T2-weighted spin-echo MR imaging of the liver: breath-hold fast spin-echo versus non-breath-hold fast spin-echo images with and without fat suppression

OBJECTIVE: The goal of our study was to compare a T2-weighted breath-hold fast spin-echo (BHSE) technique with T2-weighted non-breath-hold fast spin-echo techniques for imaging the liver. SUBJECTS AND METHODS: Thirty-three patients with hepatic lesions had T2-weighted BHSE images obtained in 22 sec and conventional T2-weighted non-breath-hold fast spin-echo images obtained in 3 min 12 sec with and without fat suppression. Images were analyzed quantitatively by measuring the lesion-liver contrast, spleen-liver contrast, and signal-to-noise ratios of lesions and qualitatively by evaluating the sharpness of hepatic contours, visibility of intrahepatic vessels and other segmental landmarks, and presence of artifacts. RESULTS: Quantitatively, lesion-liver contrast, spleen-liver contrast, and signal-to-noise ratios obtained with the BHSE technique were inferior to those obtained with fast spin-echo techniques with and without fat suppression (11.2 +/- 7.1 versus 15.4 +/- 10.6 and 14.5 +/- 9.8, p < .001; 5.3 +/- 3.7 versus 8.7 +/- 3.5 and 7.0 +/- 3.8, p < .001; 16.2 +/- 8.2 versus 20.1 +/- 10.9 and 19.7 +/- 9.5, p < .01, respectively; Student's t test). Qualitatively, image artifacts and intrahepatic vessel depiction on BHSE images were similar to those obtained with the fast spin-echo techniques. The BHSE technique was superior to fat-suppressed fast spin-echo technique for showing hepatic contours (p < .01; Wilcoxon signed-rank test). CONCLUSION: The BHSE technique is quantitatively inferior to non-breath-hold fast spin-echo techniques. However, further studies with a surgical standard of reference are needed to compare the three techniques in terms of sensitivity.     

Differentiation between hepatic cavernous hemangioma and malignant tumor with T2-weighted MRI: comparison of fast spin-echo and breathhold fast spin-echo pulse sequences

An in vitro jaw-attached brainstem preparation was developed to investigate the relationship between jaw opener and closer muscle activity during chemically induced rhythmical jaw movements in neonatal rats. In the majority of preparations examined, where a defined region of brainstem was isolated and the neuronal innervation of the jaw opener and closer muscles was left intact, bath application of the excitatory amino acid agonist N-methyl-D,L-aspartate (NMA, 20-40 microM) in combination with bicuculline (BIC 10 microM), a GABA(A) antagonist, produced rhythmical electromyogram (EMG) activity in jaw opener and closer muscles, bilaterally, in conjunction with rhythmical jaw movements. Low concentrations of NMA (20 microM) in combination with BIC produced temporally coordinated activity between the jaw opener and closer muscles, ipsilaterally. With higher doses of NMA (40 microM), each muscle group exhibited bursting, but temporal coordination between them was difficult to establish. Similarly, NMA application in combination with the glycine antagonist strychnine (STR, 10 microM), also produced rhythmical EMG activity from both opener and closer muscles, ipsilaterally, but showed no temporal coordination between the antagonist muscle pair. However, coordination of opener and closer muscle discharge could be restored by the addition of BIC to the bath. We suggest that there exist separate, but coordinated, rhythm generator circuits for opener and closer motoneuronal discharge located in close proximity to the trigeminal motor nucleus and under GABAergic control for production of temporal coordination between rhythmogenic circuits.     

Preoperative staging of endometrial carcinoma: diagnostic effect of T2-weighted fast spin-echo MR imaging

PURPOSE: To evaluate the usefulness of T2-weighted fast spin-echo magnetic resonance (MR) imaging with a 512 x 256 matrix for assessment of the preoperative stage of endometrial carcinoma. MATERIALS AND METHODS: Twenty-eight women with histopathologically proved endometrial carcinoma underwent preoperative T2-weighted fast spin-echo, dynamic T1-weighted fast spin-echo, and postcontrast T1-weighted spin-echo MR imaging with a phased-array surface coil. The uterine long-axis planes in each sequence were reviewed at separate sessions by three radiologists blinded to the histopathologic data. RESULTS: For the diagnosis of myometrial invasion, no statistically significant differences were found among T2-weighted imaging, dynamic imaging, and postcontrast T1-weighted imaging. For the diagnosis of deep myometrial invasion, T2-weighted and dynamic images showed higher specificity than postcontrast T1-weighted images (T2-weighted, 89%; dynamic, 88%; and postcontrast T1-weighted, 80%). For cervical invasion, T2-weighted and dynamic images showed larger areas under receiver operating characteristic curves than did postcontrast T1-weighted images (T2-weighted, 0.78; dynamic, 0.71; and postcontrast T1-weighted, 0.67). CONCLUSION: T2-weighted imaging is useful for identifying the stage of endometrial carcinoma.     

