Potential benefits of diagnosis and treatment on health outcomes among elderly people with symptoms of overactive bladder.

OBJECTIVES: This study examined potential benefits of diagnosing and treating elderly adults with overactive bladder (OAB) symptoms. METHODS: Data were analysed from the OAB Re-Contact Study (N = 2750), a cross-sectional, self-reported Internet survey. Elderly respondents (65+ years old) with OAB were identified according to current medication use to control OAB symptoms or by scores > 14 (men) or > 16 (women) on the OAB Awareness Tool. Treated were those currently using prescription medication and never treated were those who never used prescription medication for OAB. Outcome measures included health-related quality of life, activity impairment, OAB-related severity and symptoms, and healthcare resource use (e.g. hospitalisations). Generalised linear models predicted health outcomes as a function of diagnosis or treatment, adjusting for covariates. RESULTS: Diagnosed vs. not diagnosed elderly respondents had higher mental component summary (MCS) scores and SF-6D health utilities, and less activity impairment. Treated vs. never treated elderly respondents had higher MCS and SF-6D health utilities, less activity impairment, fewer OAB symptoms, lower OAB Awareness Tool scores, and lower odds of having bladder problems or incontinence. There were no significant differences in healthcare resource use. Further analysis by age group (middle-aged vs. elderly respondents) revealed significantly greater diagnosis- and treatment-related benefits on MCS (2.93 and 4.49 points more, respectively) and activity impairment (1.24 and 1.37 times as much, respectively) among elderly respondents. CONCLUSIONS: Diagnosis and treatment were each associated with a lower health burden for elderly adults with OAB symptoms. These findings highlighted the importance of diagnosis and treatment in alleviating OAB symptoms and their impact on health outcomes.

Prevalence, management and outcomes of medically complex vulnerable elderly patients with urinary incontinence in the United States.

OBJECTIVES: To assess the prevalence, patient-physician communication, treatment and health outcomes associated with urinary incontinence (UI) among the medically complex vulnerable elderly (MCVE) in the United States (US). METHODS: Data from the 2006 to 2012 Medicare Health Outcomes Survey (HOS) were used. MCVE patients were aged 65+ years with a HOS VE score ≥ 3. UI was reported as a small, big or no problem. Descriptive statistics were used to assess patient-physician communication and treatment. Multivariable regression analyses were performed to assess the association of small or big UI problems with various outcomes. RESULTS: The annual UI prevalence increased among MCVE [from 35.8% (2006) to 38.6% (2012)]. MCVE with big UI problems communicated with their physicians more often than those with small UI problems (77.9% and 49.6%, respectively); however, treatment of UI remained low (48.5% and 29.1%, respectively). Physical component summary (PCS) and mental component summary (MCS) scores were lower among MCVE with small or big UI problems compared with those with no UI problems, respectively. The decrements in PCS and MCS scores associated with big UI problems were greater than the decrements associated with any of the other assessed conditions. MCVE with small or big UI problems, respectively, were more likely to report past falls, depression and activity daily living limitations vs. those without UI. The odds of having experienced these outcomes were greater for those with big UI vs. small UI problems. CONCLUSIONS: Urinary incontinence prevalence in the USA increased among MCVE from 2006 to 2012, although treatment of UI remained low. UI problems, particularly big UI problems, adversely impact health outcomes. Efforts to better identify and manage UI among the MCVE are needed.

Direct and indirect cost of urge urinary incontinence with and without pharmacotherapy.

