Signal Change of Acute Cortical and Juxtacortical Microinfarction on Follow-Up MRI

BACKGROUND AND PURPOSE

Although the clinical importance of cortical microinfarcts has become well-recognized recently, the evolution of cortical microinfarcts on MR imaging is not fully understood. The aim of this study was to examine the temporal changes in acute cortical microinfarcts using susceptibility-weighted imaging and conventional MR imaging.

MATERIALS AND METHODS

Patients with acute infarcts located in the cortical and/or juxtacortical region measuring ≤10 mm in axial diameter based on diffusion-weighted imaging who had a follow-up 3T MR imaging were retrospectively included in the study. All lesions did not show hypointensity on initial T2*WI. For cortical and/or juxtacortical microinfarcts detected on initial DWI, 2 neuroradiologists evaluated the follow-up MR imaging (T2WI, FLAIR, T2*WI, and SWI) and assessed lesion signal intensities and locations (cortical microinfarcts or microinfarcts with juxtacortical white matter involvement).

RESULTS

On initial DWI, 2 radiologists observed 180 cortical and/or juxtacortical microinfarcts in 35 MR imaging examinations in 25 patients; on follow-up, the neuroradiologists identified 29 cortical microinfarcts (16%) on T2WI, 9 (5%) on FLAIR, 4 (2%) on T2*, and 97 (54%) on SWI. All cortical microinfarcts detected with any follow-up MR imaging showed hyperintensity on T2WI/FLAIR and/or hypointensity on T2*WI and SWI.

CONCLUSIONS

SWI revealed conversion (paramagnetic susceptibility changes) of acute cortical microinfarcts, suggesting that a substantial number of cortical microinfarcts may contain hemorrhagic components.

Pituitary Macroadenoma and Visual Impairment: Postoperative Outcome Prediction with Contrast-Enhanced FIESTA

BACKGROUND AND PURPOSE

Contrast-enhanced FIESTA can depict anterior optic pathways in patients with large suprasellar tumors. We assessed whether the degree of kink in the optic nerve at the optic canal orifice on contrast-enhanced FIESTA correlates with the postoperative improvement of visual impairment in patients with pituitary macroadenoma.

MATERIALS AND METHODS

Thirty-one patients with pituitary macroadenoma who underwent preoperative MR imaging and an operation were evaluated. We measured the optic nerve kinking angle on sagittal oblique contrast-enhanced FIESTA parallel to the optic nerve; the optic nerve kinking angle was defined as the angle between a line parallel to the planum sphenoidale and a line parallel to the intracranial optic nerve at the optic canal orifice. We used logistic regression analyses to determine whether the clinical (sex, age, and duration of symptoms) and imaging (tumor height, chiasmal compression severity, hyperintense optic nerve on T2WI, and optic nerve kinking angle) characteristics were associated with the postoperative improvement (good-versus-little improvement) of visual acuity disturbance and visual field defect.

RESULTS

There were 53 impaired sides before the operation: 2 sides with visual acuity disturbance alone, 25 with visual field defect alone, and 26 with both. After the operation, good improvement was found in 17 of the 28 sides with visual acuity disturbance and in 32 of the 51 sides with visual field defects. Only the optic nerve kinking angle was significantly associated with good improvement of the visual acuity disturbance (P = .011) and visual field defect (P = .002).

CONCLUSIONS

The degree of the optic nerve kinking angle was an independent predictor of postoperative improvement, indicating that irreversible damage to the optic nerve may be associated with its kinking at the optic canal orifice.

