Ultraselective transcatheter infusion of epirubicin in water-in-oil-in-water emulsion for small hepatocellular carcinoma.

OBJECTIVE: We have previously reported the clinical efficacy of water-in-oil-in-water (W/O/W) emulsions, particularly for non-selective transcatheter arterial infusion (TAI) therapy. W/O/W emulsions limit damage to normal hepatic parenchyma, because of their minimal embolic effect on peripheral arteries and slow release of anticancer agent. The purpose of this study was to evaluate the safety and effectiveness of ultraselective TAI (UTI) of a W/O/W emulsion for hepatocellular carcinoma (HCC). METHODS: 11 patients with Stage I-III small HCCs (<5 cm) underwent UTI with a W/O/W emulsion at our institute. Response was assessed using the Response Evaluation Criteria in Solid Tumors. Disease-free survival time was estimated using the Kaplan-Meier method. RESULTS: All 10 patients, excluding a patient who underwent a hepatectomy after UTI, achieved complete response. The 6, 12 and 30 month cumulative disease-free survival rates for the 10 patients were 100%, 90% and 60%, respectively. The patient who underwent hepatectomy after UTI developed complete necrosis of the HCC and peritumoral non-tumorous liver parenchyma. CONCLUSION: UTI therapy using a W/O/W emulsion for patients with small HCCs results in a good local response.

Transcatheter infusion of epirubicin in water-in-oil-in-water emulsion via a cystic artery for the treatment of hepatocellular carcinoma.

PURPOSE: We have previously reported the clinical efficacy of water-in-oil-in-water (W/O/W) emulsion containing anticancer agent. The purpose of this study was to evaluate the safety and effectiveness of transcatheter arterial infusion (TAI) of W/O/W emulsion via a cystic artery for hepatocellular carcinoma (HCC). METHODS: TAI of a W/O/W emulsion was performed at our institute in five patients with Stage III or IV HCC with blood supply from the cystic artery. In all patients, 2-12 ml/O/W emulsion was infused via a cystic artery. Therapeutic effects and complications were evaluated in these patients. RESULTS: Of the five patients treated, one achieved a complete response and two achieved a partial response. After treatment, acute cholecystitis or gallbladder ischemia that required treatment was not encountered in any patient. CONCLUSIONS: W/O/W emulsion can be safely infused via a cystic artery without major complications; it is a good therapeutic option for the patients with advanced HCC fed by a cystic artery.

Microdose study of 14C-acetaminophen with accelerator mass spectrometry to examine pharmacokinetics of parent drug and metabolites in healthy subjects.

A study of the pharmacokinetics of (14)C-labeled acetaminophen (AAP) was performed in healthy Japanese subjects receiving an oral microdose of the drug. After separation by high-performance liquid chromatography (HPLC), the levels of AAP and its metabolites in the pooled plasma specimens were quantified using accelerator mass spectrometry (AMS). The total body clearance (CL(tot))/bioavailability (F) of AAP was within the variation in the reported values at therapeutic doses, indicating the linearity of AAP pharmacokinetics. AAP-glucuronide (Glu) and AAP-4-O-sulfate satisfied the criteria of safety testing of drug metabolites. AMS could detect AAP-Cys, the active metabolite of AAP conjugated with cysteine, in the urine. Probenecid prolonged the systemic elimination of total radioactivity and caused a marked decrease in AAP-Glu levels in plasma. Probenecid likely inhibited the glucuronidation of AAP and the renal elimination of AAP-4-O-sulfate. Microdosing of (14)C-labeled drug followed by AMS is a powerful tool that can be used in the early phase of drug development for pharmacokinetic analysis of drugs and their metabolites and for detecting the formation of active metabolites in humans.

Superselective intra-arterial infusion chemotherapy for stage III/IV squamous cell carcinomas of the oral cavity: midterm results.

