Degeneration of patellar cartilage in patients with recurrent patellar dislocation following conservative treatment: evaluation with delayed gadolinium-enhanced magnetic resonance imaging of cartilage.

OBJECTIVE: To examine the characteristics of cartilage degeneration in patients with recurrent patellar dislocation (RPD) following conservative treatment using delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC). DESIGN: This study evaluated three groups of knees: group I, 35 knees from both knees of patients with bilateral RPD and dislocated side knees of patients with unilateral RPD; group II, 15 non-dislocated side knees of patients with unilateral RPD; and group III, 20 knees from both knees of healthy volunteers. Differences in post-contrast T1 [T1(Gd)] of cartilage at both medial and lateral facets between groups I, II and III were analyzed. For group I, possible relationships were evaluated between T1(Gd) of cartilage and patient age, length of time between the initial dislocation and MRI and the total number of dislocations between the initial dislocation and MRI for both medial and lateral facets. RESULTS: The mean T1(Gd) of cartilage at medial facets for groups I, II and III were 411+/-46ms, 465+/-38ms and 490+/-29ms, respectively; there were significant differences between these means (P<0.05). The mean T1(Gd) of cartilage at lateral facets for groups I, II and III were 426+/-53ms, 466+/-45ms and 510+/-36ms, respectively; there were also significant differences between these means (P<0.05). Significant correlations were observed between T1(Gd) of cartilage for both medial and lateral facets and length of time between the initial dislocation and MRI (P<0.05). No other correlations were significant. CONCLUSION: dGEMRIC may be a useful method to monitor glycosaminoglycan concentration in patients with RPD following conservative treatment.

Visualization of in vivo electroporation-mediated transgene expression in experimental tumors by optical and magnetic resonance imaging.

In vivo electroporation (EP) is an efficient method for effective gene transfer and is highly expected for application in anticancer gene therapy. Non-invasive monitoring of gene transfer/expression is critical for optimal gene therapy. Here we report in vivo optical and high-field magnetic resonance imaging (MRI) of EP-mediated transgene expression in a tumor model. Initially, we observed spatio-temporal change in in vivo EP-mediated transgene expression by optical imaging using red fluorescence protein (RFP) as a reporter gene. Next, we constructed a dual-reporter plasmid carrying a gene-encoding MRI reporter ferritin heavy chain and RFP gene to visualize the intratumoral transgene expression by dual modality. Cells transfected with this plasmid showed lower signal intensity on in vitro T(2)-weighted cellular MRI and quantitatively increased the transverse relaxation rate (1/T(2)) compared with control cells. After conducting in vivo EP in an experimental tumor, the plasmid-injected region showed both fluorescent emissions in optical imaging and detectably lowered signal on T(2)-weighted MRI. The correlative immunohistological findings confirmed that both the reporter transgenes were co-expressed in this region. Thus, our strategy provides a platform for evaluating EP-mediated cancer gene therapy easily and safely without administering contrast agent or substrate.

Proton magnetic resonance imaging of flow motion of heavy water injected into a hollow fiber dialyzer filled with saline.

Observations using MRI were performed for the motion of heavy water injected into a hollow fiber dialyzer. A cylindrical dialyzer houses a bundle of 10,000 hollow fibers. Because blood components permeate through the hollow fiber membrane from the interior to the exterior of the hollow fiber, which is the dialysate flow path, uniformity of dialysate flow is required. The dialyzer was initially filled with saline and heavy water was injected into the inlet port of the dialysate flow path. MRI tuned for protons could distinguish the injected heavy water from the already present saline. Due to the specific gravity difference, MRI could observe the sedimentation of the injected heavy water flowing beneath the already present saline. The uniformity of the dialysate flow was supported by the finding that the injected heavy water brought about uniform sedimentation and distributed the already present saline uniformly throughout the entire volume of the dialyzer.

Detection of small degree of nonuniformity in dialysate flow in hollow-fiber dialyzer using proton magnetic resonance imaging.

A small degree of nonuniformity in dialysate flow in a hollow-fiber dialyzer was detected using proton magnetic resonance imaging (MRI). Since paramagnetic ions reduce the spin-lattice relaxation time of protons around them, MRI can detect Gd in water. An aqueous solution of a chelate compound of Gd was impulsively injected into the dialysate flow path at a flow rate of 500 cm(3) /m, which is that utilized in actual dialysis. Despite the apparent elimination of Gd from the dialysate flow path by the newly injected dialysate fluid after the injection of Gd was terminated, MRI revealed that Gd remained in the interior of the hollow fiber. The observed structure pattern of the Gd concentration profile revealed that the dialysate flow had a small degree of nonuniformity despite the currently established design to restrict channeling in dialysate flow. Local nonuniformity of the hollow-fiber density and vortex generation in the dialysate flow were considered to cause the nonuniformity in the dialysate flow.

