Turbo Inversion Recovery Magnitude Sequences Research Articles

Diagnostic Contribution of Additional Sequences to the Evaluation of Cord Lesions in Patients with Cervical Spinal Multiple Sclerosis in Turkey: A Retrospective Study.

Multiple Sclerosis (MS) is the most common cause of non-traumatic disability in young adults. Spinal cord involvement is observed in 55-75% of patients with MS. To identify the strengths and shortcomings of sagittal phase-sensitive inversion recovery (PSIR), sagittal proton density/T2-weighted (PD/T2W), and axial turbo inversion recovery magnitude (TIRM) sequences in the detection of cervical MS plaques by comparing with routine sequences (axial and sagittal T2W, sagittal T1W, sagittal TIRM, fat-suppressed contrast T1W) and therefore determine their diagnostic contributions. A total of 48 patients in whom additional magnetic resonance imaging (MRI) sequences were obtained for the diagnosis of cervical MS were retrospectively identified and included in the study. A total of 111 MS plaques were analyzed in terms of visibility, number, size, border sharpness, and intensity ratio based on the routine and additional MRI sequences. The evaluation of the images was independently undertaken by two radiologists. The highest visibility was provided by sagittal PSIR, sagittal TIRM, and axial TIRM sequences (P < 0.05 for all additional sequences). Seven lesions in PD/T2W and four lesions in axial T2W sequences were unable to be detected. Lesions seen in sagittal and axial TIRM sequences were larger than the others. The sharpest borders were determined in the axial TIRM sequence, and the most diffuse borders in the PD/T2W sequence. In intensity ratio, the sagittal PSIR sequence revealed the most significant contrast difference. The sagittal PSIR sequence may improve the detection of cervical MS plaques due to the improved visibility and intensity ratios. The axial TIRM sequence may be more useful than routine axial T2W in the evaluation of visibility, border sharpness, and size measurement of MS plaques.

Comparison between T2 Turbo Inversion Recovery Magnitude and T2 Frequency Selective Fat Saturation Turbo Spin Echo MRI Sequences in Detection of Perianal Fistula

Fat suppression magnetic resonance imaging (MRI) sequences are routinely included in the MRI protocol for patients with perianal fistula to improve the visibility of the abnormal tracts and abscesses against the background of hypo-signal intensity on the image. The objective of this study is to compare the turbo inversion recovery magnitude (TIRM) and frequency selective fat saturation turbo spin echo (FSTSE) MRI sequences in detecting perianal fistulas in terms of time and clarity. The MRI protocol included a coronal T2 turbo inversion recovery magnitude sequence, a T2 fat saturation turbo spin echo, and T2 turbo inversion recovery magnitude sequences in the axial plane. The evaluation of sequence image quality involved calculating the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Additionally three radiologists assessed the best image using a questionnaire designed to align with the study’s objectives. The T2 TIRM sequence was found to have the highest number of ticked images. The inter-rater kappa agreement showed fair agreement (k = 0.370) between the raters. However, the SNR and CNR values for the T2 FSTSE were higher than those of the T2 TIRM sequence, with a p-value less than 0.001. There is a significant difference in the meantime in that the T2 TIRM sequence has less time than the T2 FSTSE with a p-value &lt; 0.001. Due to its uniform fat suppression in the MR image and shorter acquisition time, the turbo inversion recovery magnitude sequence exhibited superior performance compared to the T2 frequency-selective turbo spin echo sequence.

Sensitivity of Diffusion-Weighted Image Combined with T2 Turbo Inversion Recovery Magnitude Sequence and as an Alternative to Contrast-Enhanced MRI in the Detection of Perianal Fistula