OBJECTIVE: To evaluate the impact of treating urge urinary incontinence (UUI), including mixed urinary incontinence (MUI), on healthcare resource utilisation, productivity, activity impairment and associated costs. METHODS: The study used data from the 2011 U.S. National Health and Wellness Survey, an Internet-based questionnaire of a nationwide sample of adults. UUI or MUI respondents were identified via three Incontinence Questions. Respondents with stress urinary incontinence only, prostate cancer or (medication for) benign prostatic hyperplasia were excluded. UUI/MUI respondents were categorised as Rx users for overactive bladder (OAB) and non-Rx users (who never used Rx and whose condition reportedly interfered with life activities or was difficult to manage). Outcome measures included healthcare utilisation and Work Productivity and Activity Impairment questionnaire-based scores. Direct and indirect costs were estimated using 2010 labour and 2008 medical expenditure data sources. Generalised linear models predicted resource use and productivity as a function of treatment status, adjusting for covariates (e.g. sociodemographics, OAB severity, comorbid status) that may also predict impairment. RESULTS: Rx (vs. non-Rx) users were more likely to be female (80.7% vs. 70.0%), older (mean = 62.7 vs. 53.1) and reporting more moderate-to-severe OAB (70.9% vs. 52.6%; all p < 0.05). Adjusting for covariates, Rx (vs. non-Rx) users had significantly lower activity impairment (41.1% vs. 46.8%), more provider visits (7.42 vs. 5.60) and costs ($18,175 vs. $13,679), and higher total direct costs ($27,291 vs. $21,493), all p < 0.01. CONCLUSIONS: Urge urinary incontinence patients using, vs. never using, prescription medication reported lower activity impairment but higher direct costs. These findings may inform the degree to which UUI pharmacotherapy affects health outcomes.

Smoking, smoking cessation and smoking relapse patterns: a web-based survey of current and former smokers in the US.

AIM: The aim of this study was to characterise the natural course of smoking cessation behaviour in a web-based survey of current and former cigarette smokers (CS and FS) in the United States. METHODS: A web-based survey of CS and FS was conducted in April 2009; demographic and socioeconomic characteristics and smoking history (including the number of lifetime and length of latest quit attempts, aids used and time to relapse) were collated. The surveyed cohort was selected from prescreened CS and FS panellists and matched for age, race and education, to be representative of the US population. Descriptive statistics and time-to-event analyses using Kaplan-Meier curves were applied in the analysis of this report. RESULTS: The final cohort comprised 512 CS and 566 FS (n = 1078). A larger proportion of FS than CS reported a longest smoke-free period of > 1 year (78.8% vs. 22.4%, respectively). As a greater variety of smoking cessation products became available over time, the proportion of unassisted quit attempts decreased from 76.1% prior to 1983 to 43.9% after 2006 for CS and from 79.3% to 50.3% for FS. The cumulative proportion of subjects relapsing was 31.3% by 1 week and 79.3% by 6 months. The estimated median time to next quit attempt was approximately 360 days. CONCLUSIONS: These data confirm that relapse is common and that as the variety of cessation modalities increase, the proportion of unassisted quit attempts decreases. Self-help or cold-turkey methods still provide significant alternatives even when pharmacotherapy is available. This study provides data related to the smoking history and smoking cessation patterns of a large, nationally representative sample of CS and FS.

Prevalence and detection rate of underlying disease in men with erectile dysfunction receiving phosphodiesterase type 5 inhibitors in the United Kingdom: a retrospective database study.

AIM: To determine the rate of newly detected underlying disease in men receiving their first (index) phosphodiesterase type 5 inhibitor (PDE5i) prescription. METHODS: This non-interventional, retrospective study used anonymised patient records from UK general practices identified from the THIN database. Records of men aged ≥ 18 years, who received an index PDE5i prescription between January 1999 and June 2008 and with a continuous medical history (≥ 60 months) before the index prescription were included. Primary end-points were the prevalence of underlying disease prior to the index prescription and to establish the detection rate, defined as cumulative incidence of such a diagnosis in the 3 months following the index prescription. Assessments included comparison with age-matched controls, comparison with identical time periods immediately before and 1 year after, index prescription, and changes over time during the study period. Descriptive statistics, analysis of proportions and multivariate logistic regression analysis were used. RESULTS: Among the 24,708 patients receiving a PDE5i, the prevalence of any underlying diagnosis before the index prescription was 70.23%; prevalence of vasculogenic disease was highest (48.20%). The detection rate of any underlying disease was 11.53%, and again highest for vasculogenic disease (4.07%). Compared with an age-matched control population, the additional detection rate of an unknown underlying disease at PDE5i prescription was 45 for hypertension, 61 for hypercholesterolaemia, 38 for diabetes and 5 for hypogonadism per 10,000 men. CONCLUSION: Only a minority of men with erectile dysfunction have a previously undiagnosed important underlying disease that is uncovered at the time of an initial PDE5i prescription by a GP.

