Cranial MR imaging in Wilson's disease

OBJECTIVE: The purpose of the study was to describe the range of abnormalities seen on cranial MR images of patients with Wilson's disease and correlate the findings with clinical severity, duration of disease, and duration of neurologic signs and symptoms before treatment. In those patients with serial studies, the changes on MR images were compared with the clinical response. SUBJECTS AND METHODS: Twenty-five patients with Wilson's disease underwent MR imaging of the brain using conventional spin-echo sequences (n = 25), phase maps (n = 8), and partially refocused interleaved multiple-echo sequences (n = 5). RESULTS: MR imaging findings were abnormal in 22 patients and normal in three patients. The basal ganglia were interpreted as abnormal in 19 (86%) of 22 patients, involving the putamen in 19 (86%), the thalami in 12 (54%), the caudate head in 10 (45%), and the globus pallidus in nine (41%). We found a predilection for involvement of the outer rim of the putamen and the ventral nuclear mass of the thalami. The claustrum was abnormal in three patients. The midbrain was abnormal in 17 (77%) of these 22 patients, affecting predominantly the tegmentum but also the substantia nigra, red nuclei, inferior tectum, and crura. The pons was abnormal in 18 (82%) of 22 patients, and the cerebellum was abnormal in 11 patients (50%), with involvement of the superior and middle cerebellar peduncles. Atrophy was present in 18 (82%) of 22 patients, and cortical white matter changes were apparent in 13 (59%) of 22 patients. The scan of one untreated patient revealed shortening of the T1 relaxation time in the thalami, which was consistent with the paramagnetic effects of copper. Phase maps and partially refocused interleaved multiple-echo sequences performed in eight and five patients, respectively, and used to reveal a susceptibility change induced by iron or copper showed normal findings. We found a significant inverse relationship between severity, but not extent, of change in signal intensity and the length of untreated disease (p = .030) and the total duration of disease (p = .015). The study group was too small to show a correlation with clinical findings. Changes seen on MR images matched the clinical response to treatment in only two of the seven patients who underwent follow-up studies. CONCLUSION: MR imaging revealed abnormalities in the basal ganglia, cerebral white matter, midbrain, pons, and cerebellum. The paramagnetic effects of copper were detected only in untreated patients. Patients with a longer duration of disease had less severe changes in signal intensity. MR imaging was of limited value in follow-up.     

MR imaging and cervical fixation devices: evaluation of ferromagnetism, heating, and artifacts at 1.5 Tesla

The purpose of this study was to assess ferromagnetism, heating, and artifacts for cervical fixation devices exposed to a 1.5 T MR system. Cervical fixation devices (three halos, one tong and two halo vests) were evaluated for compatibility with MR procedures. Ferromagnetism was determined using a previously described technique. Heating was evaluated by measuring temperatures at various positions on the cervical fixation devices while applied to a volunteer subject before and during the use of various pulse sequences, including an magnetization transfer contrast (MTC) sequence. Artifacts associated with routine clinical MR imaging of the cervical spine were qualitatively evaluated with the cervical fixation devices applied to a volunteer subject. None of the devices displayed attraction to the magnetic field. The temperature changes were +/-1.5 degrees C in each instance. The MTC pulse sequence produced a sensation of "heating" the skull pins that may have been caused by vibration of the cervical fixation device. The MR images of the cervical spine were obtained without apparent artifacts using each routine, clinical pulse sequence. The lack of ferromagnetism, negligible heating, and capability of obtaining diagnostically acceptable studies of the cervical spine indicate that MR imaging performed at 1.5 T or less may be conducted safely in patients with each of the cervical fixation devices tested using conventional pulse sequences.     