PURPOSE: We performed superselective intra-arterial infusion chemotherapy (SIC) according to a protocol in which drug distribution is evaluated by the use of interventional radiology (IVR)-computed tomography (CT) system, and the chemotherapy is combined with medium-dose conformal radiation therapy (CRT). We analyzed retrospectively the factors that affect the midterm survival ratio, including local response, for stage III and IV squamous cell carcinomas of the oral cavity. MATERIALS AND METHODS: Forty consecutive patients with stage III and IV squamous cell carcinomas of the oral cavity and who had undergone both SIC and CRT were enrolled. A microcatheter was placed in the appropriate feeding artery of the tumor and cisplatin (50mg/body) was infused twice. CRT was administered with a dual-energy (4 and 10 MV) linear accelerator. The total and daily doses delivered were 30 and 2.0 Gy, respectively. Histopathologic effects were classified into five grades: grade 0 or 1 was defined as a poor response, and grade II or higher as a good response. Age, sex, stage, local response to treatment, mode of invasion and lymph node metastasis were analyzed, and differences in the midterm survival ratio were assessed. RESULTS: The 3-year survival ratio of the 40 cases was 67%. A good local response (III or IV) was achieved in 75% of the cases. The survival ratio of the good local response group was significantly better than that of the poor response group (p=0.04). Mode of invasion (p=0.03) and lymph node metastasis (p=0.01) were also predictive of survival. In the multivariable analysis of survival, however, no variables including good local response (p=0.12), were predictive. CONCLUSION: Our new protocol improved local response, but it did not contribute to the survival ratio.

Intraarterial infusion chemotherapy and conformal radiotherapy for cancer of the mouth: prediction of the histological response to therapy with magnetic resonance imaging.

BACKGROUND: Although intraarterial chemotherapy has been used to treat head and neck cancers, some cases have shown poor response. If we can predict the response to this therapy on MRI, individual treatment plans may be altered to the most appropriate form of treatment. PURPOSE: To evaluate whether MRI can predict the histological response to preoperative chemoirradiation in patients with cancer of the mouth. MATERIAL AND METHODS: This study comprised of 29 consecutive patients with 30 oral cancers. All patients underwent tumor resection after intraarterial infusion chemotherapy and conformal radiotherapy. We compared the margin of the tumor, the presence of bone invasion, tumor area, and volume on pre- and post-treatment MRI with histological responses. RESULTS: Eighteen lesions showed an excellent response, nine exhibited a good response, and three a poor response. Only the tumor area on pretreatment T1-weighted images and the tumor area and volume on pretreatment enhanced T1-weighted images were significantly correlated with the histological response (P = 0.039, 0.008, and 0.016, respectively); smaller cancers showed better responses. The other factors were not significantly correlated with the histological responses. CONCLUSION: MRI parameters, excluding initial tumor area and volume, were not predictive of the histological response of oral tumors to preoperative treatment.

Balloon catheter disruption of middle cerebral artery thrombus in conjunction with thrombolysis for the treatment of acute middle cerebral artery embolism.

BACKGROUND AND PURPOSE: The goal of this study was to prospectively assess the feasibility, safety, and efficacy of balloon disruption of the middle cerebral artery (MCA) by using a deflated balloon catheter combined with an intra-arterial thrombolysis for the treatment of acute ischemic stroke. MATERIALS AND METHODS: Seven consecutive patients with clinical findings of acute major-vessel stroke met our criteria and underwent balloon disruption of an MCA thrombus with a deflated balloon catheter. The balloon disruption was performed with a low-profile microballoon catheter. The microballoon was inflated in the distal carotid artery and then deflated and advanced just distal to the occlusion site in the MCA. Thereafter, an intra-arterial thrombolysis of the MCA was applied. The maximum time from the onset of symptoms to the start of treatment and maximum dosage of urokinase was 6 hours and 600,000 U. The outcome was classified as good for a modified Rankin Scale (mRS) score of 0 or 1, moderate for a score of 2 or 3, and poor for a score of 4 or 5. RESULTS: Complete recanalization was achieved in 5 patients and partial recanalization in 3. Three patients recovered to an mRS score of 0 or 1; 3, to scores of 2 or 3; and 1, to a score of 4. No patients died. There was no major intracerebral hemorrhage. CONCLUSIONS: The penetration of the MCA with a deflated balloon catheter combined with an intra-arterial thrombolysis may be a safe and effective treatment for acute ischemic stroke.

High-resolution constructive interference in a steady state imaging of cervicothoracic adhesive arachnoiditis.

