MR imaging of the uterus: findings from high-resolution multisection dynamic imaging with a surface coil

MR imaging of the female pelvis with a local coil (multiple phased array coils) has been reported. With this method, the signal-to-noise ratio (S/N) is improved so that high-resolution images can be obtained. Dynamic contrast-enhanced MR imaging has been reported to be useful in diagnosing uterine neoplasms. However, dynamic MR imaging is done in only limited imaging planes. When multisection dynamic MR imaging with fast gradient-echo sequences is combined with the use of a local coil, high-resolution images can be obtained throughout the entire uterus during a single breath-hold. This pictorial essay illustrates the appearance of the normal uterus and malignant uterine neoplasms on high-resolution multisection dynamic MR images obtained with a Helmholtz-type surface coil.     

Sonographic findings of rotator cuff tears: correlation with MR imaging

Sonography was performed in 41 patients with symptoms referable to the rotator cuff. Sonography was performed immediately after MR imaging, so that the information obtained by MR imaging could be applied to sonographic diagnosis. Twenty patients were diagnosed from T2-weighted images as having complete tears of the rotator cuff. Sonography showed full-thickness anechoic areas in 12 of the 20 patients, heterogeneous hyperechoic areas in seven, and no abnormal findings in the other one. Thirteen patients were diagnosed as having incomplete tears with MR imaging. Sonography showed heterogeneous hyperechoic areas in 12, but no abnormal findings in one of the 13. Hyperechoic areas in the rotator cuff were shown in four of eight patients who had been diagnosed from T2-weighted images as not having tears. We consider full-thickness anechoic areas to be specific findings of complete tears, although some patients with rotator cuff tears did not show this finding.     

Deep benign fibrous histiocytoma of the knee: CT and MR features with pathologic correlation

Magnetic resonance imaging and pathologic findings in a 28-year-old patient with a giant deep benign fibrous histiocytoma in the popliteal fossa of the right knee are described. The MR imaging findings include a well-delineated oval mass with low signal intensity on T1-, and high signal intensity on T2-weighted, images, and marked peripheral contrast enhancement. To the best of our knowledge, this is the first report on the MR findings in this entity.     

Hallervorden-Spatz disease: MR and pathologic findings

PURPOSE: To compare the MR findings of eight cases with clinical diagnosis of Hallervorden-Spatz disease (HSD) with the pathologic findings of two other cases of HSD. MATERIALS AND METHODS: The eight imaged cases were studied with 0.5-T (seven cases) and/or 1.5-T (five cases) units. Six patients also had CT scans. The two other cases with proven HSD had detailed histologic evaluation. RESULTS: The 1.5-T findings showed abnormalities confined to the pallidum, which presented a diffuse low signal intensity in T2-weighted images, and an anteromedial area of high signal intensity (eye-of-the-tiger sign). In 0.5-T studies, low signal intensity was less evident and poorly detectable in spin echo, but gradient-echo images could enhance its demonstration; the area of high signal intensity was always well demonstrated. In three cases (three with 1.5 T, one with 0.5 T) a central spot of low signal intensity was seen in this area. The pathologic cases, in addition to neuroaxonal swellings and iron deposits, exhibited areas of "loose" tissue with vacuolization and lesser amounts of iron in the anteromedial part of the pallidum, in a location corresponding to the area of high signal intensity of the imaged cases. CONCLUSION: Comparison of MR findings with the pathologic studies demonstrates that the low signal intensity in T2-weighted images at 1.5 T corresponds to iron deposits in a dense tissue, and that the high signal intensity of the eye-of-the-tiger sign corresponds to an area of loose tissue with vacuolization. No correlation was found in the two pathologic cases for the central spot of low signal intensity.     

Tuberculous tenosynovitis of the flexor tendons of the wrist: MR imaging with pathologic correlation

A 3-year-old child with a patent arterial duct underwent percutaneous transcatheter occlusion using Rashkind's "double umbrella" technique. The procedure, using a 17 mm device, was uncomplicated. An echocardiogram done 6 hr later showed a mobile 5 x 3 mm thrombus on the pulmonary aspect of the device. The thrombus resolved after 24 hr of intravenous heparin.     

