PubMed Health⌕ Search

Biomedical subjects

Catherine Roy

Publications and source records attributed to Catherine Roy.

14 recordsLinked to original sources
PubMed2007

Magnetic resonance lymphography.

PURPOSE OF REVIEW: The current methods of noninvasively staging retroperitoneal lymph nodes are suboptimal. Magnetic resonance lymphography is a new technique that might offer an important new tool in this area. Although it is still in development, more and more studies show that it is highly effective in detecting nodal metastases of various tumors. RECENT FINDINGS: Magnetic resonance lymphography yields higher sensitivity than the reference methods for detecting malignant nodes in patients with prostate, bladder, or testicular cancer. SUMMARY: In certain groups of patients with urologic cancer, magnetic resonance lymphography may obviate the need for lymphadenectomy and replace the currently used computed tomography scanning or unenhanced magnetic resonance imaging that are based on insensitive size criteria.

Diagnosis, Differential↗
PubMed2006

Osteoid osteoma: percutaneous laser ablation and follow-up in 114 patients.

PURPOSE: To retrospectively evaluate the effectiveness of interstitial laser ablation (ILA) as a curative treatment of osteoid osteoma. MATERIALS AND METHODS: Ethical review board approval was obtained for the retrospective study. Informed consent was waived. From June 1994 to June 2004, 114 patients (mean age, 22.3 years) suspected of having osteoid osteoma underwent ILA with a diode laser (805 nm). An optical fiber was introduced into the nidus of the osteoid osteoma, and 400-3000 J of energy was delivered, depending on the size and location of the nidus. Twelve spinal osteoid osteomas were treated; in five of these cases, the nidus was located fewer than 8 mm from the adjacent nerve roots, and slow epidural or periradicular infusion of normal saline was used to avoid thermal damage to neurologic structures. Pain was evaluated with a visual analog scale (VAS) and medication. ILA was considered successful (score, 0) when complete pain relief was achieved (VAS score, <1) without medication. RESULTS: One week after ILA, 112 patients had a score of 0. One week after ILA, one patient had pain that persisted for 2 months because of reflex sympathetic dystrophy. At follow-up (mean, 58.5 months; range, 13-130 months), six patients had recurrence of pain from 6 weeks to 27 months after the initial ILA. These recurrences were treated successfully with a second ILA. Only one unsuccessful treatment was encountered. CONCLUSION: Percutaneous ILA is an effective treatment for osteoid osteoma.

Adolescent↗
PubMed2006

MR Imaging of papillary renal neoplasms: potential application for characterization of small renal masses.

The purpose of our study was to evaluate the role of MRI in demonstrating the precise nature of papillary renal tumors (P RCC) and its potential application to select patients for partial surgery. Ninety-seven tumors less than or equal to 3 cm in size [55 papillary renal cell carcinoma - 42 clear cell renal carcinoma (CC RCC)] were preoperatively evaluated by MRI. Imaging findings were assessed with a special focus on the aspect of the tumoral process. Correlations were performed with pathologic staging after surgery. At pathology, 92 tumors were established to be staged p T1 and 5 were p T3 ( 3 cases of CC RCC and 2 cases of P RCC). Ninety-four percent of papillary tumors exhibited low signal intensity with homogeneous pattern on T2-weighted images. All clear cell carcinoma were hyperintense and heterogeneous on T2-weighted sequence. Enhancement was lower and delayed in the papillary type in comparison with the clear cell type. MRI is accurate enough to predict the 'histologic' nature of papillary renal carcinoma. It is an additional argument to propose that the tumor can be removed by partial surgery.

Adult↗
PubMed2005

Significance of the pseudocapsule on MRI of renal neoplasms and its potential application for local staging: a retrospective study.