PURPOSE: To assess the usefulness of constructive interference in a steady state (CISS) sequence for an evaluation of cervicothoracic adhesive arachnoiditis. METHODS: Seven patients with arachnoiditis underwent magnetic resonance imaging with T1- and T2-weighted fast spin-echo (FSE) and 3-dimensional CISS sequences. Three observers compared T2-weighted FSE and 3-dimensional CISS images with regard to image quality for spinal adhesive arachnoiditis. Magnetic resonance appearances accompanied with cervicothoracic adhesive arachnoiditis on CISS coupled with T2-weighted FSE sequences were also evaluated. RESULTS: The CISS images were superior to T2-weighted FSE images in the demarcation of spinal cord, dura matter, nerve root, and adhesive point. In our 7 cases with cervicothoracic adhesive arachnoiditis, dural thickening in 2 cases, syringomyelia in 6, arachnoidal cysts in 3, findings of presyrinx in 2, intramedullary microcyst in 2, and deformity of the spinal cord were present. CONCLUSIONS: A CISS sequence was more desirable for an evaluation of the cervicothoracic adhesive arachnoiditis than T2-weighted FSE images and could provide useful additional information.

Superselective arterial infusion chemotherapy for squamous cell carcinomas of the oral cavity: histopathologic effects on metastatic neck lymph nodes.

We have performed superselective intra-arterial infusion chemotherapy (SIC) on carcinomas of the oral cavity according to a protocol in which the distribution of the drug was evaluated by the use of a combined CT and angiography system, and the chemotherapy was combined with medium-dose conformal radiation therapy (CRT). The purpose of this study was to evaluate the pathological effect of this treatment on the metastatic neck lymph nodes (LNs). Twenty consecutive patients who had metastatic neck LNs from squamous cell carcinomas of the mouth and who underwent both SIC and CRT were included in this study, in which a total of 22 LNs were evaluated. A microcatheter was placed in the appropriate feeding artery of the tumor, such as the internal maxillary artery, facial artery, lingual artery and external carotid artery (ECA), and cisplatin (50 mg/body) was infused twice through a microcatheter. The CRT was administered with a dual-energy (4 and 10 MV) linear accelerator. The total and daily doses delivered were 30 and 2.0 Gy, respectively. Intra-arterial infusion to the LNs was divided into two groups: superselective infusion (mainly to the submandibular LNs via the facial artery, n = 10) and nonsuperselective infusion via the ECA (n = 12). The distribution of cisplatin into the LNs was confirmed by slow-infusion CT. Histopathologic effects on the LNs were evaluated on the specimens obtained during the operation and classified into five grades (0: no or minimal response: I: disappearance of less than three quarters of the tumor cells: II: disappearance of more than three quarters of the tumor cells: III: disappearance of viable tumor cells with a small amount of residual nonviable tumor cells: IV: complete disappearance of all viable and nonviable tumor cells). Grade 0 or 1 was defined as poor response and Grade II or more as good response. Twenty-three LNs from nine patients without CRT and SIC were served as control. In the superselective infusion group, all 10 LNs showed good response (response rate, 100%: grade II = 4, grade III = 3, grade IV = 3). In the non-superselective group, however, 6 of 12 LNs showed poor response (response rate, 50%: grade 0 = 2, grade I = 4, grade II = 2, grade III = 2, grade IV = 2). All 23 control LNs with no treatment showed grade 0 response. Superselective infusion seems necessary to obtain good histopathologic effects on the metastatic LNs. SIC combined with CRT can be applied to the metastatic LNs.

Diffusion-weighted imaging of metastatic brain tumors: comparison with histologic type and tumor cellularity.

BACKGROUND AND PURPOSE: On diffusion-weighted imaging (DWI), metastatic tumors of the brain may exhibit different signal intensities (SI) depending on their histology and cellularity. The purpose of our study was to verify the hypotheses (1) that SI on DWI predict the histology of metastases and (2) that apparent diffusion coefficient (ADC) values reflect tumor cellularity. MATERIALS AND METHODS: We assessed conventional MR images, DWI, and ADC maps of 26 metastatic brain lesions from 26 patients, 13 of whom underwent surgery after the MR examination. Two radiologists performed qualitative assessment by consensus of the SI on DWI in areas corresponding to their enhancing portions. We measured the contrast-to-noise ratio (CNR) on T2-weighted images and normalized ADC (nADC) values, and compared them with tumor cellularity. RESULTS: The mean SI on DWI and the CNR on T2-weighted images were significantly lower in well differentiated than in poorly differentiated adenocarcinomas and lesions other than adenocarcinoma. The mean nADC value was significantly higher in well differentiated than poorly differentiated adenocarcinomas and lesions other than adenocarcinoma. All 3 small-cell carcinomas and 1 large-cell neuroendocrine carcinoma exhibited high SI on DWI. The nADC value showed a significant inverse correlation with tumor cellularity. There was no significant correlation between the CNR and tumor cellularity. CONCLUSION: The SI on DWI may predict the histology of metastases; well differentiated adenocarcinomas tended to be hypointense, and small- and large-cell neuroendocrine carcinomas showed hyperintensity. Their ADC values reflect tumor cellularity.

