[show abstract][hide abstract] ABSTRACT: We evaluated the optimal timing for breath-hold MR imaging with bolus-injectable superparamagnetic iron oxide (SPIO) for detecting hepatocellular carcinoma (HCC).
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.
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.
Magnetic Resonance in Medical Sciences 02/2008; 7(3):123-30. · 0.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: We performed a phase I/II study of bi-weekly docetaxel in combination with concurrent radiotherapy to enhance the cytotoxic effect and radiosensitization and improve the rate of laryngeal preservation.
Patients with T2N0-1M0, T3N0M0 hypopharyngeal cancer or T2N0-1M0, T3N0-1M0 larynx cancer were enrolled. Docetaxel was administered bi-weekly (days 1, 15, 29) from the first day of radiotherapy, while 2 Gy/day of radiation was given on 5 days weekly from day 1, reaching a total of 60 Gy in 30 fractions.
12 patients took part in the phase I study. The maximum tolerated dose (MTD) was 40 mg/m2 and the recommended dose (RD) was determined as 35 mg/m2. The phase II study was conducted with docetaxel at 35 mg/m2 for 25 patients. Treatment was completed without interruption in 24 patients, with a protocol implementation rate of 96%. The complete response rate was 100% in laryngeal cancer, and 80% in hypopharyngeal cancer, and total (including partial response) overall response rate was 100%. The laryngeal preservation rate was 96%, and the overall local control rate was 92%. All patients have been alive for at least 3 years without any recurrence.
The chemoradiation therapy using bi-weekly docetaxel is an extremely effective treatment for cancer of the larynx/hypopharynx, provided that it is used for the specified stage of cancer.
Japanese Journal of Clinical Oncology 10/2007; 37(9):641-6. · 1.90 Impact Factor
[show abstract][hide abstract] ABSTRACT: We compared the effects of nilvadipine and amlodipine on the cognitive function and regional cerebral blood flow (rCBF) in patients with mild cognitive impairment (MCI) and hypertension.
Twelve patients with MCI and hypertension were randomly assigned to receive nilvadipine or amlodipine for 12-16 weeks. Before and after treatment all patients underwent neuropsychological evaluation and single photon emission computed tomography (SPECT) studies with N-isopropyl-p-[123I]iodoamphetamine.
Both nilvadipine (n=6) and amlodipine (n=6) groups had similar significant reduction in systolic and diastolic blood pressure after treatment. The Logical Memory subscore of the Wechsler Memory Scale-Revised increased significantly in the nilvadipine group, but not in the amlodipine group after treatment. Although SPECT demonstrated no significant differences in rCBF deficits at baseline between the two groups, the nilvadipine group showed an improvement of rCBF in the left frontal lobe, while the amlodipine group showed a decrease of rCBF in the left temporal lobe.
Our results suggest that nilvadipine, a highly lipophilic agent that easily penetrates the central nervous system, may have additional benefits and be potentially useful for the treatment of patients with MCI and hypertension.
Nuclear Medicine Communications 05/2007; 28(4):281-7. · 1.38 Impact Factor
[show abstract][hide abstract] ABSTRACT: We measured the thickness of the substantia innominata using magnetic resonance imaging in 122 patients with Alzheimer's disease (AD), 31 patients with dementia with Lewy bodies (DLB) and 34 patients with vascular dementia (VaD), and examined the correlates of cognitive response to donepezil. Although all dementia groups showed significant atrophy of the substantia innominata compared to 28 age-matched controls, atrophy was greater in the DLB group, but less in the VaD group than the AD group. Mini-Mental State Examination score changes at 12 weeks after donepezil administration inversely and significantly correlated with the thickness of the substantia innominata in patients with AD (n=103, r=-0.43, p<0.0001) and in patients with DLB (n=24, r=-0.57, p<0.01), but not in patients with VaD (n=12, r=-0.22, p>0.1). There may be some differences in cholinergic impairment among AD, DLB and VaD, reflecting cholinergic neuropathology. Clinical response to cholinergic therapy may be partly attributable to damaged cholinergic neurons in AD and DLB, but not in VaD, suggesting differences in the therapeutic implication of cholinergic system degeneration.