Hepatic lesions: discrimination of nonsolid, benign lesions from solid, malignant lesions with heavily T2-weighted fast spin-echo MR imaging

PURPOSE: To determine whether the combined use of heavily and moderately T2-weighted fast spin-echo magnetic resonance (MR) images improves differentiation of non-solid, benign hepatic lesions from solid malignancies. MATERIALS AND METHODS: Three radiologists reviewed moderately (n = 133) and heavily (n = 133) T2-weighted and multiphasic dynamic contrast material-enhanced (n = 93) MR images in 133 patients with proved focal hepatic lesions (95 benign, 38 malignant). The radiologists used a five-point scale to rate their confidence in determination of malignancy. RESULTS: All three reviewers were statistically significantly better able to differentiate small (diameter less than 3 cm; n = 84) benignancies from small malignancies with the combination of moderately and heavily T2-weighted images (area under the receiver operating characteristic curve, 0.99 for each reader) than with moderately T2-weighted images alone (area, 0.88-0.90; P < .05). Confident diagnoses were rendered in 69 (82%) patients, with 100% accuracy for the combined use of moderately and heavily T2-weighted images. For larger lesions (diameter 3 cm or larger; n = 49), accurate differentiation was possible with moderately T2-weighted images alone. Additional use of multiphasic images did not improve the sensitivity, specificity, or accuracy of image interpretation. CONCLUSION: The combined use of moderately and heavily T2-weighted fast spin-echo MR images improves differentiation of small benign hepatic lesions from small malignant lesions.     

Breath-hold fast spin-echo MR imaging of the liver: a technique for high-quality T2-weighted images

The added technical complexity associated with the transfixion screws for interlocking nailing has introduced new complications. We present a case of a femoral arteriovenous fistula caused by the distal interlocking screw after intramedullary nailing of a comminuted diaphyseal femoral fracture.     

T2-weighted breath-hold MRI of the liver at 1.0 T: comparison of turbo spin-echo and HASTE sequences with and without fat suppression

To compare the clinical usefulness of T2-weighted breath-hold sequences for imaging the liver, 33 patients with 97 focal hepatic lesions were studied with a 1.0-T scanner by using T2-weighted breath-hold turbo spin-echo (SE) sequences and T2-weighted breath-hold half-Fourier single-shot turbo SE (HASTE) sequences with and without fat suppression. Images were quantitatively analyzed for liver signal-to-noise ratio (SNR) and lesion-to-liver contrast-to-noise ratios (CNR). Qualitative analysis was performed for lesion conspicuity, motion artifacts, and anatomic sharpness of extrahepatic structures. Breath-hold turbo SE imaging with fat suppression showed the highest CNR for cystic lesions and the best lesion conspicuity for cystic and solid lesions among the four sequences. For solid lesions, there was no significant difference of lesion-to-liver CNR between them. HASTE sequence was superior to turbo SE sequences in terms of motion artifacts; however, the usefulness for evaluating focal hepatic lesions was limited compared with turbo SE sequence with fat suppression. Addition of fat suppression was not helpful for HASTE imaging because of decreased lesion conspicuity and extrahepatic details without the advantage of reducing motion artifacts. This study suggests that turbo SE sequence with fat suppression is most useful for breath-hold T2-weighted liver imaging at 1.0 T. Addition of imaging without fat suppression can be considered for evaluating extrahepatic structures. HASTE sequence may have a role for imaging uncooperative patients due to absence of motion artifacts.     

