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Epithelioid trophoblastic tumor (ETT) is a rare gestational trophoblastic neoplasm of chorionic-type intermediate trophoblasts, and it is most frequently located in the lower uterine segment and endocervix. Due to the epithelial-growth pattern with geographic necrosis exhibited by the neoplastic cells, ETT is commonly confused, both clinically and pathologically, with squamous cell carcinoma. Although there have been no previous reports of ETT focusing on computed tomography (CT) or magnetic resonance imaging (MRI) findings, we report a case of uterine ETT with special attention to the MRI findings referring to the pathological findings and MR images of previous reports. A 42-year-old Japanese woman (gravid 1, para 1) presented with uterus enlargement during screening, and complained of recent-onset lower abdominal pain. The MRI showed a solid tumor throughout the entire myometrium of the lower uterine segment, with the hemorrhagic cystic portion extending to the posterior subserosal space. Following hysterectomy, the final pathological diagnosis was ETT. An ETT is essentially a solid tumor composed of intermediate trophoblasts that exhibit an epithelial-like growth pattern and contain geographic necrosis with calcification. In our case, MRI revealed a non-specific-intensity solid tumor in the lower uterine segment with massive necrosis and hemorrhage extending to the subserosa. While it is difficult to distinguish between ETT and uterine carcinomas, recognition of certain tumor shapes and necrosis could enable more accurate diagnosis before treatment.

Atypical teratoid/rhabdoid tumor (AT/RT) occurs in children less than 3 years old, and has a very poor prognosis. AT/RT seldom occurs in adult. We have experienced four cases of AT/RT at our institute. The purpose of this study is to evaluate the radiological image findings of adult-onset AT/RT and to conduct a systematic review. Image findings of four AT/RTs in our institute were retrospectively evaluated by an experienced neuroradiologist. If the images were unavailable, image findings were evaluated from the former image interpretation report. We assembled papers of adult-onset AT/RT (n = 38) and evaluated the image findings. AT/RT occurs in a variety of sites (spinal region, pineal region, suprasellar region, jugular foramen, and so on). High density on computed tomography (CT) was seen in 10 of 11 cases; mixed intensity in T2-weighted image was seen in 13 of 18 cases; and high intensity on diffusion-weighted image (DWI) was seen in 3 of 3 cases. Contrast enhancement was observed in all cases in which images were available. We have experienced four adult-onset AT/RT cases at our institute and have evaluated image findings through systematic review. The image findings of high density on CT, high intensity on DWI, with low apparent diffusion coefficient, and a heterogenous component should lead to an inclusion of AT/RT in the differential diagnosis of a tumor; these findings may be able to suggest AT/RT; however, they cannot make the diagnosis.

The purpose of this prospective study was to clarify whether reducing the incidence of perivenous artifacts through craniocaudal scanning improves the quality of 64-multidetecter computed tomography (MDCT) angiography images of the whole carotid artery.Forty patients underwent MDCT angiography in the caudocranial (n=20) or craniocaudal (n=20) direction in 2007. All patients were injected with 75 ml of contrast media followed by a 35-ml saline chaser bolus at 4.0 ml/s in the right antecubital vein. Maximum intensity projection (MIP) images were scored according to image quality on a scale of 1-5. Bilateral arterial and venous attenuation was measured on 10 separated slices. We compared the mean image quality score of the two groups (i.e. those scanned caudocranially and those scanned craniocaudally). We analyzed the correlation between vascular attenuation and mean image quality.Compared with the caudocranial group, the craniocaudal group had higher image quality scores (median, 3.70 vs. 3.40; 95% CI, 3.50-3.96 vs. 3.06-3.60; p0.05), higher arterial attenuation (median, 550 HU vs. 489 HU; range, 270-686 vs. 302-574; p0.05), and lower maximum venous attenuation (median, 436 vs. 1452 HU; range, 250-617 vs. 377-2044; p0.01). Multiple regression analysis revealed that the most significant correlation factor with image quality was minimum arterial attenuation (R2=0.42, p0.001) measured near the brachiocephalic artery. In the caudocranial group only, there was a negative correlation between right brachiocephalic venous attenuation and minimum arterial attenuation.Compared with conventional caudocranial scanning, craniocaudal scanning improves the image quality of 64-MDCT angiography images of the whole carotid artery.