Neurobiology of aging 04/2007; 28(4):548-54. · 5.94 Impact Factor
[show abstract][hide abstract] ABSTRACT: We evaluated the quality of dynamic magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) in 20 normal volunteers with 40 TMJs. To confirm TMJ, we obtained static proton density weighted images (PDWI) before performing dynamic MR imaging with true-fast imaging in a steady-state precession (true-FISP) sequence. Four sequences of the first 10 volunteers were examined to determine the optimal sequence. The 4 sequences included the integrated parallel acquisition technique (iPAT) and/or fat saturation technique. The optimal sequence was then determined and performed in all 20 volunteers. The quality of imaging was evaluated, especially with respect to the conspicuity of the articular disk, mandibular condyle, articular eminence and lateral pterygoid muscle. One of 3 confidence levels was assigned for this evaluation. Neither iPAT nor fat saturation obtained the best quality imaging. Detection rates in the 20 volunteers were 83% for the articular disk, 95% for the mandibular condyle, 96% for the articular eminence and 7.5% for the lateral pterygoid muscle. We recommend dynamic MR imaging of the TMJ with the true-FISP sequence using neither iPAT nor fat saturation. Nevertheless, dynamic MR imaging was inferior to static imaging in detecting the articular disk and still requires improvement.
Magnetic Resonance in Medical Sciences 02/2007; 6(1):15-20. · 0.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: Limited resection of the lung can improve the postoperative quality of life if there is no lymph node metastasis. Small adenocarcinomas frequently appear on radiographs with areas of ground glass attenuation. We examined whether there is a correlation between the presence of lymph node metastasis and the ratio of the intratumor high-attenuation area (greatest dimension of high-attenuation area [H] to the maximum tumor dimension [T], H/T ratio) on high-resolution computed tomography (HRCT).
From January 1996 to June 2004, we studied 281 patients with lung adenocarcinomas of 3 cm or less in maximum dimension on preoperative HRCT. Each of the 281 patients had a lobectomy and lymph node dissection, and there was no case of limited resection.
Lymph node metastasis was present in 11.4% (32 of 281 cases, N1 = 13 cases, N2 = 19 cases). None of the 94 cases with an H/T ratio of 60% or less had lymph node metastasis. Moreover, lymph node metastasis was noted even in a 6-mm tumor when the H/T ratio was 100%. Of the 187 cases with tumors having an H/T ratio greater than 60%, 32 had lymph node metastasis.
The relationship between the H/T ratio and lymph node metastases was evaluated by HRCT in lung adenocarcinomas 3 cm or smaller in maximum dimension. The H/T ratio may provide useful information in deciding on limited resection for lung cancer in such cases.
Journal of thoracic oncology: official publication of the International Association for the Study of Lung Cancer 02/2007; 2(1):29-33. · 4.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: The purpose of our study was to describe the computed tomography (CT) findings of large cell neuroendocrine carcinoma (LCNEC) and to correlate radiological and pathological findings. We reviewed the CT findings of 36 patients [including the high-resolution computed tomography (HRCT) findings of 29 patients] with resected LCNEC specimens. There were 33 men (92%), and 30 patients had a smoking history (83%). Only one case was of the central type. Mediastinal or hilar lymphadenopathy was seen in 12 (33%), but only one showed bulky lymphadenopathy. The HRCT findings of LCNEC consisted of irregular margins (66%), surrounding emphysema (41%), notching (38%), calcifications (21%), and pleural indentation (24%). Our study indicates that the CT image of LCNEC generally shows a peripherally located, expansively growing, irregularly margined pulmonary mass, with or without calcification, and without bulky lymphadenopathy. While the CT image of LCNEC resembles that of squamous cell carcinoma, cavitation is infrequent. LCNEC cannot be differentiated from poorly differentiated adenocarcinoma or atypical carcinoid on the basis of CT findings.