PCLO rs2522833-mediated gray matter volume reduction in patients with drug-naive, first-episode major depressive disorder

Major depressive disorder (MDD) has been linked to differences in the volume of certain areas of the brain and to variants in the piccolo presynaptic cytomatrix protein (PCLO), but the relationship between PCLO and brain morphology has not been studied. A single-nucleotide polymorphism (SNP) in PCLO, rs2522833, is thought to affect protein stability and the activity of the hypothalamic-pituitary-adrenal axis. We investigated the relationship between cortical volume and this SNP in first-episode, drug-naive patients with MDD or healthy control subjects. Seventy-eight participants, including 30 patients with MDD and 48 healthy control subjects, were recruited via interview. PCLO rs2522833 genotyping and plasma cortisol assays were performed, and gray matter volume was estimated using structural magnetic resonance images. Among the individuals carrying the C-allele of PCLO rs2522833, the volume of the left temporal pole was significantly smaller in those with MDD than in healthy controls (family-wise error-corrected, P=0.003). No differences were detected in other brain regions. In addition, the C-carriers showed a larger volume reduction in the left temporal pole than those in the individuals with A/A genotype (P=0.0099). Plasma cortisol levels were significantly higher in MDD-affected C-carriers than in the healthy control C-carriers (12.76±6.10 vs 9.31±3.60 nm, P=0.045). We conclude that PCLO SNP rs2522833 is associated with a gray matter volume reduction in the left temporal pole in drug-naive, first-episode patients with MDD carrying the C-allele.

Skull Metastasis from Hepatocellular Carcinoma

CT, MR and angiographic findings of 6 patients with 9 skull metastases from hepatocellular carcinoma (HCC) were reviewed. In 3 of 6 patients, local pain or neurologic deficit was the initial main manifestation of the disease, although all had been treated for chronic liver disease. In the remaining 3 patients, skull metastases were detected following treatment of HCC. The metastatic lesions appeared as expansile osteolytic masses on CT and as hypervascular masses on angiography. All lesions were demonstrated on MR imaging. Compared with the brain parenchyma, the lesions were iso- or hypointense on T1-weighted and T2-weighted MR images. The lesions were moderately to markedly enhanced by Gd-DTPA. Flow voids were shown in the tumors in 5 lesions. HCC should be included in the differential diagnosis of an osteolytic hypervascular lesion of the skull, especially in Oriental patients. The relatively hypointense tumor on T2-weighted MR images associated with flow void, different from primary skull tumors or directly invasive tumors, may support the diagnosis of HCC metastasis.

Light and Electron Microscopic Observations in Atherosclerotic Rabbits following Experimental Transluminal Angioplasty

Light and scanning electron microscopy were used to assess the morphologic changes in atherosclerotic lesions in rabbits following percutaneous transluminal angioplasty. Histologic changes observed by light microscopy, i.e. fracture or separation of the plaque and overdistension of the media, were correlated with different balloon sizes. In atherosclerotic rabbits, progressive changes were observed in the vessel wall with increasing size of the balloon. Scanning electron microscopy showed denudation of the endothelial cells, exposure of the subintimal layer, and adhesion of the platelets. In addition, compression of the atheroma, circumferential endothelial rupture, flattening of the intimal fold, and undulation of the intimal fold were observed. Morphometric analysis of histologic sections of the dilated and non-dilated aortas disclosed significant differences in the thickness to width ratio of the plaque. These findings demonstrated that compression of the atherosclerotic plaque could occur.

Neonatal periventricular-intraventricular hemorrhage: Subacute and chronic MR findings

Purpose: To evaluate MR findings at subacute and chronic stages after neonatal periventricular-intraventricular hemorrhage (PIVH), and to determine the clinical significance of follow-up MR.

Material and Methods: Twenty-six children (estimated gestational age, 23-39 weeks; mean 29 weeks) with a history of previous PIVH underwent MR examination during their subacute and chronic clinical courses. PIVHs were initially detected with ultrasound examination in all cases. PIVH was divided into three grades (mild, moderate, and severe) according to the findings at the initial US studies, which were correlated to the MR findings.

Results: Abnormal signal intensities related to hemorrhage were demonstrated in 10 of 21 patients (47.6%) on initial MR studies; the very low signal intensities on T2-weighted images found on the periventricular wall with a linear or a spotty shape had disappeared at one year after the initial US. The children with ventriculomegaly and periventricular leukomalacia (PVL) were increased in number on the follow-up studies.

Conclusion: MR imaging provided valuable information about the consequences of neonatal PIVH such as developments of ventriculomegaly or PVL. It is noteworthy that hemorrhagic lesions could not be detected in half of the cases at the subacute or chronic stage of PIVH.

