T2-weighted T2-weighted Turbo Spin-echo Images Research Articles

Accelerated T2-Weighted TSE Imaging of the Prostate Using Deep Learning Image Reconstruction: A Prospective Comparison with Standard T2-Weighted TSE Imaging.

Simple SummaryMultiparametric magnetic resonance imaging (mpMRI) has become an important diagnostic tool in the assessment of clinically significant prostate cancer. The disadvantages of this technique are primarily related to its long examination time and limited availability. This prospective study presents a novel accelerated deep learning image reconstructed T2-weighted turbo spin echo (TSE) sequence providing an acquisition time reduction of more than 60%. The study results show that the acquisition of three imaging planes of the prostate is feasible within 3:50 min, using deep learning image reconstruction, compared to 10:21 min in standard imaging. Additionally, image quality parameters were evaluated to be superior in deep learning imaging.Multiparametric MRI (mpMRI) of the prostate has become the standard of care in prostate cancer evaluation. Recently, deep learning image reconstruction (DLR) methods have been introduced with promising results regarding scan acceleration. Therefore, the aim of this study was to investigate the impact of deep learning image reconstruction (DLR) in a shortened acquisition process of T2-weighted TSE imaging, regarding the image quality and diagnostic confidence, as well as PI-RADS and T2 scoring, as compared to standard T2 TSE imaging. Sixty patients undergoing 3T mpMRI for the evaluation of prostate cancer were prospectively enrolled in this institutional review board-approved study between October 2020 and March 2021. After the acquisition of standard T2 TSE imaging (T2S), the novel T2 TSE sequence with DLR (T2DLR) was applied in three planes. Overall, the acquisition time for T2S resulted in 10:21 min versus 3:50 min for T2DLR. The image evaluation was performed by two radiologists independently using a Likert scale ranging from 1–4 (4 best) applying the following criteria: noise levels, artifacts, overall image quality, diagnostic confidence, and lesion conspicuity. Additionally, T2 and PI-RADS scoring were performed. The mean patient age was 69 ± 9 years (range, 49–85 years). The noise levels and the extent of the artifacts were evaluated to be significantly improved in T2DLR versus T2S by both readers (p < 0.05). Overall image quality was also evaluated to be superior in T2DLR versus T2S in all three acquisition planes (p = 0.005–<0.001). Both readers evaluated the item lesion conspicuity to be superior in T2DLR with a median of 4 versus a median of 3 in T2S (p = 0.001 and <0.001, respectively). T2-weighted TSE imaging of the prostate in three planes with an acquisition time reduction of more than 60% including DLR is feasible with a significant improvement of image quality.

Gd-EOB-DTPA-Enhanced MR Imaging of the Liver: The Effect on T2 Relaxation Times and Apparent Diffusion Coefficient (ADC).

SummaryBackgroundTo investigate the effect of gadoxetic acid disodium (Gd-EOB-DTPA) on T2 relaxation times and apparent diffusion coefficient (ADC) values of the liver and focal liver lesions on a 1.5-T system.Material/MethodsMagnetic resonance (MR) studies of 50 patients with 35 liver lesions were retrospectively analyzed. All examinations were performed at 1.5T and included T2-weighted turbo spin-echo (TSE) and diffusion-weighted (DW) images acquired before and after intravenous administration of Gd-EOB-DTPA. To assess the effect of this hepatobiliary contrast agent on T2-weighted TSE images and DW images T2 relaxation times and ADC values of the liver and FLLs were calculated and compared pre- and post-injection.ResultsThe mean T2 relaxation times of the liver and focal hepatic lesions were lower on enhanced than on unenhanced T2-weighted TSE images (decrease of 2.7% and 3.6% respectively), although these differences were not statistically significant. The mean ADC values of the liver showed statistically significant decrease (of 4.6%) on contrast-enhanced DW images, compared to unenhanced images (P>0.05). The mean ADC value of liver lesions was lower on enhanced than on unenhanced DW images, but this difference (of 2.9%) did not reach statistical significance.ConclusionsThe mean T2 relaxation times of the liver and focal liver lesions as well as the mean ADC values of liver lesions were not significantly different before and after administration of Gd-EOB-DTPA. Therefore, acquisition of T2-weighted and DW images between the dynamic contrast-enhanced examination and hepatobiliary phase is feasible and time-saving.