Prevalence of labral tears and cartilage loss in patients with mechanical symptoms of the hip: evaluation using MR arthrography.

OBJECTIVE: To determine the prevalence of labral tears and cartilage lesions in patients with mechanical symptoms of the hip using magnetic resonance (MR) arthrography. METHODS: A total of 100 patients with mechanical symptoms of the hip such as pain, clicking, locking and giving way underwent MR arthrography of the hip to rule out a labral tear. Hip joints were evaluated for labral alterations, bone marrow edema (BME), and other pathology using a novel semi-quantitative scoring system. Cartilage changes were graded separately for the acetabulum and femoral head in the anterior, posterior, central, medial, and lateral hip joint regions (10 locations) on a 6-point scale: 0=normal; 1=signal heterogeneity; 2=fissuring, 3=thinning <50% of the normal thickness; 4=thinning >50% of the normal thickness; 5=full thickness cartilage loss. Labral tears were categorized into normal, intrasubstance degeneration, simple tear or complex tear with two or more tear regions. Statistical methods were contingency tables, Fisher's exact test for discrete outcomes (based on grade scores), Spearman's rank correlation (r) and t tests for continuous outcomes, using pooled and stratified analyses. RESULTS: On MR arthrography, labral tears were found in 66 patients (66% prevalence) with 13 having more than one location involved. Locations were 19 lateral (13 simple, six complex), 54 anterior (39 simple, 15 complex), eight posterior (six simple, two complex). Cartilage lesions were found in 76 patients (76% prevalence) with 53 demonstrating involvement of more than one compartment. The most common finding was cartilage thinning <50% in 99 regions in 44 patients. Cartilage thinning >50% was shown in 34 patients in 67 areas. When we correlated the grade of cartilage abnormality with the grade of labral tear, we found a statistically significant correlation (r=0.29; P< or =0.01). The size of cartilage abnormality was correlated with the grade of labral tear in the lateral acetabulum (r=0.38; P<0.001), anterior acetabulum (r=0.22; P< or =0.002), and lateral femoral head (r=0.29; P< or =0.004). The grade of cartilage loss was correlated with the grade of BME (r=0.44; P< or =0.001). CONCLUSION: Labral tears and cartilage loss are common in patients with mechanical symptoms in the hip. Cartilage loss, labral tears and BME appear interrelated and may represent important risk factors that may affect the development and progression of osteoarthritis in the hip joint.

Intracranial carotid artery calcification on head CT and its association with ischemic changes on brain MRI in patients presenting with stroke-like symptoms: retrospective analysis.

INTRODUCTION: Our purpose was to study the association between the intracranial arterial calcifications observed on head CT and brain infarcts demonstrated by MRI in patients presenting with acute stroke symptoms. METHODS: Institutional review board approval was obtained for this retrospective study which included 65 consecutive patients presenting acutely who had both head CT and MRI. Arterial calcifications of the vertebrobasilar system and the intracranial cavernous carotid arteries (intracranial carotid artery calcification, ICAC) were assigned a number (1 to 4) in the bone window images from CT scans. These four groups were then combined into high calcium (grades 3 and 4) and low calcium (grades 1 and 2) subgroups. Brain MRI was independently evaluated to identify acute and chronic large-vessel infarcts (LVI) and small-vessel infarcts (SVI). The relationship between ICAC and infarcts was evaluated before and after adjusting for demographics and cardiovascular risk factors. RESULTS: Statistical analysis could not be performed for the vertebrobasilar system due to an insufficient number of patients in the high calcium group. Of the 65 patients, 46 (71%) had a high ICAC grade on head CT. They were older and had a higher prevalence of cardiovascular risk factors. Acute SVI (P = 0.006), chronic SVI (P = 0.006) and acute LVI (P = 0.04) were associated with a high ICAC grade. After adjustment for age and other risk factors, only acute SVI was associated with a high ICAC grade (P = 0.002). CONCLUSION: Although age emerged as the most important determinant of ischemic cerebral changes, there were rather complex interactions among multiple risk factors with different infarct types. A high ICAC grade demonstrated a correlation with acute SVI in our patients independent of these risk factors.

