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Y Le Bras

Publications and source records attributed to Y Le Bras.

16 recordsLinked to original sources
PubMed1997

Benign hyperplasia in ectopic prostatic tissue: a rare cause of pelvic mass.

Four cases of a pelvic mass due to the development of benign hyperplasia within ectopic prostatic tissue are reported. They presented a hypoechoic homogeneous or heterogeneous pattern on transrectal ultrasonography and a high signal intensity on T2-weighted spin-echo sequences on MR. On CT the density was similar to that of prostatic tissue. No recent imaging findings of this rare entity have been described in the literature. Possible aetiologies are discussed. Even if it is a rare event, the correct diagnosis can be reached. It is important for radiologists to consider the presence of this lesion because of its benign nature.

Aged↗
PubMed1997

Small pelvic lymph node metastases: evaluation with MR imaging.

The purpose of this study was to determine if lymph node asymmetry in small (< 1.0 cm) pelvic lymph nodes was a significant prognostic feature in determining metastatic disease. Two hundred and sixteen patients who presented with pelvic carcinoma underwent magnetic resonance imaging (MRI). They were correlated with pathological findings obtained at surgery. We considered the maximum diameter (MAD) of both round- or oval-shaped suspicious masses seen in the axial plane. Two different cut-off values were determined: lymph node diameter greater than 1.0 cm (criterion 1) and lymph node diameter greater than 0.5 cm with asymmetry relative to the opposite side for lymph nodes ranging from 0.5 cm to 1.0 cm (criterion 2). With criterion 1, MRI had an accuracy of 88%, a sensitivity of 65%, a specificity of 96%, a positive predictive value (PPV) of 88% and a negative predictive value (NPV) of 88% in the detection of pelvic lymph node metastasis. By considering criterion 2, MRI had an accuracy of 85%, a sensitivity of 75%, a specificity of 91%, a PPV of 71% and a NPV of 91%. Normal small asymmetric lymph nodes were present in 5.6% of cases. Normal asymmetry of pelvic lymph nodes is not uncommon. It cannot be relied on to diagnose metastatic involvement in cases of small suspicious lymph nodes.

Adult↗
PubMed1996

[Value of asymmetry criterion in MRI for the diagnosis of small pelvic lymphadenopathies (inferior or equal to 1 cm)].

The purpose of this study was to determine if lymph node asymmetry in small (< 1.0 cm) pelvic nodes was a significant prognostic feature in determining metastatic disease. 216 patients who presented pelvic carcinoma underwent MR imaging. They were correlated to pathological findings obtained by surgery. We considered on the axial plan the maximum diameter (MAD) of both round or oval-shaped suspicious masses. Two different cut-off values were determined: node diameter superior to 1.0 cm (criterion 1) and node diameter superior to 0.5 cm with asymmetry relative to the opposite side for nodes ranging from 0.5 cm to 1.0 cm (criterion 2). With criterion 1 MR Imaging had an accuracy of 88%, a sensitivity of 65%, a specificity of 96%, a PPV of 88% and a NPV of 88% in detection of pelvic node metastasis. By considering criterion 2, MR Imaging had an accuracy of 85%, a sensitivity of 75%, a specificity of 89%, a PPV of 71% and a NPV of 91%. Normal small asymmetric lymph nodes were present in 5.6% of cases. Asymmetry of normal or inflammatory pelvic nodes is not uncommon. It cannot be relied on to diagnose metastatic involvement in cases of small suspicious lymph nodes, especially because of its low specificity and positive predictive value.

Adult↗
PubMed1995

Fast imaging MR assessment of ureterohydronephrosis during pregnancy.

PURPOSE: to assess the value of the fast imaging sequence called RARE-MR-Urography (RMU) for the diagnosis of pathologic ureterohydronephrosis during pregnancy. MATERIALS AND METHODS: 15 pregnant women with an acute flank pain were examined with RMU. Results were compared with those of ultrasonography (US), X-rays, and the evolution of symptoms. RESULTS: the accuracy of RMU in the detection of urinary tract dilatation and the localization of the level of obstruction was excellent (100%). The determination of the type of obstruction, intrinsic vs. extrinsic, was always exact. RMU alone cannot specify the exact nature of the intrinsic obstruction. Ultrasonography gave less sensitive information in terms of level (60%) and type of obstruction (53%). CONCLUSION: RMU is able to differentiate a physiological from a pathologic ureterohydronephrosis during pregnancy. It could be considered as a procedure of choice for special cases when US failed to establish this differential diagnosis.

Adult↗
PubMed1995

Strecker stent implantation in iliac arteries: patency and predictive factors for long-term success.

PURPOSE: To evaluate Strecker stent implantation in iliac arteries. MATERIALS AND METHODS: Sixty-four iliac arteries with Strecker stents were prospectively studied. Stents were placed for dissection (n = 31), total occlusion (n = 28), unsatisfactory results (n = 3) or restenosis (n = 1) after percutaneous transluminal angioplasty, and a calcified atherosclerotic lesion that bulged into the lumen (n = 1). RESULTS: Stent placement was successful in 63 arteries (98%). The overall complication rate was 12% (n = 8). During follow-up, three patients died. The stent was compromised in 18 cases because of hyperplasia (n = 10) or occlusion (n = 8). The primary patency rate was 84% at 1 year and 69% at 2 years; the secondary patency rate was 90% at 1 year and 81% at 2 years. Initial dissection (P = .046), a length of 60 mm or less for the stent region (P = .007), and total covering of the abnormal segment with the stent (P = .03) were significant predictive factors for good, long-term results. CONCLUSION: Use of the Strecker endoprosthesis appears useful but not ideal. Determination of predictive factors for long-term success may help identify indications for its use.

Aortic Dissection↗
PubMed1989

[MRI study of parathyroid adenoma. Value of T2-weighted sequences].

The authors report a series of 22 patients operated for primary hyperparathyroidism. The parathyroid adenoma was located preoperatively by MRI and ultrasonography. Measurement of the relaxation time was performed in vitro at 37 degrees C in a 0.47 Tesla field during the 30 minutes following resection. The relaxation times obtained at a precession frequency of 20 mHz were 0.844 +/- 0.16 sec for T1 and 0.082 +/- 0.025 sec for T2. MRI had a sensitivity of 73% and a specificity of 88% for the localization of the parathyroid adenoma, while ultrasonography had a sensitivity of 73% and a specificity of 98%.

Adenoma↗
PubMed1984

Effects of high hydrostatic pressure on catecholamine contents in tissues of the eel acclimatized at two temperatures.

Catecholamines (CA) are involved in many adaptative mechanisms of an organism to its environment. In fish, pressure is an environmental factor able to modify these mechanisms of adaptation, and some of the physiological perturbations observed under pressure can be compared to CA unloading. Moreover, the metabolic rate, and probably the CA metabolism of fish, are modified by the ambient temperature. This study has been conducted to measure tissue (brain and heart) CA contents (dopamine, norepinephrine, epinephrine) of eels acclimatized for 15 d at two temperatures, Tw, (15 degrees C or 25 degrees C). The measurements have been made either at atmospheric pressure (1 ATA) or after 60 min at 101 ATA of hydrostatic pressure "per se." The results show that 1) at a given Tw, pressure has no significant effect on tissue CA contents; and 2) there seems to exist a pressure-temperature antagonism concerning dopamine and epinephrine in the brain. It is suggested that this antagonism acts on enzymatic systems involved in the metabolism of these two amines.

Acclimatization↗