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.

Usefulness of quantitative susceptibility mapping for the diagnosis of Parkinson disease

BACKGROUND AND PURPOSE

Quantitative susceptibility mapping allows overcoming several nonlocal restrictions of susceptibility-weighted and phase imaging and enables quantification of magnetic susceptibility. We compared the diagnostic accuracy of quantitative susceptibility mapping and R2* (1/T2*) mapping to discriminate between patients with Parkinson disease and controls.

MATERIALS AND METHODS

For 21 patients with Parkinson disease and 21 age- and sex-matched controls, 2 radiologists measured the quantitative susceptibility mapping values and R2* values in 6 brain structures (the thalamus, putamen, caudate nucleus, pallidum, substantia nigra, and red nucleus).

RESULTS

The quantitative susceptibility mapping values and R2* values of the substantia nigra were significantly higher in patients with Parkinson disease (P < .01); measurements in other brain regions did not differ significantly between patients and controls. For the discrimination of patients with Parkinson disease from controls, receiver operating characteristic analysis suggested that the optimal cutoff values for the substantia nigra, based on the Youden Index, were >0.210 for quantitative susceptibility mapping and >28.8 for R2*. The sensitivity, specificity, and accuracy of quantitative susceptibility mapping were 90% (19 of 21), 86% (18 of 21), and 88% (37 of 42), respectively; for R2* mapping, they were 81% (17 of 21), 52% (11 of 21), and 67% (28 of 42). Pair-wise comparisons showed that the areas under the receiver operating characteristic curves were significantly larger for quantitative susceptibility mapping than for R2* mapping (0.91 versus 0.69, P < .05).

CONCLUSIONS

Quantitative susceptibility mapping showed higher diagnostic performance than R2* mapping for the discrimination between patients with Parkinson disease and controls.

Tumor consistency of pituitary macroadenomas: predictive analysis on the basis of imaging features with contrast-enhanced 3D FIESTA at 3T

BACKGROUND AND PURPOSE

Preoperative evaluation of pituitary macroadenoma tumor consistency is important for neurosurgery. Thus, we aimed to retrospectively assess the role of contrast-enhanced FIESTA in predicting the tumor consistency of pituitary macroadenomas.

MATERIALS AND METHODS

Twenty-nine patients with pituitary macroadenomas underwent conventional MR imaging sequences and contrast-enhanced FIESTA before surgery. Two neuroradiologists assessed the contrast-enhanced FIESTA, contrast-enhanced T1WI, and T2WI. On the basis of surgical findings, the macroadenomas were classified by the neurosurgeons as either soft or hard. Finally, Fisher exact probability tests and unpaired t tests were used to compare predictions on the basis of the MR imaging findings with the tumor consistency, collagen content, and postoperative tumor size.

RESULTS

The 29 pituitary macroadenomas were classified as either solid or mosaic types. Solid type was characterized by a homogeneous pattern of tumor signal intensity without intratumoral hyperintense dots, whereas the mosaic type was characterized by many intratumoral hyperintense dots on each MR image. Statistical analyses revealed a significant correlation between tumor consistency and contrast-enhanced FIESTA findings. Sensitivity and specificity were higher for contrast-enhanced FIESTA (1.00 and 0.88-0.92, respectively) than for contrast-enhanced T1WI (0.80 and 0.25-0.33, respectively) and T2WI (0.60 and 0.38-0.54, respectively). Compared with mosaic-type adenomas, solid-type adenomas tended to have a hard tumor consistency as well as a significantly higher collagen content and lower postoperative tumor size.

CONCLUSIONS

Contrast-enhanced FIESTA may provide preoperative information regarding the consistency of macroadenomas that appears to be related to the tumor collagen content.

Brain MR findings in patients with systemic lupus erythematosus with and without antiphospholipid antibody syndrome

BACKGROUND AND PURPOSE

Antiphospholipid syndrome may affect the incidence and pathogenesis of cerebrovascular diseases in patients with systemic lupus erythematosus. We compared the spectrum of MR findings in patients with systemic lupus erythematosus with and without antiphospholipid syndrome.

