Rheumatoid nodules: MR/pathological correlation

A 62-year-old female who had a complaint of palpitation was diagnosed as bicuspid aortic stenosis and left single coronary artery by the echocardiographic examination, cardiac catheterization study and coronary artery angiography. Aortic valve replacement was performed and the patient was discharged 22 days after surgery with good post-operative course. Preoperative coronary artery angiography was important in the case of aortic valvular disease.     

Bone SPECT imaging of vertebral hemangioma correlation with MR imaging and symptoms

To evaluate the bone SPECT findings of vertebral hemangioma and their relationship to symptoms and MRI findings, the authors reviewed planar and SPECT bone scans and MR images of 15 vertebral hemangioma in 10 patients. All planar bone scan images demonstrated normal findings, except one, SPECT images demonstrated normal findings in 11 vertebral hemangioma less than 3 cm in diameter. Three of four vertebral hemangioma that were 3 cm or larger showed abnormally increased or decreased uptake on SPECT images. There was a disparity between SPECT imaging and MRI.     

Multicoil MR imaging of symptomatic female urethral and periurethral disease

High-resolution magnetic resonance (MR) imaging with phased-array pelvic and endorectal coils has dramatically enhanced the ability to visualize abnormalities of the female urethra and periurethral tissues. These include developmental abnormalities (eg, urethral duplication, ectopic ureterocele), benign processes (eg, urethral diverticulum, caruncle, leiomyoma, trauma, and fistula; stress incontinence; paravaginal cyst), and malignant processes (eg, primary urethral carcinoma, secondary urethral malignancies). High-resolution MR imaging can be used to assess complications such as fistula formation and periurethral abscess, localize various entities, exclude pathologic processes whose presence could lead to an incorrect diagnosis, differentiate processes that might be confused at physical examination, and contribute to surgical planning and facilitate surgical correction.     

MR imaging of idiopathic trigeminal neuralgia: correlation with non-surgical therapy

Urinary drainage by indwelling double J ureteral stent is well documented in the urologic literature. We used these stents in 91 patients. The majority of stents were placed endoscopically (68%). Indications were: -Ureteral obstruction (39 cases) such as tuberculous ureteral strictures, obstruction due to urolithiasis and pelvic malignancies. -Upper urinary tract surgery (29 cases) mainly pyeloplasty, pyelolithotomy, ureterovaginal fistula repair and ureteroneocystostomy. -Adjunct to endourologic treatment (16 cases) such as ureteroscopy and endopyelotomy. -Preparation for extracorporeal lithotripsy (7 cases). The complication rate associated with placement of double J stents was minimal (6.6%). The major complication was migration (3 cases). The average drainage time was 5.8 weeks. In view of these results we conclude that double J stent is safe, effective and has minimal complications.     

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.     

MR imaging of the adrenal gland: radiologic-pathologic correlation

Complex physiologic and neoplastic processes affect the adrenal glands. An appreciation of the gross pathologic and histologic correlates of disease aids in understanding the mechanisms by which diagnostic imaging helps characterize adrenal masses. Computed tomographic (CT) densitometry and chemical shift magnetic resonance (MR) imaging would seem to be the most reliable tools in determining whether a given adrenal mass is specifically an adenoma. Such a determination is made on the basis of the presence of substantial amounts of intracytoplasmic lipid. Thus, although a homogeneous mass with a CT attenuation of less than 10 HU or a decrease in signal intensity at opposed-phase MR imaging is diagnostic for adenoma, lesions that do not have these features are indeterminate and may necessitate biopsy. Adrenal myelolipoma also has a distinctive imaging appearance that reflects the presence of macroscopic fat deposits. Diagnosis of adenoma or adrenal myelolipoma is very helpful in the assessment and treatment of asymptomatic patients with adrenal masses and may make biopsy unnecessary. In patients with clinical or biochemical evidence of adrenal disease, MR imaging helps confirm the presence of a mass and allows localization and further characterization of the lesion.     

