Magnetic Resonance Imaging Response Research Articles

Prognostic Value of Soluble Tumor Necrosis Factor Receptors 1 and 2 in Multiple Sclerosis Patients Treated with Interferon Beta-1b

The objective of this study was to investigate the effect of interferon (IFN) beta-1b on the serum levels of soluble tumor necrosis factor receptor 1 (sTNF-R1) and sTNF-R2 in patients with multiple sclerosis (MS) in correlation with clinical and magnetic resonance image (MRI) activity. Serum samples were obtained every 3 months from 24 patients treated with 8 × 10⁶ U of IFN beta-1b every other day (treatment group) and from 21 patients without any immunomodulatory therapy (control group) over a 15-month observation period. The cytokine receptor levels were assessed by ELISA. Cranial MRI was performed every 6 months to determine the burden of disease. In the treatment group, the MRI responders had significantly larger mean values for the area under the concentration-time curve of sTNF-R1 (p = 0.04) and sTNF-R2 (p = 0.01) when compared to the MRI nonresponders during the 15-month observation period. With regard to an increase in sTNF-R1 and -2 of more than 20% during the first 3 months of treatment, we observed a sensitivity of 33 and 58%, respectively, a specificity of 90 and 60%, respectively, and a positive predictive value of 80 and 64%, respectively, for MRI response during the 15-month observation period. A decrease in sTNF-R1 and -2 of more than 20% during the first 3 months of treatment had a sensitivity of 40 and 20%, respectively, a specificity of 100 and 100%, respectively, and a positive predictive value of 100 and 100%, respectively, for further MRI nonresponse (during the 15-month observation period). The present data suggest that assessment of sTNF-Rs may contribute to the identification of subgroups of patients who are likely to respond better than others to treatment with IFN beta-1b. This could help to establish a cost-effective prescription pattern for this expensive treatment, which is of importance for the future management of patients with MS.

Transient enlargement of contrast uptake on MRI after linear accelerator (linac) stereotactic radiosurgery for brain metastases

Purpose/Objective: With the increasing number of patients successfully treated with stereotactic radiosurgery for brain metastases, decision making after therapy based on follow-up imaging findings becomes more and more important. Magnetic resonance imaging (MRI) is the most sensitive means for follow-up studies. The objective of this study was to investigate the treatment outcome of our radiosurgery program and to describe the response of brain metastases to contrast-enhanced MRI after linear accelerator (linac) stereotactic radiosurgery and identify factors to distinguish among local control and local failure. Methods and Materials: Using serial MRI, we followed the course of 87 brain metastases in 48 consecutive patients treated between September 1996 and November 1997 with linac-based radiosurgery with 15-MV photons. Treatment planning was performed on an MR data cube. For spherical metastases, radiosurgery was delivered using a 9 noncoplanar arc technique with circular-shaped collimators. For irregularly shaped targets, radiosurgery was delivered using a manually driven multi-leaf collimator with a leaf width of 1.5 mm projected to the isocenter. Median radiosurgery dose was 20 Gy prescribed to the 80% isodose. Together with whole brain radiotherapy (20 × 2 Gy, 5/w), a median radiosurgical dose of 15 Gy was delivered. Median follow-up was 8 (range 2–36) months. Factors influencing local control and survival rates were analyzed with respect to MRI response, and Kaplan-Meier curves were calculated. Results: Actuarial local tumor control was 91% at one and two years. Patient survival at one and two years was 30% and 18%. Median survival was 9 months. During follow-up in 70 (81%) of the 87 treated metastases, the contrast-enhancing volumes on T1W images were stable or disappeared partly or completely. A transient enlargement of contrast-enhancing volumes was observed in 11 (12%) of the 87 lesions treated, while a progressive enlargement due to local treatment failure was observed in 6 (7%) of the 87 treated metastases. Younger age, early contrast onset after radiosurgery, and previous chemotherapy were associated with this transient enlargement of contrast-enhancing lesion volume. Conclusions: Linac-based radiosurgery is an effective, noninvasive, and safe treatment option for patients with brain metastases. A marked enlargement of the contrast-enhancing volume on T 1-weighted MR images after radiosurgery is a sensitive predictor for, but not equivalent with, local failure. In as many as two-thirds of the cases with contrast enlargement in MRI follow-up, the contrast enlargement is transient with no need for further treatment. While some MRI findings are more likely if transient enlargement is present, a clear decision cannot be made based on MRI, and ultimately the clinical status dictates further action.

