we conclude that DISH should be considered as an independent risk factor in the development of finger joint nodules.

Swollen lower extremity: role of MR imaging.

The authors assessed the use of magnetic resonance imaging in differentiating lymphedema, phlebedema, and lipedema of the lower limb. They examined 14 patients: five with lipedema, five with lymphedema, and four with phlebedema. T1- and T2-weighted transaxial sequences were performed before administration of gadolinium tetraazacyclododecane-tetraacetic acid (DOTA) and T1-weighted spin-echo sequences were performed after administration of Gd-DOTA in each patient. Images of patients with lipedema showed homogeneously enlarged subcutaneous layers, with no increase in signal intensity at T2-weighted imaging or after Gd-DOTA administration. Patients with phlebedema had areas containing increased amounts of fluid within muscle and subcutaneous fat. In lymphedema, a honeycomb pattern above the fascia between muscle and subcutis was observed, with a marked increase in signal intensity at T2-weighted imaging. After Gd-DOTA administration, there was only a slight increase in signal intensity in the subcutis in lymphedema and phlebedema and a moderate increase in signal intensity in muscle in phlebedema.

Diffuse idiopathic skeletal hyperostosis (DISH) of the elbow: a cause of elbow pain? A controlled study.

Elbow pain is a common complaint and elbow hyperostosis a frequent radiological condition. However, little is known about the association between the clinical and radiological findings. To evaluate the relationship between spinal and extraspinal hyperostotic features and the clinical relevance of elbow hyperostosis we have performed the first controlled, double-blinded study of 85 hospitalized probands, 33 with and 52 without thoracospinal hyperostosis on lateral chest X-ray. Elbow and shoulder hyperostosis were graded on bilateral standard radiographs. Elbow pain was assessed by an interviewer using a standardized questionnaire and extraskeletal causes of elbow pain were recorded. The prevalence of elbow hyperostosis was increased in cases with thoracospinal hyperostosis compared to controls (82% versus 58%, chi 2 = 5.32, P less than 0.025, n = 85, olds ratio (OR) 3.30 (95% CI 1.16-9.35)). Similarly, the prevalence of elbow hyperostosis was increased in cases with shoulder hyperostosis compared to controls (83% versus 60%, chi 2 = 4.51, P less than 0.05, n = 84, OR = 3.20 (95% CI 1.06-9.66)), emphasizing the multifocal nature of hyperostotic features. Elbow pain was only slightly more prevalent in cases with elbow hyperostosis compared to controls (21% versus 13%, chi 2 = 0.75, NS, OR = 1.84 (95% CI 0.46-7.44)). We conclude that elbow hyperostosis is a radiological finding of doubtful clinical relevance.

MRI and sonography of the shoulder.

We prospectively evaluated the diagnostic value of sonography and magnetic resonance imaging (MRI) in 24 shoulders in 23 patients with suspected rotator cuff tears using arthrography as gold standard. Sonography demonstrated 14 of 15, MRI 10 of 15 rotator cuff tears, respectively. Sonography diagnosed seven of nine intact rotator cuffs correctly, MRI eight of nine. In a retrospective study we reviewed the diagnostic value of sonography and MRI in other pathologies of the shoulder including intra-articular pathology, humeral head and acromioclavicular joint pathology, and calcification. We conclude that with regard to cost and patient compliance, sonography should be the first radiologic examination in suspected rotator cuff tears if performed by an experienced sonographer. MRI is superior in depicting additional pathology and is less operator dependent. It may thus become the method of choice for the evaluation of the rotator cuff and related pathology in the future.

[Rational radiology]. / Sinnvolle Radiologie.

Quality control is essential in pulmonary radiology. It concerns both image quality and radiation dose. A rational approach to radiodiagnostic investigations is mandatory. Radiological diagnosis is based upon sound knowledge and experience.

Nonionic polyethylene glycol-ferrioxamine as a renal magnetic resonance contrast agent.

The MR relaxation properties of ferrioxamine-B, a chelate of iron, were investigated in vitro and in vivo to establish the potential use of the compound as a paramagnetic contrast agent. Whereas the paramagnetic relaxivity of ferrioxamine-B is such that, compared to gadolinium-DTPA (Gd-DTPA), two to three times higher concentrations are necessary to produce the same relaxation effects, the toxicity of the iron ion should be much lower because of the availability of physiological metabolic pathways. Preliminary experiments in three dogs under invasive cardiovascular monitoring demonstrated that high-dose bolus application (0.1-0.3 mmol/kg body weight) of ferrioxamine-B leads to a precipitous blood pressure drop to almost zero, lasting for several minutes. This reaction seems most likely the result of a negative inotropic effect of ferrioxamine-B. In order to reduce these side effects ferrioxamine was modified to a nonionic derivative, PEG-ferrioxamine-B. In vivo experiments with this compound did not demonstrate any substantial change in blood pressure. Dynamic MR imaging of the kidneys and the liver was performed after bolus injection of the compound in six dogs. The results indicate that PEG-ferrioxamine-B produces effects very similar to Gd-DTPA, resulting in T1-mediated signal intensity increases in the liver and in the early stages of passage through the kidneys. During the phase of medullary concentration, T2 effects seem to dominate visualization of the renal medulla. The nonionic PEG-ferrioxamine-B derivative appears to offer an alternative to gadolinium-containing chelates as an MR contrast agent.

Diffuse idiopathic skeletal hyperostosis (DISH) of the shoulder: a cause of shoulder pain?

Shoulder pain is a common complaint and shoulder hyperostosis a frequent radiological condition. However, little is known about the association between the clinical and radiological findings. To evaluate the clinical relevance of shoulder hyperostosis we performed a controlled, blind study of 99 hospitalized probands with and without thoracospinal hyperostosis on lateral chest X-rays. The study included grading of the shoulder hyperostosis on the basis of three bilateral standard radiographs, assessing shoulder pain in a standardized way by an interviewer and recording extraskeletal causes of shoulder pain. The prevalence of shoulder hyperostosis was doubled in probands with thoracospinal hyperostosis compared to controls (chi 2 = 5.90, P less than 0.025, n = 99). Shoulder hyperostosis, irrespective of thoracospinal hyperostosis, predisposed to shoulder pain (40% versus 18%, chi 2 = 4.06, P less than 0.05, n = 74). Shoulder hyperostosis in combination with thoracospinal hyperostosis (shoulder DISH) predisposed to shoulder pain to an even greater extent (46% versus 12%, chi 2 = 6.64, P less than 0.01, n = 47). We conclude that shoulder hyperostosis is a radiological finding of potential clinical relevance.