MR-guided percutaneous sclerotherapy of low-flow vascular malformations: Clinical experience using a 1.5 tesla MR system.

PURPOSE: To demonstrate the feasibility, safety, and effectiveness of image-guided sclerotherapy of low-flow vascular malformations using a 1.5 Tesla (T) MR scanner with real-time imaging capability and in-suite fluoroscopy. MATERIALS AND METHODS: Thirty-three procedures were performed with real-time 1.5T MR-guidance on 22 patients with a vascular malformation in the neck (n = 2), chest (n = 6), abdomen and pelvis (n = 15), and extremities (n = 11). Quantitative analysis was performed for changes in (a) planning time, (b) targeting time (interval between needle skin puncture and lesion access), (c) intervention time (interval between needle skin puncture and needle removal), and (d) total procedure time. Qualitative analysis was performed for (a) success of therapy and (b) occurrence of complications. RESULTS: Technical success was achieved in 29 of 33 procedures. The average planning time did not significantly change between the first seven procedures and the last seven procedures (P = 0.447). The average targeting time decreased by 0:24:45 (hours:minutes:seconds) (P = 0.043), the average intervention time decreased by 0:26:58 (P = 0.022), and the average procedure time decreased by 0:28:41 (P = 0.046) when comparing the first seven procedures and the last seven procedures. Overall, there was an improvement in the patients' predominant symptoms following 82% of procedures, including a significant decrease in average pain following therapy (P < 0.001). There was a minor complication rate of 3% with no major complications. CONCLUSION: MR-guided percutaneous sclerotherapy seems to be a safe, effective, and versatile technique for treating low-flow vascular malformations. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:1154-1162.

Bits and bytes: the future of radiology lies in informatics and information technology.

Advances in informatics and information technology are sure to alter the practice of medical imaging and image-guided therapies substantially over the next decade. Each element of the imaging continuum will be affected by substantial increases in computing capacity coincident with the seamless integration of digital technology into our society at large. This article focuses primarily on areas where this IT transformation is likely to have a profound effect on the practice of radiology. KEY POINTS: • Clinical decision support ensures consistent and appropriate resource utilization. • Big data enables correlation of health information across multiple domains. • Data mining advances the quality of medical decision-making. • Business analytics allow radiologists to maximize the benefits of imaging resources.

Imaging in the Age of Precision Medicine: Summary of the Proceedings of the 10th Biannual Symposium of the International Society for Strategic Studies in Radiology.

During the past decade, with its breakthroughs in systems biology, precision medicine (PM) has emerged as a novel health-care paradigm. Challenging reductionism and broad-based approaches in medicine, PM is an approach for disease treatment and prevention that takes into account individual variability in genes, environment, and lifestyle. It involves integrating information from multiple sources in a holistic manner to achieve a definitive diagnosis, focused treatment, and adequate response assessment. Biomedical imaging and imaging-guided interventions, which provide multiparametric morphologic and functional information and enable focused, minimally invasive treatments, are key elements in the infrastructure needed for PM. The emerging discipline of radiogenomics, which links genotypic information to phenotypic disease manifestations at imaging, should also greatly contribute to patient-tailored care. Because of the growing volume and complexity of imaging data, decision-support algorithms will be required to help physicians apply the most essential patient data for optimal management. These innovations will challenge traditional concepts of health care and business models. Reimbursement policies and quality assurance measures will have to be reconsidered and adapted. In their 10th biannual symposium, which was held in August 2013, the members of the International Society for Strategic Studies in Radiology discussed the opportunities and challenges arising for the imaging community with the transition to PM. This article summarizes the discussions and central messages of the symposium.

MR-guided sclerotherapy of low-flow vascular malformations using T2 -weighted interrupted bSSFP (T2 W-iSSFP): comparison of pulse sequences for visualization and needle guidance.

