Biomedical subjects
Publications and source records attributed to C Tuchmann.
Post-traumatic rupture of UPJ obstruction is a rare event, with few reported cases in the literature. Diagnosis is suggested on imaging studies, especially US and CT findings. The presence of an anterior pelvic hematoma associated with thinning of kidney parenchyma, very distended pelvis and non dilated ureter is suggestive of pre-existing pathology.
Helical CT is the most useful imaging modality to evaluate kidney diseases. Different imaging protocols are used to assess the correct diagnosis in each clinical situation. The nephrographic phase (between 90 and 100 s of delay after injection) is more accurate than the cortical phase (between 30 and 40 s of delay) to depict and characterise small renal masses. Multiplanar and 3D reconstruction are useful to plan partial kidney surgery or percutaneous surgery of lithiasis. In emergency, spiral CT, if available, is suitable to assess renal colic. Spiral CT is the best modality to evaluate traumatic kidney.
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New MRI modalities today available allow exploration of many kidney diseases. Main developments have been made in the diagnosis of small tumors and tumoral extension of huge masses. The other important way of application is MR urography which perfectly show the dilated urinary tract in few seconds. Their potential application are for renal insufficiency, allergic reaction to iodine contrast media and in cases of contra indication to ionised radiations. It is a complementary sequence to assess the urinary tract in pelvic exploration. The evaluation of kidney function will be possible in the near future.
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Vesical disorders are numerous. For tumoral processes, the role of imaging modalities is limited to the loco-regional extension. In certain rare cases of benign tumors, precise diagnosis can be evocated. Nowadays, urinary insufficiency is explored by dynamic MRI. It provides a complete assessment of the whole muscular and visceral compartments of the pelvic cavity.
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In recent years, the development of noninvasive imaging modalities for exploration of the kidney has markedly reduced the use of angiography in the evaluation of renal masses. Presently, it is not required in routine practice to evaluate renal masses. Ultrasound is the most efficient procedure in detecting renal tumor. It is acknowledged that arteriography has a limited diagnostic and staging value compared with CT and MRI for the assessment of renal cell carcinomas (RCC). Most urologists recommend partial nephrectomy or tumor enucleation in an effort to preserve as much as possible functioning renal tissue. In such cases a preoperative map of the renal vasculature is not needed. Information on the main renal artery(ies) and segmental renal arteries can be provided with spiral CT or dynamic MR angiography. Arteriography remains useful in exceptional situations. Interventional arteriography is becoming an important part. It is indicated by means of selective embolization for the treatment of potentially bleeding tumor (i.e. angiomyolipoma) or in emergency in cases of acute hemorrhage. Less frequently, it may be proposed as a palliative procedure for inoperable patients with huge renal tumor. Two other indications of interventional arteriography are acknowledged. Some urologists request preoperative embolization of the tumor-harboring kidney to decrease/avoid extensive blood loss during surgery and/or to facilitate surgery with huge renal tumors when the renal vessels are difficult to reach. The complications of nephron-sparing surgery (partial nephrectomy or tumor enucleation) related to bleeding or arteriovenous fistulas may be cured by arterial embolization.
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Three unusual cases of small-size leiomyosarcoma of the perirenal space were studied with CT. The renal capsule has been proved to be the origin of this type of tumor. A CT examination is accurate in suggesting the site of origin and excluding a renal cell carcinoma. However, unless evidence of invasion is noted, it is impossible on CT features to discriminate leiomyosarcoma from a benign leiomyoma.