Magnetic resonance and the human brain: anatomy, function and metabolism.

The introduction and development, over the last three decades, of magnetic resonance (MR) imaging and MR spectroscopy technology for in vivo studies of the human brain represents a truly remarkable achievement, with enormous scientific and clinical ramifications. These effectively non-invasive techniques allow for studies of the anatomy, the function and the metabolism of the living human brain. They have allowed for new understandings of how the healthy brain works and have provided insights into the mechanisms underlying multiple disease processes which affect the brain. Different MR techniques have been developed for studying anatomy, function and metabolism. The primary focus of this review is to describe these different methodologies and to briefly review how they are being employed to more fully appreciate the intricacies associated with the organ, which most distinctly differentiates the human species from the other animal forms on earth.

Asymptomatic nonspecific serum hyperamylasemia and hyperlipasemia: spectrum of MRCP findings and clinical implications.

We assessed the magnetic resonance cholangiopancreatographic (MRCP) findings in patients with asymptomatic, mild elevations of serum amylase and lipase levels to determine whether there might be a pathoanatomic cause for these laboratory abnormalities. MRCP was performed in 633 consecutive patients. Of these, 54 (8.5%) images were obtained in patients with asymptomatic serum hyperamylasemia and hyperlipasemia. MRCP was performed on a 1.0-T MR system; breath-hold gradient-recall, half-Fourier acquisition, and rapid acquisition with relaxation enhancement sequences were obtained. Findings were verified by follow-up, biopsy, or surgery. One-sided, large-sample z tests were used to compare the incidence of abnormalities between the study and control groups (579 patients). The pancreas appeared abnormal on MRCP in 31 patients (57%), including the pancreas divisum in 10 patients (18.5%). Other findings included morphologic changes compatible with chronic pancreatitis in nine patients (16.6%) and a healed pancreatic laceration, juxtapapillary duodenal diverticulum, papillary sclerosis, intraductal pancreatic lithiasis, and hemochromatosis in one patient each (1.9%). Small cystic lesions (< 1 cm) within the pancreas were seen in 15 patients (27.8%). In eight patients, these were associated with other abnormalities (pancreas divisum in three patients, chronic pancreatitis in four, and pancreatic laceration in one). No malignancy was diagnosed. The incidences of normal examination (p = 0.01), pancreas divisum (p < 0.005), and a small cystic lesion (p = 0.01) as solitary findings in this subgroup of patients were significantly higher when compared with the remainder of the studied population. Investigation of asymptomatic patients with nonspecific hyperamylasemia and hyperlipasemia by means of MRCP yielded pancreatic findings in more than 50% of these patients. Pancreas divisum was found more often than expected in the general population.

An analysis of factors that influence the ASCUS/SIL ratio of pathologists.

In pursuit of physician-specific performance data in cytology, we have been calculating the ASCUS/SIL (atypical squamous cells of undetermined significance/squamous intraepithelial lesion) ratio of cytopathologists (CPs) and providing confidential feedback every 6 months. At the same time, thin-layer technology was introduced as an alternative to conventional smears. Thus we analyzed factors that may influence the ASCUS/SIL ratio, particularly the effect of periodic feedback on outliers (defined by a professional benchmark). For 3 years, the mean ASCUS/SIL ratio for all CPs decreased significantly from 2.92 to 1.87. There was great variability in the mean ASCUS/SIL ratio among 12 CPs (range, 1.11-5.89). Of the 6 CPs who worked continuously during this time, 2 showed a statistically significant decrease in their ASCUS/SIL ratio, including the CP with the highest ratio; 1 showed a significant increase. The mean ASCUS/SIL ratio did not correlate well with years of CP experience or with individual annual case volume. The ASCUS/SIL ratio of some CPs can decrease significantly over time. Whether it was due to feedback or the introduction of thin-layer preparations could not be determined.