PURPOSE: Image-guided treatment of low-flow vascular (venous or lymphatic) malformations presents a challenging visualization problem, regardless of the imaging modality being used for guidance. The purpose of this study was to employ a new magnetic resonance imaging (MRI) sequence, T2 -weighted interrupted balanced steady-state free precession (T2 W-iSSFP), for real-time image guidance of needle insertion. MATERIALS AND METHODS: T2 W-iSSFP uses variable flip angle balanced steady-state free precession (bSSFP, a.k.a. SSFP) to establish T2 -weighting and fat suppression. Swine (n = 3) and patients (n = 4, three female, all with venous malformations) were enrolled in the assessment. T2 -weighted turbo spin echo (T2 -TSE) with spectral adiabatic inversion recovery (SPAIR), SPAIR-T2 -TSE or T2 -TSE for short, was used as the reference. T2 -weighted half Fourier acquired single shot turbo spin echo (T2 -HASTE) with SPAIR (SPAIR-T2 -HASTE, T2 -HASTE for short), fat saturated bSSFP (FS-SSFP), and T2 W-iSSFP were imaged. Numeric metrics, namely, contrast-to-noise ratio (CNR) efficiency (CNR divided by the square root of acquisition time) and local sharpness (the reciprocal of edge width), were used to assess image quality. MR-guided sclerotherapy was performed on the same patients using real-time T2 W-iSSFP to guide needle insertion. RESULTS: Comparing the visualization of needles in the images of swine, the local sharpness (mm(-1) ) was: 0.21 ± 0.06 (T2 -HASTE), 0.48 ± 0.02 (FS-SSFP), and 0.49 ± 0.03 (T2 W-iSSFP). T2 W-iSSFP is higher than T2 -HASTE (P < 0.001). For the patient images, their CNR efficiencies were: 797 ± 66 (T2 -HASTE), 281 ± 44 (FS-SSFP), and 860 ± 29 (T2 W-iSSFP). T2 W-iSSFP is higher than FS-SSFP (P < 0.02). The frame rate of T2 W-iSSFP was 2.5-3.5 frames per second. All MR-guided sclerotherapy procedures were successful, with all needles (six punctures) placed in the targets. CONCLUSION: T2 W-iSSFP provides effective lesion identification and needle visualization. This new pulse sequence can be used for MR-guided sclerotherapy of low-flow vascular malformations. It may have potential use in other MR-guided procedures where heavily T2 -weighted real-time images are needed.

The CT scout view: does it need to be routinely reviewed as part of the CT interpretation?

OBJECTIVE: The objective of our study was to determine whether the CT scout view should be routinely reviewed by comparing diagnostic information on the scout view with that provided by the correlative CT study. MATERIALS AND METHODS: Two radiologists blinded to history and CT findings reviewed retrospectively 2032 scout views. All cases with major findings (defined as any abnormality that would prompt additional diagnostic tests or require management) were correlated with the CT study, other imaging study, or medical record when necessary by a third radiologist to determine the validity of the scout view finding and whether the finding was identifiable on the current CT study. RESULTS: Major findings were identified in 257 (13%, reader 1) and 436 (23%, reader 2) of cases. Most major findings were confirmed (69-78%) or refuted (13-16%) by the CT study. However, 15 (6%, reader 1) and 48 (11%, reader 2) of the major findings were not included in the CT FOV, of which five (2%, reader 1) and 21 (5%, reader 2) constituted a missed pathologic finding. The most common one was cardiomegaly detected on a nonchest CT scout view. Additional pathologic findings included fracture, metastasis, avascular necrosis or subluxation of the humeral head, dilated bowel, and thoracic aortic dilatation. The most common false-positive finding was cardiomegaly. CONCLUSION: In a small percentage of cases, review of the CT scout view will disclose significant pathologic findings not included in the CT FOV. The results of this study support the routine inspection of the scout view, especially for the detection of pathologic findings in anatomic regions not imaged by CT.

Percutaneous punctures with MR imaging guidance: comparison between MR imaging-enhanced fluoroscopic guidance and real-time MR Imaging guidance.