Inner ear volumetric measurements using high-resolution 3D T2-weighted fast spin-echo MR imaging: initial experience in healthy subjects

BACKGROUND AND PURPOSE: Adult size is achieved in the inner ear labyrinth by approximately 25 weeks' gestation, and minimal variability in age, sex, side, and race is found after birth. In this study, we opted to determine the reproducibility of inner ear volumetric measurements generated from high-resolution heavily T2-weighted 3D fast spin-echo MR images. METHODS: The temporal bones of 23 volunteers were imaged using a heavily T2-weighted 3D fast spin-echo MR imaging technique. The images were assessed by a neuroradiologist for the presence of inner ear configurational anomalies and, most important, for complete coverage of the inner ear labyrinth. Subsequently, the volume of the fluid in the inner ear was determined by two observers using a semiautomated segmentation algorithm. The mean, SD, range, and coefficient of variation of fluid volume in the inner ear were calculated. Age-, sex-, and side-related differences in the inner ear volumetric measurements were evaluated using analysis of variance. Interrater consistency in the inner ear volumetric measurements was evaluated by comparing the calculated coefficients of reliability. RESULTS: Volumetric measurements were available from 46 inner ears in 23 volunteers. The mean volume was 227.8 mm3 (SD, 24.4 mm3), and the coefficient of variation was 10.7%. No age-, sex-, or side-related differences in the inner ear volumetric measurements were found (F ratios were 4.33, 5.04, and 0.26, respectively). Interrater consistency, as assessed by the coefficient of reliability, was 5.3%. CONCLUSION: Reproducible volumetric measurements of the inner ear labyrinth can be obtained by applying a semiautomated segmentation algorithm to a heavily T2-weighted 3D fast spin-echo MR imaging data set. These volumetric measurements may help identify patients with congenital sensorineural hearing loss and normal inner ear configuration.     

Hepatic cavernous hemangioma: sonographic patterns and speed of contrast enhancement on multiphase dynamic MR imaging

OBJECTIVE: Our purpose was to investigate a correlation between the speed of contrast enhancement in patients with hepatic cavernous hemangioma revealed by dynamic MR imaging and the internal echo pattern revealed by sonography. MATERIALS AND METHODS: Forty-five patients underwent multiphase IV contrast-enhanced dynamic MR imaging that revealed 71 hepatic cavernous hemangiomas less than 4 cm in diameter; the MR findings were compared with the sonographic findings in these patients. On MR imaging, the hemangiomas were classified as rapid-, intermediate-, and slow-enhancing. We classified sonographic features as hypoechoic, iso- or mixed-echoic, and hyperechoic according to the relative echogenicity seen between lesions and the surrounding hepatic parenchyma. Sonographic patterns and MR imaging findings of individual lesions were then compared. RESULTS: Rapid-enhancing hemangiomas revealed on dynamic MR imaging tended to be hypoechoic on sonography (18/24, 75%; p = .0143), and lesions that were slow-enhancing on MR imaging tended to be hyperechoic (26/29, 90%; p < .0001). Hypoechoic lesions on sonography tended to be rapid-enhancing on dynamic MR imaging (18/18, 100%). Likewise, hyperechoic lesions on sonography tended to be slow-enhancing on MR imaging (26/33, 79%; p = .0009). CONCLUSION: In most patients with hepatic cavernous hemangiomas, we found that the speed of contrast enhancement on multiphase dynamic MR imaging enabled us to predict the echo pattern in sonography and vice versa.     

Comparison of turbo inversion recovery magnitude (TIRM) with T2-weighted turbo spin-echo and T1-weighted spin-echo MR imaging in the early diagnosis of acute osteomyelitis in children

OBJECTIVE: To compare turbo inversion recovery magnitude (TIRM) with standard T1-weighted (T1-W) and T2-weighted (T2-W) MR sequences in the very early detection of acute osteomyelitis in children. MATERIALS AND METHODS: In 15 children with osteomyelitis, 15 sets of T1-W spin-echo (SE) (TR/TE, 400-640/12-17), T2-W turbo spin-echo (TSE) (TR/TE/ETL, 3290-4465/112-120/11), and TIRM (TR/TE/TI, 4000-6120/60/160) images were acquired with a 1.0-T magnet. Contrast-to-noise (C/N) ratios and percentage of signal between lesion and normal bone marrow were analysed with a computer-assisted image analysing system in a region of interest (ROI). RESULTS: In 13 of 15 patients, the absolute signal enhancement in a ROI on the TIRM images was better than on the T1-W SE and T2-W TSE images and in 14 of 15 cases, C/N ratios were also better on the TIRM images than on the other sequences. In the other cases, the TIRM signal was diagnostically equivalent. On the TIRM images, the signal difference between normal and pathological tissue was increased to 43-281% (mean 124%). On the T2-W TSE images, this signal difference was 4-79% (mean 36%) and on the T1-W SE images 6-77% (mean 37%). Conclusion. The TIRM sequence is highly sensitive for detecting bone marrow oedema in the very early stage of acute osteomyelitis in children. MRI utilising the TIRM sequence allowed for an early diagnosis. With scan time of less than 4 minutes, this sequence is superior to T1-W SE and T2-W TSE images for detecting early osteomyelitis-associated bone marrow oedema.     