Introduction. Perianal fistula rapidly develops an abscess, requiring surgical decompression. However, simple cases must be managed. However, for patients with renal insufficiency, MRI with contrast is contraindicated. It is proposed to use diffusion-weighted images that can diagnose anal fistulae, showing areas of high signal intensity (inflammatory tissues). The aim is to determine sensitivity of diffusion-weighted image combined with T2 turbo inversion recovery magnitude and as an alternative technique to contrast-enhanced MRI using clinical examination as a reference.Materials and Methods. Study included fifty patients with a clinical diagnosis of perianal fistula. MRI sequences were T2 turbo inversion recovery magnitude in oblique coronal and axial planes, diffusion-weighted image, and T1 weighted image turbo spin echo (fat suppression) pre- and post-administration of contrast agents in oblique axial planes. Three radiologists evaluated the MR imaging data using a questionnaire of parameters that necessitated a binary response, “yes” or “no” answer.Results. Diffusion-weighted image combined with axial T2 turbo inversion recovery magnitude sequence had 96.7 %. All raters agreed that it is sensitive enough to correctly identify perianal fistula with a moderate Kappa agreement (k = 0.586) and p-value&lt;0.001. The mean value of rater's responses was 76.7 % represents sensitivity of diffusion-weighted images + T2 turbo inversion recovery magnitude as an alternative technique to T1-enhanced contrast with moderate (k = 0.553) agreement between raters and P-value&lt;0.001.Discussion and Conclusion. Diffusion-weighted images and T2 turbo inversion recovery magnitude sequences exhibit comparable efficacy to T1-enhanced contrast sequences in detecting perianal fistula. This may be an option for patients with renal impairment who cannot receive an MRI contrast.

Papillary Lesions of the Breast: Addition of DWI and TIRM Sequences to Routine Breast MRI Could Help in Differentiation Benign from Malignant.

We aimed to investigate the magnetic resonance imaging (MRI) features of benign, atypical, or malignant papillary breast lesions and to assess the additional value of diffusion-weighted imaging (DWI) and turbo inversion recovery magnitude (TIRM) sequences to routine breast MRI. Differentiation between benign and malignant papillary breast lesions is essential for patient management. However, morphologic features and enhancement patterns of malignant papillary lesions may overlap with those of benign papilloma. Seventy-two papillary breast lesions (50 benign, 22 atypical or malignant) were included in the current study, retrospectively. We divided the patients into two groups: benign papillary breast lesions and atypical or malignant papillary breast lesions. Morphologic, dynamic, turbo inversion recovery magnitude (TIRM) values and diffusion features of the papillary lesions were compared between two groups. Benign papillary lesions were smaller in size (p=0.006 and p=0.005, for radiologists 1 and 2 respectively), closer to the areola (p=0.045 and 0.049 for radiologist 1 and 2 respectively), and had higher ADC values (p=0.001 for two radiologists) than the atypical or malignant group. ROC curves showed diagnostic accuracy for ADC (AUC=0.770 and 0.762, p = 0.0001 for two radiologists), and showed a cut-off value of ≤ 957 x 10-6 mm2/s (radiologist 1) and ≤ 910 x 10-6 mm2/s (radiologist 2). MRI is a useful method for differentiation between benign and malignant papillary breast lesions. Centrally located, lesser in size, and higher ADC values should be considered benign, whereas peripherally located, larger in size, and lower ADC values should be considered malignant.

Appearance of recurrent dermatofibrosarcoma protuberans in postoperative MRI follow-up

Purpose: To analyze the appearance of recurrent dermatofibrosarcoma protuberans (DFSP) in postoperative MRI follow-up and to assess the occurrence of postoperative soft tissue changes detected in MRI.Methods: A total of 464 MRI follow-up scans of 32 patients with histologically proven diagnosis of DFSP were analyzed. MR imaging was performed using a 1.5T MRI system. Recurrent DFSP was examined for signal intensity, contrast behavior, appearance, and extent in MRI.Results: The mean age of the patients was 44,5±17,1 years. Recurrences of DFSP occurred 26±23.3 months after primary tumor resection in the mean (Min.: 9, Max.: 60). In 25% of the patients (n = 8), recurrences of DFSP were detected. Recurrent DFSP most often showed a nodular and homogeneous configuration with well-defined borders and marked contrast enhancement, and a hyperintense signal in PD-weighted and turbo inversion recovery magnitude sequences. All recurrences were well detected in the follow-up MRIs regardless of the performed plastic surgery procedure. Lateral and depth margins had no significant impact on the local recurrence rate. In all, 88% of the patients developed subcutaneous tissue edema (p < 0.01), followed by muscle edema (34%, p = 0.02), and postoperative seroma (22%).Conclusion: Recurrent DFSP mainly appear uniform and clearly delimitable on MRI as nodular, homogeneous, and well-defined lesions with marked contrast enhancement. Therefore, MRI is a valuable tool for postsurgical follow-up. Nearly all patients develop subcutaneous edema after the resection of DFSP.