Usefulness of measurement of the temporal stem on magnetic resonance imaging in the diagnosis of frontotemporal dementia.

PURPOSE: To investigate whether measurements of brain structures on routine magnetic resonance (MR) images can be used to distinguish between normal subjects and patients with frontotemporal dementia (FTD) or Alzheimer's disease (AD). MATERIAL AND METHODS: MRI studies were performed on 30 patients with dementia (FTD, n = 15; AD, n = 15) and 15 age-matched controls. Width measurements, obtained at the corpus callosum, the cingulate gyri, the hippocampi, and the temporal stem of the anterior temporal lobes, were compared among FTD and AD patients and control subjects on oblique-coronal T2-weighted images. RESULTS: The width of the temporal stem was significantly narrower in FTD than in AD patients and control subjects (6.3 +/- 1.3 mm, 7.8 +/- 1.1 mm, and 8.2 +/- 0.9 mm, respectively) (P < 0.05), although there was some overlapping between AD and FTD patients. All patients whose temporal stem width was < 6 mm had FTD. While the width of the corpus callosum, cingulate gyri, and hippocampi was significantly narrower in patients with AD and FTD than in the controls, there was no significant difference between the AD and FTD patients. CONCLUSION: The width of the temporal stem was significantly narrower in patients with FTD than in those with AD and controls. The described measurements can easily be obtained and may be useful for the diagnosis of FTD.

Evaluation of drainage patterns of the major anastomotic veins on the lateral surface of the cerebrum using three-dimensional contrast-enhanced MP-RAGE sequence.

BACKGROUND AND PURPOSE: Three-dimensional (3D) contrast-enhanced magnetization-prepared rapid gradient-echo (MP-RAGE) sequence has been reported useful for evaluation of the intracranial venous structures. The purpose of this study is to assess the patterns of the major anastomotic veins on the lateral surface of the cerebrum using MP-RAGE sequence. METHODS: MP-RAGE images in consecutive 100 patients (200 sides) were reviewed by two neuroradiologists in consensus to evaluate drainage patterns of the superficial middle cerebral vein (SMCV), the vein of Labbe, and the Trolard vein. RESULTS: MP-RAGE images clearly depicted the major anastomotic veins and their draining vessel. The dominant vein was the Trolard vein in 12%, the vein of Labbe in 36%, SMCV in 38%, and all three veins in 14%. The vein of Labbe was entered the transverse sinus in 80% and superior petrosal sinus in 4%. Undeveloped type of the vein of Labbe was seen in 16%. The SMCVs were entered the sphenoparietal sinus in 57%, the cavernous sinus in 19%, and the emissary vein in 5%. Basal type of the SMCVs was seen in 3% and undeveloped type in 16%. It was difficult to differentiate the Trolard vein from other cortical veins, if it was not dominant. In the most cases with the dominant Trolard vein, it located at the level of the post central vein. CONCLUSION: With MP-RAGE sequence, it is easy to identify the variation of the major anastomotic veins. Such information may be helpful to reduce the risk of damage on these important veins at surgery.

MRI of intracranial germ-cell tumours.

Our aim was to review the MRI appearances of primary intracranial germ-cell tumours (GCT). We reviewed the MRI studies of 32 patients: 19 with germinomas, five with teratomas, one with an embryonal carcinoma, five with mixed and two with malignant nongerminomatous GCT. Eleven were in the pineal region, 12 suprasellar, five in the both sites, two in the basal ganglia and two in the corpus callosum. Contrast-enhanced images were available for 27 patients. The solid parts of GCT were nearly isointense with grey matter on both T1- and T2-weighted images. In seven patients with nongerminomatous GCT high-signal components were found on T1-weighted images, representing haemorrhage, high-protein fluid or fat. Cystic components were detected in 17 of 27 patients; eight germinomas and all nine nongerminomatous GCT had cysts. The solid components of germinomas enhanced homogeneously in eight cases and heterogeneously in 10, while all nongerminomatous GCT showed heterogeneous enhancement. MRI features tumours can facilitate correct diagnosis of GCT, including histological subtypes.