MATERIALS AND METHODS

We identified 256 patients with systemic lupus erythematosus (45 with, 211 without antiphospholipid syndrome) who underwent MR studies; in 145 (57%), we detected abnormalities. These were categorized as large territorial, lacunar, localized cortical, and borderzone infarctions and as microembolisms, basal ganglia lesions, callosal lesions, hemorrhages, and white matter hyperintensity on T2-weighted and/or FLAIR images, and as stenotic arterial lesions on MR angiograms. Logistic regression analysis was performed to compare the MR findings in patients with systemic lupus erythematosus with and without antiphospholipid syndrome, with patient age and antiphospholipid syndrome as the covariates.

RESULTS

Abnormal MR findings were more common in patients with systemic lupus erythematosus with antiphospholipid syndrome (73% versus 53%). Large territorial (P = .01), lacunar (P = .01), localized cortical (P < .01), borderzone infarcts (P < .01), basal ganglia lesions (P = .03), stenotic arterial lesions (P = .04), and the rate of positive findings on MR imaging (P = .01) were significantly associated with antiphospholipid syndrome. Irrespective of age, significantly more patients with antiphospholipid syndrome manifested lacunar infarcts in the deep white matter (P < .01), localized cortical infarcts in the territory of the MCA (P < .01), bilateral borderzone infarcts (P < .01), and anterior basal ganglia lesions (P = .01).

CONCLUSIONS

Abnormal MR findings were more common in patients with systemic lupus erythematosus with than in those without antiphospholipid syndrome. Large territorial infarctions, lacunar infarctions in the deep white matter, localized cortical infarctions in the MCA territory, bilateral borderzone infarctions, anterior basal ganglia lesions, and stenotic arterial lesions are common MR findings in patients with systemic lupus erythematosus with antiphospholipid syndrome.

Normal flow signal of the pterygoid plexus on 3T MRA in patients without DAVF of the cavernous sinus

BACKGROUND AND PURPOSE

Cavernous sinuses and draining dural sinuses or veins are often visualized on 3D TOF MRA images in patients with dural arteriovenous fistulas involving the CS. Flow signals may be seen in the jugular vein and dural sinuses at the skull base on MRA images in healthy participants, however, because of reverse flow. Our purpose was to investigate the prevalence of flow signals in the pterygoid plexus and CS on 3T MRA images in a cohort of participants without DAVFs.

MATERIALS AND METHODS

Two radiologists evaluated the flow signals of the PP and CS on 3T MRA images obtained from 406 consecutive participants by using a 5-point scale. In addition, the findings on 3T MRA images were compared with those on digital subtraction angiography images in an additional 171 participants who underwent both examinations.

RESULTS

The radiologists identified 110 participants (27.1%; 108 left, 10 right, 8 bilateral) with evidence of flow signals in the PP alone (n = 67) or in both the PP and CS (n = 43). Flow signals were significantly more common in the left PP than in the right PP. In 171 patients who underwent both MRA and DSA, the MRA images showed flow signals in the PP with or without CS in 60 patients; no DAVFs were identified on DSA in any of these patients.

CONCLUSIONS

Flow signals are frequently seen in the left PP on 3T MRA images in healthy participants. This finding may be the result of flow reversal and should not be considered to indicate occult DAVF.

Comparison of brain N-acetylaspartate levels and serum brain-derived neurotrophic factor (BDNF) levels between patients with first-episode schizophrenia psychosis and healthy controls

BACKGROUND

N-acetylaspartate (NAA) levels and serum brain-derived neurotrophic factor (BDNF) levels in patients with first-episode schizophrenia psychosis and age- and sex-matched healthy control subjects were investigated. In addition, plasma levels of homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were compared between the two groups.

METHOD

Eighteen patients (nine males, nine females; age range: 13-52 years) were enrolled in the study, and 18 volunteers (nine males, nine females; age range: 15-49 years) with no current or past psychiatric history were also studied by magnetic resonance spectroscopy (MRS) as sex- and age-matched controls.