Feasibility of post mortem cardiac proton density weighted fast field echo imaging in two cases of sudden death

The aim of this work is to investigate and compare cardiac proton density (PD) weighted fast field echo (FFE) post-mortem magnetic resonance (PMMR) imaging with standard cardiac PMMR imaging (T1-weighted and T2-weighted turbo spin-echo (TSE)), postmortem CT (PMCT) as well as autopsy. Two human cadavers sequentially underwent cardiac PMCT and PMMR imaging (PD-weighted FFE, T1-weighted and T2-weighted TSE) and autopsy. The cardiac PMMR images were compared to each other as well as to PMCT and autopsy findings. For the first case, cardiac PMMR exhibited a focal region of low signal in PD-weighted FFE and T2-weighted TSE images, surrounded by a signal intense rim in the T2-weighted images. T1-weighted TSE and PMCT did not appear to identify any focal abnormality. Macroscopic inspection identified a blood clot; histology confirmed this to be a thrombus with an adhering myocardial infarction. In the second case, a myocardial rupture with heart tamponade was identified in all PMMR images, located at the anterior wall of the left ventricle; PMCT excluded additional ruptures. In PD-weighted FFE and T2-weighted TSE images, it occurred hypo-intense, while resulting in small clustered hyper-intense spots in T1-weighted TSE. Autopsy confirmed the PMMR and PMCT findings. Presented initial results have shown PD-weighted FFE to be a valuable imaging sequence in addition to traditional T2-weighted TSE imaging for blood clots and myocardial haemorrhage with clearer contrast between affected and healthy myocardium.

Regularization method for phase-constrained parallel MRI

To implement a regularization method for the phase-constrained generalized partially parallel acquisitions (GRAPPA) algorithm to reduce image artifacts caused by data inconsistencies. Phase-constrained GRAPPA reconstructions are implemented through the use of virtual coils. To that end, synthetic virtual coils are generated by using complex conjugate symmetric signals from the actual coils. Regularization is achieved by applying coefficient-based penalty factors during the GRAPPA calibration procedure. Different penalizing factors are applied for the actual and virtual coils. The method is tested in vivo using T2-weighted turbo spin echo (TSE) images. T2 signal decay perturbs conjugate k-space symmetry and produces artifacts in phase-constrained parallel MRI reconstructions of T2-weighted TSE images. Using the proposed regularization method, artifacts are suppressed at the cost of noise amplification. However, there is still a significant SNR gain compared with conventional GRAPPA. The proposed regularization method is an efficient approach for artifact suppression and maintains the SNR benefit of phase-constrained parallel MRI over conventional parallel MRI.

MAGNETIC RESONANCE IMAGING METALLIC ARTIFACT OF COMMONLY ENCOUNTERED SURGICAL IMPLANTS AND FOREIGN MATERIAL

Magnetic resonance imaging (MRI) artifacts secondary to metallic implants and foreign bodies are well described. Herein, we provide quantitative data from veterinary implants including total hip arthroplasty implants, cranial cruciate repair implants, surgical screws, a skin staple, ligation clips, an identification microchip, ameroid constrictor, and potential foreign bodies including air gun and BB projectiles and a sewing needle. The objects were scanned in a gelatin phantom with plastic grid using standardized T2-weighted turbo-spin echo (TSE), T1-weighted spin echo, and T2*-weighted gradient recalled echo (GRE) image acquisitions at 1.5 T. Maximum linear dimensions and areas of signal voiding and grid distortion were calculated using a DICOM workstation for each sequence and object. Artifact severity was similar between the T2-weighted TSE and T1-weighted images, while the T2*-weighted images were most susceptible to artifact. Metal type influenced artifact size with the largest artifacts arising from steel objects followed by surgical stainless steel, titanium, and lead. For animals with metallic surgical implants or foreign bodies, the quantification of the artifact size will help guide clinicians on the viability of MRI.

