The results of measurement of length and angles in the x-ray and ultrasound image of the infantile hip joint are dependent on the different shape of the joint but also on different x-ray projections, on a limited accuracy and incorrect technique in measurement. From our investigations on the accuracy of measurement a differentiation between normal and pathological infantile hip joints is not possible by measuring geometrical data in the x-ray resp. ultrasound image. In the x-ray the greatest possible error of the acetabular angle is +/- 3 degrees, that of the so-called "AMC-angle" +/- 5 degrees and of the Alpha- and Beta-angle in the ultrasound image +/- 10 degrees. Thus the collection of geometrical data in the x-ray and ultrasound image of the infantile hip joint is not more reliable than a qualitative assessment orientated on the osseous resp. cartilaginous corner of the acetabulum.

Acetabulum↗

PubMedDate not supplied

[Radiometry of epiphyseolysis capitis femoris. A comparison of conventional roentgen study with axial computerized tomography].

CT scans are proposed for the measurement of tibial, femoral and humeral torsion. The value of computerised tomography in the evaluation of slipped capital epiphysis is yet not discussed. Conventional roentgenographic studies have shown that the capital femoral epiphysis slips by rotating backwards. In a study of 5 cases with a right site slip of the capital femoral epiphysis of different extent a comparison of conventional radiography with CT-scan was undertaken. True lateral films of both hips were obtained at the same time when CT scan of the femoral head and the condylar region of the femur were performed. The optimal site of cross-sectioning the femoral head lies in its center. Both measurements of the epiphysial torsion vary more ore less. This is believed to be related to the different plans in which the upper femoral end is projected in conventional radiography and CT-scan. Both angles of epiphysial torsion are geometrically related. A formula is given for mathematical transfer. Only by marked epiphysial displacement both angles vary to a greater extend. CT scan is suggested to be of certain value in the preoperative evaluation in heavy slips.

Biomechanical Phenomena↗

PubMedDate not supplied

Renal artery stenosis and evaluation of the effect of endoluminal dilatation. Comparison of dynamic CT scanning and I-131-OIHA renogram.

Percutaneous transluminal dilatation was performed in 16 patients with hypertension and renal artery stenoses. Dynamic CT scanning and an I-131-OIHA renogram was performed before and after dilatation. After the procedure (follow-up greater than or equal to 3 months) the hypertension was assessed clinically as normalized in six, improved in five, and unimproved in five patients. The attenuation difference at dynamic CT scanning between both kidneys at the time of peak enhancement following intravenous bolus injection of contrast material diminished significantly from 16 +/- 4 HU before to 7 +/- 6 HU (P = 0.015) after dilatation in the patient group with cured hypertension, whereas the relative opacification of the poststenotic kidneys increased from 43.6 +/- 2.4% to 47.4 +/- 1.7% (P = 0.014). The results of the Isotope renogram showed a similar increase of the relative function of the poststenotic kidneys from 33 +/- 5% to 38 +/- 7% (P = 0.227) and significant improvement of the clearance from 112 +/- 34 to 175 +/- 48 ml/min/1.73m2 (P = 0.040). The results of both techniques did not significantly change in the group of patients with only moderate improvement of hypertension. Deterioration of the results occurred in those patients in which the hypertension remained unchanged.

Adult↗

PubMedDate not supplied

Myocardial [18F]FDG tomography using a conventional gamma camera and a seven pinhole collimator.

OBJECTIVE: Seven pinhole tomography (SPHT) is fast, inexpensive, and, because it relies on standard gamma cameras and computers, available everywhere. This article investigates the suitability of SPHT for the detection and localization of 511 keV gammas emitted from 18F without coincidence detection. MATERIALS AND METHODS: A standard SPH collimator and the table were additionally shielded with lead. For comparison, point sources and cardiac phantoms were imaged on SPHT and a triple head gamma camera (THC). The phantom studies were supplemented with patient examinations using a standard clinical protocol. Circumferential profiles allowed a direct comparison of perfusion under different conditions or perfusion plus metabolism. RESULTS: Dedicated for cardiac workup, SPHT has a 5-10 times better sensitivity (dependent on distance) than THC and gives superior resolution for the extension of a lesion perpendicular to the long cardiac axis: The full width at half-maximum for x- and y-directions (FWHMx,y) for a 99mTc-point source was found to be 35 and 22% smaller at 130 and 220 mm distances with SPHT than with THC. The SPHT even surpasses the THC at greater distances. The resolution falls off with 18F: FWHM increases by 70 and 48%, respectively, compared to 99mTc. The in-depth resolution is worse with SPHT: The FWHM (using 99mTc) is 2-3.5 times greater with SPHT than with THC and remains within this range with 18F. CONCLUSION: It is possible to image 18F distributions using SPHT with a very high sensitivity and good detail resolution, even in the presence of 99mTc and 201Tl. The SPHT compares well with THC for 99mTc, except in its in-depth resolution, and is unsurpassed in its sensitivity and ease of performance.

Deoxyglucose↗