Chondroblastoma: classic and confusing appearance at MR imaging

PURPOSE: To define the characteristics of chondroblastoma at magnetic resonance (MR) imaging and the combination of findings that are diagnostic for chondroblastoma. MATERIALS AND METHODS: From January 1987 through December 1992, 22 patients with histologically confirmed chondroblastoma and prior MR imaging examinations were seen. Patients included 16 men and six women, aged 10-58 years (median, 17 years). Retrospective analysis of findings at MR imaging, plain radiography, computed tomography, and bone scanning was performed. RESULTS: Low to intermediate heterogeneous signal intensity, lobular internal architecture, and fine lobular margins were well defined with high-resolution T2-weighted (repetition time > or = 1,500 msec, echo time > or = 70 msec) MR imaging. Adjacent bone-marrow and soft-tissue edema and periosteal reactions were more dramatically demonstrated on MR images than on radiographs. Bone marrow edema was prominent in all but five cases. Obvious periosteal reaction and adjacent soft-tissue edema were visible in 17 cases. CONCLUSION: Knowledge of the MR imaging findings of chondroblastoma will allow accurate diagnosis and help avoid confusion with infection and aggressive neoplasms.     

Complications in Paget disease at MR imaging

PURPOSE: To determine the MR imaging findings in patients with complications of Paget disease of bone. MATERIALS AND METHODS: Of 45 patients with Paget disease who underwent MR imaging, 33 (26 men, seven women; age range, 64-91 years) with known complications of the disease were examined. Imaging in this subgroup included radiography (n = 26), computed tomography (n = 12), bone scintigraphy (n = 15), and magnetic resonance (MR) imaging (n = 33). Patients were examined specifically for musculoskeletal and neurologic complications of Paget disease, including fracture, basilar impression, spinal stenosis, bone tumor, and osteoarthrosis. RESULTS: The 56 complications documented in the 33 patients were fracture (n = 17), neurologic entrapment (n = 19), neoplasm (n = 9), and arthropathy (n = 11). MR imaging was beneficial in the diagnostic evaluation of basilar impression (n = 7), spinal stenosis (n = 12), and the tumor stage (n = 9). It also helped to successfully evaluate pagetic bone narrowing of the coracoacromial arch, which was associated with impingement syndrome and rotator cuff rupture (n = 2). The signal intensities in pagetic bone were most commonly similar to those in fat; this finding had a 100% negative predictive value in excluding neoplasm. CONCLUSION: Although Paget disease is diagnosed economically with conventional radiography, MR imaging is well suited for demonstrating the presence and extent of several characteristic disease complications, including basilar impression, spinal stenosis, and secondary neoplasm.     

Intraperitoneal abscesses: diagnostic accuracy of and appearances at MR imaging

PURPOSE: Transverse retubularization of small ileal segments has been described as a new time and labor saving variation of the Mitrofanoff principle in a dog model with good functional results. We report our initial clinical experience with this technique. MATERIALS AND METHODS: From May 1996 through January 1997 a new technique of channel formation for intermittent catheterization was applied in 9 children (1 to 16 years old) and 7 adults (18 to 56) with various abnormalities of the lower urinary tract. The new method was used in primary reconstruction of the lower urinary tract and in revision procedures. An ileal segment 2 cm. long was excised. The bowel wall was opened longitudinally about 1 cm. from the mesentery. The resulting rectangle was retubularized over a 14F catheter in transverse direction. The longer portion of the tube was implanted submucosally into the native bladder, the augmented bladder or an intestinal reservoir. The shorter portion was used to form the stoma. In 4 patients we created a double tube. RESULTS: Of the patients 13 (81%) are completely continent day and night with easy catheterization postoperatively. In 2 cases of tunnel failure continuous leakage required reimplantation of the intact ileal tube to achieve continence. Minor leakage with bladder fullness in an 11-year-old boy could be obviated by adjusting the interval of catheterization. CONCLUSIONS: With the advantage of constant availability, minimal loss of bowel, relative simplicity (no mesentery interfering with implantation, high tube mobility), minimized risk of stone formation (no staples), reliable continence (no leak point) and easy catheterization (longitudinal folds), this straightforward technique is an excellent second choice use of the Mitrofanoff principle.     