Uterine Tumors: Comparison of 3D versus 2D T2-weighted Turbo Spin-Echo MR Imaging at 3.0 T—Initial Experience

To compare a three-dimensional (3D) T2-weighted turbo spin-echo (TSE) magnetic resonance (MR) sequence (VISTA; Philips Medical Systems, Best, the Netherlands) with a two-dimensional (2D) T2-weighted TSE sequence in terms of image quality, signal intensity (SI) difference ratios, conspicuity, and staging of uterine tumors. This retrospective study was approved by the institutional review board, and informed consent was waived. Sixty-one women (mean age, 53.0 years ± 13.7 [standard deviation]; range, 30-87 years) with cervical carcinoma (n = 28), endometrial carcinoma (n = 21), or leiomyoma (n = 30) of the uterus were included. Patients underwent T2-weighted MR imaging at 3 T with both 1-mm-thick 3D and 5-mm-thick 2D T2-weighted TSE sequences. Three-dimensional T2-weighted TSE images were reconstructed at 5-mm thickness with the aid of a workstation. Quantitative analyses of signal-to-noise ratio (SNR) and SI difference ratios between tumors and other tissues and qualitative analyses of image quality and tissue conspicuity were performed. Two radiologists independently assessed local-regional staging for carcinomas. Quantitative values, qualitative scores, and tumor staging were analyzed by using the paired t test, Wilcoxon signed rank test, and McNemar test, respectively. Mean myometrial SNR was higher on 3D than 2D images (14.3 vs 9.8; P < .0001). Mean SI difference ratios between cervical (0.45 vs 0.34; P < .0001) or endometrial (0.46 vs 0.40; P = .044) carcinomas and gluteal muscle were higher on 3D images, but those between leiomyoma and myometrium (0.33 vs 0.43; P < .0001) were lower than those on 2D images. Image quality (P = .0004) and carcinoma conspicuity (P < .0005) were superior with the 3D T2-weighted TSE sequence. Although multiplanar reconstruction of 3D T2-weighted TSE images was useful for staging in one case, there were no significant differences between 3D and 2D T2-weighted TSE imaging in accuracy of staging for the two readers for cervical or endometrial carcinoma. The 3D T2-weighted TSE sequence showed certain advantages over the 2D T2-weighted TSE sequence, and it has the potential to improve the performance of MR imaging for the evaluation of uterine carcinoma.

Renal imaging at 7 Tesla: preliminary results

To investigate the feasibility of 7T MR imaging of the kidneys utilising a custom-built 8-channel transmit/receive radiofrequency body coil. In vivo unenhanced MR was performed in 8 healthy volunteers on a 7T whole-body MR system. After B(0) shimming the following sequences were obtained: 1) 2D and 3D spoiled gradient-echo sequences (FLASH, VIBE), 2) T1-weighted 2D in and opposed phase 3) True-FISP imaging and 4) a T2-weighted turbo spin echo (TSE) sequence. Visual evaluation of the overall image quality was performed by two radiologists. Renal MRI at 7T was feasible in all eight subjects. Best image quality was found using T1-weighted gradient echo MRI, providing high anatomical details and excellent conspicuity of the non-enhanced vasculature. With successful shimming, B(1) signal voids could be effectively reduced and/or shifted out of the region of interest in most sequence types. However, T2-weighted TSE imaging remained challenging and strongly impaired because of signal heterogeneities in three volunteers. The results demonstrate the feasibility and diagnostic potential of dedicated 7T renal imaging. Further optimisation of imaging sequences and dedicated RF coil concepts are expected to improve the acquisition quality and ultimately provide high clinical diagnostic value.