Introduction: Multisection motion sensitized driven equilibrium (MSDE) can completely suppress any flow signal and uses gadolinium-based contrast medium. Therefore, 3-dimensional MSDE with contrast medium (3D-CE-MSDE) can visualize only abnormal enhancements. Our purpose is to determine the usefulness of 3D-CE-MSDE for primary malignant brain tumors. Method: We used a 3.0 Tesla MRI unit. The subjects were 29 consecutive patients with primary malignant brain tumors, including patients with recurrent cancer (mean age: 56.2 ± 25.2 years; 13 men and 16 women). Both 3-dimensional T1 turbo field echo with the contrast medium (3D-CE-T1TFE) and 3D-CE-MSDE were performed as preoperative studies on the same day. We calculated the contrastto- noise ratio (CNR) for each sequence. Two radiologists (A, B) independently evaluated the number of enhanced intraaxial and disseminated lesions observed in each sequence. We statistically analyzed the results using a paired t-test. Result: The 3D-CE-MSDE CNR was significantly higher than that of 3D-CE-T1TFE (p < 0.01). Radiologist A found that 3D-CE-MSDE was superior to 3D-CE-T1TFE in detecting both intraaxial lesions and disseminations (p=0.04 and p

The aim of this study was to determine the time-activity curve in the cardiac and hepatic region by 99mTc-GSA dynamic SPECT which is clinically used in liver scintigraphy and evaluate the temporal changes in the consistency and errors at the absolute scale using the regression equation of changes in the blood concentration of 99mTc-GSA.In 11 patients who underwent 99mTc-GSA dynamic SPECT over the 30 min period after IV injection, the percentages of activity in the collected blood and in the blood pool estimated by dynamic SPECT were determined as the plasma clearance by blood collection and as the blood clearance by cardiac pooling. Extrahepatic uptake, expressesd as 100--(% uptake in the liver by dynamic SPECT (%)) was calculated as the blood clearance by the liver. The regression equation (Y = Y0 + Ae(-alphat)) was determined from the changes in the counts, expressed as a percent. Percent errors and the differences in the Y-intercept (Y0), coefficient (A) and slope (alpha) on the regression curve were compared.Blood pool clearance gradually exceeded the measured plasma clearance. The clearance by the liver started from a very low initial value and gradually became equal to that of plasma clearance over the first 15 minutes and exceeded it over the second 15 minutes. The Y-intercept was significantly higher in the blood pool clearance than that in the measured plasma clearance (p0.001), and the coefficient was significantly lower in the former than the latter (p0.001). The coefficient and slope were significantly lower in the hepatic clearance than the plasma clearance (p0.001, p0.005).The time-activity curve of the blood pool showed a tendency towards overestimation in the second half of the examination, probably due to scatter effect from the liver. The time-activity curve of liver uptake showed a tendency towards overestimation in the first half of the examination, probably due to the high concentration in the hepatic blood pool, and underestimation in the second half.

Background and Purpose: We have encountered a peculiar atrophic change in the midbrain in some patients with parkinsonian syndromes. We discovered these patients had vertical supranuclear gaze-palsy, an eye movement disorder. The purpose of this study was to elucidate whether this atrophic pattern of the midbrain (which we have termed morning glory sign) is related to the vertical eye movement disorder, in particular to progressive supranuclear palsy (PSP). Methods: We reviewed T2-weighted axial images obtained from 42 patients with parkinsonian syndromes, including five patients with PSP, 23 patients with Parkinson's disease, and 14 patients with multiple system atrophy (MSA). We focused on a specific atrophy of the midbrain, the morning glory sign, which is a concavity of the lateral margin of the tegmentum of the midbrain. Results: The morning glory sign was detected in four of the five patients with PSP and in one (striatonigral degeneration; SND) of the14 patients with MSA. All morning glory sign patients had vertical supranuclear gaze-palsy, as did the one PSP patient without the morning glory sign. Vertical supranuclear gaze-palsy was seen in no other patients (23 patients with Parkinson's disease and 13 patients with MSA) who lacked the morning glory sign. Conclusions: Morphologically, the morning glory sign is believed to be related to vertical supranuclear gaze-palsy. This sign should be considered a useful clue when diagnosing PSP.