Aneurysm clips: evaluation of MR imaging artifacts at 1.5 T

PURPOSE: Endothelin-1 (ET-1), a peptide produced by the vascular endothelium, causes profound renal vasoconstriction by binding to ET-A receptors. The present study examined the renal actions of ET-1 after ET-A receptors were blocked by BE-18257B to unmask the functions of ET-B receptors. MATERIALS AND METHODS: Renal hemodynamics and clearance measurements were obtained in anesthetized dogs after intrarenal infusion of BE-18257B at 100 ng./kg./min. (Group 1), after intrarenal infusion of ET-1 at 2 ng./kg./min. (Group 2), or after intrarenal infusion of ET-1 superimposed on BE-18257B (Group 3). RESULTS: In Group 1, BE-18257B infusion did not alter arterial pressure, renal blood flow (RBF), GFR or tubular function. In Group 2, ET-1 infusion led to a significant decrease in RBF and GFR (37 and 40%, respectively) without altering arterial pressure. Urinary volume and sodium excretion were not changed but osmolality decreased significantly. In Group 3, BE-18257B infusion significantly attenuated the decrease in RBF caused by ET-1 and increased GFR by 40% without altering arterial pressure, associated with significant diuresis and natriuresis. CONCLUSION: Renal vasoconstriction caused by ET-1 is attenuated by ET-A receptor blockade with BE-18257B, which unmasks the hemodynamic and tubular actions of ET-B receptors. As a result, it limits the ET-1 induced decrease in RBF and raises GFR, and leads to a diuresis and natriuresis.     

Bone marrow necrosis in bone marrow transplantation: the role of MR imaging

We describe an ALL patient who developed extensive bone marrow necrosis at the time of relapse 2 months after allogeneic bone marrow transplantation from an HLA-identical sibling. The excruciating and diffuse bone pain, fever and precipitous drop in peripheral blood counts were characteristic. This case illustrates the importance of repeat bone marrow biopsies for the diagnosis of disease relapse and the potential application of MR imaging in the assessment of patients with bone marrow necrosis.     

MR imaging of edema accompanying benign and malignant bone tumors

To evaluate the incidence, quantity, and presentation of intra- and extraosseous edema accompanying benign and malignant primary bone lesions, the magnetic resonance (MR) studies of 63 consecutive patients with histologically proven primary bone tumors were reviewed. MR scans were assessed for the presence and quantity of marrow and soft tissue edema and correlated with peroperative findings, resected specimens and follow-up data. The signal intensity and enhancement of tumor and edema prior to and after intravenous administration (if any) of gadolinium-labeled diethylene triamine pentaacetate (Gd-DTPA) was analyzed. Marrow edema was encountered adjacent to 8 of 39 malignant tumors and 14 of 24 benign lesions. Soft tissue edema was found accompanying 28 of 39 malignancies and 10 of 24 benign disorders. On unenhanced T1-weighted MR images tumor and edema were difficult to differentiate. Tumor inhomogeneity made this differentiation easier on T2-weighted sequences. In 36 patients the contrast medium Gd-DTPA was used. Edema was present in 27 of these patients and the respective enhancement of tumor and edema could be compared. Edema always enhanced homogeneously, and in most cases it enhanced to a similar degree as or more than tumor. Marrow and, more specifically, soft tissue edema is a frequent finding adjacent to primary bone tumors. The mere presence and quantity of marrow and soft tissue edema are unreliable indicators of the biologic potential of a lesion. Unenhanced MR scans cannot always differentiate between tumor and edema, but the administration of Gd-DTPA is of assistance in differentiating tumor from edema.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diffusion-weighted MR imaging of bone marrow: differentiation of benign versus pathologic compression fractures

A sensitive and specific assay aimed at measuring 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) has been developed by associating a reversed-phase liquid chromatographic separation with an electrospray tandem mass spectrometric detection. The HPLC-MS approach in the single ion monitoring (SIM) mode and the HPLC-MS/MS assay in the multiple reaction monitoring (MRM) mode have been compared, using isotopically labeled [M+4] 8-oxodGuo as the internal standard. The limit of detection of 8-oxodGuo was found to be around 5 pmol and 20 fmol for the HPLC-MS and HPLC-MS/MS methods, respectively. The HPLC-MS/MS assay is sensitive enough to allow the determination of the level of 8-oxodGuo in cellular liver DNA and in urine samples.     