High-resolution MR imaging of stage I cervical neoplasia with a dedicated transvaginal coil: MR features and correlation of imaging and pathologic findings

OBJECTIVE: The purposes of this study were to assess the appearance of stage 1 neoplasia of the cervix by high-resolution MR imaging with an enveloping transvaginal receiver coil and to correlate the imaging findings with the pathologic findings. SUBJECTS AND METHODS: Fifteen patients (25-73 years old; mean, 40 years old) with clinical stage I disease were examined with a 37-mm-diameter ring-design solenoid receiver coil placed around the cervix. Axial 2.5-mm contiguous slices were obtained with a field of view of 10-15 cm on a 1.0-T HPQ Vista scanner with T1-weighted (660/20 msec [TR/TE]) and T2- weighted (2500/80 msec) spin-echo sequences and dynamic gradient-echo sequences during injection of gadopentetate dimeglumine (0.1 mmol/kg). Ten patients subsequently underwent Wertheim's hysterectomy, two underwent radiotherapy, two underwent extended cone biopsy for microinvasive disease, and one underwent a punch biopsy. For seven of 10 patients who had a hysterectomy, the widths of the tumor and the residual stroma were measured at eight radial points on the transverse images and at corresponding points on the histologic specimens at 5, 10, 15, 20, and 25 mm from the ectocervix. We then compared the widths of the tumor and the stroma on images and histologic specimens at each of these 40 points. Tumor volumes were calculated from the MR imaging and pathologic data and compared. For the other three patients, detailed MR imaging-pathology correlation was not possible because of multifocal tumor distribution (two patients) and insufficient detailed pathologic data (one patient). RESULTS: Three carcinoma types were recognized. Squamous carcinoma (nine cases) was seen as a centrally expanding intermediate-signal-intensity mass, whereas oat (small)-cell carcinoma (one case) and clear-cell carcinoma (one case) showed a multifocal distribution. For patients who had a radical hysterectomy, we noted good agreement between the widths of the tumor and the stroma determined by MR imaging and histology. Tumor volumes were determined to be 0-28.2 cm3 by MR imaging and 0-18.4 cm3 by pathology. We observed tumor extension into the immediate parametrium in four patients by MR imaging; one of these cases was not confirmed at surgery. Parametrial extension was not underestimated by MR imaging in any case. CONCLUSION: High-resolution imaging of the cervix with a transvaginal coil provides accurate assessment of the intra- and extracervical extents of tumors in clinical stage 1 cervical neoplasia.     

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.     

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.     

A comparative study of postmortem MR imaging and pathological examination of human brain specimens

OBJECTIVE: To determine typical outcome "benchmarks" for 18 functional tasks in patients undergoing stroke rehabilitation. The benchmarks are intended to serve as points of reference to which the outcomes of patients with similar impairments and degrees of disability can be compared. SUBJECTS: Records from 26,339 stroke patients discharged from 252 inpatient facilities across the United States that submitted 1992 data to the Uniform Data System for Medical Rehabilitation. METHODS: Stroke impairment was detailed as the presence or absence of hemiparesis resulting from stroke and the side(s) of involvement. Within each of five stroke impairment categories, patients were further classified by the Functional Independence Measure-Function-Related Groups (FIM-FRGs) into nine syndromes by degree of disability (admission motor and cognitive FIM scores) and by age. Outcomes were determined for each stroke syndrome at patients' discharge from medical rehabilitation. MAIN OUTCOME MEASURES: Patients' median performance levels on each of the 18 items making up the FIM, length of stay, and community discharge rates. RESULTS: The majority of patients whose admission motor FIM scores were above 37 were able to eat, groom, dress the upper body, and manage bladder and bowel functions independently by discharge. In addition to these tasks, most of those whose motor FIM scores were above 55 were able to dress the lower body, bathe, and transfer onto a chair/bed or toilet. The majority of patients whose initial motor FIM scores were above 62 points and whose cognitive FIM scores were above 30 gained independence in most tasks, including stair climbing and tub transfers. Community discharge rates ranged from 51.6% for the group of patients with the most severe disabilities to 99.2% for the group with the least severe disabilities. CONCLUSION: The clinician can apply these benchmarks to guideline development and quality improvement, and in establishing patient goals.     