Cholesteatomas show high intensity in diffusion-weighted imaging (DWI). We performed fused thin slice non-echo planar imaging (EPI) DWI and magnetic resonance cisternography (FTS-nEPID) for cholesteatoma patients to increase the detectability of FTS-nEPID for cholesteatoma. The subjects are 77 consecutive patients who underwent FTS-nEPID as a preoperative study (mean age: 53.3±21.8, 47 men and 30 women). Otorhinolaryngologists performed the operations. We anatomically classified the middle ear into four portions. A radiologist evaluated the images for cholesteatoma and assessed the anatomical invasive range in four portions using only FTS-nEPID. We classified large cholesteatomas that invaded more than three portions and small ones that invaded less than two portions based on the results obtained from surgery, and calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). For all cholesteatomas with an existing diagnosis, the sensitivity, specificity, PPV, and NPV were 71%, 70%, 94%, and 27%, respectively. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 49%, 85%, 77%, and 64%, respectively. For large cholesteatomas with an existing diagnosis, the sensitivity was 86%. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 51%, 57%, 88%, and 18%, respectively. For small cholesteatomas with an existing diagnosis, the sensitivity, specificity, PPV, and NPV were 59%, 78%, 92%, and 30%, respectively. In anatomical evaluation, the sensitivity, specificity, PPV, and NPV were 40%, 85%, 60%, and 71%, respectively. FTS-nEPID may be useful for diagnosing cholesteatomas. Further research is needed for anatomical evaluation because there were many false-negative results.

As a result of recent advances in magnetic resonance imaging (MRI) technology, direct imaging of the intraparotid facial nerve has become possible. The usefulness of MRI is well known in the diagnosis of parotid tumors. Using a 0.5 T midfield MR unit, this study aimed to visualize the intraparotid facial nerve in 5 normal volunteers and 14 patients with parotid tumors (on 24 normal sides and 14 affected sides). Under appropriate conditions for MRI, the facial nerve was detectable on 9 out of 10 affected sides and 17 out of 20 normal sides. The running course of the facial nerve was consistent with MRI findings in five patients who underwent surgery. The imaging conditions suitable for visualizing the intraparotid facial nerve are reported and the usefulness of MRI in the diagnosis of parotid tumors is discussed.

Fulminant hepatic failure is associated with a high mortality rate. Thus, accurate assessment of hepatic functional reserve and hepatic regeneration is important. We describe a 67-year-old woman who survived subacute hepatic failure. We had an opportunity to monitor the clinical course of the patient using single photon emission computed tomography (SPECT) with 99mTc-galactosyl-human serum albumin (99mTc-GSA) and frequent hematological examinations. On admission, prothrombin time was remarkably prolonged (23.1% of control). The liver uptake of 99mTc-GSA was also considerably low. She responded well to treatment. Four weeks after admission, SPECT analysis showed a dramatic increase in liver uptake of 99mTc-GSA, suggesting promotion of hepatic regeneration. Moreover, functional liver volume calculated from the SPECT data showed a marked increase at 4 weeks after admission, whereas CT scan showed no change at that point. This indicated that SPECT with 99mTc-GSA reflected functional hepatocytes more accurately than liver volume determined by CT scan, which cannot exclude nonfunctional hepatocytes. The patient's condition improved in parallel with the improvements in the indices measured by SPECT and hematological examinations. SPECT analysis is practically useful for the prompt assessment of improvement in patients with fulminant hepatic failure.

BACKGROUND AND PURPOSE: The trochlear nerve is so thin that it is rarely observed with MR imaging. Therefore, we used high-resolution MSDE to reliably visualize the cisternal segments of the trochlear nerve. MATERIALS AND METHODS: Participants were 10 healthy young adults (mean age, 24 years), and 20 trochlear nerves were examined. HR-MRC, BS-MRC, and HR-MSDE were performed. A neuroradiologist judged the visibility of the trochlear nerves as 1 of 4 grades (“Excellent,” “Good,” “Fair,” and “Not”) in each MR imaging sequence. The findings were then statistically analyzed with the χ(2) test. RESULTS: Of all 20 trochlear nerves, 6 with HR-MRC, 13 with BS-MRC, and 18 with HR-MSDE were judged as “Excellent.” CSF flow-related artifacts and vessels in the cistern and cerebellar tentorium in HR-MRC tended to prevent the neuroradiologists from identifying the trochlear nerve. Vessels in the cistern and cerebellar tentorium in BS-MRC also tended to prevent the neuroradiologists from identifying the trochlear nerve. Compared with other sequences, HR-MSDE visualized the trochlear nerve more often. The χ(2) test revealed statistically significant differences among the 3 MR imaging sequences (P < .01). The scan time of HR-MSDE was approximately 1.5–2.2 times longer than that of the other sequences. CONCLUSIONS: HR-MSDE is able to clearly visualize the trochlear nerve and has the same or better ability to delineate the trochlear nerve compared with other MR imaging sequences, though its long scan time does not yet yield practical use.