Gadolinium-enhanced MR imaging of temporomandibular disorders: improved lesion detection of the posterior disk attachment on T1-weighted images obtained with fat suppression

OBJECTIVE: The purpose of this study was to assess the potential for improved lesion detection in the posterior disk attachment and its surrounding tissue in temporomandibular disorders when gadolinium-enhanced MR imaging performed with fat suppression is used. MATERIALS AND METHODS: Forty-five patients underwent MR imaging with conventional T1- and T2-weighted, gadolinium-enhanced T1-weighted, and gadolinium-enhanced fat-suppressed spin-echo imaging sequences. Qualitative and quantitative assessments of the contrast enhancement of each type of imaging were also performed. RESULTS: The contrast-enhanced fat-suppressed T1-weighted imaging sequence had several advantages over the other imaging techniques in detecting abnormalities of the posterior disk attachment and in detecting bone marrow lesions in the mandibular condyle. The most significant advantage was better enhancement of lesion conspicuity. The diagnostic accuracy of contrast-enhanced fat-suppressed imaging was 77% versus 70% for conventional contrast-enhanced imaging. The kappa value for interobserver agreement was .95 for contrast-enhanced fat-suppressed imaging and .72 for conventional contrast-enhanced imaging. CONCLUSION: Contrast-enhanced fat-suppressed T1-weighted spin-echo MR imaging is a valuable technique for visualizing the extent and degree of lesions in the posterior disk attachment and bone marrow lesions in the mandibular condyle.     

Postoperative sella: evaluation with fast spin echo T2-weighted high-resolution imaging

OBJECTIVE: The purpose of this study was to investigate the magnetic resonance features of the postoperative sella with fast spin echo (FSE) T2-weighted high-resolution imaging and to evaluate the benefits of the sequence using a follow-up magnetic resonance imaging protocol after transsphenoidal surgery. METHODS: Coronal spin echo (SE) T1-weighted and FSE T2-weighted images were prospectively obtained in 24 patients after surgery for pituitary adenomas. We observed the signals and the contour of normal structures, fluid collection, implanted materials, and mass lesions, including granulation tissue and adenoma. RESULTS: The pituitary gland was delineated in 51 of 59 FSE T2-weighted images, 90.2% of which presented clear boundaries. Whereas the gland was detected in 49 of 58 SE T1-weighted images, only 20.4% showed the boundaries. A mass lesion was identified in each of 12 patients with good resolution on FSE T2-weighted images. SE T1-weighted images detected mass lesions in 7 of 12 patients without distinctive boundaries. Contrast enhancement had little advantage in clarifying the boundaries between normal and abnormal structures. For the detection of mass lesions in the sella, the kappa values for interobserver agreement were 0.8 for FSE T2-weighted images and 0.25 for SE T1-weighted images. CONCLUSION: FSE T2-weighted imaging is a reliable method with which to assess the sella with sufficient resolution after transsphenoidal surgery. The combination of unenhanced SE T1-weighted and FSE T2-weighted images may reduce the use of contrast material after pituitary surgery.     

