[Hemophiliac arthropathy of the knee joint. Gd-DTPA-enhanced MRI; clinical and roentgenological correlation]

17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRT before and after i.v. bolus injection of Gadolinium-DTPA (0.1 mmol/kg body weight). After contrast enhancement, synovial proliferations exhibited an increase of signal intensity (SI) on FFE and SE images of 47.7% and 37.4% respectively, whereas muscle and fatty tissue, tendons, bone marrow and joint effusion revealed only minor increase in SI. The gradient of signal intensity (ratio SI/time) of pannus was 39.6%/min. Gd-DTPA enhanced MRI studies delineate and quantify the synovial proliferations in hemophilic arthropathy. Dynamic studies in hemophilic arthropathy do not provide qualitative assessment of the inflammatory process.

[Primary amyloid tumor of the lung]

Primary idiopathic amyloidosis may be a diagnostic problem because of its low incidence and its variable manifestations. The clinical and radiographic findings in a patient with accidentally discovered primary amyloidosis of the lung are presented. The extensive mediastinal and hilar lymph-node enlargement was striking. Peripheral bronchial carcinoma was initially suspected because of the radiographic and CT findings. Various patterns of pulmonary amyloidosis have to be considered in the differential diagnosis of nodules and interstitial changes of the lung.

[Manganese-DPDP in the MR tomography of malignant liver tumors. The initial results with a new hepatobiliary contrast agent]

The new hepatobiliary contrast agent Mangan-DPDP, unlike extracellular Gd-DTPA, leads to a constant increase in signal intensity of normal liver tissue in MR imaging of the liver which lasts at least for 30 minutes. In 19 patients with malignant liver tumors there was no difference in the contrast between tumor and liver when using a dose of 5 or 10 mumol/kg. Contrast enhanced T1-w SE- and T1-w GE sequences show a significant increase in tumor/liver contrast compared with T1-weighted unenhanced sequences. This increase was also significant when compared with T2-w SE sequences. In 16% additional focal lesions were detected on the enhanced scan.

Pneumocystis carinii pleuropneumonia after aerosolized pentamidine prophylaxis

We observed an atypical Pneumocystis infection with spontaneous pneumothorax, bronchopleural fistulae, an apical cyst and Pneumocystis pleuritis after aerosolized pentamidine prophylaxis in an AIDS patient. These findings suggest a failure of pentamidine aerosol in controlling active Pneumocystis infection in peripheral pulmonary areas. A relapse of Pneumocystis carinii pneumonia (PCP) must be suspected when pneumothorax occurs during secondary prophylaxis with aerosolized pentamidine. It should always be confirmed by bronchoalveolar lavage or transbronchial or open biopsy. Cases presenting as atypical Pneumocystis pneumonia may additionally reveal extrapulmonary dissemination of Pneumocystis infection.

[Progressive cytomegalovirus encephalitis in successful ganciclovir therapy of cytomegalovirus retinitis in an AIDS patient]

We describe a case of an HIV-infected intravenous drug-abuser who died of progressive cytomegalovirus encephalitis despite successful treatment of cytomegalovirus retinitis with ganciclovir. On autopsy, complete remission of retinitis and widespread cytomegalovirus-encephalitis could be demonstrated. Therapeutic failure therefore seems attributable to insufficient CNS-distribution of ganciclovir rather than to ganciclovir-resistant cytomegalovirus strains.

[Course and diagnosis of pulmonary Kaposi sarcoma in patients with AIDS]

Diagnosis of pulmonary Kaposi's sarcoma can be difficult. Clinical findings and chest X-rays are non-specific and endobronchial diagnostic in about 50% of cases. Additional concomitant infectious complications are frequent. Symptomatic pulmonary Kaposi's sarcoma most oftenly is progressive and has a poor prognosis. Preliminary data suggest effective palliation with radio- and chemotherapy and an improved survival time in selected cases. We present six cases of proven pulmonary Kaposi's sarcoma and discuss clinical course and diagnostic difficulties. Based on this view we propose a diagnostic approach to warrant therapeutic success.

[Non-selective digital subtraction angiography of aortocoronary bypasses]

Intra-arterial DSA was performed on 225 patients with a total of 552 coronary bypasses (515 aorto-coronary venous bypasses and 37 internal mammary artery bypasses). Four hundred and ninety-five bypasses were examined in the four weeks following surgery; of these, 428 (85.9%) were patent. Demonstration of the distal anastomosis was obtained in 40.4% of bypasses of the right anterior interventricular artery and in 36.1% of the right coronary artery, at least in their proximal parts. Bypasses of smaller branches showed filling in 12.8 to 19.2%. Because of the unsatisfactory demonstration of distal vessels by non-selective intra-arterial DSA, this method is suitable only for showing the patency of a bypass in the postoperative phase, but should not be used for investigating cardiac signs and symptoms following a bypass examination.

[Cardiomyopathy in progressive muscular dystrophy]

A dilated cardiomyopathy with clear signs of left-ventricular functional abnormalities occurred in a 21-year-old man with known Duchenne's progressive muscular dystrophy. Echocardiography and magnetic resonance imaging delineated the regional disorder of ventricular wall motion and defined its segmental extent. With neither method was it possible to analyse texture with demonstration of differential regional involvement. As a noninvasive method echocardiography is suitable for diagnosing Duchenne's cardiomyopathy and monitoring its progression.

