The CUSUM test applied in prospective nuchal translucency quality review.

OBJECTIVES: To design a cumulative sum (CUSUM) test for prospective nuchal translucency (NT) measurement quality review that is as stringent as the retrospective quality review methods based on distribution parameters currently in use. METHODS: The database including all fetal NT measurements obtained during a 2-year period in a single center was reviewed, and measurements obtained by sonologists who measured fewer than 100 cases were excluded. The NT distribution parameters proposed by The Fetal Medicine Foundation (FMF) and the Women & Infants Hospital of Rhode Island (WIHRI) were assessed in the whole NT series and in sonologist-specific distributions. A previously described CUSUM model was adapted to fulfil our objective. RESULTS: Two thousand four hundred and seventy-five NT measurements were obtained by seven sonologists during the study period (January 2007-December 2008). In the assessment of sonologist-specific NT distributions, two sonologists fulfilled all the FMF and WIHRI criteria, one showed NT overestimation and four failed due to NT underestimation. Our new CUSUM test model, based on multiples of the median deviations, showed good agreement with the FMF and WIHRI methods in the assessment of sonologist-specific performance. CONCLUSIONS: Our CUSUM test model showed close agreement with the retrospective quality review methods based on distribution parameters currently in use, but with the advantage that it can be applied prospectively, allowing for earlier correction of deviations from target performance.

Comparative study of whole-body MRI and bone scintigraphy for the detection of bone metastases.

AIM: To assess and compare the diagnostic accuracy of whole-body magnetic resonance imaging (MRI) and bone scintigraphy in the detection of metastases to bone. MATERIAL AND METHODS: Forty randomly selected patients with known malignant tumours were prospectively studied using bone scintigraphy and whole-body MRI. Two patients were excluded. Symptoms of bone metastasis were present in 29 (76%) patients and absent in nine (24%). Findings were classified into four categories according to the probability of bone metastasis: (1) negative, (2) probably negative, (3) probably positive, and (4) positive. Diagnostic accuracy was determined according to the area under the receiver operating characteristic (ROC) curve. The definitive diagnosis was reached using other imaging techniques, biopsy, or 12 months clinical follow-up. RESULTS: Metastases were present in 18 patients. The sensitivity, specificity, and diagnostic accuracy were 94, 90, and 92%, respectively, for whole-body MRI and 72, 75, and 74%, respectively, for bone scintigraphy. Diagnostic accuracy measured by the area under the ROC curve was significantly higher for whole-body MRI (96%) than for bone scintigraphy (77%; p<0.05). Interobserver agreement measured by the kappa index was significantly higher for whole-body MRI (0.895) than for bone scintigraphy (0.524; p<0.05). Whole-body MRI detected lesions in tissues other than bone in 17 (45%) patients. CONCLUSIONS: Whole-body MRI is more accurate and more objective than bone scintigraphy for the detection of bone metastases. Whole-body MRI can also detect lesions in tissues other than bone.

The value of endorectal MRI in the early diagnosis of prostate cancer.

OBJECTIVE: Assess the value of endorectal MR imaging (EMRI) in the early diagnosis of prostate cancer (PCa) and compare this test to prostate specific antigen (PSA) and digital rectal examination (DRE) in the prediction of negative biopsies. MATERIAL AND METHODS: 92 patients with elevated PSA (>4 ng/ml) and/or abnormal DRE were studied. All patients underwent an EMRI previous to transrectal ultrasound guided needle sextant biopsies (3 cores in each peripheral zone), and were followed up. We performed a total of 184 biopsies: 92 patients underwent 1 biopsy; out of them, 61 patients underwent 2 biopsies, 27 patients 3 biopsies, 3 patients 4 biopsies and 1 patient 5 biopsies. 67 patients had a final negative biopsy and 25 had a final positive biopsy. Mean PSA was 10.44 ng/ml, and the mean % fPSA/tPSA was 0.20. Uni- and multivariate analysis and ROC curves were used to compare the accuracy of the different tests. The probability of positive biopsy with each technique was also assessed. RESULTS: EMRI had a high negative predictive value (91.07%) and the highest accuracy (77%) of all tests, higher than PSA (62%). Mean PSA was not statistically different in patients with negative biopsies (9.44 ng/ml) and positive biopsies (11.8 ng/ml) (p=0.064). The association of EMRI-DRE-PSA had the highest accuracy (83%) significantly higher than DRE-PSA (70%). The probability of positive biopsy in patients with negative DRE and EMRI, and PSA values between 5 and 15 ng/ml was 5-10% at first and second biopsies, but decreased progressively on subsequent biopsies (<8% at third biopsy, <5% at fourth biopsy and <3% at fifth biopsy). CONCLUSION: In patients with elevated PSA and/or abnormal DRE with two previous negative biopsies, an EMRI is a useful test to rule out PCa, when negative, and avoid subsequent biopsies, as they have a low chance of positive biopsy.