Bayesian regression methodology for estimating a receiver operating characteristic curve with two radiologic applications: prostate biopsy and spiral CT of ureteral stones.

RATIONALE AND OBJECTIVES: The authors evaluated two Bayesian regression models for receiver operating characteristic (ROC) curve analysis of continuous diagnostic outcome data with covariates. MATERIALS AND METHODS: Full and partial Bayesian regression models were applied to data from two studies (n = 180 and 100, respectively): (a) The diagnostic value of prostate-specific antigen (PSA) levels (outcome variable) for predicting disease after radical prostatectomy (gold standard) was evaluated for three risk groups (covariates) based on Gleason scores. (b) Spiral computed tomography was performed on patients with proved obstructing ureteral stones. The predictive value of stone size (outcome) was evaluated along with two treatment options (gold standard), as well as stone location (in or not in the ureterovesical junction [UVJ]) and patient age (covariates). Summary ROC measures were reported, and various prior distributions of the regression coefficients were investigated. RESULTS: (a) In the PSA example, the ROC areas under the full model were 0.667, 0.769, and 0.703, respectively, for the low-, intermediate-, and high-risk groups. Under the partial model, the area beneath the ROC curve was 0.706. (b) The ROC areas for patients with ureteral stones in the UVJ decreased dramatically with age but otherwise were close to that under the partial model (ie, 0.774). The prior distribution had greater influence in the second example. CONCLUSION: The diagnostic tests were accurate in both examples. PSA levels were most accurate for staging prostate cancer among intermediate-risk patients. Stone size was predictive of treatment option for all patients other than those 40 years or older and with a stone in the UVJ.

On determination of sample size in hierarchical binomial models.

We consider a two- and a three-stage hierarchical design containing the effects of k clusters with n units per cluster. In the two-stage model, the conditional distribution of the discrete response Y(i) is assumed to be independent binomial with mean n(straight theta)i (I=1,....k). The success probabilities, straight theta(i)'s, are assumed exchangeable across the k clusters, each arising from a beta distribution. In the three-stage model, the parameters in the beta distribution are assumed to have independent gamma distributions. The size of each cluster, n, is determined for functions of straight theta(i). Lengths of central posterior intervals are computed for various functions of the straight theta(i)'s using Markov chain Monte Carlo and Monte Carlo simulations. Several prior distributions are characterized and tables are provided for n with given k. Methods for sample size calculations under the two- and three-stage models are illustrated and compared for the design of a multi-institutional study to evaluate the appropriateness of discharge planning rates for a cohort of patients with congestive heart failure.

A detailed audit of reimbursement for abdominal CT in an academic practice.

RATIONALE AND OBJECTIVES: Declining fee schedules, decreasing operating margins, and increasingly stringent compliance regulations create a need for intense scrutiny and optimization of a radiology organization's billing and collection procedures. The authors' goal was to analyze the effectiveness of departmental professional billing procedures, identify controllable factors, and intervene when they could be improved. MATERIALS AND METHODS: A detailed audit of professional claims and payments was performed for all patients who underwent abdominal-pelvic computed tomography (CT) during July 1999 (n = 717). The adequacy of indication for the CT examination as given by the referring physician and modified by the radiology staff, the time required for claim generation, and the status of reimbursement within 120 days were assessed by an interdisciplinary team. After an intervention was performed to improve adequacy of the available clinical indication, the audit was repeated in December 1999 (n = 710). RESULTS: Despite a significant (P < .05) improvement in wording of clinical indications for billing purposes between July (68%) and December (85%), there was no significant change in reimbursement against gross charges. The vast majority of claims (97% in July, 99% in December) were generated in less than 30 days. At 120 days after the date of service, payments had been received that amounted to only 66% and 54% of discounted professional fees for July and December, respectively. For examinations performed in December, payment was delayed beyond contracted time periods in 138 cases (19%). CONCLUSION: Optimum billing and collection for imaging studies is an increasingly complex task. Even when substantial efforts are devoted to eliciting the proper indication for the study, reimbursement remains low primarily because of payer delays.