PURPOSE: To evaluate and compare the technical accuracy and feasibility of magnetic resonance (MR) imaging-enhanced fluoroscopic guidance and real-time MR imaging guidance for percutaneous puncture procedures in phantoms and animals. MATERIALS AND METHODS: The experimental protocol was approved by the institutional animal care and use committee. Punctures were performed in phantoms, aiming for markers (20 each for MR imaging-enhanced fluoroscopic guidance and real-time MR imaging guidance), and pigs, aiming for anatomic landmarks (10 for MR imaging-enhanced fluoroscopic guidance and five for MR imaging guidance). To guide the punctures, T1-weighted three-dimensional (3D) MR images of the phantom or pig were acquired. Additional axial and coronal T2-weighted images were used to visualize the anatomy in the animals. For MR imaging-enhanced fluoroscopic guidance, phantoms and pigs were transferred to the fluoroscopic system after initial MR imaging and C-arm computed tomography (CT) was performed. C-arm CT and MR imaging data sets were coregistered. Prototype navigation software was used to plan a puncture path with use of MR images and to superimpose it on fluoroscopic images. For real-time MR imaging, an interventional MR imaging prototype for interactive real-time section position navigation was used. Punctures were performed within the magnet bore. After completion, 3D MR imaging was performed to evaluate the accuracy of insertions. Puncture durations were compared by using the log-rank test. The Mann-Whitney U test was applied to compare the spatial errors. RESULTS: In phantoms, the mean total error was 8.6 mm ± 2.8 with MR imaging-enhanced fluoroscopic guidance and 4.0 mm ± 1.2 with real-time MR imaging guidance (P < .001). The mean puncture time was 2 minutes 10 seconds ± 44 seconds with MR imaging-enhanced fluoroscopic guidance and 37 seconds ± 14 with real-time MR imaging guidance (P < .001). In the animal study, a tolerable distance (<1 cm) between target and needle tip was observed for both MR imaging-enhanced fluoroscopic guidance and real-time MR imaging guidance. The mean total error was 7.7 mm ± 2.4 with MR imaging-enhanced fluoroscopic guidance and 7.9 mm ± 4.9 with real-time MR imaging guidance (P = .77). The mean puncture time was 5 minutes 43 seconds ± 2 minutes 7 seconds with MR imaging-enhanced fluoroscopic guidance and 5 minutes 14 seconds ± 2 minutes 25 seconds with real-time MR imaging guidance (P = .68). CONCLUSION: Both MR imaging-enhanced fluoroscopic guidance and real-time MR imaging guidance demonstrated reasonable and similar accuracy in guiding needle placement to selected targets in phantoms and animals.

Neuroradiology second opinion consultation service: assessment of duplicative imaging.

OBJECTIVE: The purpose of this study was to characterize the performance of the Neuroradiology Second Opinion Consultation Service (NSOCS) at our institution to establish the rate, causes, and implications of requests for repeat imaging. MATERIALS AND METHODS: We queried 11,753 complete reports of all NSOCS studies for calendar year 2010 for the words "repeat" and "follow-up." We categorized study limitations described in these reports into poor image quality, missing or inadequate MR sequences or CT reformats, lack of IV contrast administration where otherwise deemed appropriate, an "other" category for miscellaneous items, and a "clarification" category for indeterminate findings or recommendations for more advanced protocols. The corresponding available electronic medical records were reviewed. An estimated financial analysis of the NSOCS was additionally performed. RESULTS: Repeat imaging studies were recommended in 1.5% of cases. In 0.3% of all cases, a subsequent repeat examination was documented in the electronic medical records. Study limitations were most commonly due to poor image quality (77.5%), followed by missing or inadequate MR sequences or CT reformats (20.3%). The additional estimated cost of repeat imaging was calculated at $14,019.34, with an overall per-patient cost of $2.12 for the service. CONCLUSION: Reviewing outside studies generates a very low rate of requests for and performance of repeat studies, and is not a major additional health care expense.

Reporting of critical findings in neuroradiology.