RESULTS

Levels of NAA/Cr in the left basal ganglia (p=0.0065) and parieto-occipital lobe (p=0.00498), but not in the frontal lobe, were significantly lower in patients with first-episode schizophrenia psychosis than in control subjects. No difference was observed between the serum BDNF levels of patients with first-episode schizophrenia psychosis and control subjects. In regard to the plasma levels of catecholamine metabolites, plasma MHPG, but not HVA, was significantly lower in the patients with first-episode psychosis than in control subjects. In addition, a significantly positive correlation was observed between the levels of NAA/Cr of the left basal ganglia and plasma MHPG in all subjects.

CONCLUSION

These results suggest that brain NAA levels in the left basal ganglia and plasma MHPG levels were significantly reduced at the first episode of schizophrenia psychosis, indicating that neurodegeneration via noradrenergic neurons might be associated with the initial progression of the disease.

Effect of tube voltage on image quality in 64-section multidetector 3D CT angiography: Evaluation with a vascular phantom with superimposed bone skull structures

BACKGROUND AND PURPOSE

Optimal tube voltage and tube current settings are not well established. The purpose of our study was to investigate the image quality on 3D CT angiograms of the brain at various kilovoltage settings by evaluating the depiction of simulated intracranial lesions by using a vascular phantom.

MATERIALS AND METHODS

An anthropomorphic vascular phantom with superimposed bone skull structures was designed to simulate various intracranial aneurysms with aneurysmal blebs. We performed CT angiography by using a 64-detector row CT scanner for various effective tube currents with 4 tube voltages of 80, 100, 120, and 135 kV(p). Simulated aneurysm enhancement and image noise were quantified; SNR and CNR were calculated. The depiction of the simulated aneurysms and blebs on 3D CT angiograms obtained with the volume-rendering technique was subjectively assessed. The effective dose was calculated on the basis of a CTDIw. The results of several protocols were compared by using the Student t test.

RESULTS

At identical doses levels (CTDIw), the mean SNR and CNR at 100 kV(p) were significantly higher than those at 80, 120, and 135 kV(p); and the mean qualitative image score at 100 kV(p) was significantly superior to those at 80 and 135 kV(p).

CONCLUSIONS

Our phantom study suggests that the tube voltage of 100 kV(p) is desirable for cerebral 3D CT angiograms, and the higher or lower kilovoltage settings may result in the degradation in diagnostic image quality.

Reduction of the radiation dose for multidetector row CT angiography of cerebral aneurysms using an edge-preserving adaptive filter: a vascular phantom study

To determine how much the radiation dose can be reduced in multidetector row CTA using a QDS, we performed CTA at various exposure settings using a vascular phantom simulating various aneurysms with superimposed bone skull structures, and postprocessed the image data with QDS. Our results demonstrated that the radiation dose of CTA can be reduced by at least 25% and the image quality for visualizing aneurysms can be preserved by applying the QDS.

Effect of 8-MHz radiofrequency-capacitive regional hyperthermia with strong superficial cooling for unresectable or recurrent colorectal cancer

A well-known disadvantage of a radiofrequency-capacitive device for deep-seated tumours is preferential heating of the subcutaneous fat tissue. The authors previously developed the hyperthermia with their own external cooling unit and achieved strong superficial cooling, and reported its usefulness for the reduction of the preferential heating. The purpose of the present study was to evaluate the effect of hyperthermia with strong superficial cooling on the treatment results for unresectable or recurrent colorectal cancers. From 1986 to 2002, 44 patients with primary unresectable or locally recurrent colorectal cancer treated with thermoradiotherapy were analysed retrospectively. The patients with obesity as a subcutaneous fat thickness more than 3 cm, a high age or other serious complications did not undergo therapy. The results were compared between 17 cases with strong superficial cooling treated after 1997 (Group A) and 27 cases without strong superficial cooling treated before 1996 (Group B). Significant differences in thermometry data of T(max), T(ave) and T(min) were noted between Groups A (45.3, 44.4 and 43.6 degrees C, respectively) and B (42.9, 42.0 and 41.1 degrees C, respectively) (p<0.01). Complete response plus partial response rates were better for Group A than for Group B (59 versus 26%, p = 0.05). Multivariate analysis by logistic regression to evaluate the effects of certain factors on complete response plus partial response was strongly correlated with strong superficial cooling (p<0.05). The median survival times for overall survival were 24.3 months for Group A and 17.1 months for Group B (p<0.05). Eight-megahertz radiofrequency-capacitive regional hyperthermia with strong superficial cooling is potentially useful for improving treatment results in unresectable or recurrent colorectal cancers.