Skeletal Muscle Involvement in Wilson Disease: Clinical and Magnetic Resonance Imaging (MRI) Observations in 2 Families

Skeletal muscle involvement in Wilson disease is rare. Calf muscle pain might be attributed as growing pain in children. We report calf muscle involvement in Wilson disease and describe the magnetic resonance imaging (MRI) findings of leg, differential diagnosis with literature review. Our observations describe calf muscle MRI abnormality in 5 cases of Wilson disease from 2 families. The clinical presentations were neurologic in 3, hepatic in 1, and asymptomatic in 1 patient. We systematically describe the clinical characteristics and their calf muscle MRI findings. Three patients had bilateral calf pain and intermittent cramps. The pain was of mild to moderate intensity and managed symptomatically. Serum alkaline phosphatase, creatinine phosphokinase, and needle electromyography were normal. Turbo inversion recovery magnitude sequence MRI of calf muscle revealed hyperintensity in bilateral gastrocnemii muscles. These muscles appear hyperintense in diffusion-weighted imaging. The calf muscle involvement could be attributed to muscle edema due to copper-induced muscle toxicity mediated by inhibition of Na+/K+-ATPase on cellular membranes of fast-twitch gastrocnemii muscles which contain predominant type II myofiber. In Wilson disease patients with calf pain or cramps, muscle MRI may show nonspecific gastrocnemius hyperintensity. Further evaluation may give insight into its pathophysiology.

Investigation of the Possibility to Reduce Susceptibility Artifacts in MRI Knee Examination

The aim of this present study is to evaluate the reduction of susceptibility artifacts by increasing bandwidth (BW) and echo train length (ETL) in proton density turbo spin echo (PD TSE) sequences with and without fat saturation (FS) and in turbo inversion recovery magnitude (TIRM) sequences. We compared: (1) TIRM coronal (COR) with TIRM COR with high (H) BW and Long ETL; (2) PD TSE sagittal (SAG) FS with the PD TSE SAG FS with (H) BW; (3) PD TSE SAG with PD TSE SAG with (H) BW; (4) PD TSE SAG with PD TSE SAG with (H) BW and Long ETL. A quantitative analysis measured the extent of the susceptibility artifacts. A qualitative analysis evaluated the susceptibility artifacts, image distortion and effectiveness of fat suppression. The depiction of cartilage, menisci, muscles, tendons and bone marrow were also qualitatively analyzed. In the quantitative analysis, modified TIRM appears superior. In the qualitative analysis, the modified TIRM appears superior in 8/10 characteristics. The modified PD TSE FS is superior to the conventional regarding the susceptibility artifacts, image distortion and the depiction of bone marrow and cartilage and fat saturation. The modified PD TSE with (H) BW is found to be superior to the conventional PD TSE only in cartilage. In these sequences, when ETL was increased there were significant differences in four characteristics (ghost artifacts, cartilage, menisci and muscles). TIRM sequences with an increased BW and ETL are proposed to be used in daily clinical practice.

Magnetic Resonance Imaging Signal Characteristics of Medishield: Early Postoperative Profile in a Rabbit Interlaminotomy Model

Application of Medishield to the nerve root is common during spinal surgery to create a mechanical barrier from pain mediators and reduce scar formation. However, Medishield's signal characteristics on magnetic resonance imaging (MRI) have not yet been examined. Microsurgical interlaminotomy was performed on 2 lower lumbar segments in 17 adult New Zealand white rabbits. After dural exposure, applications of 1 mL (autologous blood clot or Medishield) were randomized for each level. On postoperative days 1 through 3, various MRI sequences in 1.5T were performed including T1-weighted, T2-w, T1-gadolinium-weighted, susceptibility-weighted and turbo inversion recovery magnitude (TIRM) sequence. Signaling characteristics were analyzed by 3 blinded observers. Inter-rater agreement was calculated using Fleiss's kappa coefficient (κ). Positive and negative likelihood ratios in detecting Medishield by MRI were determined. Of 24 MRIs performed, TIRM sequence identified Medishield with the highest likelihood ratio. Medishield's positive likelihood ratio was highest (5.8) on postoperative day 1 with interobserver agreement of 93% (κ= 0.75); these rates declined to 2.5 and 1.4 on postoperative days 2 and 3 with interobserver agreements of 71% (κ= 0.43) and 83% (κ= 0.67), respectively. Medishield adherence was confirmed in each rabbit by histologic examinations. Understanding that radiologic detection of Medishield diminished over time as its signal characteristics became less distinguishable from a blood clot is essential in clinical practice. Medishield was detected on postoperative day 1 but not 2 days later after hemodynamic changes had occurred. These results may provide a guide for postoperative findings, such as differential diagnosis of hematoma.

