Faculty Bibliography

We retrospectively assessed the longitudinal changes of rheumatoid arthritis under rituximab therapy by use of quantitative and dynamic contrast-enhanced 3-T magnetic resonance (MR) imaging of the metacarpophalangeal joints of 10 patients at baseline and 26 weeks (n = 10). Additional studies were available at 12 weeks (n = 9) and at 52 weeks (n = 5). Clinical activity was assessed by use of the 28-joint disease activity score (DAS28). MR imaging was used to assess volumes of synovial enhancement, osseous enhancement, and erosions and early rapid enhancement. DAS28 and serum C-reactive protein trended down over time and were significantly lower at 26 weeks. Volume of synovial enhancement and early rapid enhancement showed a significant minimum at 26 weeks and increased thereafter. The erythrocyte sedimentation rate paralleled these two trends. Osseous enhancement did not significantly change over time. Erosions showed a significant progression. Trends of DAS28 and erosions were significantly different (P = 0.0075). In conclusion, our preliminary results suggest that rituximab is associated with a decrease of the inflammatory activity of synovitis with a minimum at 26 weeks and increasing activity thereafter suggesting recurrence. Our results further suggest subclinical progression of erosions with an inverse relationship to decreasing disease activity scores. Further studies are needed to confirm these results.

PURPOSE/OBJECTIVE:To describe whole-body magnetic resonance (MR) imaging appearance of chronic recurrent multifocal osteomyelitis (CRMO) and assess the role of MR imaging versus radiography in diagnosis of disease and correlation with clinical findings and laboratory data. MATERIALS AND METHODS/METHODS:Institutional review board approved this retrospective HIPAA-compliant study; informed consent was waived. T1-weighted, short inversion time inversion-recovery, and contrast material-enhanced T1-weighted whole-body MR imaging was performed and two-plane radiographs, clinical findings, and laboratory data were reviewed in 13 children (median age, 13 years) with CRMO. Lesion depiction, location, and characterization and extraskeletal abnormalities were evaluated. MR imaging findings were compared with clinical and laboratory data and radiographic results. Data analysis was performed, and diagnostic performance statistics of radiography, physical examination results, and serum inflammatory markers were calculated. General multilevel linear modeling framework was used. Odds ratios were calculated to estimate effect of age, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) level on reliabilities. Associations of ESR and CRP level with total number of lesions were assessed (chi(2) test). RESULTS:MR imaging depicted 101 ill-defined edemalike osseous lesions. Most frequent anatomic sites were distal femur (21%, 21 of 101), proximal tibia (17%, 17 of 101), and distal tibia and fibula (14% each, 14 of 101). In tubular bones (70 anatomic sites), metaphysis (86%, 60 of 70) and epiphysis (67%, 47 of 70) were involved. Contiguous physeal relationship (89%, 66 of 74), periosteal reaction (48%, 48 of 101), and symmetric involvement (85%, 11 of 13) were present. MR imaging demonstrated multifocality in all patients. There were no extraskeletal abnormalities and no relationship between serum inflammatory markers and number of symptomatic anatomic sites (P = .472). Sensitivity for radiography was 0.13 (70 of 119); physical examination, 0.31 (52 of 299); and serum inflammatory markers, 0.15 (two of 13). CONCLUSION/CONCLUSIONS:Whole-body MR imaging is useful for detection of CRMO, particularly in indeterminate cases, because it is more likely to show abnormalities.

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/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/CONCLUSIONS: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.

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/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/CONCLUSIONS: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.

OBJECTIVE:Our objective was to describe the spectrum of MRI features in patients with deep and generalized morphea. CONCLUSION/CONCLUSIONS:Imaging features of morphea are not specific and usually overlap with those of other disorders involving the skin, fascia, and musculature, such as some types of fasciitis, myositis, and so forth. Nevertheless, the imaging features of morphea reflect pathomorphologic changes of this rare disorder and enable a complete assessment of the disease extent, including depth of infiltration and disease activity.

If low back pain does not improve with conservative management, the cause of the pain must be determined before further therapy is initiated. Information obtained from the patient's medical history, physical examination, and imaging may suffice to rule out many common causes of chronic pain (eg, fracture, malignancy, visceral or metabolic abnormality, deformity, inflammation, and infection). However, in most cases, the initial clinical and imaging findings have a low predictive value for the identification of specific pain-producing spinal structures. Diagnostic spinal injections performed in conjunction with imaging may be necessary to test the hypothesis that a particular structure is the source of pain. To ensure a valid test result, diagnostic injection procedures should be monitored with fluoroscopy, computed tomography, or magnetic resonance imaging. The use of controlled and comparative injections helps maximize the reliability of the test results. After a symptomatic structure has been identified, therapeutic spinal injections may be administered as an adjunct to conservative management, especially in patients with inoperable conditions. Therapeutic injections also may help hasten the recovery of patients with persistent or recurrent pain after spinal surgery.