Soft tissue osteosarcoma with telangiectatic features: MR imaging findings in two cases

Extraskeletal osteosarcomas are rare tumors, and the telangiectatic variety is the least common histological variety in this group. This report describes the clinical and MR imaging findings in two cases arising in the pretibial soft tissues. Both tumors demonstrated marked inhomogeneity with T2-weighted spin echo and STIR sequences. One of the tumors revealed numerous fluid levels within the lesion. A review of the MRI features of these tumors is provided. Osteosarcoma with telangiectatic features should be considered in the differential diagnosis of a soft tissue mass with fluid-fluid levels in patients 40 years of age or older.     

Brachial plexus: MR imaging with a dedicated phased array of surface coils

A phased array of surface coils was constructed for magnetic resonance imaging in three different regions in the brachial plexus. Four-coil subsets of the six-coil array were activated at any given time during imaging in three volunteers. An in vivo estimate of the signal-to-noise ratio (S/N) at three locations in the brachial plexus indicated that the phased-array coil provided a signal-to-noise ratio that was three to six times higher than that of the body coil.     

Diagnosis of intraductal spread of breast cancer by high-resolution MR imaging: correlation between MR imaging and pathohistological findings

The main purpose of this study was to investigate pathohistological factors that affect the MR findings of intraductal spread (IDS) of breast cancer. The subjects of the present study were 42 breast cancer patients who were examined by MR imaging. Fat-suppressed high-resolution T1-weighted spin-echo images [350/13/1 (TR/TE/excitations), 16-cm FOV, 5-mm section thickness, and 512 x 256 matrix] were obtained one minute after the intravenous administration of Gd-DTPA. In this protocol, contrast determination time was 1 min 48 sec. Of the 42 cases, IDS was found to be located more than 1 cm from the primary focus in 22 cases (52%). Rates of sensitivity, specificity and accuracy of MR imaging for the detection of IDS were 82%, 80%, and 81%, respectively. The probable cause of misdiagnosis was parenchymal enhancement due to severe fibrocystic disease and normal menstrual cycle. In 21 of 42 cases, the MR findings were precisely correlated with the pathohistologic findings of almost the same cross-section. The MR findings of IDS varied greatly with observation of linear, band-like, branch-like, plate-like and minute ring enhancements. These findings closely reflected the size, aggregation pattern, and distribution of intraductal lesions. In particular, minute ring enhancement was only observed in 4 comedo-type lesions. This pattern of enhancement is considered to reflect elevated intraductal cellular density with necrosis in the central region.     

Fibromyxoma of the retropharyngeal space: MR appearance with pathologic correlation

A 19-year-old woman reported difficulties in swallowing and breathing. A submucosal mass, shown by MR imaging in the retropharyngeal space, was the cause of her symptoms. Histologically, the mass proved to be a fibromyxoma. The oval well-delineated lesion appeared hypointense relative to muscle and strongly enhanced after injection of contrast material on T1-weighted images; on T2-weighted images, it appeared hyperintense, and was seen to contain fibrous septa, which were hypointense on all sequences. This case delineates the characteristic MR features of a fibrous component within a rare benign tumor of the retropharyngeal space.     

MR imaging of the anterior cruciate ligament: frequency of discordant findings on sagittal-oblique images and correlation with arthroscopic findings

OBJECTIVE: The purposes of this study were to determine the frequency of discordant MR findings of the anterior cruciate ligament (ACL) using sagittal-oblique images and the arthroscopic integrity of the ACL in knees with a discordant MR appearance. MATERIALS AND METHODS: The frequency of discordant MR features was determined by independently reviewing the sagittal-oblique images of 53 consecutive patients undergoing subsequent arthroscopic surgery. The first 25 consecutive knees were examined using a conventional, dual-echo, T2-weighted spin-echo (SE) sequence; the subsequent 28 consecutive knees were examined using both a T1-weighted SE(T1) and a fat-suppressed, fast spin-echo (FSE) T2-weighted sequence. Two examiners who were unaware of patient identification and arthroscopic results evaluated only the sagittal images that included the ACL. Each reviewer graded the ACL as torn or intact. The MR appearance was considered discordant when one MR sequence showed disrupted or poorly seen ACL fibers and the other sequence showed intact ACL fibers. The arthroscopic integrity of the ACL was determined for the 20 knees with a discordant MR appearance. RESULTS: A discordant MR appearance of the ACL was seen in 20 of the 53 knees (38%), including 10 knees evaluated using conventional T2-weighted sequences (40%) and 10 knees using T1/FSE T2 (36%) sequences. Arthroscopic examination of these knees showed intact ACL fibers in all 20 knees; the ACL was normal in 18 knees and a partial tear was questioned in two knees. CONCLUSION: A discordant appearance of the ACL was frequently encountered (38%) using either conventional T2-weighted sequences or T1 and FSE MR sequences in the sagittal-oblique plane. Intact ACL fibers were found during arthroscopy in all 20 knees with a discordant MR appearance.     