The purpose of this study was to determine the accuracy of high resolution CT (HRCT) in the detection of facial canal dehiscence and semicircular canal fistula, the preoperative evaluation of both of which is clinically very important for ear surgery. We retrospectively reviewed the HRCT findings in 61 patients who underwent mastoidectomy at Yamagata University between 1989 and 1993. The HRCT images were obtained in the axial and semicoronal planes using 1 mm slice thickness and 1 mm intersection gap. In 46 (75%) of the 61 patients, the HRCT image-based assessment of the facial canal dehiscence coincided with the surgical findings. The data for the facial canal revealed sensitivity of 66% and specificity of 84%. For semicircular canal fistula. in 59 (97%) of the 61 patients, the HRCT image-based assessment and the surgical findings coincided. The image-based assessment in the remaining two patients, who both had massive cholesteatoma, was false-positive. HRCT is useful in the diagnosis of facial canal dehiscence and labyrinthine fistula, but its limitations should also be recognized. 12 refs., 3 figs., 6 tabs.

Objective Our purpose is to demonstrate the deformity of the cranial nerves by arterial compression using a novel technique, multislice motion-sensitized driven equilibrium (MSDE). Methods Subjects were 10 patients with neurovascular compression (5 patients with trigeminal neuralgia and 5 patients with hemifacial spasm). We observed the existence and extent of deformity of nerves by MSDE. Afterward, we compared operative findings with preoperative imaging findings and evaluated the validity of the latter. Results All compressing, blood vessels could be correctly identified through preoperative evaluation. Of all patients, 7 showed deformity of the cranial nerves, which was consistent with operative findings except in one case. In postoperative evaluation, patients' neurological symptoms improved and the deformity disappeared. Three patients did not show deformity on preoperative MSDE images. In these patients, neural compression was also not observed during the operation. Conclusions The deformity of cranial nerves in patients with neurovascular compression was clearly shown using MSDE.

We report a case of a fetal omphalocele in which the internal structure of the hernia sac was imaged in detail by magnetic resonance (MR) imaging. The hernia sac consisted of amnion, Wharton jelly, and externally, peritoneum. The umbilical vascular channels (2 arteries, one vein) were surrounded by Wharton jelly. Use of MR imaging facilitates a more accurate evaluation of fetal omphalocele with regard to hernial sac, intestinal structure, and differential diagnosis.

Purpose We experienced an outbreak of enterohemorrhagic Escherichia coli (EHEC) colitis. The purpose of this study was to reveal the computed tomographic (CT) findings on EHEC colitis. Methods The subjects were 7 patients with EHEC colitis, which was caused by eating a contaminated Japanese rice cake. Contrast CT was performed on all patients. Two radiologists evaluated the CT findings (the thickness of colon wall, the range of thickened colon, and the existence of dirty fat signs around the colon, ascites, and swelling of lymph nodes), in accordance with our PACS system. Results Wall swelling of the proximal colon from cecum to ascending colon was noted in all patients. Small intestine lesions were not noted in any cases. Conclusions We should consider EHEC infection as part of a differential diagnosis when the findings of severe right colitis are seen without enteritis.

The asialoglycoprotein receptor (ASGPR) is abundantly expressed on the sinusoidal surfaces of hepatocytes. However, regional expression and clinical significance of the ASGPR in acute hepatic damage is presently unknown. Our aim was to clarify the clinical significance of the regional expression of ASGPR in human livers with acute hepatitis (AH) and fulminant hepatic failure (FHF). Eighteen volunteers, 42 patients with AH and 10 with FHF were studied using a newly developed, conventional 99mTc-GSA SPECT analysis. Using Cantlie's line as a guide, ASGPR expression was analyzed separately in the right and left hepatic lobes, as well as in the whole liver, using novel indices (the liver uptake ratio [LUR] and liver uptake density [LUD], which reflect the amount and density of ASGPRs in the liver, respectively). Mean LUR and LUD values for the whole liver and the right and left lobes decreased in accordance with the severity of acute hepatic damage. In the FHF group, the reduction in LUR and LUD values in the right lobes was more significant than in the left lobes. The LUR and LUD values for the whole liver correlated well with hepatic functional reserve and total bilirubin levels. The right LUR and LUD values in particular correlated well with these parameters. A time-course observation of 13 patients with either AH or FHF revealed that the expression of ASGPRs in the right lobe recovered faster than in the left. We first evaluated the regional expression of AGSPRs by 99mTc-GSA SPECT analysis in both AH and FHF patients, which is a clinically useful and reliable indicator for assessing the severity of regional hepatic damage and evaluating regional liver regeneration.