SU-E-I-62: Reduction of Susceptibility Artifacts by Increasing the Bandwidth (BW) and Echo Train Length (ETL)

Purpose: The aim of this present study is to increase bandwidth (BW) and echo train length (ETL) in Proton Density Turbo Spin Echo (PD TSE) sequences with and without fat saturation (FS) as well as in Turbo Inversion Recovery Magnitude sequences (TIRM) in order to assess whether these sequences are capable of reducing susceptibility artifacts. Methods: We compared 1) TIRM coronal (COR) with the same sequence with increased both BW and ETL 2) Conventional PD TSE sagittal (SAG) with FS with an increased BW 3) Conventional PD TSE SAG without FS with an increased BW 4) Conventional PD TSE SAG without FS with increased both BW and ETL. A quantitative analysis was performed to measure the extent of the susceptibility artifacts. Furthermore, a qualitative analysis was performed by two radiologists in order to evaluate the susceptibility artifacts, image distortion and fat suppression. The depiction of cartilage, menisci, muscles, tendons and bone marrow were also qualitatively analyzed. Results: The quantitative analysis found that the modified TIRM sequence is significantly superior to the conventional one regarding the extent of the susceptibility artifacts. In the qualitative analysis, the modified TIRM sequence was superior to the corresponding conventional one in eight characteristics out of ten that were analyzed. The modified PD TSE with FS was superior to the corresponding conventional one regarding the susceptibility artifacts, image distortion and depiction of bone marrow and cartilage while achieving effective fat saturation. The modified PD TSE sequence without FS with a high (H) BW was found to be superior corresponding to the conventional one in the case of cartilage. Conclusion: Consequently, TIRM sequence with an increased BW and ETL is proposed for producing images of high quality and modified PD TSE with H BW for smaller metals, especially when FS is used.

Usefulness of metal artifact reduction with WARP technique at 1.5 and 3T MRI in imaging metal-on-metal hip resurfacings.

To evaluate the usefulness of the metal artifact reduction technique "WARP" in the assessment of metal-on-metal hip resurfacings at 1.5 and 3T in the context of image quality and imaging speed. Nineteen patients (25 hip resurfacings) were randomized for 1.5 and 3T MRI, both including T1 and T2 turbo spin-echo as well as turbo inversion recovery magnitude sequences with and without view angle tilting and high bandwidth. Additional 3T sequences were acquired with a reduced number of averages and using the parallel acquisition technique for accelerating imaging speed. Artifact size (diameter, area), image quality (5-point scale) and delineation of anatomical structures were compared among the techniques, sequences and field strengths using the Wilcoxon sign-rank and paired t-test with Bonferroni correction. At both field strengths, WARP showed significant superiority over standard sequences regarding image quality, artifact size and delineation of anatomical structures. At 3T, artifacts were larger compared to 1.5T without affecting diagnostic quality, and scanning time could be reduced by up to 64% without quality degradation. WARP proved useful in imaging metal-on-metal hip resurfacings at 1.5T as well as 3T with better image quality surrounding the implants. At 3T imaging could be considerably accelerated without losing diagnostic quality.

Cardiac MRI in the Assessment of Cardiac Injury and Toxicity From Cancer Chemotherapy