Hepatocellular carcinoma: evaluation with dynamic and static gadobenate dimeglumine-enhanced MR imaging and histopathologic correlation

PURPOSE: To analyze the potential of gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging for the characterization and diagnosis of hepatocellular carcinoma (HCC) by using static and dynamic sequences. MATERIALS AND METHODS: Twenty-eight patients with histopathologically proved HCC were evaluated with T1- and T2-weighted spin-echo and static and dynamic gradient-echo sequences before, during, and after intravenous administration of 0.1 mmol/kg gadobenate dimeglumine (0.5 mol/L). RESULTS: During the perfusion phase of the dynamic sequence, all 16 nodular well-differentiated HCC lesions showed a rapid increase in signal intensity 10-30 seconds after injection followed by a progressive decrease in signal intensity. The nine poorly differentiated HCC lesions showed no rapid increase in signal intensity. All eight large (> 3 cm), nodular, well-differentiated HCC lesions showed a hypointense rim before injection and both hypo- and hyperintense rims (double-ring sign) immediately after injection, compared with normal liver parenchyma. About 55 seconds after injection, substantial single-rim enhancement was detected in 21 of the 28 HCC lesions. CONCLUSION: Dynamic gadobenate dimeglumine-enhanced MR imaging allows improved characterization of HCC lesions, which show rapid increase in signal intensity during the early, arterial phase in well-differentiated HCC lesions and a double-ring sign in large well-differentiated nodular HCC lesions.     

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.     

Hyperparathyroidism--comparison of flash imaging with spin echo MR imaging

MR images of the neck were prospectively studied in 19 patients with hyperparathyroidism. Fast low angle shot (FLASH) sequence was performed in addition to T1- and T2-weighted spin echo (SE) sequences. FLASH images were obtained with 320/12/20 degrees (TR/TE/flip angle) using presaturation technique. TE of 12 ms was chosen to eliminate high signal of fat tissue. In the evaluation of detectability, a combination of T1-weighted SE and FLASH images (T1WI + FLASH) was compared with a combination of T1- and T2-weighted SE images (T1WI + T2WI). MR imaging correctly depicted 20 of 30 abnormal glands on both T1WI + FLASH and T1WI + T2WI. FLASH imaging effectively eliminated high signal of fat tissue. Nineteen abnormal glands demonstrated higher signal than surrounding tissues on FLASH images, whereas 12 glands were high-intense on T2-weighted SE images. We conclude that FLASH imaging provides improved tissue contrast and anatomic delineation and, thus, may replace T2-weighted SE imaging in the neck.     

Severe occlusive carotid artery disease: hemodynamic assessment by MR perfusion imaging in symptomatic patients

BACKGROUND: The purpose of this study was to assess the capability of magnetic resonance imaging (MRI) and cytology and flow cytometric (FCM) deoxyribonucleic acid (DNA) analysis in fine-needle aspiration biopsy (FNAB)-derived materials for diagnosing malignancy of the parotid lesions and the efficacy of FCM analysis in FNAB. METHODS: Magnetic resonance imaging findings and FCM results (ploidy and S + G2 + M phases [S + G2M] fraction) and cytology in FNAB-derived materials in 26 patients with 26 parotid lesions (12 benign lesions, 14 malignancies) were assessed for predicting malignancy. Flow cytometric results in aspirates were compared with those in surgically resected tissues. RESULTS: When a single predictor was used, cytology (92% accuracy) was most accurate for malignancy, followed by ill-defined margin (88% accuracy) and aneuploidy (88% accuracy). The combination of FCM and cytology raised the rate of sufficient materials from 92% to 100% and accuracy from 92% to 96% compared with cytology alone. The same highest accuracy (96%) was obtained with the combination of the ill-defined margin or other findings such as cytology, aneuploidy, or a high (S + G2M) fraction (6% <). Deoxyribonucleic acid ploidy in the FNAB showed full agreement with that in the surgical specimens. Receiver operating characteristic curves showed that the diagnosis of malignancy with (S + G2M) fraction in FNAB was superior to that in surgical specimens, but no significant difference was noted. CONCLUSIONS: A combination of MRI findings, cytology, and FCM results is optimal for diagnosing malignancies of the parotid lesions, and FNAB may replace the surgical specimens in FCM analysis.     