To analyze the retention process of technetium-99m ethyl cysteinate dimer (99mTc-ECD) in normal and ischemic lesions, we developed a super rapid dynamic SPECT system based on the CERASPECT (DSI, Inc., Waltham, MA, USA). The system made it possible to take a SPECT series every 2 seconds. Each SPECT series contains a maximum of 16 slices (6.6 mm slice interval) in a matrix size of 32 x 32. The sensitivity of this system is 175 kcps/MBq/ml/cm slice thickness, and resolution is 12 mm FWHM at the center of a 20 cm(phi) water phantom. Using the super rapid SPECT system, the kinetic behavior of the 99mTc-ECD during retention in normal and ischemic lesions was analyzed. Twenty patients with ischemic lesions that were clearly demonstrated by 133Xe-rCBF (regional cerebral blood flow) SPECT but unclear on static 99mTc-ECD SPECT were examined. For the dynamic SPECT, 700 MBq of 99mTc-ECD was injected intravenously, and dynamic SPECT data were acquired every 2 seconds during a 90-second period. The serial dynamic SPECT and time-activity curves at some lesions with reduced rCBF and at the contralateral normal brain were analyzed. These dynamic SPECT data were compared with conventional static 99mTc-ECD SPECT and quantitative 133Xe-rCBF SPECT. All of mildly or moderately reduced rCBF lesions on the 133Xe-rCBF SPECT were recognized as low activity regions only at the early phase (during about 2-20 sec or less), with the lesions then gradually vanishing. These lesions were not recognized on the conventional static SPECT taken after the dynamic study. The time-activity curve at the reduced rCBF lesion was lower than that of contralateral normal brain at the early phase, and overtook the activity in the normal region with a gradual increase. The early phase images of 99mTc-ECD SPECT within 20 seconds by the super rapid dynamic SPECT were very useful to the same extent as the 133Xe-rCBF SPECT for detecting mild or moderate ischemic lesions. This study suggests that esterase activity, participating in the ECD retention mechanism, may be tolerable to mild or moderate ischemia. This tolerance may be the main cause of the nonlinear relationship between ECD accumulation and cerebral blood flow.

The asialoglycoprotein receptor (ASGPR) is abundantly expressed on the sinusoidal surfaces of hepatocytes. We aimed to clarify the clinical significance of the regional distribution of ASGPRs in the human liver, especially in chronic viral hepatitis. Eighteen volunteers, 34 patients with chronic hepatitis, and 33 patients with cirrhosis (11/Child-Pugh A, 11/Child-Pugh B, 11/Child-Pugh C) were studied using a newly developed, conventional technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin (99mTc-GSA), single photon emission computed tomography (SPECT) method. Using Cantlie's line as a guide, ASGPR dynamics were analyzed separately in the right and left lobes, as well as in the whole liver, using novel indices (the liver uptake ratio [LUR] and the liver uptake density [LUD], which reflect the amount and density of ASGPRs in the liver, respectively). Mean LUR and LUD values for the whole liver and the right and left lobes decreased with increasing progression of chronic viral hepatitis. The LUR for the whole liver correlated well with parameters measuring the hepatic functional reserve and the platelet count. The right LUR correlated particularly well with conventional liver function tests, and comparison of the right LUD with histologic findings showed that it was a good indicator of periportal and/or bridging necrosis and fibrosis. In conclusion, our 99mTc-GSA SPECT method was clinically useful in evaluating regional hepatic function and the progression of chronic viral hepatitis using dynamic changes in ASGPRs. (Hepatology 2003;38:1401-1409.)