We report a case of granulocytic sarcoma exclusively manifesting as diffuse intramuscular infiltration of the proximal upper and lower limb girdle and the torso muscles in a patient with previous history of acute myelogenous leukemia 5a. Whole-body CT showed widespread distribution of ill-defined intramuscular, homogeneously enhancing lesions. On whole-body MRI, lesions were homogeneously hyperintense on fat saturated T2-weighted images, isointense on T1-weighted images and strongly enhancing after intravenous gadolinium contrast administration. Histopathology revealed muscular infiltration of blast cells with identical immunochemistry to the initial manifestation of leukemia, diagnostic for an extramedullary relapse manifesting as granulocytic sarcoma. CT and MRI characteristics of this previously undocumented manifestation of granulocytic sarcoma should assist in the identification of such cases.

PURPOSE/OBJECTIVE:To evaluate the feasibility and technique effectiveness of magnetic resonance (MR)-guided radiofrequency (RF) ablation of hepatic malignancies. MATERIALS AND METHODS/METHODS:In 64 patients, 100 primary (N = 19) or secondary (N = 81) liver tumors (mean diameter = 24.7 mm; range = 4-60 mm) were treated with 87 sessions of MR-guided RF ablation. The entire ablation procedure was carried out at an 0.2-T open MR system by using MR-compatible internally cooled electrodes. T2-weighted turbo spin echo sequences (TR/TE = 3500 msec/110 msec) were used to monitor thermally induced coagulation. Technique effectiveness was assessed four months after the last RF ablation by dynamic MR imaging at 1.5-T. RESULTS:MR-guided RF ablation procedures were technical successful in 85 of 87 (97.7%) assessed at the end of each session. Complete coagulation was intended in 99 of 100 tumors. Technique effectiveness was observed in 92 of 99 (92.9%) of these tumors. To achieve complete coagulation 82 of 92 (89.1%) tumors required a single session. T2-weighted sequences were accurate to monitor the extent of coagulation and were supportive to guide overlapping ablation. There were two of 87 (2.3%) major and seven of 87 (8.0%) minor complications. CONCLUSION/CONCLUSIONS:MR-guided RF ablation is a safe and effective therapy in the treatment of hepatic malignancies. MR imaging offers an accurate monitoring of thermally-induced coagulation, thus enabling complete tumor coagulation in a single session.

OBJECTIVE:Chloroma, also know as granulocytic sarcoma, is a localized extramedullary tumor composed of malignant cells of the myeloid cell line. It occurs most frequently secondary to a history of myelogenous leukemia as extramedullary relapse. New treatment regimens, including allogeneic stem cell transplantation, extensive use of donor lymphocyte infusion, and second transplantation, are associated with increased rates of chloroma of up to 21%. The purpose of this article is to highlight the sites of involvement as well as the morphologic and imaging features of chloroma in patients with myelogenous leukemia. CONCLUSION/CONCLUSIONS:Allogeneic stem cell transplantation now represents the treatment of choice for leukemia and for patients with leukemia relapse. Therefore, the rate of chloroma is likely to increase. Because clinical and laboratory data are frequently not indicative, radiologic diagnosis of chloroma will become more important.

OBJECTIVE:We sought to evaluate the relationship between parameters of bipolar radiofrequency (RF) ablation using internally cooled electrodes. MATERIALS AND METHODS/METHODS:Bipolar RF ablations (n = 24) were performed in ex vivo bovine liver using an internally cooled applicator with 2 electrodes located on the same shaft. The power-output was systematically varied (20-75 W). On the basis of our experimental data, mathematical functions were fitted and the goodness-of-fit was assessed by the parameter R. RESULTS:The duration to induce an increase of tissue resistance and the amount of applied energy increased with a decreased power-output. The maximum short-axis was 4.5 cm (20 W) and required an application of 64 kilojoules (kJ). The volume of coagulation can be determined as a function of the duration of energy application (R = 0.954) and the amount of applied energy (R = 0.945). CONCLUSION/CONCLUSIONS:The amount of applied energy and the duration of energy application can predict the volume of induced coagulation and may be useful to control internally cooled bipolar RF ablation.