Evaluation of MRI-TRUS fusion versus cognitive registration accuracy for MRI-targeted, TRUS-guided prostate biopsy.

OBJECTIVE: The purpose of this article is to compare transrectal ultrasound (TRUS) biopsy accuracies of operators with different levels of prostate MRI experience using cognitive registration versus MRI-TRUS fusion to assess the preferred method of TRUS prostate biopsy for MRI-identified lesions. SUBJECTS AND METHODS; One hundred patients from a prospective prostate MRI-TRUS fusion biopsy study were reviewed to identify all patients with clinically significant prostate adenocarcinoma (PCA) detected on MRI-targeted biopsy. Twenty-five PCA tumors were incorporated into a validated TRUS prostate biopsy simulator. Three prostate biopsy experts, each with different levels of experience in prostate MRI and MRI-TRUS fusion biopsy, performed a total of 225 simulated targeted biopsies on the MRI lesions as well as regional biopsy targets. Simulated biopsies performed using cognitive registration with 2D TRUS and 3D TRUS were compared with biopsies performed under MRI-TRUS fusion. RESULTS: Two-dimensional and 3D TRUS sampled only 48% and 45% of clinically significant PCA MRI lesions, respectively, compared with 100% with MRI-TRUS fusion. Lesion sampling accuracy did not statistically significantly vary according to operator experience or tumor volume. MRI-TRUS fusion-naïve operators showed consistent errors in targeting of the apex, midgland, and anterior targets, suggesting that there is biased error in cognitive registration. The MRI-TRUS fusion expert correctly targeted the prostate apex; however, his midgland and anterior mistargeting was similar to that of the less-experienced operators. CONCLUSION: MRI-targeted TRUS-guided prostate biopsy using cognitive registration appears to be inferior to MRI-TRUS fusion, with fewer than 50% of clinically significant PCA lesions successfully sampled. No statistically significant difference in biopsy accuracy was seen according to operator experience with prostate MRI or MRI-TRUS fusion.

Repeat prostate biopsy accuracy: simulator-based comparison of two- and three-dimensional transrectal US modalities.

PURPOSE: To compare the accuracy of biopsy with two-dimensional (2D) transrectal ultrasonography (US) with that of biopsy with conventional three-dimensional (3D) transrectal US and biopsy with guided 3D transrectal US in the guidance of repeat prostate biopsy procedures in a prostate biopsy simulator. MATERIALS AND METHODS: The institutional review board approved this retrospective study. Five residents and five experts performed repeat biopsies with a biopsy simulator that contained the transrectal US prostate images of 10 patients who had undergone biopsy. Simulated repeat biopsies were performed with 2D transrectal US, conventional 3D transrectal US, and guided 3D transrectal US (an extension of 3D transrectal US that enables active display of biopsy targets). The modalities were compared on the basis of time per biopsy and how accurately simulated repeat biopsies could be guided to specific targets. The probability for successful biopsy of a repeat target was calculated for each modality. RESULTS: Guided 3D transrectal US was significantly (P < .01) more accurate for simulated biopsy of repeat targets than was 2D or 3D transrectal US, with a biopsy accuracy of 0.86 mm +/- 0.47 (standard deviation), 3.68 mm +/- 2.60, and 3.60 mm +/- 2.57, respectively. Experts had a 70% probability of sampling a prior biopsy target volume of 0.5 cm(3) with 2D transrectal US; however, the probability approached 100% with guided 3D transrectal US. Biopsy accuracy was not significantly different between experts and residents for any modality; however, experts were significantly (P < .05) faster than residents with each modality. CONCLUSION: Repeat biopsy of the prostate with 2D transrectal US has limited accuracy. Compared with 2D transrectal US, the biopsy accuracy of both experts and residents improved with guided 3D transrectal US but did not improve with conventional 3D transrectal US.

Reliability and comparison of acromion assessment techniques on X-ray and magnetic resonance imaging (reliability of acromion assessment techniques).

OBJECTIVE: To determine the reliability and correlation of plain radiography and magnetic resonance imaging (MRI) in the assessment of acromion morphology. MATERIALS AND METHODS: Acromion morphology was assessed using the lateral acromion angle (LAA) and the acromion-humeral interval (AHI). Thirty patients who had X-rays and MRI for impingement syndrome were included. Six blinded observers assessed the acromion morphology subjectively and objectively. RESULTS: Neither acromion assessment technique demonstrated a positive correlation (kappa and intraclass coefficient < 0.55) between X-ray and MRI. Both techniques were reliable (kappa and intraclass coefficient > 0.55) when measured objectively by experienced observers. CONCLUSION: The LAA and the AHI are both reliable acromion assessment techniques on X-ray and MRI when measured objectively and by experienced observers.

The spectrum of ulnar collateral ligament injuries as viewed on magnetic resonance imaging of the metacarpophalangeal joint of the thumb.

OBJECTIVE: To elucidate the spectrum of ulnar collateral ligament (UCL) injuries detectable by magnetic resonance imaging (MRI). METHODS: Twenty-one patients (12 male and 9 female, aged 14-62 years) with acute hyperabduction injuries of the first metacarpophalangeal joint underwent MRI for clinically suspected UCL injuries. All scans were performed in either a large-bore, 1.5-T imager or an experimental small-bore, 1.9-T imager. MRI findings and clinical evaluations of all patients and surgical reports of those who underwent surgery (n = 10) were reviewed and correlated retrospectively. RESULTS: A total of 6 patients demonstrated injuries that did not fall into previously described categories of UCL injuries and therefore illustrated the existence of a subclass of UCL injuries. We divided the MRI findings into 5 categories: Stener's lesions (n = 6), moderately displaced (> or = 3 mm) complete tears (n = 5), minimally displaced (< 3 mm) complete tears (n = 4), nondisplaced complete tears (n = 3) and partial tears (n = 3). None of the MRI scans demonstrated a normal UCL. Although sensitivity and specificity were not calculated, only 2 cases demonstrated discordance between the MRI results and surgical findings or clinical outcomes. CONCLUSION: There is a spectrum of UCL injuries that have not previously been described.