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PURPOSE: To evaluate the clinical and biologic safety of ultrasmall superparamagnetic iron oxide particles (AMI-227) as a contrast agent for magnetic resonance (MR) lymphography and to assess their efficacy for the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancer. MATERIALS AND METHODS: Thirty adults suspected of having lymph node metastases underwent MR imaging before and 22-26 hours after intravenous infusion of AMI-227 (1.7 mg Fe/kg). Sixty histopathologically proved lymph nodes were analyzed on MR images, and 29 of these nodes were also analyzed quantitatively. RESULTS: AMI-227 was well tolerated with no major side effects. It allowed the detection of 10 additional nodes relative to those detected at MR imaging without AMI-227. None of the 27 metastatic nodes showed a decrease in signal intensity (SI) on AMI-227-enhanced images; nine of 27 metastatic nodes showed an increase in SI on T1-weighted images, probably resulting from altered capillary permeability in the tumor. A visually perceptible reduction in SI, indicating active AMI-227 uptake, was observed on postcontrast T2- and T2*-weighted images in 16 of 21 benign nodes. The SI ratio of benign nodes was lower than that of metastatic nodes on T2- and T2*-weighted images. The sensitivity of AMI-227-enhanced MR lymphography was 100%, and the specificity was 80%. CONCLUSION: AMI-227 is safe and may facilitate the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancers.
A very unusual CT appearance of renal cel carcinoma is presented, in which the fatty density mimicked a benign angiomyolipoma.
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.
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.
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.
PURPOSE: We assessed the value of renal duplex Doppler sonography in diagnosing obstruction in patients with acute renal colic. METHODS: We compared the results of renal duplex Doppler sonography with those of intravenous urography (IVU) in 65 patients presenting with symptoms of renal colic. The Doppler spectral waveforms were used to calculate the resistance index (RI). The difference between the mean RIs (delta RI) in the 2 kidneys was calculated for each patient. The sensitivity, specificity, and accuracy of delta RI for the diagnosis of obstruction were calculated with several discriminatory thresholds. RESULTS: All patients had an obstruction on IVU. When a high delta RI threshold for obstruction (delta RI > or = 0.1) was applied, the sensitivity and specificity of duplex Doppler sonography were 10% and 80%, respectively. When the delta RI threshold was decreased, the sensitivity increased but the specificity decreased, and both remained quite low. Twelve patients had a lower mean RI in the obstructed kidney than in the normal contralateral kidney. Among 14 patients without pyelocaliceal dilatation, the sensitivity of duplex Doppler sonography was 70% with a delta RI threshold of 0.03. CONCLUSIONS: Duplex Doppler sonography is not sensitive enough to diagnose obstruction in patients with acute renal colic.
PURPOSE: Duplex Doppler sonography of the cavernosal arteries of the penis with intracavernous injection (ICI) of vasoactive agents has been widely used to evaluate arterial insufficiency in impotence. Our goal was to assess the potential value of peak systolic velocity (PSV) measurements on the flaccid penis in the diagnosis of arteriogenic impotence. METHODS: Forty-four men underwent duplex Doppler sonography with PSV measurements before and after ICI of prostaglandin E(1). Three different cutoff values for lowest normal PSV before injection-5 cm/second, 10 cm/second, and 15 cm/second-were tested. RESULTS: Thirteen patients had arteriogenic insufficiency based on post-ICI duplex sonography and clinical response. Results for our different cutoff PSV values of 5 cm/second, 10 cm/second, and 15 cm/second in diagnosing arteriogenic impotence were, respectively: sensitivity 29%, 96%, and 100%; specificity 100%, 92%, and 23%; negative predictive value 80%, 92%, and 100%; positive predictive value 100%, 81%, and 41%; and overall accuracy 79%, 93%, and 44%. In the flaccid state, there was a significant difference in mean PSV between the "normal" group (12.6 +/- 0.9 cm/second) and the arteriogenic impotence group (7.7 +/- 1.1 cm/second). Twenty-nine patients with a bilateral PSV of 10 cm/second or less before ICI had a normal clinical response. CONCLUSIONS: A cutoff PSV value of 10 cm/second in the flaccid state had the best accuracy in predicting arterial insufficiency. Duplex Doppler sonography is proposed as the initial test to evaluate the penile arterial supply and to determine whether patients are good candidates for therapy with ICI.