Comparison of correlated receiver operating characteristic curves derived from repeated diagnostic test data.

RATIONAL AND OBJECTIVES: It is common to administer the same diagnostic test more than once to the same set of patients. The purpose of this study was to develop two statistical methods for estimating and comparing correlated receiver operating characteristic (ROC) curves for data derived from repeated diagnostic tests. MATERIAL AND METHODS: Parametric and semiparametric transformation models were developed. These estimation methods were illustrated with data from 72 pigmented lesions suspected of being malignant melanoma. A diagnostic scoring system based on asymmetry, border irregularity, color variation, and diameter was used repeatedly, with or without a dermoscope. Statistical hypothesis tests were conducted to evaluate whether a dermoscope improved the clarity of the lesion features in the scoring system. The resulting ROC curves were constructed, along with characteristics and summary measures. RESULTS: The areas under the ROC curves were 0.885 (parametric method) and 0.893 (semiparametric method) without the dermoscope, and 0.916 (parametric) and 0.912 (semiparametric) with the dermoscope. The statistical hypothesis tests did not yield statistically significant differences between the underlying ROC curves for either estimation method. CONCLUSION: The two transformation models yielded similar results for estimation and comparison of the ROC curves. Although a dermoscope did not add extra information, the scoring system was accurate for diagnosing malignant melanoma.

Primary versus secondary ovarian malignancy: imaging findings of adnexal masses in the Radiology Diagnostic Oncology Group Study.

PURPOSE: To analyze ultrasonographic (US), computed tomographic (CT), and magnetic resonance (MR) imaging features of primary and secondary ovarian malignant neoplasms to determine if there is any significant difference in their appearance. MATERIALS AND METHODS: Analysis of the multi-institutional Radiology Diagnostic Oncology Group data revealed 86 patients with primary ovarian carcinoma and 24 patients with a secondary ovarian neoplasm. Numerous imaging features that had been recorded for the adnexal masses with each imaging modality were reviewed and compared between primary and secondary malignant ovarian neoplasms. RESULTS: Of the imaging features assessed with all three modalities, multilocularity as determined at US (P =.02) or MR imaging (P: =.01) was the only significant feature. At US, 30 (37%) of 81 primary ovarian cancers were multilocular, whereas only three (12%) of 24 metastatic neoplasms were multilocular. At MR imaging, 40 (74%) of 54 primary ovarian cancers were multilocular, whereas only five (36%) of 14 metastatic neoplasms were multilocular. Neither a predominately solid appearance nor bilaterality was significantly different between primary and secondary neoplasms. CONCLUSION: For malignant ovarian masses, multilocularity at MR imaging or US favors the diagnosis of primary ovarian malignancy rather than secondary neoplasm, but it is difficult to accurately distinguish between primary and secondary ovarian malignancies.

Lateral ulnar collateral ligament of the elbow: optimization of evaluation with two-dimensional MR imaging.