[Computed tomography in orbital trauma]

The results of CT in 104 patients with traumatic lesions of the orbits have been analysed retrospectively. Eighty-four fractures of the orbital skeleton were diagnosed in 58 patients; in 18 cases there was peri-orbital, retrobulbar or intrabulbar bleeding and two patients had a ruptured globe. A foreign body was demonstrated in 20 cases. Additional fractures of neighbouring paranasal sinuses were present in 22 cases. Mucosal swelling or bleeding in the sinus was found in 59 cases and orbital emphysema in 22 patients. The particular value of CT in the diagnosis of orbital trauma lies in the certainty with which bony injury of the orbit and peri-orbital structures can be demonstrated.

[In vivo measurement of tissue relaxation times using localized 31P and 1H MR spectroscopy]

Methods of in vivo determination of 31P longitudinal relaxation times within image-determined volume selected MRI spectroscopy have been investigated. T1 values for phosphor compounds in skeletal muscle and in brain have been measured. The 1H relaxation times of T1 and T2 of diffuse parenchymal liver disease, using inversion recovery and spin echo sequences were compared with quantitative MR tomography. Clinically, spectroscopic techniques are particularly useful where there is superimposition of water and lipid signals during MR imaging.

[Qualitative control over quantitative MR tomography: in vitro and in vivo checks on relaxation time measurements]

In-vivo and in-vitro checks on measurements of relaxation times in MRI have been carried out as part of quality control. For the in-vitro experiments we used 13 reagents consisting of varying concentrations of copper sulphate manganese sulphate, gadolinium solutions and various oils as well as water. For in-vivo measurements we used liver parenchyma and fat in three subjects. Eight different sequences were performed; intra- and interindividual variations and comparison of three similar MRI units showed average variations of 2-3% for T1 and 3-4% variations for T2 relaxation times. This margin of error makes quantitative MRI acceptable for clinical use.

[Qualitative and quantitative NMR tomographic findings in focal nodular hyperplasia of the liver]

The qualitative and quantitative MRI findings in 16 patients with focal nodular hyperplasia (FNH) of the liver are described; nine of these were confirmed histologically. A central scar is typical of FNH and provides a reliable diagnosis. This finding was seen in half the cases. If the scar is not demonstrable, the following features suggest the diagnosis: smooth margins, homogeneous signal distribution, increased signal intensity in T2-weighted spin-echo images and reduced signal intensity in inversion-recovery sequences. The T1 and T2 relaxation times in FNH are increased by about 30% compared with normal liver tissue.

[Relaxation time measurements in the differential magnetic resonance tomographic diagnosis of liver tumors]

T1-weighted IR sequences and T2-weighted SE sequences and combined SE/IR sequences were carried out in 62 patients with malignant and 50 patients with benign liver tumours and the T1 and T2 relaxation times were measured. IR sequences proved the most sensitive method for imaging focal liver lesions and providing good contrast between liver tissue and tumour. For lesions above 1.5 cm, quantitative MRI achieved an accuracy better than 95% in distinguishing between haemangiomas and malignant lesions. Routine quantitative measurements of relaxation times were sufficiently reproducible for clinical use.

[MR tomography, CT and angiography of vascular malformations of the central nervous system]

The findings on MR tomography in 31 vascular malformations of the central nervous system are described; 26 of these had angiography and 24 were examined by CT. There were 19 A-V angiomas, 7 cavernomas and 5 large aneurysms. MRT provided a correct diagnosis in 29 out of 31 cases, angiography succeeded in 19 out of 26 cases and CT in 20 of 24. MRT was superior to CT and angiography. Nevertheless, it cannot replace arteriography, since this is the only method for demonstrating the vascular supply of angiomas and small aneurysms can be demonstrated only by arteriography.

[CT portography in malignant space-occupying lesions of the liver]

CT portography was performed in 32 patients with liver tumours and in four patients with cirrhosis of the liver, but without evidence of tumour, after angiographic injection of contrast into the superior mesenteric or splenic arteries. Compared with CT using no contrast, or contrast by intravenous injection, CT portography has the following advantages: better tumour detection, better detection of tumour size, better demarcation and localisation of tumours, better demonstration of the portal system, more inhomogeneity of the parenchyma. Of 12 patients with a number of tumours shown on CT, CT portography demonstrated tumours in four cases, which could not be shown by any other imaging method. Problems concerning CT portography in patients with cirrhosis of the liver are discussed.

Cerebral sarcoidosis presenting as supranuclear gaze palsy with hypokinetic rigid syndrome

A 31-year-old man with histologically documented pulmonary sarcoidosis developed a severe hypokinetic rigid syndrome with a supranuclear gaze palsy following recurrent lymphocytic meningitis and occlusive hydrocephalus. Magnetic resonance imaging (MRI) showed multiple hyperintense foci in the CNS, not detectable by computed tomography (CT). Long-term steroid therapy led to clinical complete remission.

[MR tomography of hepatic hemangioma]

MR tomography of the liver using 1.5 T has been carried out in 63 patients with focal lesions in order to demonstrate haemangiomas and to differentiate these from primary and secondary malignant liver tumours. This differentiation was possible in all patients, using conventional spin echo and inversion recovery sequences in combination with sonography. Accuracy was much less good when using gradient echo sequences. With sufficiently large tumours, measurement of relaxation time made possible diagnosis of all the 22 haemangiomas.

[Artifact reduction via motion-compensating gradient shifting in MR tomography]

In 62 patients spinecho or gradientecho sequences compensated for motion were compared with corresponding non-compensated sequences. Compensation during MRT reduces those artifacts which are caused by regular motion. This is particularly effective during examination of the brain stem, spinal canal and the heart. The improved demonstration of the morphology of normal and diseases organs simplifies the analysis of the types of movement.