BACKGROUND AND PURPOSE: To our knowledge, inner structural alterations of the hippocampus have never been demonstrated because of the lack of contrast between the hippocampus proper and the superficial medullary lamina. We sought to demonstrate the anatomic details of the inner hippocampus and to elucidate its alterations in Alzheimer disease (AD) in vivo. METHODS: We obtained multishot diffusion- and T2-weighted MR images in 14 healthy control subjects and 26 patients with mild or moderate AD (diagnosis based on Mini-Mental Status Examination scores). We measured the width of the subiculum, CA1 and CA3–4, and the height of CA3–4 on coronal images. RESULTS: The subiculum and hippocampus proper were demonstrated as whirlpool-shaped hyperintense areas, and the superficial medullary lamina was visible as a hypointense structure along the inner margin of the hippocampus proper. Regarding the width of the subiculum and CA1, intergroup analysis revealed significant differences between the control and mild or moderate AD groups. In the width of CA3–4, we found no significant difference between the control and mild AD groups; however, differences between the control and moderate AD groups and between the mild and moderate AD groups were significant. In the height of CA3–4, we observed no significant differences between groups. CONCLUSION: We clearly visualized the inner structure of the hippocampal formation by using multishot diffusion-weighted imaging. The subiculum and CA1 are the most vulnerable regions in AD, and atrophy of these structures was evident in both mild and moderate AD.

Multiplanar reconstruction (MPR) images along the facial nerve canal were prepared with high-resolution computed tomography (HRCT) and their clinical usefulness was evaluated. Over a period of 6 years, temporal bone HRCT was performed on 628 cases. Of these cases, 6 patients exhibited facial nerve lesions, including facial nerve schwannoma (n = 3), traumatic facial nerve palsy (n = 2) and congenital facial nerve palsy (n = 1). Thirty patients without facial nerve lesions, such as chronic otitis media, were randomly selected as controls. Two types of MPR image were composed. One was along the labyrinthine and tympanic segment, and the other was along the tympanic and mastoid segment. Other MPR images, such as those along the facial nerve canal and bone fracture line, were composed as needed. All MPR images were prepared with real-time observation of delicate angles. In all cases, MPR images delineated the labyrinthine and tympanic segment in one image, and the tympanic and mastoid segment in another image. In two patients with traumatic facial nerve palsy, the MPR images revealed a relationship between the facial nerve canal and the bone fracture. In conclusion, MPR images of the facial nerve canal are easy to obtain and are useful in detecting facial nerve schwannoma, traumatic facial nerve palsy and congenital facial nerve palsy.

This study was conducted to assess the usefulness and limitation of high-resolution CT for evaluating the condition of ossicular chain in the middle ear. Preoperative CT findings of the ossicular chain were compared with the operative findings of ossicles in 26 patients with chronic otitis media or congenital ossicular anomaly who underwent tympanoplasty. Total defect of head of the malleus, body of the incus and long process of the incus were completely detected by high-resolution CT. But the reliability in detecting the defect of handle of the malleus and superstructure of the stapes were 33.3% and 60%, respectively. Defect of the I-S joint (1 case) and partial defect of stapes crus (2 cases) could not be diagnosed correctly in the preoperative estimation. Although these findings demonstrate the limitations of high-resolution CT in the diagnosis of ossicular chain, it will be diminished by the advanced space resolution of CT in the future.

This study was conducted to assess the usefulness and limitations of high-resolution CT for diagnosing the ossicular chain in the middle ear. The CT images in this study were obtained in as much detail as possible and 2 direction images. Preoperative CT findings of the ossicular chain were compared with operative findings in 26 patients with ossicular defects. Preoperative detection of the complete defect of the malleus head and the body and long process of the incus by high-resolution CT was possible in all cases, while detection of the defect of the manubrium of the malleus and superstructure of the stapes could be made in 33.3 and 60%, respectively. The defect of the incudostapedial joint (1 case) and partial defect of the stapes crus (2 cases) could not be diagnosed correctly by preoperative estimation.

As a new parametric image of cerebral lesions, a map of the ratio between regional cerebral blood flow (rCBF) and the 2nd image of a series of dynamic images was proposed and tested. Three classes (poor, mild and well) were defined based on the degree of coupling between the rCBF and the new parametric image of the affected lesion. In 16 patients with cerebral infarction, those in the acute stage (within 1 week after onset) were found to belong to the poor coupling group, and the subacute group (1 to 4 weeks) showed mild coupling. In the chronic group (over 4 weeks), well coupling was observed. All patients of TIA fell into the mild coupling group. In a stimulation study with 5% CO2 mixed air, all of the well or mild-coupled lesions changed to uncoupled. These clinical findings demonstrate the characteristics of the new proposed image.