Dynamic MR imaging of neurohypophyseal germ cell tumors for differential diagnosis of infundibular diseases.

PURPOSE: To investigate the MR dynamic patterns of neurohypophyseal germ cell tumors (GCTs) for differential diagnosis of infundibular diseases affecting young people. MATERIAL AND METHODS: Eleven patients with neurohypophyseal GCTs underwent dynamic MR studies with Tl-weighted spin-echo (SE) or turbo SE techniques. Other infundibular lesions, including adenohypophysitis (n=3), Langerhans' cell histiocytosis (LCH, n=2), and 1 hemangioblastoma from von Hippel-Lindau disease, were also evaluated. Serial images were obtained every 15 s (turbo SE) or 30 s (SE technique) for 240 s after rapid injection of contrast medium. The dynamic patterns were analyzed quantitatively with the contrast medium enhancement ratio. RESULTS: On dynamic MR images, GCTs typically showed a gradual enhancement increase with a peak between 105 s and 180 s, while two showed a relatively rapid increase. LCH and hemangioblastoma showed a dynamic pattern similar to GCTs, while adenohypophysitis demonstrated a sharp rise and a steeper wash-out with an obvious peak before 90 s. CONCLUSION: Typical dynamic pattern of GCTs was the gradual enhancement increase without wash-out. Dynamic MR imaging can distinguish GCTs from adenohypophysitis, but is not useful for differentiation from LCH.

Posttherapeutic intraaxial brain tumor: the value of perfusion-sensitive contrast-enhanced MR imaging for differentiating tumor recurrence from nonneoplastic contrast-enhancing tissue.

BACKGROUND AND PURPOSE: Differentiation of tumor recurrence from treatment-related changes may be difficult with conventional MR imaging when newly enhancing lesions appear. Our aim was to determine the value of perfusion-sensitive contrast-enhanced MR imaging for differentiating recurrent neoplasm from nonneoplastic contrast-enhancing tissue. METHODS: Twenty patients in whom new enhancing lesions developed within irradiated regions were examined prospectively with perfusion-sensitive contrast-enhanced MR imaging. Twelve of them also underwent thallous chloride Tl 201 single-photon emission tomography (201Tl-SPECT). Normalized relative cerebral blood volume (rCBV) ratios and thallium indexes were evaluated to determine whether the new enhancing lesions were recurrent or not. Five instances of tumor recurrence and one of radiation necrosis were verified histologically; in the others, tumor recurrence was distinguished by lesions that progressively increased in size on serial MR examinations over at least 5 months, and nonneoplastic contrast-enhancing tissue was distinguished by lesions that disappeared or decreased in size on serial MR studies over at least 9 months. RESULTS: When normalized rCBV ratios were higher than 2.6 or lower than 0.6, enhancing lesions were either recurrent (n = 5) or nonneoplastic contrast-enhancing tissue (n = 3), respectively. All nonneoplastic contrast-enhancing tissue had a low thallium index, whereas three of four recurrent lesions had a high index. CONCLUSION: An enhancing lesion with a normalized rCBV ratio higher than 2.6 or lower than 0.6 may suggest tumor recurrence or nonneoplastic contrast-enhancing tissue, respectively. In these cases, further examination with 201Tl-SPECT may not be necessary. However, when the normalized rCBV ratio is between 0.6 and 2.6, 201Tl-SPECT may be useful in making the differentiation.

Evaluation of dural sinus invasion and extension of extra-axial intracranial tumors. The advantages of a high-resolution postcontrast 3-D gradient-echo technique.