OBJECTIVE: The objective of our study was to assess compliance among academic neuroradiologists in reporting institutionally derived critical findings. MATERIALS AND METHODS: We analyzed 3054 neuroradiology CT and MRI reports generated in 1 month. Reports were categorized by whether or not they contained a critical finding based on a previously established list. The reports were subcategorized by whether the reporting neuroradiologist flagged the report as containing a critical finding and whether the radiologist verbally communicated the critical finding to the referring clinician. Reports were divided into day or night categories and the frequency of critical findings for each time period was calculated. RESULTS: Of the 3054 reports included in this study, 301 (9.9%) had critical findings. Of those 301 reports, 233 (77.4%) were flagged and the referring clinician was called. Of the remaining 68 reports with critical findings, the reporting radiologist did not call the clinician about 35.3% of them (24/68). Of the 2753 reports without critical findings, 2658 (96.5%) were appropriately not flagged and the clinician was not called. However, radiologists called clinicians about 3.5% (95/2753) of the reports without critical findings and erroneously flagged 68.4% (65/95) of those reports as critical. A majority of the cases with critical findings were reported at night (55.1%) despite the fact that 67.2% of the studies occurred during the day. CONCLUSION: Compliance with reporting and communicating critical findings must be monitored. Calling clinicians to report noncritical findings may result in unnecessary interruptions in work flow for radiologists and referring health care providers.

Modified map-seeking circuit: use of computer-aided detection in locating postoperative retained foreign bodies.

BACKGROUND: More than 98% of intra-operative X-rays taken to search for postoperative retained foreign bodies (RFBs) have negative findings; in over 30% of cases of such X-rays, the finding is a false negative. Newer technologies created to find RFBs must not only reduce the false-negative rate, but also must not increase the burden of detecting RFBs. We have introduced the use of computer-aided detection (CAD) to facilitate the detection of RFBs on X-rays utilizing a modified version of map-seeking circuit (MSC) algorithm the referenced map-seeking circuit (RMSC), for our proof-of-concept study for detection of needles in plain abdominal X-rays. METHODS: Images were obtained by using a portable cassette-based X-ray machine and a C-arm (digital) machine, both of which are commonly used in the operating room. The images obtained using these machines were divided into subimages of approximately 250 × 250 pixels each, for a total of 455 subimages from the cassette-based machine (A) and 365 from the digital machine (B) for use as test samples. Images obtained from A and B were analyzed separately using our modified MSC algorithm with a minimum (τ = 0) and a maximum threshold (τ = 0.5). RESULTS: The automated detection rate (positive predictive value) was 86%, with a false positive/negative rate of 10% to 15% when τ was zero. CONCLUSION: The CAD-based RMSC algorithm has the potential to improve the accuracy with which RFBs can be found in X-rays. Further research is needed to optimize the detection rate and to identify a wider range of RFBs.

Prevalence of honorary coauthorship in the American Journal of Roentgenology.

OBJECTIVE: The objective of our study was to determine the prevalence of honorary authorship in articles published in the American Journal of Roentgenology (AJR) and to evaluate the factors that might influence the perception of honorary authorship. MATERIALS AND METHODS: Corresponding authors of 1333 Original Research articles published in AJR between 2003 and 2010 were invited by e-mail to complete a Web-based, self-administered survey. Univariable analysis of sample proportions was performed using the chi-square test. Multivariable logistic regression models were used to assess the independent factors that were associated with the probability of honorary authorship. RESULTS: Responses were received from authors of 490 articles (36.8% response rate). Most respondents were aware of the authorship guidelines proposed by the International Committee of Medical Journal Editors (n = 399, 81.4%) and the issue of honorary authorship (n = 353, 72.0%). Authorship was most commonly decided by the first author (n = 256, 52.2%). One hundred twenty-one authors (24.7%) perceived that one or more coauthors listed for the respective article did not make sufficient contributions. Factors most strongly associated with honorary authorship included a work environment where a senior department member was automatically listed (odds ratio [OR], 1.33), the suggestion that an honorary author should be included (OR, 5.96), and the perception that a coauthor performed only a single nonauthor task (i.e., reviewing the manuscript: OR, 1.54). CONCLUSION: A substantial proportion of articles had evidence of honorary authorship. The rate of honorary authors was higher among authors who worked in an environment where senior members were routinely added to all manuscripts submitted for publication, authors who perceived that a coauthor listed had only reviewed the manuscript, and authors who reported that someone suggested they should include an honorary author.

Globalization of P4 medicine: predictive, personalized, preemptive, and participatory--summary of the proceedings of the Eighth International Symposium of the International Society for Strategic Studies in Radiology, August 27-29, 2009.