Distinctly abnormal brain metabolism in late-onset ornithine transcarbamylase deficiency.

OBJECTIVE: To assess alterations in brain metabolites in patients with late-onset ornithine transcarbamylase deficiency (OTCD). METHODS: Six unrelated, asymptomatic Japanese late-onset OTCD patients were analyzed by proton MRS ((1)HMRS) using a point-resolved spectroscopy technique (repetition and echo times, 5000 and 30 ms). Localized spectra for the centrum semiovale were acquired and absolute metabolite concentrations were calculated using an LCModel. RESULTS: Compared with age-matched controls, N-acetylaspartate and creatine concentrations were normal in all patients. The glutamine (Gln) plus glutamate concentration was increased in four patients, which progressed in proportion to the clinical stage. myo-inositol (mI) could not be detected in five symptomatic patients. A decreased choline (Cho) concentration was detected in two clinically severe patients. (1)HMRS after liver transplantation in one patient revealed the normalization of all metabolites. CONCLUSION: These findings suggest progression of neurochemical events in OTCD, i.e., mI depletion and Gln accumulation followed by Cho depletion, which is reverse of that in hepatic encephalopathy, i.e., Cho depletion followed by mI depletion and Gln accumulation.

Brain N-acetylaspartate is elevated in Pelizaeus-Merzbacher disease with PLP1 duplication.

OBJECTIVE: To assess alterations in brain metabolites of patients with Pelizaeus-Merzbacher disease (PMD) with the proteolipid protein gene 1 (PLP1) duplications using quantitative proton MRS. METHODS: Five unrelated male Japanese patients with PMD with PLP1 duplications were analyzed using automated proton brain examination with the point resolved spectroscopy technique (repetition and echo time of 5,000 and 30 msec). Localized spectra in the posterior portion of the centrum semiovale were acquired, and absolute metabolite concentrations were calculated using the LCModel. RESULTS: Absolute concentrations of N-acetylaspartate (NAA), creatine (Cr), and myoinositol (MI) were increased by 16% (p < 0.01), 43% (p < 0.001), and 31% (p < 0.01) in patients with PMD as compared with age-matched controls. There was no statistical difference in choline concentration. CONCLUSION: The increased concentration of NAA, which could not be detected by previous relative quantitation methods, suggests two possibilities: axonal involvement secondary to dysmyelination, or increased cell population of oligodendrocyte progenitors. Elevated Cr and MI concentrations may reflect the reactive astrocytic gliosis. Our study thus emphasizes the importance of absolute quantitation of metabolites to investigate the disease mechanism of the dysmyelinating disorders of the CNS.

Long-term assessment of posttransplant renal prognosis with 31 P magnetic resonance spectroscopy.

BACKGROUND: 31P-magnetic resonance spectroscopy (MRS) has been widely used to study pretransplantation renal viability, and although some had discussed posttransplant renal viability, no one has examined long-term posttransplant renal prognosis. We discuss the use of 31P-MRS to assess the long-term prognosis from the time when MRS was performed. METHODS: We studied 20 patients with renal allografts. 1.5 Tesla clinical magnetic resonance imaging (MRI) and 15 cm surface coil was used for 31P-MRS. Localized 31P-MRS was done using image selected in vivo spectroscopy (ISIS) method. Individual peaks were fitted by Lorenzian line-shapes with a least square method and peak area ratios were calculated. RESULTS: A beta-adenosine triphosphate/inorganic phosphate (beta-ATP/Pi) ratio >1.2 had sensitivity of 92.8%, specificity of 100%, and accuracy of 95% for predicting 3-year renal survival; a beta-ATP/Pi ratio >1.2 had sensitivity of 90.9%, specificity of 66.7%, and accuracy of 76.9% for predicting 5-year renal survival. We compared 31P-MRS spectra data between the survived group and failed group. The survived group had significantly higher beta-ATP/Pi, alpha-ATP/Pi, and phosphodiester (PDE)/Pi ratios than the failed group. CONCLUSIONS: We discussed the beta-ATP/Pi value as a parameter for predicting long-term survival of a transplanted kidney from the time when MRS was performed. A value above 1.2 suggests a high probability of 3-year renal survival, whereas a value over 2.5 indicates that the transplanted kidney could survive over 5 years. 31P-MRS may be useful for predicting long-term survival of transplanted kidneys, but additional studies are needed.

