Magnetic resonance imaging of the normal prostate at 1.5 T.

Prostatic magnetic resonance images of 22 male volunteers less than 30 years old and with no known genito-urinary tract disease were obtained at 1.5 T. Normal anatomical features of the prostate were studied with spin-echo techniques. Different zones of the normal gland are shown by T2-weighted images: the anterior fibromuscular fascia, the central prostate, the peripheral prostate and the periurethral zone can be differentiated. The normal prostate gland is shown on T1-weighted images as a homogeneous appearance. It is important to recognize the normal zonal anatomy of the prostate since prostatic disorders arise in different anatomical zones.

[NMR evaluation of neoplastic invasion of the pulmonary artery]. / NMR-Beurteilung neoplastischer Pulmonalarterien-Invasionen.

Bronchial tumors that invade the mediastinum are not necessarily inoperable. Whether surgery is possible depends, among other things, on the extent of pulmonary artery invasion. The authors have studied the value of cardiac-gated MRI and compared it with CT and venous DSA for staging tumor invasion. CT demonstrated the areas of contact between tumor and mediastinum. The MRI planes were transverse and also in the main axis of the pulmonary arteries. Twenty-one patients were studied and in 16 the findings could be checked during surgery. In all cases the findings on MRI were confirmed. In eight patients MRI provided more information than CT and DSA combined and thereby showed its superiority for evaluating arterial invasion.

Hypothesis: reduced renal mass with glomerular hyperfiltration, a cause of renal hyperechogenicity in children.

A group of 10 pediatric patients had renal hyperechogenicity and reduced renal mass. The authors wish to suggest a relationship between renal hyperechogenicity and glomerular hyperfiltration according to Brenner's theory on the progressive nature of kidney disease. Reduced renal mass was related to multicystic dysplastic kidney (3 cases) nephrectomy (3 cases) and to reflux nephropathy (4 cases). The hyperechogenicity was diffuse in 6 cases with the preservation of cortico-medullary differentiation and was localized in all four cases of reflux nephropathy producing a "pseudotumoral" appearance. Hyperfiltration was confirmed by isotope studies in all 3 cases where it was performed. This condition together with secondary glomerulosclerosis could explain hyperechogenicity. The predictive value of such patterns are still unclear; yet such findings should lead to appropriate radiolocal, functional, clinical and dietary measures.

[Diagnostic role of MRI in localized cancer of the prostate]. / Place diagnostique de l'IRM dans le cancer localisé de la prostate.

The authors extracted 11 case files of patients undergoing radical prostatectomy following MRI studies from a series of 192 MRI examinations of the prostate with histological confirmation of the diagnosis. This series is part of a prospective study in which MRI was always interpreted prior to histological results. The diagnosis of prostatic cancer was confirmed in 9 cases on the basis of a hyposignal on T2-weighted scans. In 4 cases, extracapsular spread of the tumour was demonstrated by MRI and was confirmed at surgery. In the cases in which the cancer was visible on MRI, the diagnosis of local spread proved to be accurate. The debate concerning the role of MRI in prostatic disease is not definitively resolved, but this preliminary series indicates the potential and the limitations of this technique.

Cysts of the prostate and seminal vesicles: MR imaging findings in 11 cases.

Cysts of the prostate and seminal vesicles are confusing abnormalities because they are uncommon and their origin is uncertain. Several approaches to diagnosis have been used, most recently CT and transrectal sonography. In this study, we investigated the value of MR imaging in the diagnosis of six cases of prostatic cyst and five cases of cysts of the seminal vesicles. All patients were symptomatic. T1- and T2-weighted spin-echo images were obtained in all cases; pathologic confirmation was available in four patients. MR images were analyzed prospectively without knowledge of clinical data or the results of other imaging procedures. In all cases, low- and high-signal masses were observed on T1- and T2-weighted images, respectively. The cysts were unilocular with a sharply defined margin, ranging from 0.5 to 3.0 cm in diameter. The thin wall was of low signal intensity on T2-weighted images. Our experience suggests that MR imaging is useful in demonstrating the liquid content of prostatic and seminal-vesicle cysts and in establishing their size and location.