PURPOSE: To compare, in a cadaveric model, magnetic resonance (MR) imaging techniques with differing contrast and spatial resolution properties in the evaluation of disruption of the lateral ulnar collateral ligament (LUCL) at the elbow. MATERIALS AND METHODS: LUCL tears were surgically created in eight of 28 cadaveric elbow specimens. All specimens underwent 1.5-T MR imaging with the following pulse sequences: T1-weighted spin echo (SE), intermediate-weighted fast SE, fat-suppressed T2-weighted fast SE, gradient-recalled echo (GRE) with high spatial resolution, intermediate-weighted fast SE with high spatial resolution, and fat-suppressed T1-weighted SE with intraarticular administration of gadopentetate dimeglumine (MR arthrography). All images were obtained in the oblique coronal plane. Two radiologists independently graded the LUCL with separate and side-by-side assessment. RESULTS: Areas under the receiver operating characteristic curve were as follows for readers A and B, respectively: T1-weighted SE imaging, 0.64 and 0.62; intermediate-weighted fast SE imaging, 0.87 and 0.67; T2-weighted fast SE imaging, 0.68 and 0.69; GRE imaging, 0.56 and 0.68; MR arthrography, 0.84 and 0.85; and intermediate-weighted imaging with high spatial resolution, 0.92 and 0.88. Interobserver reliability was poor with T1-weighted SE imaging (kappa = 0.13) and GRE imaging (kappa = 0.18), fair with T2-weighted fast SE imaging (kappa = 0.36), and moderate with MR arthrography (kappa = 0.46), intermediate-weighted fast SE imaging (kappa = 0.55), and intermediate-weighted imaging with high spatial resolution (kappa = 0.59). CONCLUSION: Intermediate-weighted imaging with high spatial resolution and MR arthrography showed the greatest overall ability to enable the diagnosis of LUCL tears.

Evaluation of three-dimensional finite element-based deformable registration of pre- and intraoperative prostate imaging.

In this report we evaluate an image registration technique that can improve the information content of intraoperative image data by deformable matching of preoperative images. In this study, pretreatment 1.5 tesla (T) magnetic resonance (MR) images of the prostate are registered with 0.5 T intraoperative images. The method involves rigid and nonrigid registration using biomechanical finite element modeling. Preoperative 1.5 T MR imaging is conducted with the patient supine, using an endorectal coil, while intraoperatively, the patient is in the lithotomy position with a rectal obturator in place. We have previously observed that these changes in patient position and rectal filling produce a shape change in the prostate. The registration of 1.5 T preoperative images depicting the prostate substructure [namely central gland (CG) and peripheral zone (PZ)] to 0.5 T intraoperative MR images using this method can facilitate the segmentation of the substructure of the gland for radiation treatment planning. After creating and validating a dataset of manually segmented glands from images obtained in ten sequential MR-guided brachytherapy cases, we conducted a set of experiments to assess our hypothesis that the proposed registration system can significantly improve the quality of matching of the total gland (TG), CG, and PZ. The results showed that the method statistically-significantly improves the quality of match (compared to rigid registration), raising the Dice similarity coefficient (DSC) from prematched coefficients of 0.81, 0.78, and 0.59 for TG, CG, and PZ, respectively, to 0.94, 0.86, and 0.76. A point-based measure of registration agreement was also improved by the deformable registration. CG and PZ volumes are not changed by the registration, indicating that the method maintains the biomechanical topology of the prostate. Although this strategy was tested for MRI-guided brachytherapy, the preliminary results from these experiments suggest that it may be applied to other settings such as transrectal ultrasound-guided therapy, where the integration of preoperative MRI may have a significant impact upon treatment planning and guidance.

Noncontrast MR imaging and MR arthrography of the ulnar collateral ligament of the elbow: prospective evaluation of two-dimensional pulse sequences for detection of complete tears.