Differentiation between hepatic haemangiomas and cysts with an inversion recovery single-shot turbo spin-echo (SSTSE) sequence using the TI nulling value of hepatic haemangioma with sensitivity encoding

To evaluate the additional value of inversion recovery (IR) single-shot turbo spin-echo (SSTSE) imaging with sensitivity encoding (SENSE) using the inversion time (TI) value of hepatic haemangioma as a supplement to conventional T2-weighted turbo spin-echo (TSE) imaging for the discrimination of hepatic haemangiomas and cysts. A total of 134 lesions (77 hepatic haemangiomas, 57 hepatic cysts) in 59 patients were evaluated. Three readers evaluated these images and used a five-point scale to evaluate the lesion status. A receiver operating characteristic (ROC) analysis and 2 x 2 table analysis were used. The ROC analysis for all the readers and all the cases revealed a significantly higher area under the curve (AUC) for the combination of moderately and heavily T2-weighted TSE with IR-SSTSE images (0.945) than for moderately and heavily T2-weighted TSE images alone (0.894) (P < 0.001). For the combination of T2-weighted TSE with IR-SSTSE versus T2-weighted TSE alone, the 2 x 2 table analysis revealed a higher true-positive rate; this difference was statistically significant (P < 0.0001). The introduction of IR-SSTSE with SENSE sequences significantly improves the diagnostic accuracy of the differentiation of hepatic haemangioma and cysts while increasing the time required for routine abdominal imaging by only 20 s.

MRI Artifact Reduction and Quality Improvement in the Upper Abdomen with PROPELLER and Prospective Acquisition Correction (PACE) Technique

The purpose of this study was to evaluate the effectiveness of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER [BLADE in the MR systems from Siemens Medical Solutions]) with a respiratory compensation technique for motion correction, image noise reduction, improved sharpness of liver edge, and image quality of the upper abdomen. Twenty healthy adult volunteers with a mean age of 28 years (age range, 23-42 years) underwent upper abdominal MRI with a 1.5-T scanner. For each subject, fat-saturated T2-weighted turbo spin-echo (TSE) sequences with respiratory compensation (prospective acquisition correction [PACE]) were performed with and without the BLADE technique. Ghosting artifact, artifacts except ghosting artifact such as respiratory motion and bowel movement, sharpness of liver edge, image noise, and overall image quality were evaluated visually by three radiologists using a 5-point scale for qualitative analysis. The Wilcoxon's signed rank test was used to determine whether a significant difference existed between images with and without BLADE. A p value less than 0.05 was considered to be statistically significant. In the BLADE images, image artifacts, sharpness of liver edge, image noise, and overall image quality were significantly improved (p < 0.001). With the BLADE technique, T2-weighted TSE images of the upper abdomen could provide reduced image artifacts including ghosting artifact and image noise and provide better image quality.

Combined morphological, [1H]-MR spectroscopic and contrast-enhanced imaging of human prostate cancer with a 3-Tesla scanner: preliminary experience