7Li 2D CSI of human brain on a clinical scanner.

Lithium salts have been widely used in the treatment of mood disorders, but the mechanism of action is still not clear. In this work, a methodology for two-dimensional Lithium-7 imaging on clinical systems is presented. The data were acquired using a phosphorus volume head coil that was re-tuned for the Lithium-7 frequency. A spectroscopic sequence was used to acquire the free induction decay (FID) after volume excitation using a hard pulse. The results obtained on the head of patients undergoing lithium treatment (n = 7, 0.6 mEq/l average serum level) demonstrate that images of adequate signal to noise ratio (100:1) can be obtained in acceptable imaging times (55 min) using the proposed methodology. The distribution of 7Li appears uniform in the brains of the patients studied.

Seizure frequency and bilateral temporal abnormalities: a proton magnetic resonance spectroscopy of temporal lobe epilepsy.

Proton magnetic resonance spectroscopy ((1)H-MRS) was performed in seven healthy volunteers and 17 patients with temporal lobe epilepsy (TLE) to clarify the correlation of the severity of epilepsy with bilateral temporal changes in N-acetylaspartate (NAA), choline-containing compounds (Cho) and creatine + phosphocreatine (Cr). Despite unilateral EEG focus, bilateral temporal reduction in NAA /(Cho + Cr) was revealed in patients with intractable seizures. The potential for seizure generation correlated with the NAA /(Cho + Cr) reduction not only on the ipsilateral side but also on the contralateral side. Proton MRS proved to be a useful measurement for obtaining important information about the neuronal changes as well as the lateralization of the epileptogenic focus in TLE patients.

Selective hydrogenation of benzophenones to benzhydrols. Asymmetric synthesis of unsymmetrical diarylmethanols

[reaction: see text] trans-RuCl2[P(C6H4-4-CH3)3]2(NH2CH2CH2NH2) acts as a highly effective precatalyst for the hydrogenation of a variety of benzophenone derivatives to benzhydrols that proceeds smoothly at 8 atm and 23-35 degrees C in 2-propanol containing t-C4H9OK with a substrate/catalyst ratio of 2000-20000. Use of a BINAP/chiral diamine Ru complex effects asymmetric hydrogenation of various ortho-substituted benzophenones and benzoylferrocene to chiral diarylmethanols with consistently high ee.

A preliminary study for clinical pharmacokinetics of oral fluorine anticancer medicines using the commercial MRI system 19F-MRS.

These preliminary studies of dynamic natural abundance 19F-magnetic resonance spectroscopy (19F-MRS) on 5-FU based medicines were performed in the human liver using commercial 1.5 T MRI equipment. A single tuned, custom-made circular shape surface coil with a diameter of 15 cm operating at 60 MHz was used for the 19F-MRS study. Localized proton shimming with a whole body coil was performed with adequate volume to include the observing area of the surface coil, and the line width of the water signal was less than 40 Hz. Very different spectroscopic appearance patterns of 5-FU were observed. We examined whether the pharmacokinetics in the liver of orally administered 1-hexylcarbamoyl-5-fluorouracil (HCFU) differ from those of orally administered 5'-deoxy-5-fluorouridine (5'-DFUR). This preliminary study suggested the 19F-MRS technique could be a useful method of evaluating in vivo the metabolism of 5-FU based medicines.

Acute pan-costochondritis demonstrated by gallium scintigraphy.

Costochondral inflammation is a rare clinical finding. A case is presented, in which acute chostochondritis is demonstrated by gallium scinitigraphy.

Multiple extra-bone accumulations of technetium-99m-HMDP.

Bone scintigraphy was performed on a woman 2 y and 10 mo after surgery for rectal cancer. Intense extra-bone accumulations of 99mTc-HMDP were visible in an aortic atherosclerosis lesion and in a metastatic liver tumor. Uptake in the metastatic lesion was confirmed by x-ray CT. Uptake in the aortic lesion was shown as typical calcification by x-ray CT.

Hot spots observed on pulmonary perfusion imaging: a case report.

A case of hot spots observed on perfusion lung images is presented. This artifact is well known, however, it is rarely seen in our experience. Although this artifact can occur if a faulty injection technique is used, the artifact also may be caused by embolization of the MAA in the upper extremity venous blood after injection. This cause of the artifact is beyond the control of the nuclear medicine professional.