In August 2009, the International Society for Strategic Studies in Radiology held its eighth biennial meeting. The program focused on the globalization of predictive medicine--or P4 medicine--as it relates to the practice of radiology and radiology research. P4 medicine refers to predictive, personalized, preemptive, and participatory medicine and was the inspiration of Elias Zerhouni, MD, former director of the National Institutes of Health. This article is a summary of some of the key concepts presented at the meeting by an international group of radiologists, imaging scientists, and leaders of industry. In predictive medicine, imaging and imaging-related technologies will likely play an increasing role in the early detection of disease and, thus, the preemption of the development of advanced, hard-to-treat disease. Research into systems biology and molecular imaging promises to personalize medicine, facilitating the provision of the right care to the right patient at the right time. In participatory medicine, increasing interactions with referring physicians and patients will be helpful in raising awareness and recognition of the role of radiologists and will have a positive effect on professionalism. There is also a need to increase awareness of the vital role of radiologists as imaging and radiation safety experts who evaluate the necessity and appropriateness of examinations, monitor performance quality, and are available for postexamination consultations.

Second-opinion consultations in neuroradiology.

PURPOSE: To assess the patient care benefit of a recently implemented institutional policy requiring official second-opinion consultation for all studies performed outside the institution. MATERIALS AND METHODS: The institutional review board approved the retrospective review of patient data for this HIPAA-compliant study and waived the need for individual informed consent. The second-opinion consultation reports for outside neuroradiology studies finalized by subspecialty-trained neuroradiologists within calendar year 2008 were compared with the outside reports provided with the images. The reports were categorized by using a five-point scale: 1 indicated no difference in interpretation; 2, clinically unimportant difference in detection; 3, clinically unimportant difference in interpretation; 4, clinically important difference in detection; and 5, clinically important difference in interpretation. Clinically important differences were defined as those likely to change patient care or diagnoses. Statistical comparisons were performed by using two-sample continuity-corrected Z tests with two-sided alternatives. Bonferroni corrections were performed when more than two rates were compared. Confidence intervals for all rates were constructed by using the score interval along with the Yates continuity correction. RESULTS: Of 7465 studies, 4534 (60.7%) had an outside report for comparison. There were 347 (7.7%) instances with clinically important differences. Of these 347 discrepancies, 233 (67.1%) were category 4 and 114 (32.9%) were category 5. When the final diagnosis was determined from pathology reports, clinical assessments, and/or imaging follow-up, the second-opinion consultation was noted to be correct in 163 (84.0%) of 194 studies with category 4 or 5 discrepancies. CONCLUSION: A 7.7% rate of discrepant interpretations (347 of 4534 studies) was noted for a service offering second-opinion consultations for outside examinations. Most were discrepancies in detecting abnormalities rather than in interpreting identified findings. When a definitive diagnosis was obtainable, the second-opinion consultation was more accurate in 84% of studies. Review of outside studies benefits patient care.

MR monitoring of NaCl-enhanced radiofrequency ablations: observations on low- and high-field-strength MR images with pathologic correlation.

PURPOSE: To test the hypothesis that magnetic resonance (MR) imaging can be used to monitor both intraparenchymal injection of NaCl solution and subsequent radiofrequency ablation (RFA) within tissues pretreated with NaCl, report the low- and high-field-strength MR appearance of NaCl-enhanced RFAs, and compare MR findings with pathologic findings. MATERIALS AND METHODS: Ten ex vivo calf liver specimens were injected with saturated NaCl (seven were mixed with methylene blue during MR fluoroscopic monitoring) and reexamined with fast imaging with steady-state progression (FISP), true FISP, reversed FISP (PSIF), and fast spin-echo T2-weighted MR sequences. The NaCl-to-liver contrast-to-noise ratio (CNR) was calculated for various sequences, and CNRs were compared with the Student t test. Distribution on MR images was compared with the results of pathologic analysis. Forty additional in vivo monopolar RFAs were performed in paraspinal muscles of seven minipigs after animal care committee approval (10 standard control ablations, 30 were preceded by direct injection of saturated NaCl at various volumes [3-9 mL] and rates [1 or 6mL/min]). Postablation low-field-strength (n = 20) and high-field-strength (n = 20) MR examinations consisted of T2-weighted imaging, short inversion time inversion-recovery (STIR) imaging, and contrast material-enhanced T1-weighted imaging. Ablation shape, conspicuity, volume, and signal intensity were compared between the two groups and with the results of pathologic analysis. The difference in volumes with and without NaCl injection was evaluated by using two-way analysis of variance. RESULTS: Mean CNR was highest on fast spin-echo T2-weighted images and was significantly higher for PSIF than for FISP (P < .0001) or true FISP (P = .003). NaCl distribution on MR images corresponded with the results of pathologic analysis in ex vivo livers. Interactive in vivo monitoring of NaCl injection and electrode placement was feasible. NaCl-enhanced ablations had irregular shapes, a higher CNR, and significantly larger volumes (F = 22.0; df = 1, 90; P < .00001). All ablations had intermediate or low signal intensity with high-signal-intensity rims on all images. Fluid signals overlaid NaCl-enhanced ablations on fast spin-echo T2-weighted and STIR images, particularly on high-field-strength MR images. CONCLUSION: MR imaging can be used to reliably monitor the distribution of injected NaCl solution in tissues. Interventional MR imaging techniques can be used to guide and monitor RFAs within NaCl pretreated tissues, with good correlation with pathologic results.

