2,3-Dimethoxy-2,3-dimethyl-1,4-dioxane as a useful precursor to 2,3-dimethylene-1,4-dioxane for [4+2] cycloaddition reaction.

2,3-Dimethoxy-2,3-dimethyl-1,4-dioxane readily prepared from biacetyl serves as a stable precursor to 2,3-dimethylene-1,4-dioxane which undergoes a [4+2] cycloaddition reaction with dienophiles to give functionalized cyclohexene derivatives. The cycloaddition adducts obtained by the present procedure are transformed into potentially useful intermediates for biologically important materials.

Detection of hepatocellular carcinoma with ferucarbotran (resovist)-enhanced breath-hold MR imaging: feasibility of 10 minute-delayed images.

PURPOSE: We evaluated the optimal timing for breath-hold MR imaging with bolus-injectable superparamagnetic iron oxide (SPIO) for detecting hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty patients with 62 HCCs (52 hypervascular, 10 non-hypervascular) underwent MR imaging that included unenhanced and SPIO-enhanced T1-weighted gradient echo (GRE) and T2-weighted fast spin echo (FSE) sequences, perfusion study, and SPIO-enhanced T2*-weighted GRE sequences. We obtained SPIO-enhanced T2*-weighted sequences 10 and 30 min after injecting SPIO and made 2 image sets, comprising 10- or 30-min delayed T2*-weighted images. Three observers performed alternative free response receiver operating characteristic (AFROC) analysis, and quantitative evaluation was performed. RESULTS: Only Observers 2 and 3 recognized a significant difference in the area under the AFROC curve (Az) value in the 10-min delayed images; no significant difference was observed in the 30-min delayed images. There was no significant difference in the sensitivity of individual observers between 10- and 30-min delayed images. The contrast-to-noise (C/N) ratio of the 30-min delayed images was significantly higher than that of the 10-min delayed images. The C/N ratio of hypervascular HCCs in the 30-min delayed images was significantly higher than in the 10-min delayed images, but that of non-hypervascular HCCs showed no significant difference. CONCLUSION: In most cases, 10-min delayed SPIO-enhanced T2*-weighted images are sufficient to detect HCCs.

Characterization of an orbital melanoma and mucosa associated lymphoid tissue (MALT) lymphoma by dual phase N-isopropyl-p-I-123 iodoamphetamine.

Usefulness of N-isopropyl-p-I-123 iodoamphetamine (I-123 IMP) for the detection of malignant melanoma and malignant lymphoma is well known. The appropriate interval from administration until image acquisition is unusual because the accumulation mechanism is different. We present a case of choroidal melanoma of the right orbit with a history of low-grade mucosa-associated lymphoid tissue lymphoma of the left lacrimal gland. She was followed with magnetic resonance imaging and dual phase I-123 IMP imaging 3 times. Viability of the melanoma was estimated by I-123 IMP delayed image obtained 24 hours after intravenous injection. In spite of cryosurgery twice, the accumulation of the tracer remained unchanged. Subsequent tumor excision proved the lesion to be a viable malignant melanoma. On the other hand, posttherapeutic mucosa-associated lymphoid tissue lymphoma of the left lacrimal gland was followed by the early image obtained 20 minutes after radionuclide injection. The accumulation increased gradually and the recurrence was pointed out. In the same way, magnetic resonance imaging examination was undertaken 3 times. Both lesions were obvious, but the findings were entirely unchanged in each examination.

New semiquantitative assessment of 123I-FP-CIT by an anatomical standardization method.

UNLABELLED: We evaluated a new semiquantitative procedure to more easily and objectively estimate the striatal uptake of 123I-FP-CIT in patients with Parkinsonian syndrome (PS) and essential tremor (ET), using an anatomical standardization method, the Neurostat. METHODS: Eleven patients with PS and 8 with ET were examined by clinical assessment and 123I-FP-CIT SPECT imaging. The modified Hoehn and Yahr Staging Scale and Unified Parkinson's Disease Rating Scale (UPDRS) were used to assess the stage and severity of the disease. The co-registered MR and SPECT images were created with fusion software included in Neurostat. On the cross section, which shows the largest area of striate, irregular shaped regions of interest corresponding to the striate and occipital cortex were drawn. Then the ratio of specific striatal uptake to non-specific occipital cortex, V3"(F), was calculated. Another calculation was done by VOIClassic, which is a software included in Neurostat to estimate the counts per voxel of anatomically defined regions such as caudate nucleus, putamen, occipital cortex, and total cortex. Using these count data, the ratio of specific striatal uptake to non-specific occipital cortex, V3"(OC), and total cortex, V3"(TC), was calculated. RESULTS: A fair linear correlation was observed between V3"(OC) and V3"(F) (y = 1.53x + 1.40; r = 0.756; p < 0.01), as well as between V3"(TC) and V3"(F) (y = 1.24x + 1.43; r = 0.713; p < 0.01). Both V3"(OC) and V3"(TC) yielded similar tendencies. Concerning discrimination between ET and PS, there was a significant difference between the mean V3" of PS and ET (p < 0.01). Concerning the correlation between V3" value and the severity of PS, the UPDRS motor score significantly correlated with the V3"(F) value (rs = -0.816). However, V3"(OC) and V3"(TC) correlated less with UPDRS (rs = -0.667 and -0.645, respectively). CONCLUSIONS: Semiquantitative parameters, V3"(OC) and V3"(TC), calculated by VOIClassic including the Neurostat system are useful and easily calculable parameters as well as V3"(F) for the differential diagnosis of PS from ET.

Perfusion study of hypervascular hepatocellular carcinoma with SPIO.

PURPOSE: We evaluated whether a perfusion study with Resovist is useful to assess blood flow in tumors in patients with hypervascular hepatocellular carcinoma (HCC). SUBJECTS AND METHODS: The subjects were 28 patients; the lesions consisted of 68 hypervascular HCC, 14 post-treatment nodules, and 7 hepatocellular hypovascular nodules. After rapid intravenous injection of Resovist, 7-phase imaging was performed using the single-shot echo-planar method. Diagnostic accuracy and tumor vascularity were evaluated by 3 radiologists using the alternative free response receiver operating characteristic method. Sensitivity, Az values, and positive predictive values were calculated. To assess interobserver variability, we evaluated the kappa static to measure the degree of agreement. RESULTS: The 3 observers indicated no significant difference in Az value related to the presence or absence of a perfusion study, and only one remarked a significant difference in sensitivity. However, kappa values were better in the presence than in the absence of a perfusion study. Blood flow assessment was poor in less than 1 cm. The 3 observers showed a positive predictive value of 90% or more. CONCLUSION: A perfusion study may facilitate the diagnosis of hypervascular HCC, improving the diagnostic accuracy.