[show abstract][hide abstract] ABSTRACT: To determine whether combined studies of Mini-Mental State Examination (MMSE) and brain single photon emission CT (SPECT) would provide more useful means of differentiating between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD), we studied 36 patients with probable DLB and 96 patients with probable AD. DLB patients had significantly better performance on word recall, but more impaired attention and copying than AD patients. We confirmed that a weighted score derived by Ala et al. [Ala, T.A., Hughes, L.F., Kyrouac, G.A., Ghobrial, M.W., Elble, R.J. The Mini-Mental State exam may help in the differentiation of dementia with Lewy bodies and Alzheimer' disease. Int J Geriatr Psychiatry 2002;17:503-9]: (Attention-5/3.Memory+5.Construction), was helpful in discriminating between DLB and AD. SPECT study revealed that medial occipital perfusion significantly decreased in DLB patients than AD patients. Combined studies of MMSE and brain SPECT achieved a high discrimination between DLB and AD with a sensitivity of 81% and a specificity of 85%, suggesting that there is a useful and practical approach to differentiate DLB from AD. Our findings will need to be substantiated in an independent and prospective study sample.
Journal of the Neurological Sciences 01/2007; 250(1-2):97-102. · 2.24 Impact Factor
[show abstract][hide abstract] ABSTRACT: 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.
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.
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).
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.
Annals of Nuclear Medicine 09/2006; 20(7):477-84. · 1.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: Both decreased occipital perfusion on brain single-photon emission computed tomography (SPECT) and reduction in cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake are characteristic features of dementia with Lewy bodies (DLB), and potentially support the clinical diagnosis of DLB. The aim of this study was to compare the diagnostic value of these two methods for differentiation of DLB from Alzheimer's disease (AD).
The study population comprised 19 patients with probable DLB and 39 patients with probable AD who underwent both SPECT with N-isopropyl-p-[(123)I]iodoamphetamine and MIBG myocardial scintigraphy. Objective and quantitative measurement of perfusion in the medial occipital lobe, including the cuneus and lingual gyrus, was performed by the use of three-dimensional stereotactic surface projections.
Medial occipital perfusion was significantly decreased in the DLB group compared with the AD group. The mean heart/mediastinum ratios of MIBG uptake were significantly lower in the DLB group than in the AD group. Although SPECT failed to demonstrate significant hypoperfusion in the medial occipital lobe in five patients with DLB, marked reduction of MIBG uptake was found in all patients with DLB. Receiver operating characteristic analysis revealed that MIBG myocardial scintigraphy enabled more accurate discrimination between DLB and AD than was possible with perfusion SPECT.
MIBG myocardial scintigraphy may improve the sensitivity in the detection of DLB. In particular, this method may provide a powerful differential diagnostic tool when it is difficult to distinguish cases of DLB from AD using brain perfusion SPECT.
European journal of nuclear medicine and molecular imaging 04/2006; 33(3):248-53. · 5.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: Treatment with acetylcholinesterase inhibitors (AchEIs) is beneficial for patients with Alzheimer's disease (AD). But the clinical response varies. Functional neuroimaging techniques might allow objective evaluation of the topographic correlates of the effect of therapy on brain functioning. We attempted to evaluate the possible correlation between regional cerebral blood flow (rCBF) differences in patients with AD and response to donepezil hydrochloride (Donepezil) therapy.
The subjects of this study were 51 consecutive patients with AD receiving Donepezil who underwent SPECT at baseline and 10-14 months later. We divided the patients into stabilized (n = 19) and nonstabilized (n = 32) subgroups based on changes in the Mini Mental State Examination (MMSE) score. Analysis of single-photon emission computed tomography (SPECT) data was done using 3-dimensional stereotactic surface projections (3D-SSP) and the stereotactic extraction estimation (SEE) method. We compared differences in rCBF between the two subgroups at baseline and follow-up, and between the baseline and follow-up in each subgroup.