During the past 30 years, there has been a significant decrease in cancer mortality rates, predominantly attributable to improvements in treatment options.1 However, survivors are at increased risk of premature cardiac disease,2 both because of the overlap in risk factors for cancer and cardiovascular disease3 and the cardiotoxic effects of cancer chemotherapy. Two chemotherapeutic agent classes that are commonly associated with cardiotoxicity are the anthracyclines and tyrosine kinase inhibitors, both of which can cause left ventricular (LV) dysfunction and heart failure (HF).4,5 Mechanisms of cardiac injury from cancer therapy have been summarized elsewhere.4,6 Briefly, anthracycline cardiotoxicity has been attributed to reactive oxygen species formation, transcriptional changes in intracellular adenosine triphosphate production in cardiac myocytes, and, more recently, through interaction with cardiac topoisomerase IIβ.4,6 Trastuzumab cardiotoxicity seems to be because of inhibition of cardiomyocyte human epidermal growth factor receptor 2, resulting in ATP depletion and contractile dysfunction.4 Other proposed mechanisms include immune-mediated destruction of cardiomyocytes.4,6 At the tissue level, early anthracycline toxicity has been associated with myocardial inflammation,7–9 vacuolization,9–12 and cell swelling/edema.11,13 These changes seem to occur before myocardial functional abnormalities.11,13 Later stages of toxicity are associated with myocardial fibrosis.14,15 Unfortunately, the use of myocardial biopsy is not feasible for diagnostic purposes in this setting. However, once HF manifests, the 2-year mortality can be as high as 60%.16 This emphasizes the importance of early recognition of cardiac injury and institution of cardioprotective therapy in an effort to prevent development of HF and allow uninterrupted completion of cancer therapy.17 Thus, the diagnosis is dependent on either direct evidence of myocardial damage or functional disturbance. Either signal may be identified …

Sensory neuronopathy involves the spinal cord and brachial plexus: a quantitative study employing multiple-echo data image combination (MEDIC) and turbo inversion recovery magnitude (TIRM)

Sensory neuronopathy (SNN) is a distinctive subtype of peripheral neuropathies, specifically targeting dorsal root ganglion (DRG). We utilized MRI to demonstrate the imaging characteristics of DRG, spinal cord (SC), and brachial plexus at C7 level in SNN. We attempted multiple-echo data image combination (MEDIC) and turbo inversion recovery magnitude (TIRM) methods in nine patients with sensory neuronopathy and compared with those in 16 disease controls and 20 healthy volunteers. All participants underwent MRI for the measurement of DRG, posterior column (PC), lateral column, and spinal cord area (SCA) at C7 level. DRG diameters were obtained through its largest cross section, standardized by dividing sagittal diameter of mid-C7 vertebral canal. We also made comparisons of standardized anteroposterior diameter (APD) and left-right diameters of SC and PC in these groups. Signal intensity and diameter of C7 spinal nerve were assessed on TIRM. Compared to control groups, signal intensities of DRG and PC were higher in SNN patients when using MEDIC, but the standardized diameters were shorter in either DRG or PC. Abnormal PC signal intensities were identified in eight out of nine SNN patients (89%) with MEDIC and five out of nine (56%) with T2-weighted images. SCA, assessed with MEDIC, was smaller in SNN patients than in the other groups, with significant reduction of its standardized APD. C7 nerve root diameters, assessed with TIRM, were decreased in SNN patients. MEDIC and TIRM sequences demonstrate increased signal intensities and decreased area of DRG and PC, and decreased diameter of nerve roots in patients with SNN, which can play a significant role in early diagnosis.

Distinct lesion morphology at 7-T MRI differentiates neuromyelitis optica from multiple sclerosis

To investigate distinct white matter and cortical gray matter pathology in neuromyelitis optica spectrum disorders (NMOSDs) and multiple sclerosis (MS) at 7-T MRI in a cross-sectional study. We included 10 patients with NMOSDs and 18 patients with MS in our 7-T MRI study. The imaging protocol comprised T2*-weighted fast low angle shot and turbo inversion recovery magnitude sequences. White matter and cortical gray matter lesions were assessed with special regard to their (perivascular) localization as well as the expression of a hypointense rim. In total, we detected 140 white matter lesions in 7 of 10 patients with NMOSDs. In contrast to MS plaques, which were nearly exclusively centered by a small vein (92%) and showed a characteristic hypointense rim (23%), white matter changes in patients with NMOSDs were nonspecific in appearance and were only infrequently neighbored by a blood vessel (49 lesions [35%], p = 0.003). Hypointense rims were very rarely detectable (3 lesions [2%], p < 0.001). Cortical pathology was absent in NMOSDs. In our MS cohort, we detected 36 leukocortical, 8 intracortical, and 8 subpial cortical lesions in 7 of 18 patients. The MRI features of white matter and the absence of cortical gray matter findings substantially differentiate NMOSDs from MS and can be used as a potential marker to distinguish these 2 entities. The fact that cortical pathology is common in MS but is not present in patients with NMOSDs may reflect the difference in the underlying pathogenesis.