OBJECTIVE: The purpose of our study was to evaluate the role of MRI in showing a pseudocapsule for local staging of renal tumors, and its potential application to select patients for partial surgery. MATERIALS AND METHODS: Eighty tumors (73 renal cell carcinomas [RCCs] and seven oncocytomas) were preoperatively evaluated by MRI. MRI findings were assessed with a special focus on perinephric fat and pseudocapsule. Correlations were performed with pathologic staging after surgery. RESULTS: At pathology, a pseudocapsule was recognized in 79 cases. Twenty-three RCC were staged pT3a (21 clear cell; two papillary). MR images exhibited a pseudocapsule in 90% of cases as a hypointense rim surrounding the tumor on T2-weighted images. MRI findings concerning isolated analysis of the pseudocapsule for differentiating stage T1/T2 from T3a were sensitivity: 86%, 50%; specificity: 95%, 92%; positive predictive value: 95%, 33%; negative predictive value: 88%, 92%; and accuracy: 93%, 89%, for clear cell and papillary types, respectively. For stage T3a, with both abnormalities of the pseudocapsule and perirenal fat, results were, for overall RCC sensitivity: 84%; specificity: 95%; positive predictive value: 91%; negative predictive value: 91%; and accuracy: 91%. CONCLUSION: The identification of the pseudocapsule offers an additional value for local staging by MRI. The presence of an intact pseudocapsule is a sign of lack of perinephric fat invasion. It is more likely to predict that the tumor can be removed by partial surgery.

Adenoma, Oxyphilic↗
PubMed2004

Papillary renal cell carcinoma in allograft kidney.

Papillary renal cell carcinoma is a subgroup of malignant renal epithelial neoplasms. Its occurrence in allograft transplanted kidney has not been debated in the literature. We report two pathologically proven cases and discuss the clinical hypothesis for such neoplasms and the aspect on MR images. The paramagnetic effect of the iron associated with an absence of signal coming from calcifications is a plausible explanation for this unusual hypo-intense appearance on T2-weighted sequence.

Adult↗
PubMed2004

Prognostic value of multifocality on progression and survival in localized renal cell carcinoma.

OBJECTIVE: Incidence of multifocality in Renal Cell Carcinoma (RCC) is estimated at between 5 and 25%. Multifocality has been largely studied because of the growing interest in conservative surgery which is a risk of local recurrence. The aim of this study is to evaluate the relationship between multifocality and other prognostic parameters and whether it is an independent prognostic factor. MATERIAL AND METHODS: From 1980 to 1990, 255 patients (median age: 60.9 years) were treated by radical nephrectomy for pT1 to pT3b N0M0 RCC. The median follow-up time was 183 months. Multifocality was defined as the existence of at least one other tumoral localization, macroscopically and microscopically diagnosed as renal cell carcinoma, in the same kidney. Studied parameters were: age, sex, side, size, stage, Fuhrman's grade, capsular invasion, renal vein involvement and microvascular invasion. Survival was assessed with Kaplan-Meier and Cox models. RESULTS: 37 cases of multifocal RCC were diagnosed (14.5%). There was only a significant correlation with stage (p=0.002) and with capsular invasion (p=0.002). No other factor was correlated with multifocality. It had no influence on the risk of metastatic progression, overall or specific survival. CONCLUSION: There is a significant correlation between capsular invasion and multifocality that has to be considered before proposing conservative surgery for a localized RCC. Multifocality has no influence on survival or metastatic progression in case of radical nephrectomy.

Adolescent↗
PubMed2004

Three-dimensional virtual cholangioscopy: a reliable tool for the diagnosis of common bile duct stones.

