Early detection of avascular necrosis of the femoral head following renal transplantation.

This prospective study included 43 patients undergoing renal transplantations. Magnetic resonance imaging (MRI) and X-rays of the hip joints were produced 3 and 12 months after transplantation. In 6 hip joints of 4 patients (9.3%), we discovered femoral head necroses just 3 months after transplantation. Three of the hip joints affected were symptomatic and 3 painless. The MR images taken 12 months after transplantation revealed no additional femoral head necrosis. A core decompression was performed on 3 joints. In contrast to those with core decompression, the femoral heads without core decompression showed a progression of the necrosis in 2 of 3 cases. All 4 patients with femoral head necroses were younger than 50 years and exhibited a premature conversion of the haematopoietic marrow to fatty marrow in the area of the proximal femoral metaphysis. A similar premature conversion to fatty marrow was seen in 6 of the 22 (27.2%) patients younger than 50 years and without femoral head necroses. The doses in long-term steroid medication and the steroid doses during the rejection periods of the patients with femoral head necroses were not significantly higher than those for the patients with premature conversion to fatty marrow. The latter had also not received significantly higher doses than the patients whose MRI findings were inconspicuous.

Intracranial stenoocclusive disease: MR angiography with magnetization transfer and variable flip angle.

PURPOSE: To assess time-of-flight MR angiography that uses magnetization transfer contrast (MTC) pulses, tilted optimized nonsaturating excitation (TONE), and a 256 x 512 image matrix for the detection of small intracranial arteries and for the detection and quantification of intracranial arterial stenoocclusive disease. METHODS: To assess anatomic sensitivity, six interpreters, in a blinded fashion, reviewed the MTC/TONE MR angiograms and selective intraarterial angiograms obtained in 70 patients within a mean interval of 5.5 days (SD, 1.5). In addition, all intracranial angiograms were evaluated with regard to presence and degree of arterial stenosis and anatomic variants. RESULTS: Interobserver correlations for determining vessel length were comparably high for both methods. A strong correlation was found between measurements obtained on MR angiograms and those obtained on intraarterial angiograms. The mean vascular length averaged across all arteries was 34.8 mm (SD, 28.1) on MR angiograms and 53.2 mm (SD, 36.8) on intraarterial angiograms. Forty-one stenoses and occlusions and 30 anatomic variants were identified with intraarterial angiography. All arterial variants and 100% of occluded vessels were graded correctly. Moreover, 80% of stenoses greater than 70% and 88% of stenoses less than 70% were quantified correctly at MR angiography. Specificity for identifying stenotic disease was 99%. CONCLUSION: Despite inferior display of vessel length, MTC/TONE MR angiography with increased spatial resolution was able to show the vast majority of high grade lesions visible at selective intraarterial angiography and may suffice for clinical decision making in many patients.

[Proton spin tomographic changes of the femoral shaft in patients with kidney transplantation]. / Kernspintomographische Veränderungen des Femurschaftes bei nierentransplantierten Patienten.

In a prospective study 43 patients were reviewed 3 and 12 months after renal transplantation. The patients had MRI examinations and plain x-rays of the hips as well as punch biopsies of the iliac crest. In 9 patients diffuse, inhomogeneous bilateral changes of the MRI-signal patterns of the femoral diaphysis were seen. They were hypointense in the T1-weighted images and hyperintense in the STIR-images. All plain x-rays were inconspicuous. These changes of the femoral shaft were significantly more frequent in patients with renal osteodystrophy of the histological type Delling Ila. We conclude that these changes of MRI-signals patterns might be connected with an osteoidosis.

[Clinical long-term results after corrective surgery of tetralogy of Fallot]. / Klinische Langzeitergebnisse nach Korrekturoperation einer Fallotschen Tetralogie.

We studied 246 consecutive patients, mean age 11.9 +/- 6.7 years, with primary (n = 155) or secondary (n = 91) complete repair of tetralogy of Fallot (TOF) between 1961 and 1972. Prospective follow-up was complete and ranged from 18.1 to 29.3 (mean: 20.3 +/- 4.2) years. There were 46 operative and 21 late deaths. Cumulative survival was 0.76 +/- 0.03 after 1 year, 0.72 +/- 0.03 (10 years), 0.68 +/- 0.04 (20 years) and 0.63 +/- 0.05 (25 years). After 20 years of follow-up, which was a follow-up time available for all patients, cumulative complication rates were 0.17 +/- 0.03 for documented ventricular tachycardias/fibrillation, 0.16 +/- 0.03 for right-heart failure, 0.13 +/- 0.03 for left-heart failure and 0.11 +/- 0.03 for infective endocarditis. Eighteen of the 21 late deaths were from cardiac causes: sudden (n = 9), infective endocarditis (n = 4), left-heart failure (n = 3), and right-heart failure (n = 2). The hazard for ventricular arrhythmias was inconstant and increasing with time from the initial operation. After 20 years of follow-up, the cumulative incidence of sudden death, documented ventricular tachycardia/fibrillation was 0.81 +/- 0.07. Younger age at surgery resulted in a significantly better long-term prognosis (p = 0.03) with cumulative survival rates after 20 years being 0.90 +/- 0.06 (ages 1-9 years), 0.92 +/- 0.04 (10 to 14 years), 0.83 +/- 0.09 (15 to 19 years) and 0.69 +/- 0.11 for patients being operated beyond age 20. Twenty years following TOF repair 59.2% of the late survivors were in NYHA functional class I and 36.2% in NYHA II.

[Functional imaging of the brain using low dose gadolinium-DTPA and Turbo-FLASH sequences]. / Funktionelle Bildgebung des Gehirns mit niedrigdosiertem Gadolinium-DTPA und Turbo-FLASH-Sequenzen.

A method for measuring regional blood volume and flow is described based on the reduced relaxation time following intravenous injection of Gd-DTPA. The optimal Gd dose and other parameters were first determined using turbo-flash sequences and a dilution phantom. A single maximum was found for a Gd-DTPA concentration of 4 mmol/l. Taking account of normal heart/time volumes and in order to stay below this arterial value Gd-DTPA was injected as a bolus at the rate of 1 mmol/sec. From the phantom measurements there appears to be a functional connection between measured signal intensity and Gd concentration. The method was applied to 15 patients with cerebral tumours, using altogether 26 perfusion examinations. The results from 4 patients are given as examples; in these, blood volume and flow were calculated for each pixel in a 128 x 128 matrix. It was found that the Gd-DTPA injected is sufficient to be shown with certainty in the grey and white matter and that this is able to demonstrate pathological changes in a functional manner. Comparison with Gd-DTPA doses such as are used for morphological imaging (typically, 10 mmol corresponding to 0.1 mmol/kg body weight) has shown that doses above 1.6 mmol may lead to distortion of the concentration curves.