Arthritic temporomandibular joint: correlation of macromolecular contrast-enhanced MR imaging parameters and histopathologic findings

PURPOSE: To assess the utility of macromolecular contrast material-enhanced magnetic resonance (MR) imaging parameters for determining the histopathologic severity of temporomandibular joint (TMJ) arthritis. MATERIALS AND METHODS: Ovalbumin was used to induce arthritis in the TMJs of 10 previously sensitized adult white rabbits. Five rabbits composed the sham-treated control group. Dynamic spin-echo imaging was performed immediately before and for 30 minutes after injection of macromolecular contrast medium. Histologic specimens of TMJ were assessed quantitatively for arthritis. Changes in MR signal intensity were derived from the synovial and subsynovial tissues of the TMJ, and plasma volume (PV) and permeability surface area product (PS) were calculated. These MR parameters and the arthritic scores were compared between sham-treated and antigen-challenged TMJs. The relationships between MR parameters and histopathologic indexes were also determined. RESULTS: Arthritic TMJs showed marked enhancement of the synovial and subsynovial tissues over the imaging period. PS and all histopathologic indexes of arthritis were significantly greater (P < .005) in antigen-challenged than in sham-treated TMJs. PS demonstrated strong positive relationships with all histologic parameters of arthritis, indicating its utility for assessing the severity of joint inflammation. CONCLUSION: Macromolecular contrast-enhanced MR imaging enables quantification of PS and PV in inflamed joints. This technique may provide insights into the pathogenesis of joint inflammation and noninvasive monitoring of disease severity and treatment response in arthritis.     

Gorham disease: correlation of MR findings with histopathologic changes

Gorham disease is a rare disorder of unknown etiology characterized by bone destruction and abnormal proliferation of thin-walled vascular channels including lymphatic capillaries. Starting monocentrically in a single bone, the angiomatous masses in this disease extend to adjacent bones and soft tissues without respecting articular barriers. Herein we report a case of Gorham disease with its MR and histopathologic appearance.     

Normal uterus and FIGO stage I endometrial carcinoma: dynamic gadolinium-enhanced MR imaging

Dynamic magnetic resonance (MR) imaging was performed on a 1.5-T superconducting unit for evaluation of 26 stage I endometrial carcinomas. To establish the appearance of the normal uterus, 27 normal uteri were also evaluated. After rapid injection of gadopentetate dimeglumine, dynamic images were obtained every 30 seconds with the spin-echo technique in the sagittal plane. On dynamic studies of endometrial carcinoma, the tumor-myometrial contrast was marked at 120 seconds after administration of gadopentetate dimeglumine (contrast-to-noise ratio [C/N], 26.0). The tumor-myometrial contrast on the dynamic study was more marked than that on postcontrast T1-weighted images (C/N, 10.0) and on T2-weighted images (C/N, 2.14). Dynamic and postcontrast MR images were superior in enabling differentiation of viable tumors from necrosis or residual secretion in the endometrial cavity. In the evaluation of presence of tumor and myometrial invasion, the accuracy of T2-weighted imaging and dynamic imaging was 67.9% and 84.9%, respectively.     