The objective of this study was to explore the feasibility of combined morphological magnetic resonance imaging (MRI), [(1)H]magnetic resonance spectroscopic imaging (MRSI) and quantitative dynamic contrast-enhanced MRI (DCE-MRI) of human prostate cancer at 3 Tesla using a pelvic phased-array coil. MRI, MRSI and DCE-MRI with a 3-Tesla whole-body scanner were performed in 30 patients with biopsy-proven prostate cancer before radical prostatectomy. High-resolution T2-weighted turbo spin echo (TSE) images were evaluated for visualisation of the peripheral zone, central gland, visibility of the cancer lesion, prostatic capsule delineation and overall image quality according to a five-point scale. Relative levels of the prostate metabolites citrate, choline and creatine were determined in cancer and in the normal peripheral zone (PZ) and central gland (CG). Spectra were also evaluated for the separation of the signal of citrate, choline and creatine and suppression of lipid and water signals. Time-intensity curves were obtained for prostatic cancer and healthy PZ and CG from DCE-MRI. Finally, time of arrival, time to peak, maximum enhancement and wash-in rate in cancer, normal PZ and CG were calculated. The high signal-to-noise ratio (SNR) at 3 Tesla provided T2-weighted TSE images with excellent anatomical detail (in-plane voxel size of 0.22 x 0.22 mm) and good T2 contrast. The increased spectral resolution was sufficient to separate the choline and creatine resonances and allow delineation of the four peaks of citrate resonance. The (choline + creatine)/citrate ratio was elevated in cancer in comparison with PZ and CG (p<0.001). Dynamic contrast-enhanced images showed good temporal resolution. All parameters obtained from DCE-MRI showed a statistically significant (P<0.05) difference between cancer tissue and normal PZ and CG. Wash-in rate and (choline+creatine)/citrate ratio were significantly correlated (r=0.713, P=0.001) in PZ cancer, whereas the correlation was not significant (r=0.617, P=0.06) in CG and in PZ (r=0.530, P=0.08). It is possible to perform MRI of prostate cancer at 3 Tesla using a pelvic phased-array coil with high spatial, temporal and spectral resolution. The combination of vascular information from DCE-MRI and metabolic data from MRSI has excellent potential for improved accuracy in delineating and staging prostate carcinoma. These results suggest that high magnetic field strengths offer the possibility of studying prostate cancer without use of an endorectal coil.

Diffusion tensor imaging of the normal prostate at 3 Tesla

The aim of this study was to assess the feasibility of diffusion tensor imaging (DTI) of the prostate and to determine normative fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of healthy prostate with a 3-Tesla magnetic resonance imaging (MRI) system. Thirty volunteers with a mean age of 28 (25-35) years were scanned with a 3-Tesla MRI (Intera Achieva; Philips, The Netherlands) system using a six-channel phased array coil. Initially, T2-weighted turbo spin-echo (TSE) axial images of the prostate were obtained. In two subjects, a millimetric hypointense signal change was detected in the peripheral zones on T2-weighted TSE images. These two subjects were excluded from the study. DTI with single-shot echo-planar imaging (ssEPI) was performed in the remaining 28 subjects. ADC and FA values were measured using the manufacturer supplied software by positioning 9-pixel ROIs on each zone. Differences between parameters of the central and peripheral zones were assessed. Mean ADC value of the central (1.220 +/- 0.271 x 10(-3) mm(2)/s) was found to be significantly lower when compared with the peripheral gland (1.610 +/- 0.347 x 10(-3) mm(2)/s) (P < 0.01). Mean FA of the central gland was significantly higher (0.26), compared with the peripheral gland (0.16) (P < 0.01). This study shows the feasibility of prostate DTI with a 3-Tesla MR system and the normative FA and ADC values of peripheral and central zones of the normal prostate. The results are compatible with the microstructural organization of the gland.

Iron-oxide-enhanced MR imaging of bone marrow in patients with non-Hodgkin's lymphoma: differentiation between tumor infiltration and hypercellular bone marrow.

The aim of this study was to differentiate normal, hypercellular, and neoplastic bone marrow based on its MR enhancement after intravenous administration of superparamagnetic iron oxides in patients with cancer of the hematopoietic system. Eighteen patients with cancer of the hematopoietic system underwent MRI of the spine before and after infusion of ferumoxides ( n=9) and ferumoxtran ( n=9) using T1- and T2-weighted turbo spin-echo (TSE) and short tau inversion recovery sequences (STIR). In all patients diffuse or multifocal bone marrow infiltration was suspected, based on iliac crest biopsy and imaging such as conventional radiographs, MRI, and positron emission tomography. In addition, all patients had a therapy-induced normocellular ( n=7) or hypercellular ( n=11) reconversion of the normal non-neoplastic bone marrow. The MRI data were analyzed by measuring pre- and post-contrast signal intensities (SI) of hematopoietic and neoplastic marrow and by calculating the enhancement as deltaSI(%) data and the tumor-to-bone-marrow contrast as contrast-to-noise ratios (CNR). Changes in bone marrow signal intensity after iron oxide administration were more pronounced on STIR images as compared with T1- and T2-weighted TSE images. The STIR images showed a strong signal decline of normal and hypercellular marrow 45-60 min after iron oxide infusion, but no or only a minor signal decline of neoplastic bone marrow lesions; thus, deltaSI% data were significantly higher in normal and hypercellular reconverted marrow compared with neoplastic bone marrow lesions ( p<0.05). Additionally, the contrast between focal or multifocal neoplastic bone marrow infiltration and normal bone marrow, quantified by CNR data, increased significantly on post-contrast STIR images compared with precontrast images ( p<0.05). Superparamagnetic iron oxides are taken up by normal and hypercellular reconverted bone marrow, but not by neoplastic bone marrow lesions, thereby providing significantly different enhancement patterns on T2-weighted MR images; thus, superparamagnetic iron oxides are useful to differentiate normal and neoplastic bone marrow and to increase the bone marrow-to-tumor contrast.