Collision tumors of the adrenal gland: demonstration and characterization at MR imaging

PURPOSE: To evaluate the magnetic resonance (MR) imaging findings in collision tumors of the adrenal gland. MATERIALS AND METHODS: MR images obtained in 104 patients with a known primary malignant tumor and an adrenal mass were reviewed to find adrenal glands that contained two contiguous but histologically distinct masses. The findings in such cases were correlated with histopathologic findings. RESULTS: In two (2%) cases, both MR and histopathologic findings showed a mass within the adrenal gland that consisted of contiguous adrenal adenoma and metastasis, which represented a collision tumor. The adenomatous component in each tumor showed a (quantitative) decrease in signal intensity relative to that of the liver (79% and 61%) on opposed-phase images, whereas the metastatic component showed an increase in signal intensity (50% and 15%). Similarly, the adrenal lesion-to-spleen signal intensity ratio on opposed-phase images was lower for the adenomatous component in each (0.39 and 0.43) than for the metastatic component (1.17 and 0.90). CONCLUSION: MR imaging can demonstrate and enable characterization of the separate components of collision tumors within the adrenal gland. These findings can be crucial in planning and guiding subsequent percutaneous needle biopsy and patient care.     

Hepatic lesion detection at MR imaging: a comparative study with four sequences

PURPOSE: To compare results with the following magnetic resonance (MR) imaging sequences in the detection of focal hepatic lesions: fast spin-echo (SE) before and after administration of superparamagnetic iron oxide (SPIO) particles, fat-suppressed T2-weighted SE, and dynamic gadolinium-enhanced fast low-angle shot (FLASH). MATERIALS AND METHODS: In 26 patients with known malignancy and documented focal liver lesions, 1.0-T MR imaging was performed prior to hepatic resection. All images were reviewed independently by four blinded observers. Sensitivity was calculated for each sequence and for each observer by means of alternative-free-response receiver operating characteristic (ROC) methods. RESULTS: The mean area under the alternative-free-response ROC curve with SPIO-enhanced fast SE (0.85) was significantly greater (P < .02) than that with all other sequences. Detection was significantly improved with SPIO-enhanced fast SE compared with dynamic gadolinium-enhanced FLASH (which was the best of the other three sequences) for all lesions (P < .002) and for malignant lesions (P < .0002). CONCLUSION: Findings with the SPIO-enhanced fast SE sequence improved detection of focal liver lesions and had the highest diagnostic accuracy.     

Peroneus quartus muscle: MR imaging features

PURPOSE: To determine the prevalence of the peroneus quartus (PQ) muscle, to demonstrate the morphology of this accessory muscle on magnetic resonance (MR) images, and to reassess the reported association of the PQ muscle with a hypertrophic peroneal tubercle. MATERIALS AND METHODS: A retrospective review was performed of 136 consecutive ankle MR imaging studies. The origins, insertions, and variations in size of the muscle and the dimensions of the peroneal tubercle and retrotrochlear eminence were recorded. RESULTS: The prevalence of the PQ muscle was 10% (14 of 136 cases). The accessory muscle and tendon unit descended medial and posterior to the peroneal tendons. The site of insertion was variable and included the calcaneus, peroneus longus tendon, peroneus brevis tendon; and cuboid bone. The calcaneus was the insertion site in 11 cases. The accessory tendon attached to the retrotrochlear eminence of the calcaneus. In the group with the PQ muscle, the retrotrochlear eminence was significantly taller (P < .01) than in the group without the PQ muscle. CONCLUSION: Contrary to previous reports, the peroneocalcaneal variant of the PQ muscle appears to insert in the retrotrochlear eminence of the calcaneus rather than the peroneal tubercle. The presence of the PQ muscle is associated with a prominent retrotrochlear eminence but not with an enlarged peroneal tubercle.     