OBJECTIVE: To assess the usefulness of a postcontrast 3-D Fourier transform (3DFT) gradient-echo (GRE) technique in dural sinus invasion and extension of extraaxial intracranial tumors in comparison with a conventional spin-echo (SE) technique. MATERIAL AND METHODS: Fourteen consecutive patients with 15 extra-axial tumors in contiguity with the dural sinus, including 14 meningiomas and 1 adenoid cystic carcinoma, underwent postcontrast T1-weighted SE and GRE MR studies. Detectability of dural sinus invasion and extension was evaluated using two sequences by two neuroradiologists in a blinded manner and compared with surgical results. Quantitative analysis was also performed to calculate the contrast-to-noise ratio (CNR) between lesion and dural sinus on SE and GRE images. The data were analyzed statistically using a matched paired t-test. RESULTS: In the qualitative evaluation, the detectability of dural sinus invasion in 3DFT-GRE images was superior to that using SE images. The mean CNR for all lesions was 3.86 on SE images and 5.63 on 3DFT-GRE images (p = 0.03). CONCLUSION: For evaluation of dural sinus invasion and the extension of extra-axial tumors, postcontrast 3DFT-GRE MR images were superior to conventional SE images.

Detection of intracranial hemorrhage with susceptibility-weighted MR sequences.

BACKGROUND AND PURPOSE: Detection of hemorrhage is important in the diagnosis and management of a variety of intracranial diseases. We evaluated the sensitivity of the following sequences for depicting chronic hemorrhagic foci associated with susceptibility dephasing: gradient-recalled echo (GRE) imaging, GRE-type single-shot echo-planar imaging (GRE-EPI), spin-echo-type single-shot echo-planar imaging (SE-EPI), turbo spin-echo (TSE) imaging, half-Fourier single-shot turbo spin-echo (HASTE) imaging, and segmented HASTE (s-HASTE) imaging. To our knowledge, no previous comparison has been made with these techniques in the same patient. METHODS: Fifty patients with suspected chronic hemorrhage were examined prospectively with the above six sequences. Contrast-to-noise ratio (CNR), sensitivity to detection of lesions, conspicuity of internal architecture, and sensitivity to small hemorrhagic foci were evaluated. RESULTS: Hemorrhagic foci were found in 35 patients. The CNR of the GRE, GRE-EPI, SE-EPI, TSE, s-HASTE, and HASTE sequences was 30.9, 23.7, 3.6, 6.1, -29.3, and -13.1, respectively; the number of small hemorrhagic foci detected was 85, 96, 44, 22, two, and one, respectively, for the supratentorial white matter; 70, 40, 19, four, zero, and zero, respectively, for the supratentorial cortical/subcortical region; and 73, 50, 26, 37, zero, and zero, respectively, for the infratentorial/skull-base region. CONCLUSION: The GRE sequence was best for detecting susceptibility dephasing associated with chronic intracranial hemorrhage. GRE-EPI, while comparable to GRE in the supratentorial compartment, was reduced in its sensitivity near the skull base, and may be used as an alternative to GRE in uncooperative, unsedated, pediatric, or claustrophobic patients. SE-EPI should not be used in screening for intracranial hemorrhage.

[One-hour protocol stress myocardial scintigraphy: prospective study of diagnostic accuracy for the detection of coronary artery stenosis].

A one-hour protocol for stress myocardial scintigraphy using technetium-99m-tetrofosmin (Tc-tetrofosmin) was compared with coronary arteriography for the detection of coronary artery stenosis in 90 consecutive patients without prior myocardial infarction, revascularization procedure or vasospastic angina. Tc-tetrofosmin stress myocardial scintigraphy acquired a rest image 20 min after intravenous administration of Tc-tetrofosmin (185 MBq, 1/5 vial) using a three-head gamma camera collecting 20-sec views over 360 degrees. The stress test using bicycle ergometer was performed and administration of Tc-tetrofosmin (740 MBq, 4/5 vial) was repeated at the peak stress point. The stress image was acquired 15 min after the second injection with 5-sec views over 360 degrees. Coronary arteriography revealed the presence of significant coronary artery stenosis (> 75%) in 56 vessels of 45 patients, including 35 patients with single-vessel disease, 5 with two-vessel disease, 2 with three-vessel disease, and 3 with left main trunk disease. The overall sensitivity and specificity for the detection of coronary artery disease by visual analysis were 91.1% and 77.8%, respectively, and by quantitative analyses (using bull's-eye method) were 95.6% and 91.1%, respectively. The individual stenotic vessel sensitivities in the right coronary artery, left anterior descending artery, and left circumflex artery were 84.6%, 90.9%, and 78.6%, respectively. The specificities were 97.3%, 95.9%, and 100.0%, respectively. These results suggest that stress myocardial scintigraphy using the present new protocol is a promising approach for the detection of coronary artery stenosis.

