Utility and limitations of 3-Tesla diffusion-weighted magnetic resonance imaging for differentiation of renal tumors.

OBJECTIVE: To investigate utility and limitations of 3-Tesla diffusion-weighted (DW) magnetic resonance imaging (MRI) for differentiation of benign versus malignant renal lesions and renal cell carcinoma (RCC) subtypes. MATERIALS AND METHODS: Sixty patients with 71 renal lesions underwent 3 Tesla DW-MRI of the kidney before diagnostic tissue confirmation. The images were retrospectively evaluated blinded to histology. Single-shot echo-planar imaging was used as the DW imaging technique. Apparent diffusion coefficient (ADC) values were measured and compared with histopathological characteristics. RESULTS: There were 54 malignant and 17 benign lesions, 46 lesions being small renal masses ≤ 4 cm. Papillary RCC lesions had lower ADC values (p=0.029) than other RCC subtypes (clear cell or chromophobe). Diagnostic accuracy of DW-MRI for differentiation of papillary from non-papillary RCC was 70.3% resulting in a sensitivity and specificity of 64.3% (95% CI, 35.1-87.2) and 77.1 (95% CI, 59.9-89.6%). Accuracy increased to 83.7% in small renal masses (≤ 4 cm diameter) and sensitivity and specificity were 75.0% and 88.5%, respectively. The ADC values did not differ significantly between benign and malignant renal lesions (p=0.45). CONCLUSIONS: DW-MRI seems to distinguish between papillary and other subtypes of RCCs especially in small renal masses but could not differentiate between benign and malignant renal lesions. Therefore, the use of DW-MRI for preoperative differentiation of renal lesions is limited.

Three-Tesla dynamic contrast-enhanced MRI: a critical assessment of its use for differentiation of renal lesion subtypes.

PURPOSE: To evaluate the ability of dynamic contrast-enhanced (DCE) 3-T MRI for preoperative differentiation between benign and malignant renal tumors and RCC subtypes. METHODS: Sixty consecutive patients undergoing preoperative DCE 3-T MRI of the kidney were evaluated in this retrospective IRB-approved evaluation. Fifty-four malignant tumors and 17 benign tumors upon surgical verification were included. Relative enhancement values of complete lesions and the most enhancing part of the lesions (hotspot) were measured using four repetitions: precontrast, arterial, venous, and delayed. RESULTS: Mean relative enhancement patterns between malignant and benign lesions did not differ significantly during any postcontrast phase (p > 0.05). The highest mean enhancement during all postcontrast phases was identified in clear cell RCC followed by chromophobic RCC. The enhancement pattern in papillary RCC was significantly less than that of non-papillary RCC lesions. Arterial enhancement was an independent predictor for RCC subtypes (papillary vs. non-papillary, p = 0.008). The diagnostic accuracy for differentiation of papillary from non-papillary RCC based on ROC analysis was 76.4% [95% CI 62.2-87.2%]; p < 0.0001. CONCLUSIONS: Dynamic contrast-enhanced MRI at 3 T showed intermediate diagnostic capability for differentiation between papillary and non-papillary RCC subtypes but could not differentiate between benign and malignant renal lesions.

[Freiburg index of patient satisfaction: interdisciplinary validation of a new psychometric questionnaire to describe treatment-related patient satisfaction]. / Freiburger Index für Patientenzufriedenheit: Interdisziplinäre Validierung eines psychometrischen Instrumentes zur Erfassung behandlungsbezogener Patientenzufriedenheit.

BACKGROUND: The recently introduced Freiburg index of patient satisfaction (FIPS) is a new questionnaire to assess treatment-related patient satisfaction after surgery and interventional procedures. The questionnaire had first been tested psychometrically in a mixed population of urology patients. The current study describes the results of an interdisciplinary validation. In addition, an English version is presented. METHODS: The questionnaire was used in two cohorts of cardiology (n = 120) and surgical (n = 127) patients. The evaluation included a comprehensive methodological and statistical evaluation including validation in comparison to the ZUF-8 questionnaire. RESULTS: The psychometric evaluation showed good results. The analyzed samples showed no missing values or ceiling effects. Furthermore, a high reliability (Cronbach's alpha 0.82), unidimensionality, sufficient distribution of values and validity (high correlation to the ZUF-8, r = 0.65, p < 0.001) of the questionnaire could be confirmed. CONCLUSIONS: The FIPS constitutes an interdisciplinary validated questionnaire to evaluate treatment-related patient satisfaction which can be used to objectify and compare results from clinical studies and quality in patient care. Colleagues of English-speaking countries are invited to participate in the validation of the hereby presented English version.

Incidence of balanitis xerotica obliterans in boys younger than 10 years presenting with phimosis.

OBJECTIVE: Evaluation of the true incidence of balanitis xerotica obliterans (BXO) among boys younger than 10 years. METHODS: In a period of 13 months, 75 boys younger than 10 years were treated for phimosis. Suspicion of BXO was raised in phimosis grade 2 or 3 (classification by Kikiros). Patients were offered primarily either circumcision or conservative therapy and circumcision secondarily (if treatment failed in the conservative group). Each circumcision specimen was examined histopathologically. RESULTS: Circumcision was primarily performed in 29 and secondarily in 17 patients. The mean age was 3.7 years (range 1-10). BXO, chronic inflammation, and normal histological results were found in 8/26/12 (17.4/56.5/26.1%) cases, respectively. The mean follow-up was 8.1 months. No recurrences were reported. CONCLUSIONS: The incidence of BXO appears to be higher than previously reported. The clinical appearance in children may be confusing. The preoperative BXO suspicion did not correlate with the final histopathological results.