Adv Urol. 2008; 2008: 213516.
introduction三段论： 第一段讲述目前的一般诊断方法，以及其基本情况；第二段，however,指明其中的不足，如侵入性手段等不利因素第三段，回归到本文的方法学的优点。以及本文中采取的方法和手段 The incidence of urethral diverticula is thought to occur in 1–5% of the general female population [1, 2]. Presenting symptoms classically consist of dysuria, post void dribbling, dyspareunia, recurrent urinary tract infections (UTI), and stress incontinence. In fact, studies suggest that 1.4% of patients with stress incontinence have a urethral diverticulum [3]. Clinical diagnosis can be difficult due to the nonspecific nature of presenting symptoms and the possibility of concomitant genitourinary pathology. However, it has been shown that in about 60% of cases a careful and thorough physical exam can make an accurate diagnosis of urethral diverticulum [3]. Ancillary modalities such as cystoscopy, voiding cystourethrogram (VCUG), and urethrography are reported to be diagnostic in 65–96% of cases, depending on the study [4–7]. Traditionally, the gold standard of diagnosis has been one or more of these ancillary and invasive techniques. These invasive studies are difficult to perform properly and can be quite uncomfortable for patients. Recent advances and improvements in magnetic resonance imaging (MRI) have increased its use in the diagnosis of urethral pathology. MRI has multiplanar imaging capabilities with excellent tissue contrast, especially on T2-weighted images. Gadolinium enhancement can help define internal diverticular architecture [7]. Isolated studies in past literature demonstrated MRI to have a high sensitivity in the diagnosis of urethral diverticulum [7–10]. We report on a cohort of contemporary cases to determine whether the diagnosis of urethral diverticulum can be made on physical exam with or without MRI, exclusive of invasive cystoscopy or VCUG.
Adv Urol. 2008; 2008: 213516.
三段论形式：1 病例入选原则，情况2 研究的目的3 MRI诊断方法标准 Following IRB approval, female patients diagnosed with urethral diverticulum from 1999 to 2004 were identified by a retrospective chart review using electronic medical records and paper charts. Information about presenting symptoms, urological history, diagnosis method, imaging studies, and outcomes at last followup was documented. Surgical operative reports and pathology reports were also reviewed for final diagnosis. Cases were reviewed to assess the method of initial diagnosis (physical exam, MRI, VCUG, cystoscopy, or urethrography). Our goal was to determine how the diverticula were diagnosed and to determine what studies were most sensitive at making the diagnosis. Therefore, any additional studies, as well as their contribution to diagnosis and surgical planning, were recorded. Outcomes at last followup were correlated with the type of imaging modality used for diagnosis and/or surgical planning. MRI studies (if obtained) were performed at this institution using a 1.5 Tessla magnet with a phase-array pelvic coil. Axial, coronal, and sagittal T2 weighted sequences were obtained using fast spin echo technique. Axial and sagittal T1 weighted sequences were obtained before and after intravenous gadolinium contrast. Computer tomographic (CT) scans were used in four cases due to clinical contraindications for MRI.
Adv Urol. 2008; 2008: 213516.
Figure 1 Urethral diverticulum on MRI (T2 weighted, fast spin echo). Patient presented with dyspareunia, urinary urgency and a normal physical exam. VCUG showed no evidence of urethral diverticulum. MRI revealed the correct diagnosis.
Adv Urol. 2008; 2008: 213516.
Urethral diverticula can be easily diagnosed on physical exam based on symptoms and clinical suspicion. MRI can be a useful adjunct for defining diverticular extent in surgical planning especially in women with proximal diverticula; it should be the modality of choice if patient presentation is suggestive and physical exam findings are lacking. Additional invasive imaging, like VCUG, may still have a role in patients with concomitant urological disease. Otherwise, VCUG adds little to accurate diagnosis and treatment of urethral diverticula, and its elimination does not impact accurate diagnosis or operative outcomes.
The Journal of Neuroscience, December 5, 2007, 27(49):13393-13401
MRI protocol. Whole brain blood oxygen level-dependent functional MRI (fMRI) data were collected on a 3-T scanner (General Electric, Milwaukee, WI) with a General Electric echo-planar imaging pulse sequence acquisition of 24 contiguous slices (echo time, 30 ms; repetition time, 2 s; flip angle, 90°; field of view, 24 cm; matrix, 64 x 64; voxel dimensions, 3.75 x 3.75 x 5 mm). The first four scans were discarded to allow for signal saturation. Stimuli were presented via a back-projection system, and responses were recorded through a fiberoptic response box, which allowed the measurement of the accuracy and reaction time for each trial.
The Journal of Neuroscience, December 5, 2007, 27(49):13393-13401
Figure 2. Regions activated in the contrasts of interest (left), corresponding ROIs with COMT Val>Met effects (middle), and extracted signal from the prefrontal ROI according to COMT genotype (right).
Cancer Imaging. 2006; 6(Spec No A): S32–S41.
MRI protocol and data post-processing Two MRI examinations were performed within 1 week prior to surgery prospectively in two imaging centers with 1.5-T MR units using standard circular-polarized head coils within a minimum time interval of 1 day and a maximum interval of 3 days. Two MRI examinations were necessary because of the long imaging time needed for the functional MRI methods under test and the fact that both DCE and DSC MRI require specific contrast medium administration. In all patients, there were no substantial changes in tumor morphology (e.g. caused by intratumoral bleeding) between both MR examinations that would have meant exclusion of the study. With the first MR unit (Edge whole body system, Marconi Medical Systems, Cleveland, OH), standard anatomic MRI and DSC MRI were performed. With the second MR unit (Magnetom Vision Plus, Siemens, Erlangen, Germany), MRSI, ASL, and DCE MRI were performed. The main features of the functional MRI techniques used in our study are given in Table 1.
Infarct VolumetryInfarct volumetry was based on MRI (fluid-attenuated inversion recovery; n=19) or CT (n=31) scans performed on average 4.5±4.1 days after symptom onset. One patient showed loss of brain stem reflexes within 24 hours after stroke onset, and a second brain scan could not be obtained. For infarct volumetry on MRI scans, we used commercially available software (MRVision; MRVision Inc), and for CT scans, we used public domain software from the National Institutes of Health. In patients with DHC, the most recent scan obtained before DHC was used for volumetry. Measurements of lesion volume were performed independently by 2 observers, 1 of whom was blinded to all other data. Interobserver agreement revealed a single measure intraclass correlation coefficient of 0.98 (95% CI, 0.96 to 0.99; Cronbach’s =0.99). Final analysis was based on the consensus achieved between both observers at joint re-evaluation of their data previously obtained independently.