OBJECTIVE: To compare MR imaging techniques with differing contrast and spatial resolution for evaluation of complete disruption of the ulnar collateral ligament (UCL) anterior bundle in a cadaveric elbow model. DESIGN: Complete UCL tears were surgically created at the typical location for clinical tears in eight of 28 fresh frozen cadaveric elbow specimens. All specimens underwent 1.5 T MR imaging in the oblique coronal plane, using an extremity coil. The sequences employed were: T1-weighted spin echo (T1 SE), proton density-weighted (PD) fast spin echo (FSE), fat-suppressed T2-weighted FSE (T2 FSE), gradient recalled echo (GRE) with a high matrix, PD FSE with a high matrix (HRPD), and fat suppressed T1-weighted SE with intra-articular gadolinium (MRAr). Two radiologists independently graded the UCL with separate and side-by-side assessments. RESULTS: Sensitivity/specificity pairs were as follows for reader A and reader B, respectively: T1 SE: 0.25/0.95, 0.50/0.95; PD FSE: 0.38/1.00, 0.25/1.00; T2 FSE: 0.50/0.95, 0.63/0.95; GRE: 0.63/0.85, 0.63/0.60; MRAr: 0.88/1.00, 1.00/0.80; HRPD: 0.50/1.00, 0.88/0.80. Kappa statistics for measuring interobserver reliability for each sequence were poor under T1 SE (-0.13) and GRE (0.19), moderate under HRPD (0.41) and T2 FSE (0.44) and good under MRAr (0.62) and PD FSE (0.78). For both readers, the rating for overall image quality was highest for HRPD, and the rating for UCL lesion conspicuity was the highest for MRAr. CONCLUSIONS: Of the MR imaging pulse sequences tested, MRAr showed the greatest ability to identify complete ligamentous injuries with good agreement between readers and had the highest subjective preference for lesion conspicuity. However, HRPD had the least interobserver variability and the highest subjective preference for overall image quality.

MR imaging-guided percutaneous cryotherapy of liver tumors: initial experience.

PURPOSE: To describe the cryoablation of liver tumors by using a percutaneous approach and intraprocedural magnetic resonance (MR) imaging monitoring and to assess the feasibility and safety of the procedure. MATERIALS AND METHODS: Fifteen hepatic tumors (mean diameter, 2.9 cm) in 12 patients were treated (18 total cryoablations). Fourteen were metastases and one was a hemangioma; all were proved at biopsy. By using a 0.5-T open MR imaging system, cryoneedles were placed and lesions ablated by using real-time monitoring. Clinical signs and symptoms were assessed and laboratory tests performed. Intraprocedural depictions of iceballs were compared with contrast material-enhanced MR imaging-based estimates of cryonecrosis that were obtained 24 hours after cryoablation. RESULTS: MR imaging-guided percutaneous cryotherapy resulted in no serious complications and no clinically important changes in serum liver enzymes or creatinine or myoglobin levels. Intraprocedural MR imaging demonstrated iceballs as sharply marginated regions of signal loss that expanded and engulfed tumors. The maximal iceball size was 4.9 x 2.2 x 2.2 cm with the use of one cryoneedle and 6.0 x 5.6 x 4.9 cm with three cryoneedles. Intraprocedural iceball depictions correlated well with postprocedural cryonecrosis estimates. CONCLUSION: MR imaging-guided percutaneous cryotherapy of liver tumors is feasible and safe. MR imaging can be used to estimate cryotherapy effects and guide therapy intraprocedurally.

Multi-component apparent diffusion coefficients in human brain: relationship to spin-lattice relaxation.

In vivo measurements of the human brain tissue water signal decay with b-factor over an extended b-factor range up to 6,000 s/mm(2) reveal a nonmonoexponential decay behavior for both gray and white matter. Biexponential parametrization of the decay curves from cortical gray (CG) and white matter voxels from the internal capsule (IC) of healthy adult volunteers describes the decay process and serves to differentiate between these two tissues. Inversion recovery experiments performed in conjunction with the extended b-factor signal decay measurements are used to make separate measurements of the spin-lattice relaxation times of the fast and slow apparent diffusion coefficient (ADC) components. Differences between the spin-lattice relaxation times of the fast and slow ADC components were not statistically significant in either the CG or IC voxels. It is possible that the two ADC components observed from the extended b-factor measurements arise from two distinct water compartments with different intrinsic diffusion coefficients. If so, then the relaxation results are consistent with two possibilities. Either the spin-lattice relaxation times within the compartments are similar or the rate of water exchange between compartments is "fast" enough to ensure volume averaged T(1) relaxation yet "slow" enough to allow for the observation of biexponential ADC decay curves over an extended b-factor range. Magn Reson Med 44:292-300, 2000.