MR imaging

MRI is a tool of unprecedented capabilities for evaluating arthritis and its progression. Not only can it non-invasively delineate the anatomy of all components of a joint with unparalleled clarity, MRI is also capable of probing important functional and compositional parameters of disease in these tissues. Particularly intriguing is MRI's potential for identifying very early changes of joint disease when clinical symptoms may be minimal or absent. Early detection of patients who are at risk for developing progressive disease may allow appropriate treatment to be initiated earlier, when there may be a greater chance of favourable outcome. MRI can, furthermore, provide objective and quantitative measures of disease progression and treatment response. Certain parameters, such as articular cartilage volume, have been validated cross-sectionally; however, their longitudinal performance has yet to be established. Further work is, therefore, necessary to thoroughly validate and optimize some of these measures so that they can begin to be used in more powerful ways to explore the pathophysiology and potential therapies of arthritic disorders.     

Intravascular MR imaging of atherosclerotic plaque: ex vivo analysis of human femoral arteries with histologic correlation

Protein tyrosine phosphorylation was examined on a human glioblastoma cell line, T98G, after exposure to oxidative stress in vitro. Hydrogen peroxide (1 mM) markedly induced tyrosine phosphorylation of a 125 kDa protein at 30 min after stimulation. The 125-kDa molecule phosphorylated was revealed to be a focal adhesion kinase (FAK). Tyrosine phosphorylation of p125FAK continued at least up to 5 h, and decreased after 8 h concomitant with apoptosis. Tyrosine phosphorylation of p125FAK was blocked by herbimycin A, a potent inhibitor of protein tyrosine kinases, while apoptosis was accelerated. When T98G cells were incubated with FAK antisense oligonucleotide, apoptosis was also accelerated. These results suggest that tyrosine phosphorylation of p125FAK plays a suppressive role in hydrogen peroxide-induced apoptosis.     

MR imaging in patients with strabismus

The patients with strabismus, including 8 with superior oblique paresis, 1 with inferior rectus paresis, and 1 with congenital constant exotropia, were examined with MR imaging at 1.5 tesla (T) or 0.5T with a surface coil. Abnormal findings of extraocular muscles were identified in 8 of the 10 patients and most of them were consistent with the clinical findings. Deviation of the optic nerves was noted in 5 patients. Coronal short repetition time (RT) and echo time (ET) images were used to measure the concerned extraocular muscles and the optic nerves. The differences in diameters between the concerned extraocular muscles of both the diseased and normal eyes were calculated. MR imaging is considered to be advantageous and can be favorably used to observe and measure the extraocular muscles and other intraorbital structures in patients with strabismus.     

Diagnosis of bronchial rupture with MR imaging

Tracheobronchial rupture is a serious injury occurring in approximately 1.5% of cases of major chest trauma. This injury is associated with significant mortality and morbidity and may be difficult to recognize both clinically and radiologically. Radiologic signs are mostly nonspecific, with pneumothorax and pneumomediastinum being the most common. A high level of suspicion is required to make the diagnosis. Computed tomography (CT) can be helpful; however, it provides only indirect evidence for the diagnosis. This report describes a case of complete transection of the right main bronchus, suspected at plain radiography and CT and clearly shown on magnetic resonance (MR) images. MR imaging, with its multiplanar capabilities, can be helpful in defining the location and extent of injury and in diagnosing injury not suspected or clearly demonstrated with other imaging modalities.