Brain lesions: when should fluid-attenuated inversion-recovery sequences be used in MR evaluation?

PURPOSE: To compare qualitatively and quantitatively the contrast of brain lesions detected with fluid-attenuated inversion-recovery (FLAIR) and intermediate-weighted sequences at magnetic resonance (MR) imaging. MATERIALS AND METHODS: In this prospective study, 47 patients suspected of having a brain lesion underwent MR imaging with FLAIR, intermediate-weighted, and T2-weighted sequences. Qualitative assessment was performed of lesion conspicuity, detection, overall image artifact, and additional clinical information. Contrast and contrast-to-noise ratio (CNR) were calculated between lesions and the normal brain or cerebrospinal fluid (CSF). RESULTS: FLAIR images were equal to intermediate-weighted images for overall lesion conspicuity and detection but were associated more often with image artifacts. Lesion-to-background contrast was significantly higher on FLAIR than on intermediate-weighted images. FLAIR images failed to demonstrate multiple sclerosis (MS) plaques located in the basal ganglia and brain stem. CONCLUSION: Although FLAIR images provided additional information in some cases, they did not have distinct advantages over intermediate-weighted images. When cases of MS are evaluated, intermediate-weighted images are preferable to FLAIR images. Except in cases of MS, either FLAIR or intermediate-weighted sequences should be added to T2-weighted sequences at MR imaging.

Ultrafast FLAIR imaging with single-shot echo-planar technique in evaluation of intracranial lesions.

We evaluated the detection of the brain lesions with single-shot echo-planar FLAIR imaging (EP-FLAIR) relative to fast spin-echo FLAIR imaging (fast-FLAIR). In 30 patients with variety of intracranial lesions, a prospective comparison of EP-FLAIR and fast-FLAIR was performed. Data acquisition time per image was 0.1 s with EP-FLAIR. Quantitative and qualitative criteria as well as lesion detectability were evaluated. EP-FLAIR provided almost same tissue contrast and CSF suppression as fast-FLAIR did. In the quantitative analysis, contrast and contrast-to-noise ratio (C/N) of EP-FLAIR were comparable to those of fast-FLAIR, and there was no significant difference between them. The increased magnetic susceptibility effect was useful in screening for subtle hemorrhage. However, EP-FLAIR was degraded by susceptibility artifacts at the skull base and posterior to the frontal sinuses. Motion artifacts were not encountered owing to the very short imaging time, and EP-FLAIR was particularly useful in screening for the lesions in uncoorporative patients.

MR imaging of Tornwaldt's cysts.

OBJECTIVE: The purpose of this study was to assess the characteristics of Tornwaldt's cysts as revealed by routine MR studies. MATERIALS AND METHODS: We retrospectively reviewed MR images of the brain in 1208 consecutive subjects who ranged in age from 3 weeks to 93 years (mean, 57.1 years). The signal intensity, shape, and size of Tornwaldt's cysts were assessed. Patients with Tornwaldt's cysts were then questioned about the presence of persistent nasal discharge, occipital headaches, and halitosis and an unpleasant taste in the mouth and about a history of adenoidectomy. RESULTS: Tornwaldt's cysts were found in 23 patients (1.9%) who ranged in age from 39 to 78 years (mean, 57.3 years). Of the 23 Tornwaldt's cysts, all were isointense to CSF on T2-weighted images and hyperintense to gray matter on the fluid-attenuated inversion-recovery images. The cysts showed high signal intensity compared with muscle on T1-weighted images. Nineteen cysts were round and four were oval. The mean size of the lesions was 6.0 mm in the major axis and 5.5 mm in the minor axis. Two patients with Tornwaldt's cysts had persistent nasal discharge and occipital headaches, and another patient had occipital headaches alone. None of the patients had undergone an adenoidectomy. CONCLUSION: Lesions consistent with Tornwaldt's cysts were found in 1.9% of the routine MR studies of the brain. The cysts had high signal intensity on T1-weighted, T2-weighted, and fluid-attenuated inversion-recovery images.