Hemangioma and Hepatocellular Carcinoma: Distinction with Superparamagnetic Iron Oxide-Enhanced MR Imaging

Purpose: To compare liver hemangioma with hepatocellular carcinoma (HCC), as seen on superparamagneticiron oxide (SPIO)-enhanced MR images. Materials and Methods: The study involved 30 patients with 51 focal hepatic mass lesions (31 hemangiomas, 20 HCCs). Breath-hold T1-weighted fast low angle shot (FLASH) and respiratory-triggered T2-weighted turbo-spin echo (TSE) images were obtained at 1.5 T before and after intravenous administration of SPIO particles. For quantitative analysis, percentage signal intensity change (PSIC) and contrast-to-noise ratio (CNR) of the lesions were calculated for T1-weighted FLASH and T2-weighted TSE before and after intravenous administration of SPIO particles. In addition, lesion conspicuity and imaging artifacts were analyzed qualitatively. Results: After SPIO administration, percentage signal intensity increase on T1-weighted FLASH images was 73.0 22.1% for hemangiomas and 21.8 12.6% for HCCs, the difference being significant (p 0.05). Taking a signal increase of 40% on postcontrast T1-weighted FLASH as the cut-off value, sensitivity and specificity for hemangiomas were 96.8% and 100%, respectively. In addition, the percentages of signal intensity loss on T2-weighted TSE images for hemangiomas and HCCs were 35.5 17.2% and 0.2 10.5%, respectively (p 0.05). A comparison of lesion to liver CNR before and after SPIO infusion showed readings-for hemangiomas and HCCs, respectively - of 15.4 6.0 and 4.7 4.4 on T1-weighted FLASH images, and -2.6 0.7 and 2.7 4.4 on T2-weighted TSE images (p 0.05). Qualitative analysis indicated that the conspicuity of HCCs was noticeably greater on postcontrast T2-weighted TSE images than on precontrast images (p 0.05). Conclusion: The positive enhancement seen on T1-weighted FLASH images and the negative enhancement on T2 weighted TSE observed in liver hemangiomas after the administration of SPIO particles are valuable diagnostic features that can help characterize hemangiomas and differentiate them from HCCs.

Detectability of Hepatocellular Carcinoma: Comparison of Gd-DT PA-Enhanced and SPIO-Enhanced MR Imaging