OBJECTIVE: Our goal was to evaluate the clinical reliability of a new software system employing 3-dimensional (3D) virtual anatomic reconstruction and intraluminal virtual exploration for detection of choledocholithiasis and preoperative visualization of the biliary anatomy. SUMMARY BACKGROUND DATA: Virtual reality systems have been proposed for gastroscopy, bronchoscopy, and colonoscopy, as well as for the 3D reconstruction of liver anatomy and hepatic lesions. The impact of these systems in preoperative diagnostics has not been established due to the lack of large clinical series evaluating their reliability. METHODS: From November 2000 to July 2002, all patients presenting to our Institute with suspected choledocholithiasis were prospectively included in the study. All patients underwent conventional magnetic resonance cholangiopancreatography (MRCP) and either intraoperative cholangiogram (IOC) or endoscopic retrograde cholangiopancreatography (ERCP). The digital data from MRCP were incorporated into an original virtual reality software system to generate a 3D reconstruction. All 3D reconstructions were evaluated by a surgeon and a computer software engineer who were blind to the results of the IOC or ERCP. Sensitivity and specificity were then calculated based on the results of either the IOC or ERCP. RESULTS: Sixty-five patients were enrolled in the study. The average time required to reconstruct the images into navigable virtual reality was 7.5 minutes (range, 4-13.5). The 3D virtual cholangioscopy had sensitivity and specificity rates of 71% and 91%, respectively, compared with 61% and 86% of the standard MRCP. CONCLUSION: : The 3D virtual cholangioscopy provides detailed preoperative reconstruction of biliary anatomy and reliable identification of choledocholithiasis with acceptable sensitivity and specificity in a clinical setting. Newer software developments may further enhance its accuracy, so that virtual cholangioscopy might challenge or replace more invasive diagnostic measures in the near future.

Cholangiography↗
PubMed2004

[Urothelial tumors].

Explore the source record for details and available documents.

Carcinoma, Transitional Cell↗
PubMed2003

Contrast enhanced color Doppler endorectal sonography of prostate: efficiency for detecting peripheral zone tumors and role for biopsy procedure.

PURPOSE: We evaluated the accuracy of contrast enhanced color Doppler endorectal ultrasound to guide biopsy for the detection of prostate cancer. MATERIALS AND METHODS: A total of 85 patients were evaluated with gray scale and color Doppler before and during intravenous injection of ultrasound contrast agent made of galactose based air microbubbles. Our biopsy protocol was performed during contrast injection. An additional 18 directed cores were obtained based on contrast enhanced imaging. Diagnostic efficiency with and without contrast medium injection for detecting prostate cancer were compared based on biopsy results. RESULTS: Cancer was identified in a total of 58 biopsy sites in 54 patients. Gray scale imaging revealed 96 abnormal hypoechoic nodules or irregular zones inside the outer gland, of which 48 were malignant on pathological evaluation. Contrast enhanced color Doppler had higher sensitivity (93%) than unenhanced color Doppler (54%), while specificity increased only 79% to 87% for enhanced imaging. Nine of 10 isoechoic suspicious zones were depicted with enhancement, while unenhanced Doppler detected 7 of them. There was no significant difference between the intensity of enhancement and tumor Gleason scores. CONCLUSIONS: Contrast enhanced color Doppler endorectal sonography increases the detection of prostate cancer. Improvement in sensitivity was high, while the difference in specificity was not as pertinent. It is accurate when using a common and routine application ultrasound unit. This technique is easy to perform and not time-consuming. Obtaining additional biopsy cores of suspicious enhancing foci significantly improves the detection rate of cancer.

Aged↗
PubMed2002

Imaging of cystic masses of the mediastinum.

Cystic masses of the mediastinum are well-marginated round lesions that contain fluid and are lined with epithelium. Major cystic masses include congenital benign cysts (ie, bronchogenic, esophageal duplication, neurenteric, pericardial, and thymic cysts), meningocele, mature cystic teratoma, and lymphangioma. Many tumors (eg, thymomas, Hodgkin disease, germ cell tumors, mediastinal carcinomas, metastases to lymph nodes, nerve root tumors) can undergo cystic degeneration-especially after radiation therapy or chemotherapy-and demonstrate mixed solid and cystic elements at computed tomography (CT) or magnetic resonance (MR) imaging. If degeneration is extensive, such tumors may be virtually indistinguishable from congenital cysts. A mediastinal abscess or pancreatic pseudocyst also appears as a fluid-containing mediastinal cystic mass. However, clinical history and manifestations, anatomic position, and certain details seen at CT or MR imaging allow correct diagnosis in many cases. Familiarity with the radiologic features of mediastinal cystic masses facilitates accurate diagnosis, differentiation from other cystlike lesions, and, thus, optimal patient treatment.