MRI of Functional Deactivation: Temporal and Spatial Characteristics of Oxygenation-Sensitive Responses in Human Visual Cortex

Magnetic resonance imaging (MRI) of neuronal “activation” relies on the elevation of blood flow and oxygenation and a related increase of the blood oxygenation level-dependent (BOLD) MRI signal. Because most cognitive paradigms involve both switches from a low degree of activity to a high degree of activity and vice versa, we have undertaken a baseline study of the temporal and spatial characteristics of positive and negative BOLD MRI responses in human visual cortex. Experiments were performed at 2.0 T using a multislice gradient-echo EPI sequence (TR=1 s, mean TE=54 ms, flip angle 50°) at 2 × 2-mm2spatial resolution. Activation and “deactivation” processes were accomplished by reversing the order of stimulus presentations in paradigms using homogeneous gray light and an alternating checkerboard as distinct functional states. For sustained stimulation (≥60 s) the two conditions resulted in markedly different steady-state BOLD MRI signal strengths. The transient responses to brief stimulation (≤18 s) differed insofar as activation processes temporally separate positive BOLD and negative undershoot effects by about 10 s, whereas negative BOLD effects and undershoot contributions overlap for deactivation processes. Apart from differences in stimulus features (e.g., motion) the used activation and deactivation protocols revealed similar maps of neuronal activity changes.

Acute encephalopathy and idiopathic hypereosinophilic syndrome: clinical and MRI response to early steroid treatment

A 31‐year‐old woman with hypereosinophilic syndrome developed left hemiplegia with confusion over a few hours. Brain magnetic resonance imaging (MRI) showed a diffuse meningeal gadolinium enhancement and periventricular nodular lesions. After 20 months of continuous steroid treatment, the patient is clinically asymptomatic and there were an obvious regression of MRI abnormalities. These findings indicate that an early steroid treatment is able to prevent irreversible damage in hypereosinophilic syndrome.

Evaluation of neoadjuvant chemotherapeutic response of locally advanced breast cancer by magnetic resonance imaging

The implementation of new treatment protocols for locally advanced breast cancer is currently limited by inaccurate evaluation of response to neoadjuvant chemotherapy. A recently developed dedicated breast magnetic resonance imaging (MRI) method (RODEO MRI) was evaluated as a tool for determining tumor response and extent of residual disease after neoadjuvant chemotherapy. Thirty-nine patients with Stage II, III, or IV breast carcinoma were prospectively evaluated prior to and following neoadjuvant chemotherapy by MRI, physical examination, and mammography. Assessment of response determined by the three methods was compared. In addition, detailed pathologic correlation of residual disease was determined by serial sectioning of 31 mastectomy specimens from 30 patients. Nine patients had breast conservation, and were included in the response evaluation only. Estimates of tumor response were made by both surgical and medical oncologists. Independent interpretations of MRI studies without knowledge of clinical response were made by three radiologists. The surgical oncologists assessed complete response (CR), partial response (PR), and no response (NR) in 11, 22, and 7 cases, respectively. The medical oncologists assessed CR, PR, and NR in 12, 21, and 7 cases, respectively. The surgical and medical oncologists' clinical assessment of response agreed with the results of MRI in 52% and 55% of cases, respectively, and with each other in 30 of 40 cases (75%). Mammography correlated with MRI response in only 52% of cases. However, MRI accurately predicted the pathologic determination of residual disease in 30 of 31 cases (97%). There was no disagreement in the assessments of residual disease or response among the three radiologists. RODEO breast MRI accurately estimates residual disease after induction chemotherapy. It assesses response to neoadjuvant chemotherapy better than traditional methods of physical examination or mammography. The information obtained from this MRI technique may be used as an objective tool during clinical trials, and to select patients better for breast conservation after neoadjuvant chemotherapy for locally advanced disease.

A correlation of cervical magnetic resonance imaging and discography/computed tomographic discograms.

The morphology of sagittal T2-weighted magnetic resonance imaging (MRI) of the cervical spine was correlated with provocative discography and subsequent computed tomography (CT) discograms in 52 patients with discogenic pain. The authors determined if the morphology of cervical spine discs, as seen on MRI, correlates with discography/CT discograms in patients with discogenic pathology. Several studies have demonstrated a correlation between MRI and discography in the lumbar spine. No studies have attempted to show if this relationship exists in the cervical spine region. The morphology of cervical T2-weighted MRI was characterized with regard to the disc nuclear signal and posterior anulus status. Provocative discography was evaluated with regard to positive or negative responses. Computed tomography was performed after discography on each patient. There was no correlation between pain response or morphology as seen on either discography or CT discography. A significant correlation was found between abnormality as seen on MRI and pain response on discography but the false-positive and false-negative rates were high. Our results suggest that several MRI patterns correlate well with positive or negative cervical discography responses while several other patterns are equivocal. Magnetic resonance imaging is a useful adjunct to cervical discography but there are some MRI patterns that cannot be considered pathologic, and discography is required to diagnose discogenic pain syndrome.