MRI of the uterus, uterine cervix, and vagina: diagnostic performance of dynamic contrast-enhanced fast multiplanar gradient-echo imaging in comparison with fast spin-echo T2-weighted pulse imaging

The aim of this study was to compare the diagnostic performance of contrast-enhanced fast multiplanar gradient-echo (GRE) and T2-weighted fast spin-echo (FSE) image sets in the assessment of uterus, cervix, and vagina. Fast (up to 20 contiguous sections in 23 s) multiplanar GRE and FSE images of 45 patients referred for imaging of the female pelvis were evaluated retrospectively with regard to overall image quality and the ability to detect normal anatomic structures, as well as lesion conspicuity. Results were compared with histologic findings (n = 29) or clinical follow-up. Furthermore, a quantitative assessment of contrast-to-noise ratios among normal uterine and cervical structures as well as uterine lesions was performed for both sequences. On GRE images, uterine and cervical differentiation was best seen on the image sets acquired 15 and 60 s following contrast enhancement and results were significantly better compared with delayed images (p < 0.05). Delineation of the junctional zone was significantly (p < 0.05) better on FSE compared with GRE images; no significant difference was seen for the other anatomic structures. Overall image quality of GRE and FSE images was similar. Sensitivity for lesion detection based on both GRE and FSE images was 96% with a sensitivity of 93% for GRE, and 81% for FSE images alone, respectively. Using the extended McNemar chi 2 test, the difference in diagnostic performance between FSE and GRE revealed no significant difference, whereas the combination of both techniques performed better than FSE imaging alone (p < 0.05). The presented data suggest that dynamic contrast-enhanced GRE imaging should be part of an MR examination of the female pelvis. Combined GRE and FSE imaging provide an excellent sensitivity in the assessment of uterine and vaginal pathologies.     

MR sialography: initial experience using a T2-weighted fast SE sequence

OBJECTIVE: To determine whether reactive oxygen species in peritoneal fluid might be a factor in infertility. DESIGN: Prospective study. SETTING: Andrology laboratory and gynecology clinic at a tertiary care facility. PATIENT(S): Women with endometriosis (n = 15) or idiopathic infertility (n = 11) who underwent laparoscopy for infertility. Patients undergoing tubal ligation served as controls (n = 13). INTERVENTION(S): Aspiration of peritoneal fluid. MAIN OUTCOME MEASURE(S): Reactive oxygen species levels, presence of polymorphonuclear granulocytes, and leukocyte distribution in peritoneal fluid. RESULT(S): Reactive oxygen species were present in the peritoneal fluid of patients with endometriosis, idiopathic infertility, and tubal ligation. Levels of reactive oxygen species did not show a statistically significant difference between patients with endometriosis and the control group in either unprocessed or processed (cell-free) peritoneal fluid, but did differ significantly between patients with idiopathic infertility and controls in processed peritoneal fluid. Polymorphonuclear granulocytes (> 1 x 10(6)/mL) were not present in the peritoneal fluid of any patient. Macrophage concentrations of peritoneal fluid did not differ significantly between controls and patients with endometriosis or idiopathic infertility. CONCLUSION(S): Reactive oxygen species in the peritoneal fluid may not affect fertility directly in women with endometriosis; however, they may have a role in patients with idiopathic infertility.     

Hemorrhagic and nonhemorrhagic stroke: diagnosis with diffusion-weighted and T2-weighted echo-planar MR imaging

PURPOSE: To determine if diffusion- and T2-weighted echo-planar magnetic resonance (MR) imaging can be used to detect acute hemorrhagic stroke and to differentiate hemorrhagic from nonhemorrhagic stroke. MATERIALS AND METHODS: A total of 118 examinations (diffusion- and T2-weighted MR imaging) in 19 patients with 27 nonhemorrhagic strokes and in six patients with seven hemorrhagic strokes were performed. The ratios of apparent diffusion coefficient and of signal intensity on T2-weighted MR images in lesions to those in contralateral control areas were calculated. RESULTS: Decreased ADC was shown in lesions of acute (0-3 days) hemorrhagic stroke, as well as in lesions of acute nonhemorrhagic stroke. Hypointense areas were seen on T2-weighted MR images in patients with acute hemorrhagic stroke, in contrast to normal to increased signal intensity in those with acute nonhemorrhagic stroke. Apparent diffusion coefficient tended to remain decreased in hemorrhagic stroke lesions even 100 days after onset, in contrast to the increased coefficient in nonhemorrhagic stroke lesions at the late chronic stage (31 days or older). CONCLUSION: Diffusion- and T2-weighted echo-planar MR imaging can be used to detect and distinguish between acute hemorrhagic and nonhemorrhagic stroke.     