Abscess↗
PubMed1997

Percutaneous Laser Photocoagulation of Osteoid Osteomas.

Osteoid osteoma is a painful benign bone tumor. The curative treatment of this tumor consists of complete surgical or percutaneous excision of the nidus with immediate and dramatic relief of symptoms. Interstitial laser photocoagulation (ILP) is a low-invasive percutaneous technique of thermal destruction (coagulation) of deep-seated tumors elsewhere in the body, using low-power laser energy. The aim of ILP is the local destruction of osteoid osteoma without bone weakening. Twenty-two patients with osteoid osteoma were treated with percutaneous ILP of the nidus under computed tomography guidance. The laser energy was provided by a high-power semiconductor diode laser (805 nm) with a 400-&mgr;m optical fiber. Complete pain relief was obtained in 21 patients. Percutaneous ILP of osteoid osteoma seems to be a promising, simple, precise, and minimally invasive technique as an alternative to traditional surgical and percutaneous ablations.

Journal Article↗
PubMed1997

New Trends in Interstitial Laser Photocoagulation of Bones.

Interstitial laser photocoagulation (ILP) was performed in experimental models prior to clinical trials to determine the feasibility of bone photocoagulation using an 805-nm diode laser and to define parameters influencing lesion size and shape. Laser energy was applied in continuous-wave mode at a power of 2 W to an ex vivo freshly ablated pig femur. Two hundred and eighty ILPs were performed followed by histologic examinations to determine the coagulation size with a freshly cleaved fiber tip compared to a precharred fiber tip. Another study was designed to determine the temperatures achieved in bone using ILP and to correlate them with histologic findings. Histologic examination has underestimated the coagulation size with precharred fibers that varied from 3.4 mm (200 J) to 9.2 mm (1200 J) in diameter. Thermal data were significantly different with presumed lesions of 16 mm in diameter for 1200 J energy.

Journal Article↗
PubMedDate not supplied

Bronchial carcinoid tumors of the thorax: spectrum of radiologic findings.

Bronchial carcinoid tumors are neuroendocrine neoplasms that range from low-grade typical carcinoids to more aggressive atypical carcinoids and therefore demonstrate a wide spectrum of clinical behaviors and histologic features. Typical and atypical bronchial carcinoids have similar imaging features. Because most bronchial carcinoids are located in central airways, radiologic findings are usually related to bronchial obstruction. Central bronchial carcinoids manifest as an endobronchial nodule or hilar or perihilar mass with a close anatomic relationship to the bronchus. The mass is usually a well-defined, round or ovoid lesion and may be slightly lobulated at radiography and computed tomography (CT). Associated atelectasis, air trapping, obstructing pneumonitis, and mucoid impaction may also be seen. Peripheral bronchial carcinoids appear as solitary nodules. Calcification is common and is easily visualized at CT. Bronchial carcinoids demonstrate high signal intensity on T2-weighted and short-inversion-time inversion recovery magnetic resonance images. Prognosis of bronchial carcinoids is highly dependent on histologic findings: Atypical carcinoids have certain features that suggest a more aggressive nature. Typical bronchial carcinoids generally have an excellent prognosis, whereas atypical bronchial carcinoids have a worse prognosis. Therefore, understanding the histologic, clinical, and radiologic features of bronchial carcinoids facilitates accurate diagnosis and helps optimize surgical planning.

Adult↗