Freehand real-time MRI-guided lumbar spinal injection procedures at 1.5 T: feasibility, accuracy, and safety.

OBJECTIVE: The purpose of this study was to test the hypothesis that freehand real-time MRI-guided lumbar spinal injection procedures are feasible, accurate, and safe when performed with a clinical open-bore 1.5-T MRI system. MATERIALS AND METHODS: A retrospective analysis was made of spinal injection procedures performed over an 18-month period. Forty-nine procedures were performed on 37 patients (23 women, 14 men; mean age, 36 years; range, 18-48 years). A rapid FLASH 2D MRI sequence (TR/TE, 9.3/3.5; slice thickness, 5 mm; acquisition time, 1 second) was used for real-time needle placement with freehand technique. Data assessed were type of procedure, qualitative and quantitative image quality, dimensions of needle artifact, rate of successful drug delivery, rate of vascular uptake, time requirements, and occurrence of complications. RESULTS: Among the 49 procedures, 22 (45%) were nerve root injections, 18 (37%) were facet joint injections, and nine (18%) were epidural injections. The quality of real-time FLASH 2D MR images was sufficient in all cases. Contrast-to-noise ratios were sufficiently high for good delineation of relevant structures. The needle artifact made was remarkably constant with an average overestimation of length of 1.0 +/- 0.2 [SD] mm. Drug delivery was successful in all selective nerve root injections and epidural injections. The rate of successful drug delivery was 89% (16 of 18) for facet joint injections. No complete intravascular injections occurred. The mean table time was 36 minutes (range, 23-75 minutes). The mean real-time MRI time was 38 seconds (range, 12-185 seconds). No major complications occurred. CONCLUSION: We accept the hypothesis that freehand real-time MRI-guided lumbar spinal injection procedures are feasible, accurate, and safe when performed with a clinical open-bore 1.5-T MRI system. We note that real-time MRI guidance has the additional advantage of a complete absence of patient and operator exposure to ionizing radiation.

MRI-guided injection procedures of the temporomandibular joints in children and adults: technique, accuracy, and safety.

OBJECTIVE: The purpose of our study was to test the hypothesis that real-time MRI-guided, selective injection procedures of the temporomandibular joints are feasible, accurate, and safe when performed on a clinical open-bore 1.5-T MR system. MATERIALS AND METHODS: A retrospective analysis of 67 injection procedures of the temporomandibular joints (55% [37/67] were therapeutic injections, 27% [18/67] were diagnostic injections, and 18% [12/67] were arthrocentesis procedures), performed in 31 patients (58% [18/31] female, 42% [13/31] male; mean age, 14 years; age range, 3-34 years), was made. Seven of 38 (18%) subjects had two temporally separate procedures. Determinations of skin entry points, puncture, and injection were performed under real-time MRI. Data were assessed for rate of successful injections, quantitative and qualitative image quality, time requirements, and occurrence of complications. RESULTS: Drug delivery was successful in all procedures. The quality of real-time FLASH 2D MR images was sufficient in all cases. Real-time MRI proved to be helpful to achieve high rates of intraarticular injections. Contrast-to-noise ratios were sufficiently high for good delineation of relevant structures. Average length of time was 25 minutes (range, 16-53 minutes). No major complications occurred. CONCLUSION: We accept the hypothesis that real-time MRI-guided selective injection procedures of the temporomandibular joints are feasible, accurate, and safe when performed on a clinical open-bore 1.5-T MR system.