Comparison of ultrafast half-Fourier single-shot turbo spin-echo sequence with turbo spin-echo sequences for T2-weighted imaging of the female pelvis

1. This investigation was undertaken to compare pre- and postjunctional receptors involved in the responses of the canine mesenteric and pulmonary arteries to angiotensin II. 2. In the mesenteric artery, angiotensin II caused an enhancement of tritium overflow evoked by electrical stimulation (EC30% = 5 nM), the maximal effect representing an increase by about 45%. Postjunctionally, angiotensin II caused concentration-dependent contractions (pD2 = 8.57). Saralasin antagonized both pre- and postjunctional effects of angiotensin II, but it was more potent at post- than at prejunctional level (pA2 of 9.51 and 8.15, respectively), while losartan antagonized exclusively the postjunctional effects of angiotensin II (pA = 8.15). PD123319 had no antagonist effect either pre- or postjunctionally. 3. In the pulmonary artery, angiotensin II also caused an enhancement of the electrically-evoked tritium overflow (EC30% = 1.54 nM), its maximal effect increasing tritium overflow by about 80%. Postjunctionally, angiotensin II caused contractile responses (pD2 = 8.52). As in the mesenteric artery, saralasin antagonized angiotensin II effects at both pre- and postjunctional level and it was more potent postjunctionally (pA2 of 9.58 and 8.10, respectively). Losartan antagonized only the postjunctional effects of angiotensin II (pA2 = 7.96) and PD123319 was ineffective. 4. It is concluded that in both vessels: (1) pre- and postjunctional receptors belong to a different subtype, since they are differently antagonized by the same antagonists; (2) postjunctional receptors belong to AT1 subtype, since they are blocked by losartan but not by AT2 antagonists; (3) prejunctional receptors apparently belong to neither AT1 or AT2 subtype since they are blocked by neither AT1 nor AT2 antagonists.     

Bithalamic hyperintensity on T2-weighted MR: vascular causes and evaluation with MR angiography

PURPOSE: To determine whether MR angiography can be used to differentiate between the two vascular causes of bithalamic hyperintensity on T2-weighted MR images: "top of the basilar" artery occlusion and deep cerebral vein thrombosis. METHODS: A retrospective review identified six patients with bithalamic T2 hyperintensity of vascular causes. MR angiography was performed in four patients, MR angiography and conventional angiography in one patient, and conventional angiography in one patient. Data pertaining to clinical presentation and hospital course were collected. MR angiographic techniques were multislab overlapping three-dimensional time-of-flight, 2-D time-of-flight, and 2-D phase-contrast. RESULTS: Three cases of top of the basilar artery occlusion and three cases of deep cerebral vein thrombosis were recognized. In all cases, T2 hyperintensity in a vascular distribution suggested cerebral occlusive disease. Infarction involving the thalami and basal ganglia was present in two cases of deep cerebral vein thrombosis. Infarction of the thalami, mesodiencephalic region, and cerebellar hemispheres was present in two cases of basilar artery occlusion. Bithalamic infarction alone was seen in one case of deep cerebral vein thrombosis and one case of basilar artery occlusion. In the five cases in which MR angiography was used, this technique accurately distinguished the vessels involved (arterial or venous). CONCLUSION: MR angiography is a useful adjunct to MR imaging in the evaluation of bithalamic T2 hyperintensity. It does help distinguish between the two vascular causes: top of basilar artery occlusion and deep cerebral vein thrombosis.     

Multishot echoplanar MR imaging of the female pelvis: comparison with fast spin-echo MR imaging in an initial clinical trial