Significant correlation was recognized between the mean Z score changes of the left frontal lobe, left limbic lobe, and MMSE change. There were no significant baseline differences in rCBF in any region of the brain between the two subgroups. At the study endpoint, the nonstabilized subgroup showed lower rCBF in the lateral and medial frontal lobes, limbic lobe, lower lateral temporal lobe, and cingulate gyrus compared to the stabilized subgroup. Both patient groups showed a significant post-treatment increase over baseline values in the frontal lobe, and the stabilized group had more extensive and intense increases in the lateral and medial frontal lobes and orbital surface.
Our study suggests that the diversity of clinical responses to Donepezil therapy in patients with AD is associated with rCBF changes, mainly in the frontal lobe. SPECT may be a promising tool to assess the impact of AchEI therapy on the brain function of patients with AD.
Journal of Neuroimaging 02/2006; 16(1):16-23. · 1.41 Impact Factor
[show abstract][hide abstract] ABSTRACT: Reduction in cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake is a characteristic feature of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), and is useful in distinguishing them from other neurodegenerative disorders. The aim of this study was to investigate the role of this method of scintigraphy in the differential diagnosis of dementia in our Memory Clinic. We performed MIBG scintigraphy in patients with dementia referred to the Memory Clinic and compared the heart-to-mediastinum (H/M) ratio of MIBG uptake. Thirty out of 32 patients with DLB and all 9 PD with dementia patients had reduced H/M ratios, whereas 37 out of 40 patients with Alzheimer's disease had normal H/M ratios. Most patients with vascular dementia, frontotemporal dementia, and other dementias had normal H/M ratios. The overall sensitivity to positively identify patients with Lewy body disease (including DLB and PD with dementia) was 95%, and the specificity to distinguish them from patients with other types of dementias was 87%. MIBG scintigraphy showed a high sensitivity for the detection of Lewy body disease, and also a high specificity for discrimination from other types of dementia. The scintigraphy may provide a valuable and adjunctive method in the diagnosis of Lewy body disease and a differential diagnostic tool for patients with dementias.
[show abstract][hide abstract] ABSTRACT: We evaluated whether a perfusion study with Resovist is useful to assess blood flow in tumors in patients with hypervascular hepatocellular carcinoma (HCC).
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.
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.
A perfusion study may facilitate the diagnosis of hypervascular HCC, improving the diagnostic accuracy.
Magnetic Resonance in Medical Sciences 01/2006; 4(4):151-8. · 0.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: To assess myometrial invasion and cervical invasion by endometrial carcinoma, using CO2-volumetric interpolated breathhold examination (VIBE) enabling more precise evaluation of depth of tumor invasion.
CO2-VIBE was performed in 21 cases of endometrial carcinoma (Stage Ia-IIb) prior to treatment. The images were interpreted by performing multiplanar reconstruction (MPR), and the findings obtained from the images (degree of myometrial invasion and presence or absence of cervical invasion) were assessed in comparison with the histopathological diagnosis.
The sites of the endometrial carcinoma lesions were clearly visualized by the CO2-VIBE method. Evaluation of the degree of myometrial invasion enabled a high correct diagnosis rate of 90.5%, and evaluation for the presence of cervical invasion also allowed a high correct diagnosis rate of 90.5%.
VIBE permits evaluation of any plane desired by means of thin slices, and it is a truly revolutionary method for preoperative evaluation of depth of invasion of endometrial carcinoma that enables highly accurate determination of the extent of lesion sites and degree of invasion before treatment.