Diagnostic and interventional MRI of the sacroiliac joints using a 1.5-T open-bore magnet: a one-stop-shopping approach.

OBJECTIVE: The objective of our study was to prospectively test the hypothesis that combined diagnostic and interventional MRI of the sacroiliac joints can be performed efficiently and effectively. SUBJECTS AND METHODS: Over a 12-month period, 60 patients (32 women and 28 men; median age, 28 years; age range, 18-49 years) with chronic lower back pain suspected to originate from the sacroiliac joints were enrolled in the study. Based on diagnostic MRI findings, MR fluoroscopy-guided sacroiliac joint injections were performed in 57 (95%) patients. Diagnostic injections (35, 58.3%) were performed if nonspecific or degenerative MRI findings were present. Therapeutic injections (22, 36.7%) were performed in patients with inflammatory arthropathy. In three (5%) patients, no injections were performed. Technical effectiveness was assessed by analyzing, first, the rate of intraarticular injection; second, the time required for the procedure; third, image quality; and, fourth, occurrence of complications and clinical outcome by analyzing pain intensity changes and volume and signal intensity of sacroiliac inflammatory changes. RESULTS: The rate of intraarticular injection was 90.4% (103/114). The mean length of time for the procedure was 50 minutes (range, 34-103 minutes), with exponential shortening over time (p < or = 0.001). The contrast-to-noise ratios of the needle and tissues were sufficiently different for excellent delineation of the needle. No complications occurred. Diagnostic injections identified the sacroiliac joints as generating significant pain in 46.9% (15/32) of the patients. Three months after therapeutic injections, pain intensity had decreased by 62.5% (p < or = 0.001) and the volume and relative signal intensity of inflammatory changes had decreased by 37.5% (p = 0.003) and 47.6% (p < or = 0.001), respectively. CONCLUSION: We accept the hypothesis that combined diagnostic and interventional MRI of the sacroiliac joints can be performed efficiently and effectively for comprehensive diagnosis and therapy of lower back pain originating from the sacroiliac joints.

Creating a Clinical Interventional MRI Service.

The expansive technological developments that occurred over the past decades have clearly moved the field of Interventional MRI beyond the arena of the "proof of concept" to a viable option for minimally invasive diagnosis and therapy. State-of-the-art MRI technology can currently be employed to identify an occult target pathology, confidently steer an interventional device into complex anatomy, accurately deliver a device, drug, or energy, and/or monitor the real time effect of a treatment. Implementing a full-scope interventional MRI service requires substantial physical and conceptual modifications of the traditional diagnostic MRI environment. As such, it is essential to recognize that interventional MRI does not only involve the actual MRI-guided interventional event but should rather be perceived as a whole foundation of technology, development, set-up, conceptual training, and an institutional culture that realizes the opportunities offered by and understands the challenges and limitations of MRI-guided interventions. At Emory University, we had the privilege to build a de novo interventional MRI suite and to subsequently operate a high volume clinical interventional MRI service. The Emory program was launched with the goal of establishing a destination site for a comprehensive clinical service of MRI-guided interventions. The experience gained and the lessons learned are shared with the readers in this article.

Intraoperative MRI with a rotating, tiltable surgical table: a time use study and clinical results in 122 patients.