Signal intensity of the motor cortex on phase-weighted imaging at 3T

BACKGROUND AND PURPOSE

It is known that the motor cortex shows hypointensity on T2-weighted images in older patients. The goal of this study was to assess the signal intensity of the motor cortices on the phase-weighted imaging performed with a Windows-based software program that we developed ourselves.

MATERIALS AND METHODS

All studies were performed at 3T MR imaging. First, the TE for the phase-weighted image was optimized; the best contrast between the motor and other cortices was obtained with a TE of 40 ms. The study population consisted of 45 healthy subjects (23 females, 22 males; mean age, 32.1 years). The signal intensity of the motor cortices was divided into 3 grades by 2 neuroradiologists in comparison with that of the superior frontal cortex (SFC): In grade I, the motor cortex was isointense to the SFC; in grade II, the motor cortex was slightly hypointense to the SFC; and in grade III, the motor cortex was markedly hypointense to the SFC.

RESULTS

The motor cortex was classified as either grade II or III in all subjects older than 20 years of age on the phase-weighted images. Even at 10-19 years of age, the grade II or III appearance was found in 14 (88%) of 16 motor cortices (8 subjects) on the phase-weighted images.

CONCLUSION

In adolescents, the motor cortex is hypointense to other cerebral cortices on phase-weighted MR imaging, which probably reflects differences in the concentration of nonheme iron and/or in the tissue architecture.

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.

Detection of cerebrospinal fluid leakage: initial experience with three-dimensional fast spin-echo magnetic resonance myelography

BACKGROUND

The pathogenesis of cerebrospinal fluid (CSF) hypovolemia is supposed to be caused by CSF leakage through small dural defects.

PURPOSE

To compare source three-dimensional (3D) fast spin-echo (FSE) images of magnetic resonance (MR) myelography with radionuclide cisternography findings, and to evaluate the feasibility of MR myelography in the detection of CSF leakage.

MATERIAL AND METHODS

A total of 67 patients who were clinically suspected of CSF hypovolemia underwent indium-111 radionuclide cisternography, and 27 of those who had direct findings of CSF leakage were selected for evaluation. MR myelography with 3D FSE sequences (TR/TE 6000/203 ms) was performed at the lumbar spine for all patients. We evaluated source images and maximum intensity projection (MIP) images of MR myelography, and the findings were correlated with radionuclide cisternography findings. MR myelography of five healthy volunteers was used as a reference. The MR visibility of the CSF leakage was graded as definite (leakage clearly visible), possible (leakage poorly seen), or absent (not shown).

RESULTS

CSF leakage was identified with source 3D FSE images in 22 (81.5%) of 27 patients. Of the 22 patients, 16 were graded as definite and six were graded as possible. For the definite cases, 3D FSE images clearly showed the extent of the leaked CSF in the paraspinal structures. In the remaining five patients with absent findings, radionuclide cisternography showed only slight radionuclide activity out of the arachnoid space.

CONCLUSION

Source 3D FSE images of MR myelography seem useful in the detection of CSF leakage. Invasive radionuclide cisternography may be reserved for equivocal cases only.

Differentiation between paraclinoid and cavernous sinus aneurysms with contrast-enhanced 3D constructive interference in steady- state MR imaging

BACKGROUND AND PURPOSE

Differentiation between paraclinoid and cavernous sinus aneurysms of the internal carotid artery (ICA) is critical when considering treatment options. The purpose of this study was to determine whether contrast-enhanced (CE) 3D constructive interference in steady state (CISS) MR imaging is useful to differentiate between paraclinoid and cavernous sinus aneurysms.