Cavernous hemangioma of the liver: pathologic correlation with dynamic CT findings

Malignant mixed mesodermal tumors (MMMT) are the most malignant neoplasms known to occur in the uterus. The most important prognostic factors are the extent of tumor at diagnosis, depth of myometrial invasion, and, as regarded by some authors, the sarcomatous component. We report on a retrospective analysis in 83 patients with MMMT. By univariate analysis survival was dependent on stage, depth of myometrial invasion, kind of therapy, age at menopause, and parity. However, the sarcomatous component did not significantly influence survival. Using the multivariate Cox regression analysis stage and parity or depth of myometrial invasion and parity were found to independently predict prognosis. Despite an interval of more than 20 years from the last childbirth to tumor appearance a beneficial influence of parity on the prognosis of MMMT was identified. This is unique in oncology. Especially patients with more than three children formed a subgroup of long-term survivors. It is interesting to note that parity was found by means of a Cox regression analysis to be statistically independent, and no correlation with other classical prognostic factors was detected.     

Virtual colonoscopy: imaging features with colonoscopic correlation

BACKGROUND: We determined whether activation of the nitric oxide/cyclic guanosine monophosphate pathway by sodium nitroprusside (SNP) protects hearts subjected to cardioplegic arrest and prolonged hypothermic storage. METHODS: Isolated rat hearts arrested with St. Thomas' II cardioplegia and stored at 3 degrees +/- 1 degree C for 8 hours were reperfused at 37 degrees C in Langendorff (10 minutes) and working (60 minutes) modes. RESULTS: During reperfusion, left ventricular work was depressed in stored hearts relative to fresh hearts. When present during arrest, storage, and both reperfusion phases, SNP (200 mumol/L) improved work to values close to those in fresh hearts. When added only during the 10-minute period of Langendorff reperfusion, SNP also improved the subsequent recovery of work. This effect was antagonized by the soluble guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). Poststorage coronary perfusion was not increased by SNP. CONCLUSIONS: The ability of SNP to enhance recovery independent of changes in coronary perfusion and in an ODQ-sensitive manner suggests that SNP-induced protection is due to activation of the myocardial nitric oxide/cyclic guanisine monophosphate pathway. These results suggest that supplementing cardioplegic solutions with SNP, administering SNP during early reperfusion, or both may offer additional means to improve donor heart preservation.     

Early advanced hepatocellular carcinoma: evaluation of CT and MR appearance with pathologic correlation

PURPOSE: To determine the computed tomographic (CT) and magnetic resonance (MR) imaging appearances of early advanced hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-seven surgically resected cases of early advanced HCC were studied with CT, CT during arterial portography, CT arteriography, and MR imaging. RESULTS: The sensitivity of standard CT (unenhanced, early, and late CT combined) for the detection of early advanced HCC was 81%, while that of standard MR imaging (T1- and T2-weighted MR imaging combined) was 83%. A nodule-in-nodule appearance was identified in approximately one-third to one-half of cases. Signal behavior of early and advanced components of early advanced HCC followed the expected behaviors of isolated early HCC and isolated advanced HCC, respectively. Tumor size was accurately estimated with standard CT and standard MR imaging. CONCLUSION: More research must be performed to ascertain whether any relationship exists between the different types of HCC and the clinical outcome.     

High-resolution magnetic resonance imaging of articular cartilage: correlation with histology and pathology

Current explanations of the link between magnetic resonance (MR) images and cartilage histology are reviewed. The influence of the three-dimensional cartilage matrix structure on T2 decay is emphasized and illustrated through the use of MR microimaging, T2 mapping, and correlative scanning electron microscopy (SEM). Special emphasis is given to the topics of T2 heterogeneity and orientation anisotropy. Common degenerative changes in the structure and biochemistry of cartilage are discussed and illustrated with examples of MR microimaging and T2 quantification with correlative SEM and light microscopy.     

Thrombosis of the deep cerebral veins: CT and MRI findings with pathologic correlation

Deep cerebral vein thrombosis can present with acute, severe neurological symptoms and may be rapidly fatal as in the 20-year-old woman reported here. Although MRI is superior for establishing the diagnosis, CT is usually the first examination performed in the clinical setting. It is therefore important to recognise certain indicators such as extensive bithalamic low density. These and certain other less specific signs are correlated with the MRI and autopsy findings.