OBJECTIVE: The objective of our study was to evaluate intraoperative low-field MRI for the frequency and duration of imaging sessions needed during surgery, the direct additional procedure time attributable to imaging, and the proportion of cases in which information provided by intraoperative MRI led to a change in the procedure or otherwise was deemed valuable by operating surgeons. MATERIALS AND METHODS: One hundred twenty-two patients (65 males, 57 females; age range, 6-77 years; mean age, 43.8 years) underwent 130 neurosurgical and ENT procedures (106 craniotomies, 17 transsphenoidal pituitary resections, three biopsies, three intracranial cyst aspirations or injections, and one skull base resection) in a specially designed surgical MRI suite equipped with a 0.2-T imager and a prototype rotating, tiltable surgical table. The intraoperative MR sequences included free induction with steady-state precession (fast imaging with steady-state precession [FISP]), steady-state free precession T2-weighted, reverse fast imaging with steady-state free precession (PSIF), FLASH, spin-echo T1-weighted, turbo spin-echo (TSE) T2-weighted, and TSE FLAIR. Each case was analyzed for the number of imaging sessions, duration of each session, total imaging time during surgery, and impact of imaging information on procedure. RESULTS: Each patient underwent between one and five intraor postoperative imaging sessions. Imaging times were 1.7 seconds-8 minutes 31 seconds per sequence. The mean total imaging time was 35 minutes 17 seconds per surgical procedure. Imaging was continuous during biopsy and cyst aspiration procedures and averaged 200.67 and 54.66 minutes, respectively. Additional surgical resection based on intraoperative imaging findings was performed in 72.8% of the cases. CONCLUSION: Intraoperative low-field MRI provides valuable information for surgical decision making that is predominantly related to detection of residual tumor and the exclusion of complications. The benefits of this technology surpass the time cost associated with its implementation when using proper imaging strategies.

Suppression of prostate carcinogenesis by dietary supplementation of celecoxib in transgenic adenocarcinoma of the mouse prostate model.

Epidemiological studies and clinical observations suggest that nonsteroidal anti-inflammatory drugs and certain selective cyclooxygenase (COX)-2 inhibitors may reduce the relative risk of clinically evident prostate cancer. This prompted us to investigate the chemopreventive potential of celecoxib, a selective COX-2 inhibitor, against prostate carcinogenesis in a transgenic adenocarcinoma of the mouse prostate (TRAMP) model. Similar to prostate cancer in humans, prostate malignancies in TRAMP mice progress from precursor intraepithelial lesions, to invasive carcinoma that metastasizes to lymph nodes, liver, lungs, and occasionally to bone. The basal enzyme activity and protein expression of COX-2 is significantly higher (>4-fold) in the dorsolateral prostate of TRAMP mice up to 24 weeks of age compared with their nontransgenic littermates. Eight-week-old TRAMP mice were randomly divided and fed either control diet (AIN 76A) or a custom prepared AIN 76A diet containing 1500-ppm celecoxib ad libitum for 24 weeks, a dosage that would compare with the normal recommended dose for the treatment of human disease. Studies from two independent experiments, each consisting of 10 mice on test, showed that the cumulative incidence of prostate cancer development at 32 weeks of age in animals fed with AIN 76A diet was 100% (20 of 20) as observed by tumor palpation, whereas 65% (13 of 20), 35% (7 of 20), and 20% (4 of 20) of the animals exhibited distant site metastases to lymph nodes, lungs, and liver. Celecoxib supplementation to TRAMP mice from 8-32 weeks of age exhibited significant reduction in tumor development (5 of 20) with no signs of metastasis. Celecoxib feeding resulted in a significant decrease in prostate (56%; P < 0.0003) and genitourinary weight (48%; P < 0.008). Sequential magnetic resonance imaging analysis of celecoxib-fed mice documented lower prostate volume compared with the AIN 76A-fed group. Histopathological examination of celecoxib-fed animals showed reduced proliferation, and down-modulation of COX-2 and prostaglandin E2 levels in the dorsolateral prostate and plasma, respectively. These results correlated with retention of antimetastasis markers, viz E-cadherin, and alpha- and beta-catenin, along with a significant decrease in vascular endothelial growth factor protein expression. Celecoxib supplementation also resulted in enhanced in vivo apoptosis in the prostate as monitored by several techniques including a recently perfected technique of 99mTc-labeled annexin V in live animals followed by phosphor imaging. One striking observation in an additional study was that celecoxib feeding to mice with established tumors (16 weeks of age) significantly improved their overall survival (P = 0.014), compared with AIN 76A-fed group. Our findings suggest that celecoxib may be useful in chemoprevention of prostate cancer.