OBJECTIVE: The purpose of this study was to apply multishot echoplanar MR imaging (EPI) to the female pelvis and compare image quality with that of fast spin-echo MR imaging. SUBJECTS AND METHODS: Twenty-one patients with suspected pelvic disease and five healthy female volunteers were prospectively examined. MR imaging was obtained using an EPI-capable 1.0-T imager and a pelvic phased-array coil. Axial EPI and fast Spin-echo sequences were obtained at identical image locations in each patient and volunteer. Spin-echo EPI images were obtained using a multishot number of 16. Acquisition time for each EPI sequence was 2 min 10 sec. Fat-suppressed T2-weighted fast spin-echo images were obtained in 2 min 12 sec. Paired EPI and fast spin-echo MR images were independently evaluated by three reviewers. RESULTS: Delineation of the perivaginal and parametrial venous plexus on EPI was rated superior to the fast spin-echo images in 62 (77%) of 81 cases. On EPI, uterine zone anatomy and ovary visualization were judged to be inferior in 44 (56%) of 78 cases and in 18 (33%) of 54 cases, respectively. For delineation of uterine abnormalities, including leiomyoma and adenomyosis, both sequences performed almost equally well. However, ovarian cystic lesions were revealed more precisely by the fast spin-echo sequence. An overall fat-suppression effect was seen on EPI images in 62 (77%) of 81 cases. CONCLUSION: Multishot EPI cannot replace fast spin-echo sequences for imaging the female pelvis; however, because EPI has a potent fat-suppression effect and heavily T2-weighted contrast, EPI sequences can be a valuable adjunct to routine examination.     

Non-breath-hold fast spin-echo versus breath-hold fast spin-echo and spoiled gradient-recalled echo MR imaging in the detection of hepatic tumors: correlation with surgical findings

OBJECTIVE: Our objective was to compare the sensitivity of non-breath-hold T2-weighted fast spin-echo with and without fat suppression, breath-hold T2-weighted fast spin-echo without fat suppression, and spoiled gradient-recalled echo (GRE) MR imaging for detecting hepatic tumors using surgical findings as the standard of reference. SUBJECTS AND METHODS: Eighteen patients with 36 surgically proven hepatic tumors had non-breath-hold T2-weighted fast spin-echo (6000/117 [TR/effective TE; echo train length, 16) MR imaging with and without fat suppression, breath-hold T2-weighted fast spin-echo MR imaging (2700/105; echo train length, 20), and spoiled GRE images (10.1/1.9; flip angle, 30 degrees) obtained before and after injection of a gadolinium chelate. Images were analyzed separately by two independent readers, with disagreements resolved by consensus reading. RESULTS: Non-breath-hold T2-weighted fast spin-echo MR imaging with and without fat suppression depicted 22 (61%; 95% confidence interval [CI], 43-77%) and 20 (56%; 95% CI, 37-72%) of 36 hepatic tumors, respectively. Breath-hold T2-weighted fast spin-echo imaging allowed detection of 19 (53%; 95% CI, 35-69%) of 36 hepatic tumors. Unenhanced and gadolinium chelate-enhanced spoiled GRE images allowed depiction of 18 (50%; 95% CI, 33-67%) and 29 (81%; 95% CI, 63-91%) of 36 hepatic tumors, respectively. Gadolinium chelate-enhanced spoiled GRE images allowed depiction of significantly more hepatic tumors than any of the other pulse sequences. CONCLUSION: Gadolinium chelate-enhanced spoiled GRE imaging is more sensitive than T2-weighted MR imaging obtained with a breath-hold or a non-breath-hold technique.     

Anterior cruciate ligament injury: fast spin-echo MR imaging with arthroscopic correlation in 217 examinations

OBJECTIVE: Our objective was to evaluate the accuracy of MR imaging strategy that uses primarily fast spin-echo sequences for the diagnosis of anterior cruciate ligament tears. MATERIALS AND METHODS: The original clinical interpretations of MR images of 217 examinations of the knee joint were correlated with subsequent arthroscopic results. Each MR examination included a double-echo fast spin-echo sequence as the only imaging sequence in the sagittal plane. Subsequent discordant MR and arthroscopic examinations were then subjected to reanalysis by two observers who were unaware of arthroscopic results to determine if misinterpretations were observer or image dependent. Two hundred sixteen patients who underwent MR imaging for suspected internal derangement of the knee subsequently underwent arthroscopic surgery. Two patients had both knees evaluated. One patient was excluded because he was referred for evaluation for osteomyelitis, not internal derangement. This yielded a total number of 217 MR examinations for suspected internal derangement of the knee. RESULTS: For 56 arthroscopically proven tears, the sensitivity of MR imaging was 96%. The specificity was 98%, yielding an overall accuracy rate of 98%. The positive and negative predictive values were 95% and 99%, respectively. These values are within the ranges of previously reported MR imaging strategies using conventional spin-echo sequences. CONCLUSION: Fast spin-echo MR imaging of the knee can be an alternative to conventional spin-echo imaging for the detection of anterior cruciate ligament tears.