MATERIALS AND METHODS

This study included 11 aneurysms in 10 consecutive female patients, ranging from 52 to 66 years of age. All aneurysms were adjacent to the anterior clinoid process. After conventional and CE 3D-CISS imaging on a 1.5T MR imaging unit, all patients underwent surgery, and the relationship between the aneurysms and the dura was confirmed. Two neuroradiologists evaluated the location of the aneurysms on CE 3D-CISS images and classified them as intradural, partially intradural, and extradural aneurysms. Operative findings were used as a reference standard. To understand the imaging characteristics, we assessed the boundary and signal intensity of the cavernous sinus, CSF, and carotid artery on the side contralateral to the lesion.

RESULTS

Operative findings disclosed that 5 aneurysms were intradural and 6 were extradural. All except 2 were accurately assessed with CE 3D-CISS imaging. One intradural aneurysm adjacent to a large cavernous aneurysm and 1 cavernous giant aneurysm were assessed as partially intradural. On CE 3D-CISS images, the boundary between the CSF, cavernous sinus, and carotid artery was identified by high signal-intensity contrast in all cases.

CONCLUSION

CE 3D-CISS MR imaging is useful for the differentiation between paraclinoid and cavernous sinus aneurysms.

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.

A cone-beam volume CT using a 3D angiography system with a flat panel detector of direct conversion type: usefulness for superselective intra-arterial chemotherapy for head and neck tumors

BACKGROUND AND PURPOSE

The development of flat panel detectors (FPDs) has made cone-beam CT feasible for practical use in a clinical setting. Our purpose was to assess the usefulness of cone-beam CT using the FPD in conjunction with conventional digital subtraction angiography (DSA) for performing superselective intra-arterial chemotherapy for head and neck tumors.

MATERIALS AND METHODS

Twenty-three consecutive patients (43 feeding arteries) were prospectively examined. All of the patients underwent intra-arterial rotational angiography using an FPD system, and the cone-beam CT was reconstructed from the volume dataset. Two radiologists evaluated the quality of the cone-beam CT and then evaluated whether the additional information provided by the cone-beam CT was useful for the interventional procedures.

RESULTS

In 41 (95%) of 43 arteries, the extent of contrast material perfusion was sufficiently visualized on cone-beam CT. In 20 (47%) of 43 arteries, the DSA plus cone-beam CT was superior to the DSA alone regarding the precise understanding of vascular territory of each artery. This information was helpful for predicting the drug delivery for superselective intra-arterial chemotherapy, especially in deeply invasive tumors with multiple feeding arteries.

CONCLUSION

In superselective intra-arterial chemotherapy for head and neck tumors, cone-beam CT with FPD provides useful additional information, which allows interventional radiologists to determine the feeders, as well as the dose of antitumor agent for each feeder.

3D digital subtraction angiography of intracranial aneurysms: comparison of flat panel detector with conventional image intensifier TV system using a vascular phantom

BACKGROUND AND PURPOSE

Compared with the image intensifier (I.I.)-TV system, the flat panel detector (FPD) system of direct conversion type has several theoretic advantages, such as higher spatial resolution, wide dynamic range, and no image distortion. The purpose of this study was to compare the image quality of 3D digital subtraction angiography (DSA) in the FPD and conventional I.I.-TV systems using a vascular phantom.

MATERIALS AND METHODS

An anthropomorphic vascular phantom was designed to simulate the various intracranial aneurysms with aneurysmal bleb. The tubes of this vascular phantom were filled with 2 concentrations of contrast material (300 and 150 mg I/mL), and we obtained 3D DSA using the FPD and I.I.-TV systems. First, 2 blinded radiologists compared the volume-rendering images for 3D DSA on the FPD and I.I.-TV systems, looking for pseudostenosis artifacts. Then, 2 other radiologists independently evaluated both systems for the depiction of the simulated aneurysm and aneurysmal bleb using a 5-point scale.

RESULTS

For the degree of the pseudostenosis artifacts at the M1 segment of the middle cerebral artery at 300 mg I/mL, 3D DSA with FPD system showed mild stenoses, whereas severe stenoses were observed at 3D DSA with I.I.-TV system. At both concentrations, the FPD system was significantly superior to I.I.-TV system regarding the depiction of aneurysm and aneurysmal bleb.