Normal placenta: gadolinium-enhanced dynamic MR imaging

PURPOSE: Many patients with urological disease do not speak English. In medical studies restricting patients to those who speak only English undermines efforts to understand disease because restrictions decrease efficiency of patient recruitment, and because language and culture are associated with variable outcomes. In Spanish speaking locations, such as South Florida, studies would suffer severe selection bias if patients were required to speak English. To allow grouping in future studies of English and Spanish speaking patients we examined the English-Spanish reliability of select instruments that measure health related quality of life in patients with urological disease. MATERIALS AND METHODS: We assembled available Spanish versions and translated English versions of questions regarding satisfaction, the American Urological Association symptom index, the University of California, Los Angeles Prostate Cancer Index and a pain inventory. We then examined English-Spanish reliability by asking bilingual men 50 years old or older to complete English and Spanish versions at the same sitting. A convenience sample was recruited from outpatients and volunteers at the Miami Veterans Affairs Medical Center and population based subjects living in largely Hispanic Hialeah, Florida. Reliability estimates were calculated with kappa coefficients for categorical data and intraclass correlation coefficients for quantitative data. RESULTS: A total of 100 subjects a median of 59 years old completed the questionnaire, including 55 born in Puerto Rico or Cuba, while the remainder were born at various sites throughout the Americas and Spain. Reliability estimates showed that kappa = > 0.81 for almost all items. For 2 items relating to health and social interactions reliability was poor, and stratification showed that poor reliability was primarily a feature of subjects in good health who are theoretically socially active. CONCLUSIONS: Almost all items tested have excellent English-Spanish reliability in a mixed sample of bilingual men. Nonreliability of 2 items relating to health and social interactions probably originates from the effect of language on perception, and invalidates English and Spanish grouping of these items. Because the sample represents many dialects of Spanish, the translations tested may be transported to other cities. In studies that use these instruments investigators can reasonably group answers from English and Spanish speaking study subjects or study the effects of acculturation on quality of life.     

Breast disease: dynamic spiral MR imaging

The cochleo- and tonotopic organization of the second auditory area (AII) was investigated in cats anaesthetized with pentobarbital using a combination of macro- and microelectrode recording technique. The results obtained following electrical stimulation of the neural fibres innervating different regions of the organ of Corti indicate the existence of two complete representations of the cochlea in area AII: one in the dorsocaudal portion, the other in its ventrorostral portion. These two cortical representations of the cochlea differ in size and spatial orientation. The dorsocaudal projection area extends over a distance of 2.6-3.2 mm from the basal to the apical focus and is arc-shaped. The spatial orientation of cochlea representation within the dorsocaudal region of AII is similar to that described in AI, in that stimulation of the cochlea base results in maximal responses in the more rostral portion of AII and stimulation of the apex evokes cortical responses more caudally. The ventrorostral region within AII is smaller (1.4-2.5 mm length), and has the opposite cochleotopic orientation (base and apex stimulation represented caudally and rostrally, respectively). In both AII zones, there was a proportionally greater cortical representation of basilar membrane than of middle and apical portions. Although two distinct zones with the overall cochleotopic pattern described above were noted in all cats, their precise size and location considerably varied in different animals. Using microelectrode recordings, a cortical tonotopic organization can be observed that was consistent with and expanded on the earlier cochleotopic data. Within the dorsocaudal region of AII, neurons with higher best frequency responses were located in more rostral regions, while those with lower best frequencies were located caudally. An orderly progression of best frequency responses was noted as serial recordings carried out along the full extent of the representation. Neurons within the ventrorostral region of AII also displayed an orderly progression of best frequencies, but in the opposite direction, with higher best frequencies noted more caudally and lower best frequencies more rostrally.     

Dilated fallopian tubes: MR imaging characteristics

A complex of four proteins isolated from neuronal membranes has ligand binding sites for N-methyl-d-aspartate (NMDA) receptor agonists and antagonists and forms NMDA-activated ion channels upon reconstitution into lipid membranes. In this study, the cDNA of a subunit of this complex containing binding sites for the competitive antagonists of NMDA receptors was cloned. The cDNA clone coded for a protein of 719 amino acids (78.9 kDa). The expressed protein had binding activity for the agonists l-[3H]glutamate and [3H]glycine, the antagonist (+/-)-[3H]-(E)-2-amino-4-propyl-5-phosphonopentanoic acid ([3H]CGP 39653), but not the ion channel inhibitors. The cloned cDNA had no homology to other cloned cDNAs. Northern blot analyses indicated high expression of an 3.8 kb poly(A+) RNA in brain, but not in other tissues. These findings indicate that proteins that have recognition sites for NMDA receptor activators and inhibitors and that differ from the well-characterized NMDA receptor proteins NR1-3 are expressed in mammalian brain.     