Periventricular venous density in multiple sclerosis is inversely associated with T2 lesion count: a 7 Tesla MRI study

Background: Damage to venules in multiple sclerosis was first described decades ago. Today, ultrahigh magnetic field strength T2*-weighted magnetic resonance imaging (MRI) techniques depict very small cerebral veins in vivo with great anatomical detail. Objective: We aimed to investigate alterations of periventricular small blood vessel appearance in relation to T2 lesion count and distribution in multiple sclerosis and clinically isolated syndrome in comparison with healthy control subjects at 7 Tesla MRI. Methods: We investigated 38 patients (including 16 with early multiple sclerosis and seven with clinically isolated syndrome) and 22 matched healthy controls at 7 Tesla. The protocol included T2*-weighted Fast Low Angle Shot, and T2-weighted Turbo Inversion Recovery Magnitude sequences. We quantified periventricular venous density by a novel region-of-interest-based algorithm, expressing the ratio of ‘veins per region-of-interest’ as well as of ‘periventricular vascular area’. Results: Our study revealed significantly decreased venous density in multiple sclerosis patients compared with healthy controls. Venous alterations were already detectable in clinically isolated syndrome and early multiple sclerosis, although to a smaller extent. Venous density correlated inversely with periventricular and whole-brain T2 lesion count. Furthermore, we found no indication for cerebral venous congestion in multiple sclerosis. Conclusion: High spatially resolving anatomical T2*-weighted MRI revealed vascular alterations in early stages of multiple sclerosis, presumably as a part of widespread haemodynamic and metabolic alterations.

Ulnar Neuropathy at the Elbow: MR Neurography—Nerve T2 Signal Increase and Caliber

To assess nerve T2 signal and caliber as diagnostic signs at magnetic resonance (MR) neurography in ulnar neuropathy at the elbow (UNE). This prospective study was approved by the institutional review board, and written informed consent was obtained from all participants. Twenty patients with UNE were graded by using clinical criteria and nerve conduction studies as mild (n = 12) and severe (n = 8) and were compared with 20 healthy control subjects. All subjects underwent ulnar nerve MR neurography (in-plane resolution of 0.4 × 0.4 mm) covering the elbow region, including T2-weighted imaging with fat suppression (turbo inversion-recovery magnitude sequence: repetition time msec/echo time msec/inversion time msec, 6, 120/66/180) and T1-weighted turbo spin-echo imaging (843/16). Nerve T2 signal increase, measured by using T2-weighted contrast-to-noise ratios across the cubital tunnel, and nerve caliber, determined by using T1-weighted pixelwise measurement of cross-sectional nerve area, were evaluated as diagnostic signs. Qualitative assessment by using visual grading was performed additionally. Diagnostic performance, as determined with area under the receiver operating characteristic curve (AUC), was excellent for nerve T2 signal to discriminate UNE from a normal finding (AUC = 0.94; 95% confidence interval [CI]: 0.87, 1.00) and was excellent for nerve caliber to discriminate severe from mild UNE (AUC = 0.95; 95% CI: 0.85, 1.00). Qualitative assessment demonstrated sensitivity of 83% and specificity of 85% for MR neurography of UNE. Nerve T2 signal increase seems to be an accurate sign to determine the presence of UNE. Nerve caliber enlargement discriminates severe from mild UNE. UNE may be diagnosed with high accuracy by means of quantitative or qualitative evaluation of these signs.

Correlation of signal intensity ratio on orbital MRI-TIRM and clinical activity score as a possible predictor of therapy response in Graves’ orbitopathy—a pilot study at 1.5 T