CONCLUSION

Compared with the I.I.-TV system, the FPD system could create high-resolution 3D DSA combined with a reduction of the pseudostenosis artifacts.

Reduction of radiation dose for cerebral angiography using flat panel detector of direct conversion type: a vascular phantom study

BACKGROUND AND PURPOSE

Compared with image intensifier television (I.I.-TV) system, an angiography system using the flat panel detector (FPD) of direct conversion type has a high spatial resolution, which may improve image quality, reduce patient exposure, or both. Our purpose was to evaluate the detection of simulated aneurysmal blebs under dose reduction with the FPD system in comparison with the I.I.-TV system.

MATERIALS AND METHODS

A vascular phantom was designed to simulate various intracranial aneurysms with and without blebs, and this phantom was filled with 3 different concentrations of contrast material (300, 150, and 100 mg I/mL). 2D digital subtraction angiography (DSA) at low-dose mode of FPD system was compared with 2D DSA at a standard-dose mode of FPD system and a conventional mode of I.I.-TV system. Data analysis was based on 171 observations (57 aneurysms [20 with bleb and 37 without bleb] x 3 contrast material concentrations) by each of 7 radiologists, and the detection performances of blebs were compared using a receiver operating characteristic (ROC) analysis.

RESULTS

The mean dose measurements with a phantom during 2D DSA were 0.36 mGy/frame with low-dose mode of FPD system, 0.72 mGy/frame with standard-dose mode of FPD system and 0.76 mGy/frame with I.I.-TV system. The mean Az at 100 mg I/mL was significantly higher for low-dose mode of FPD than for conventional-dose mode of I.I.-TV mean Az, 0.85 versus 0.56; P < .01), though differences were not significant with 150 and 300 mg I/mL between both systems.

CONCLUSION

The FPD system allows a considerable dose reduction during 2D DSA without loss of the image quality.

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.

An unusual case of split cord malformation

We present a variant of a split cord malformation with coexisting segmental spinal dysgenesis. CT myelography showed the left hemicord with a small remnant of subarachnoid space running through an intravertebral cleft in a spine anomaly. The left hemicord had no apparent intradual connection to the upper cord on any radiologic examination, though functional electrical stimulation studies revealed an intact efferent pathway that connected the left hemicord to the main spinal cord.

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.

Cytogenetic analysis of myxoid liposarcoma and myxofibrosarcoma by array-based comparative genomic hybridisation

AIM

To investigate overall chromosomal alterations using array-based comparative genomic hybridisation (CGH) of myxoid liposarcomas (MLSs) and myxofibrosarcomas (MFSs).

MATERIALS AND METHODS

Genomic DNA extracted from fresh-frozen tumour tissues was labelled with fluorochromes and then hybridised on to an array consisting of 1440 bacterial artificial chromosome clones representing regions throughout the entire human genome important in cytogenetics and oncology.

RESULTS

DNA copy number aberrations (CNAs) were found in all the 8 MFSs, but no alterations were found in 7 (70%) of 10 MLSs. In MFSs, the most frequent CNAs were gains at 7p21.1-p22.1 and 12q15-q21.1 and a loss at 13q14.3-q34. The second most frequent CNAs were gains at 7q33-q35, 9q22.31-q22.33, 12p13.32-pter, 17q22-q23, Xp11.2 and Xq12 and losses at 10p13-p14, 10q25, 11p11-p14, 11q23.3-q25, 20p11-p12 and 21q22.13-q22.2, which were detected in 38% of the MFSs examined. In MLSs, only a few CNAs were found in two sarcomas with gains at 8p21.2-p23.3, 8q11.22-q12.2 and 8q23.1-q24.3, and in one with gains at 5p13.2-p14.3 and 5q11.2-5q35.2 and a loss at 21q22.2-qter.

CONCLUSIONS

MFS has more frequent and diverse CNAs than MLS, which reinforces the hypothesis that MFS is genetically different from MLS. Out-array CGH analysis may also provide several entry points for the identification of candidate genes associated with oncogenesis and progression in MFS.