Adrenal adenoma and hematoma mimicking a collision tumor at MR imaging

Fas ligand (FasL), a cell surface molecule belonging to the tumor necrosis factor family, binds to its receptor Fas, thus inducing apoptosis of Fas bearing cells. In the present study we assessed the expression of Fas, activation molecule interleukin (IL)-2 receptor alpha chain (CD25) and an index of functional activity such as thymidine uptake under mitogen stimulation of tumor associated lymphomonocytes (TALM) from 7 neoplastic effusions of advanced cancer patients. The same parameters were studied in peripheral blood mononuclear cells (PBMC) of 7 patients with cancer of different sites and in 7 normal subjects. The proliferative response to phytohemagglutinin (PHA), measured as [3H]-thymidine uptake, of TALM was significantly lower than that of PBMC of cancer patients. The expression of CD25 on unstimulated fresh TALM was slightly higher than that of PBMC from normal subjects: after 24 h of PHA stimulation the CD25 was expressed both on TALM and PBMC from normal subjects. The expression of Fas was assessed on unstimulated TALM, PBMC from cancer patients and normal subjects immediately after (by 2 h, t0) the cell separation, and at different times (24 h and 48 h) thereafter, and on PHA-stimulated TALM, PBMC from cancer patients and normal subjects after 24 h and 48 h of culture (in RPMI 1640). At all times (t0, 24 h and 48 h) the Fas expression by unstimulated TALM was significantly higher than that of PBMC from normal subjects: the Fas expression by PBMC from cancer patients was roughly in the same range as PBMC from normal subjects. At 24 h the Fas expression by PHA-stimulated TALM was significantly higher than that of PBMC from normal subjects, whereas at 48 h the difference was not significant. The TALM studied by us showed to be functionally defective and expressing relatively high levels of Fas showing the characteristics to be considered as a target for FasL expressing tumor cells, which in this way may escape immune control.     

The normal and pathologic ischiorectal fossa at CT and MR imaging

A wide spectrum of disease processes involve the ischiorectal fossa, including congenital and developmental lesions; inflammatory, traumatic, and hemorrhagic conditions; primary tumors; and pathologic processes outside the ischiorectal fossa with secondary involvement. Both computed tomography (CT) and magnetic resonance (MR) imaging are useful in the definitive diagnosis of these pathologic conditions, with MR imaging being the modality of choice because of its superior contrast resolution and multiplanar capability. In Gartner duct cyst, both CT and MR imaging demonstrate a well-defined, round mass; in tailgut cyst, CT demonstrates a well-defined retrorectal mass with a solid or cystic appearance. MR imaging in particular plays a major role in the assessment of fistula in ano, infection, and hematoma. Lipoma and pelvic plexiform neurofibroma typically have low attenuation and high signal intensity at CT and MR imaging, respectively. Recurrent rectal tumor appears at both modalities as an irregular soft-tissue mass with or without central necrosis in the presacral space, perineum, or pelvic sidewall. Familiarity with the imaging features and differential diagnoses of various ischiorectal pathologic processes will facilitate prompt, accurate diagnosis and treatment.     

Cognitive stimulation with the Wisconsin Card Sorting Test: functional MR imaging at 1.5 T

Recent studies using interleukin (IL)-4-deficient animals have highlighted the existence of IL-4-independent immunoglobulin (Ig)E induction. We have established transgenic mice expressing IL-13 from a transgene comprising a genomic fragment containing the IL-13 gene and the human CD2 locus control region. The transgenes were expressed in lymphoid tissues and induced by T cell activators, suggesting regulation by elements of the IL-13 promoter. IL-13 transgenic lines expressed 10-100-fold higher levels of serum IgE than their littermate controls, but had normal levels of other serum Ig isotypes. Elevated IgE levels were also detected in sera from IL-4-deficient mice carrying IL-13 transgenes, indicating that IL-4 is not required for IL-13-induced IgE expression in the mouse. Expression of IL-13 also perturbed the development of thymocytes. Although thymocyte development was normal up to 4 wk of age, thymocyte number decreased dramatically thereafter, reaching 10% of normal by 10 wk, and despite normal size and appearance, histological examination demonstrated that transgenic thymi contained only small foci of thymocytes. The reduction in thymocyte number was due mainly to a depletion of CD4(+)CD8(+) thymocytes, and did not affect significantly the composition of peripheral T cell populations. These data indicate that expression of IL-13 transgenes in vivo can regulate IgE production in the mouse, and that IL-13 may also influence thymocyte development.