This study seeks to describe the predictive value of the signal intensity ratio (SIR) in magnetic resonance imaging-turbo inversion recovery magnitude (MRI-TIRM) in patients with Graves' orbitopathy (GO) with regard to predictability of therapy response. Included in this prospective pilot study were 36 consecutive patients with GO and 25 control subjects. Patients were clinically assessed according to the European Group on Graves' Orbitopathy recommendations with active GO defined by a clinical activity score (CAS) > or = 3. On magnetic resonance (MR) imaging, muscle inflammation was measured with a region of interest set within the brightest extra-ocular muscle both on coronal turbo inversion recovery magnitude (TIRM) and on fat suppressed gadolinium-enhanced T1-weighted sequences. To calculate the SIR, the measured signal intensity was set in proportion to that of the ipsilateral temporalis muscle. Signal intensity ratio in coronal T2-weighted TIRM sequences in either group ranged from 1.22 to 4.92 (mean 2.04) in patients with GO and from 1.18 to 2.4 (mean 1.63) in controls without GO. The observed differences were significant on the TIRM sequences (right eye p = 0.023; left eye p = 0.022), whereas, no significant differences could be detected on the T1-weighted sequences (right eye p = 0.396; left eye p = 0.498). A cut off value of SIR > 2.5 for a CAS > or = 4 to discriminate active from inactive patients was statistically calculated. T2 relaxation time is a reliable tool in detecting active GO. The difference in T2-SIR versus T1-SIR is helpful to distinguish inflammatory oedema of the extra ocular muscles from intra-orbital congestion due to reduced venous outflow.

Detection of Pulmonary Nodules With Move-During-Scan Magnetic Resonance Imaging Using a Free-Breathing Turbo Inversion Recovery Magnitude Sequence

Detection of pulmonary metastases is still a challenging task for magnetic resonance imaging (MRI). It was the aim of this study to evaluate the potential of a free-breathing move-during-scan turbo inversion recovery magnitude sequence for the detection of pulmonary nodules. The sensitivities and positive-predictive values of 2 radiologists to detect pulmonary nodules in 41 move-during-scan MRI examinations of 38 patients with different malignancies were calculated and subgroup analyses according to lesion size and localization were performed. Multidetector computed tomography served as the standard of reference. Additionally, 6 radiologists rated the confidence for the presence of nodular lesions in 212 regions-of-interest, which were randomly selected to represent lesions of various sizes as well as negative findings. Receiver-operator-characteristic was performed. Three hundred twenty-one nodules were found in 30 patients by multidetector computed tomography. Sensitivity and specificity of MRI to detect pulmonary nodules larger than 3 mm on a per-patient basis were 81.8% and 94.7%, respectively. On a per-lesion basis, MRI revealed a sensitivity of 79.0% to 80.7% for lesions larger than 3 mm, if high conspicuity ratings were counted as positive, and 84.6%, if medium and high conspicuity ratings were counted as positive. Sensitivity increased uniformly with lesion size, and all lesions larger than 12 mm were detected. Receiver-operator-characteristic analysis revealed a mean accuracy of 0.90 and sensitivities over 90% for lesions larger than 3 mm with a specificity of 96.1%. For lesions larger than 6 mm the accuracy was 0.99. Detection of pulmonary nodules with a move-during-scan turbo inversion recovery magnitude sequence is feasible. Excellent detection of lesions larger than 6 mm is achievable with free-breathing moving-table MRI.

Diagnostic evaluation of magnetic resonance imaging with turbo inversion recovery sequence in head and neck tumors

The clinical outcome of patients with head and neck cancer depends on many factors such as tumor size, metastatic involvement and angioarchitecture of the tumor. The correct staging of tumor extension, presence of cervical lymph node metastases and evaluation of vascular infiltration are essential diagnostic steps before treatment. The aim of this study was to evaluate the accuracy of turbo inversion recovery magnitude (TIRM) magnetic resonance imaging (MRI) in the diagnosis of head and neck tumors with special attention to tumor size and tumor spread according to the current TNM classification. TIRM sequence with short T1 relaxation and long TE (echo time) improves imaging contrast because of the increased T1-weighting and the inherent fat suppression. In a prospective clinical study, 32 patients underwent preoperative MRI. Diagnosis was confirmed histologically in all cases. Scanning was performed on a 1.0-T unit applying TIRM as well as T1- and T2-weighted turbo spin echo (TSE) sequences. In all sequences, tumor size was overestimated due to reactive inflammatory changes surrounding the tumor tissue. The least overestimation was documented on TIRM and post-contrast T1 TSE. The highest values of relative tumor signal intensities were obtained in TIRM (3.5+/-0.9) and T2 TSE (3.5+/-0.8) followed by post-contrast T1 TSE (1.6+/-0.7) and pre-contrast T1 TSE (1.2+/-0.3). Due to the inherent fat suppression, tumor delineation was most obvious in TIRM. In patients with suspected cancer of the head and neck, TIRM should be considered as a standard and a diagnostically relevant sequence in the MRI staging protocol.