Purpose : To compare the detectability of hepatocellular carcinoma (HCC) using superparamagnetic iron oxide (SPIO)-enhanced T2-weighted turbo spin echo (TSE), SPIO-enhanced -weighted FISP, and dynamic Gd-DTPA-enhanced fast low-angle shot (FLASH) MR images. Materials and Methods : In order to assess their hepatic lesions, 25 patients (20 men and 5 women) with HCC were enrolled in an MR study in which both gadolinium and SPIO were used. Since the lesions were most conspicuous during the phase of dynamic arterial dominant phase of dynamic gadolinium-enhanced imaging, this was the phase used for analysis. Images were analyzed qualitatively and quantitatively, and to compare the diagnostic value of gadolinium-enhanced imaging with that of SPIO-enhanced imaging for the detection of HCCs, a receiver-operated characteristic curve was obtained. Results : Qualitative analysis revealed a significantly higher percentage of signal loss and a higher liver-lesion contrast-to-noise ratio on SPIO-enhanced FISP imaging than on SPIO-enhanced T2-weighted TSE imaging (p0.05). It also showed that the lesions were most clearly visible on SPIO-enhanced FISP imaging(and signifi-cantlyso), followed by SPIO-enhanced T2-weighted TSE imaging, and dynamic gadolinium-enhanced imag-ing. Imaging artifacts were more prominent on SPIO-enhanced T2-weighted TSE than on SPIO-enhanced PISF imaging or dynamic gadolinium-enhanced imaging(p0.05). According to ROC analysis, SPIO-enhanced T2-weighted turbo spin echo(TSE) or SPIO-enhanced FISP imaging achieved higher accuracy than did dynamic gadolinium-enhanced FLASH imaging(p0.05). Conclusion : For the detection of hepatocellular carcinomas, SPIO-enhanced MR imaging is better than gadolinium-enhanced FLASH imaging.

Do T2-weighted pulse sequences help with the differential diagnosis of enhancing lesions in dynamic breast MRI?

In this study, our purpose was to determine whether T2-weighted images are a useful diagnostic adjunct for lesion characterization in dynamic breast MRI. On a 1.5-T system, 205 enhancing benign and malignant breast tumors were examined. The standardized protocol consisted of a T2-weighted turbo spin echo (TSE) pulse sequence with and without spectral fat suppression (SPIR), followed by a two-dimensional dynamic series with subtraction postprocessing. In 59 cases, T2*-weighted gradient-echo images also were obtained. Two independent radiologists visually rated the lesions (101 malignant, 104 benign) as having either a low or a high signal with respect to the adjacent glandular tissue. To assess age dependency of lesion enhancement velocities and T2-TSE signal intensities, we compared the results for patients at or below the age of 50 (group A), between 40 and 50 (group B), and beyond the age of 50 (group C). In T2-weighted TSE images, breast cancers were iso- or hypointense with respect to breast parenchyma in 87% of cases, whereas fibroadenomas were hyperintense in 71%. Visual assessment of lesion appearance in T2-weighted TSE images allowed to distinguish between fibroadenomas and breast cancers, with a respective sensitivity, specificity, positive predictive value, and negative predictive value of 72%, 75%, 46%, and 90% for young patients; 94%, 66%, 78%, and 89% for the patients between 40 and 50; and 89%, 62%, 85%, and 68% for the patients over 50 years of age. No significant difference was found for the distribution of signal intensities of lesions in T2*-weighted images or in fat-suppressed images. In a contrast-enhancing breast lesion, careful analysis of T2-weighted TSE images can improve differential diagnosis. The accuracy of this criterion varies with age.

Carcinoma of the uterine cervix

Purpose: To compare high-resolution contrast-enhanced (Gd-DTPA) dynamic MR imaging with T2-weighted turbo spin-echo (TSE) imaging in the evaluation of uterine cervical carcinomaMaterial and Methods: Thirty-two patients with cervical carcinoma underwent MR imaging on a 1.5 T superconductive unit to have the extension of the disease assessed before treatment. A phased-array coil was used in all patients. In 25 patients, surgical confirmation of the diagnosis was obtained after imaging. Radiation therapy was selected for the remaining 7 patients with advanced carcinoma. Qualitative and quantitative image analyses were also performedResults: The cervical carcinomas showed maximum contrast in the cervical stroma and myometrium in the early dynamic phase. The tumor/cervical-stroma contrast in the early dynamic phase obtained with the T1-weighted TSE technique (contrast-to-noise ratio 22.6) was significantly higher than that obtained in T2-weighted TSE imaging (contrast-to-noise ratio 4.3). In the evaluation of ...