Dialysate pressure isobars in a hollow-fiber dialyzer determined from magnetic resonance imaging and numerical simulation of dialysate flow.

A procedure to determine dialysate pressure isobars by comparing the results of magnetic resonance imaging (MRI) and numerical simulation of the dialysate flow was established. The assumption used in the filtration analyses, that the dialysate pressure varies only in the central-axial direction, is supported by the finding that the determined isobars have no steep radial gradient. MRI of the contrast solution permeating the hollow fibers verifies the uniformity of the hollow fiber density in the dialyzer.

Occult intestinal bleeding imaged by technetium-99m-HSA-D radionuclide angiography: a case report.

Radionuclide angiography (RNA) with 99mTc-diethylenetriamine pentaacetic acid human serum albumin (99mTc-HSA-D) is a sensitive screening method for diagnosing systemic perfusion abnormalities. Sometimes the results produce unexpected information. This information is helpful when considering the clinical perfusion pathophysiology. Recently, we were able to detect an intestinal bleeding lesion clearly for a patient by using RNA.

Human hepatic carbohydrate metabolism. Dynamic observation using 13C MRS without proton decoupling.

PURPOSE: Dynamic natural-abundance 13C MR spectroscopy (MRS) studies without proton decoupling were performed in the human liver using commercial 1.5 T MR equipment. MATERIAL AND METHODS: A single tuned custom-made circular surface coil with an OD of 20 cm operating at 16.04 MHz was used for the 13C study. Seventy-five grams of glucose dissolved in water was administered for the natural-abundance 13C-MRS dynamic study which lasted for approximately 40 to 60 min. Data acquisition was broken into 20-min and 1.7-min blocks. Localized proton shimming with a whole-body coil was performed with sufficient volume to include the observing area of the surface coil; the line width of the water signal was less than 20 Hz. RESULTS AND CONCLUSION: The glucose and glycogen spectra were clearly visible at 80 to 120 ppm after oral administration of the glucose solution. These data demonstrate that dynamic hepatic carbohydrate metabolism can be observed with commercially available MR equipment. Given that the human hepatic glycogen pool reaches maximum level within less than 10 min, this technique should provide a direct diagnosis of hepatic carbohydrate metabolic disorders.

Magnetic resonance imaging of reticulo-endothelial system in patients with idiopathic thrombocytopenic purpura.

Idiopathic thrombocytopenic purpura (ITP) is characterized by accelerated platelet destruction in the reticulo-endothelial system (RES). We performed magnetic resonance imaging (MRI) to estimate the degree of activated RES. MRI was performed with a Gyroscan S-15 (1.5 tesla) in 7 healthy volunteers and 22 patients with ITP. The 22 patients included 19 who were at initial diagnosis or were nonresponders to the therapy (non-DX group), and 3 who were responders. For the non-DX group, the T1 relaxation time of the spleen was initially significantly shorter than for healthy volunteers, but normalized after responding to the therapy. The initially shorter T1 values of the spleen for ITP patients correlated with a low platelet count (P < 0.05). This condition may indicate foam cells or fatty components due to platelet destruction. There was no significant relationship between the sequestration in (111)In-scan and T1 values of the liver or spleen. However, MRI is a noninvasive method, and it may be a clinically useful tool in the evaluation of RES in patients with ITP.

[Measurement of cerebral blood flow using phase-contrast MRI].

The development of phase-contrast magnetic resonance imaging(P-C MRI) provides a noninvasive method for measurement of volumetric blood flow(VFR). The VFR of the left and right internal carotid arteries and basilar artery were measured using P-C MRI, and total cerebral blood flow(tCBF) was calculated by summing up the VFR values in three vessels. We investigated the changes in these blood flows as influenced from age, head size, height, weight, body surface area and handedness. Moreover, regional CBF(rCBF) was measured by combining with the single photon emission computed tomography(SPECT) of 123I. The blood flows were 142 +/- 58 mL/ min(mean +/- SD) in the basilar artery, 229 +/- 86 mL/min in the left, 223 +/- 58 mL/min in the right internal carotid artery, and tCBF was 617 +/- 128 mL/min(Ref. Magn Resn Imaging 14:P. 1143, 1996). Significant increases were observed in head-size-related change of VFR in the basilar artery and height-related change of tCBF. The value of rCBF was easily acquired in combination with SPECT. Phase-contrast MRI is useful for a noninvasive and rapid analysis of cerebral VFR and has potential for clinical use.