Journal of Magnetic Resonance Imaging 03/2005; 21(2):166-71. · 2.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: We compared regional cerebral blood flow (CBF) patterns in patients with dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) using single photon emission computed tomography (SPECT) and investigated the diagnostic utility of SPECT study in differentiating between DLB and AD. SPECT data on 20 patients with DLB and 75 patients with AD were analyzed using three-dimensional stereotactic surface projections. Regional CBF reduction was determined by quantitative analysis using stereotactic extraction estimation method. The DLB group showed a significant CBF reduction in the temporoparietal, frontal lobe and posterior cingulate, similar to the CBF pattern in the AD group, but regional CBF in the medial and lateral occipital lobes decreased significantly in patients with DLB compared with patients with AD. Receiver operating characteristic analysis revealed that regional CBF measurement of the medial occipital lobe, including the cuneus and lingual gyrus, yielded a sensitivity of 85% and a specificity of 85% in discriminating DLB from AD. Objective and quantitative CBF measurement in the medial occipital lobe may be useful in the clinical differentiation of DLB and AD.
[show abstract][hide abstract] ABSTRACT: The purpose of this study was to evaluate the utility of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) for the quantitative evaluation of hepatocellular carcinoma (HCC) and dysplastic nodules in the hepatobiliary phase.
The subjects comprised 12 patients with 27 lesions (22 HCCs and 5 dysplastic nodules). Chemical-shift-selective fat-suppressed T1-weighted sequences were obtained before and 10, 20, and 40 min after the injection of Gd-EOB-DTPA. Quantitative analyses were performed with the enhancement ratio of the lesion and the contrast-to-noise (C/N) ratio.
The enhancement ratios of the HCCs were 44.0+/-36.5, 44.7+/-46.8, and 47.7+/-52.8 (%) at 10, 20, and 40 min, respectively, after the injection of Gd-EOB-DTPA. The enhancement ratios of the dysplastic nodules were 36.2+/-34.3, 44.3+/-37.3, and 40.1+/-46.8 (%). The C/N ratios of the HCCs were 0.2+/-6.6 for the precontrast image, and -9.2+/-12.6, -9.9+/-14.8, and -12.7+/-15.7 at 10, 20, and 40 min, respectively, after the injection of Gd-EOB-DTPA. The C/N ratios of the dysplastic nodules were 1.4+/-8.0, -13.7+/-11.1, -13.3+/-7.6, and -13.1+/-10.4. No significant differences were found between the HCCs and the dysplastic nodules in the enhancement ratio and the C/N ratio. Only two HCCs showed a positive C/N ratio value, and these HCCs were pathologically confirmed to be a well differentiated and a moderately differentiated carcinoma, respectively.
HCCs and some of the dysplastic nodules showed hypointensity in the hepatobiliary phase in Gd-EOB-DTPA-enhanced MRI. No specific enhancement was observed, regardless of tumor differentiation.
Magnetic Resonance in Medical Sciences 02/2005; 4(1):1-9. · 0.75 Impact Factor
[show abstract][hide abstract] ABSTRACT: We compared magnetization transfer ratios (MTRs) in the brains of patients with dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) to determine whether regional differences in the brain structures between DLB and AD are detectable with magnetization transfer imaging. Seventeen patients with DLB, 31 patients with AD and 18 elderly normal controls were included. Although no significant differences were found in MTRs in the frontal white matter between the three groups, MTRs in the hippocampus, parahippocampus, and posterior cingulate white matter in both patients with DLB and AD were significantly lower than those in age-matched control subjects. However, MTRs in the hippocampus of patients with DLB were significantly higher than those in patients with AD. Logistic regression analysis revealed that hippocampal MTR yielded a sensitivity of 76% and a specificity of 71% in discriminating DLB from AD. These results may reflect underlying histopathological differences with less severe neuronal degeneration in the hippocampus of DLB. MTR measurement of the hippocampus may contribute to the clinical differentiation between DLB and AD.
[show abstract][hide abstract] ABSTRACT: The findings of contrast-enhanced cardiac magnetic resonance imaging of a 19-year-old man with perimyocarditis in the subacute and chronic stage are presented. In perimyocarditis., it is useful to check the presence of delayed contrast enhancement to confirm the presence of the lesion and to evaluate the severity of inflammation in the acute stage as well as to determine the extent of fibrosis in the pericardium and myocardium in the chronic stage.
The International Journal of Cardiovascular Imaging 01/2005; 21(2-3):325-9. · 2.65 Impact Factor