Quantitative T1 mapping of the substantia nigra using phase-sensitive inversion recovery sequence at 3.0-T: a healthy volunteer study.

BACKGROUND: Quantitative evaluation of degeneration of the substantia nigra (SN) is important for early, pre-symptomatic diagnosis of Parkinson's disease (PD). Accordingly, a clinically feasible imaging and quantification technique are needed. PURPOSE: To investigate the T1 value of the SN in healthy individuals from phase-sensitive inversion recovery (PSIR) images and to clarify its correlation with the SN characteristics on neuromelanin (NM) images to identify an imaging biomarker for early diagnosis of PD. MATERIAL AND METHODS: T1-weighted and NM images of the SN from 32 healthy volunteers were obtained using PSIR and turbo spin-echo sequences. The contrast between the SN and cerebral peduncle (CP) and area of the SN were measured; the T1 values of the SN from PSIR images and relationships between the T1 value and age/SN area were evaluated. RESULTS: There was a significant negative correlation between age and the SN area obtained using PSIR imaging. The SN area on PSIR images (104.9 ± 20.9 mm2) was significantly larger than that on NM images (72.1 ± 14.9 mm2). There was a significant negative correlation between the SN area and the T1 value of the SN obtained from PSIR images. CONCLUSION: In healthy adults, the area and T1 value of the SN measured on PSIR images were different from those obtained from NM images. This suggests that PSIR imaging may help in the assessment of SN degeneration.

Arterial spin-labeling MR imaging of cerebral hemorrhages.

INTRODUCTION: The purpose of this study is to identify the characteristics of brain perfusion measured by arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cerebral hemorrhages. METHODS: Brain blood flow values (CBF-ASL values) for cerebral and cerebellar hemispheres and segmented cerebral regions were measured by ASL-MRI in 19 putaminal hemorrhage patients and 20 thalamic hemorrhage patients in acute or subacute stages. We assessed the lateralities of CBF-ASL values and the relationships between CBF-ASL values and other imaging findings and clinical manifestations. RESULTS: Both the 19 putaminal hemorrhage patients and the 20 thalamic hemorrhage patients had significantly low CBF-ASL values of the contralateral cerebellum in subacute stage, suggesting that ASL-MRI might delineate crossed cerebellar diaschisis (CCD). Ipsilateral low CBF-ASL values were observed in frontal lobes and thalami with a putaminal hemorrhage and lentiform nuclei, temporal lobes, and parietal lobes with a thalamic hemorrhage, suggesting that ASL-MRI showed the ipsilateral cerebral diaschisis (ICD). In the putaminal hemorrhage patients, the hematoma volume negatively affected both the bilateral cerebellar and cerebral hemispheric CBF-ASL values. In the thalamic hemorrhage patients, a concomitant intraventricular hemorrhage caused low cerebral hemispheric CBF-ASL values. CONCLUSION: The use of ASL-MRI is sensitive to the perfusion abnormalities and could thus be helpful to estimate functional abnormalities in cerebral hemorrhage patients.

CT findings of thoracic manifestations of primary Sjögren syndrome: radiologic-pathologic correlation.

Primary Sjögren syndrome is an immune-mediated exocrinopathy characterized by lymphoplasmacytic infiltration of the salivary and lacrimal glands. Various systemic extraglandular disorders are associated with primary Sjögren syndrome, and the thorax is commonly affected. The pulmonary manifestations of primary Sjögren syndrome may be categorized as airway abnormalities, interstitial pneumonias, and lymphoproliferative disorders; in each category, bronchiectasis or centrilobular nodules, nonspecific interstitial pneumonia, and lymphoid interstitial pneumonia are common. These manifestations do not usually occur in isolation; they are concomitantly seen with other types of lesions. Mucosa-associated lymphoid tissue (MALT) lymphoma and amyloidosis are key components of lymphoproliferative disorders, and MALT lymphoma should always be considered because its morphologic characteristics are similar to those of benign lymphoproliferative disorders. Amyloidosis is rare but important because it carries a risk for underlying MALT lymphoma or plasmacytoma, and it may lead to hemoptysis during biopsy. In addition, thin-walled air cysts are characteristic of primary Sjögren syndrome, irrespective of the main pulmonary manifestations. Lymphadenopathy and multilocular thymic cysts may be seen in the mediastinum. During the follow-up period, there is a risk for acute exacerbation of interstitial pneumonia and development of malignant lymphoma. Often, primary Sjögren syndrome is subclinical, but there are various underlying risks. Thus, imaging findings are important. In addition to the various types of interstitial pneumonia and airway abnormalities, air cysts and mediastinal manifestations may help diagnose primary Sjögren syndrome.

CT-gastrography for early gastric cancer visualized by wall-carving technique using contrast-enhanced MDCT for portal phase.

OBJECTIVE: The wall-carving (WC) imaging technique is used to evaluate early gastric cancer using multidetector row computed tomography (MDCT) image data for only the arterial phase. Our purpose was to investigate if WC images derived from portal phase MDCT images can enhance the visualization of early gastric cancer. SUBJECTS AND METHODS: Fourteen consecutive patients (average age/age range (years) = 75.8/61 to 86; male/female = 9/5) were enrolled. They were diagnosed with early gastric cancer and underwent contrast-enhanced MDCT before treatment. WC images of the arterial and portal phases were created from images scanned by 64-detector-row MDCT 40 and 60 seconds after the initiation of the contrast material injection, respectively. The correlation between the detection rates of lesions in the WC images and pathological findings was investigated. RESULTS: Totals of 71.4% (10/14) of arterial phase WC images and 71.4% (10/14) of portal phase WC images showed lesions. The imaging ability improved to 85.7% (12/14) when the two sets of images were combined. Well-differentiated adenocarcinomas tended to be visualized better in WC images of any phases. CONCLUSION: WC is an excellent image analysis technique for visualizing early gastric cancer lesions. The depiction rates were improved by using a combination of arterial and portal WC images. The scan timing after the contrast material injection should be carefully investigated to improve the detection rate of lesions.

A technical perspective for understanding quantitative arterial spin-labeling MR imaging using Q2TIPS.

We illustrate the fundamental theoretical principles of arterial spin-labeling (ASL) magnetic resonance imaging (MRI) and show a system that employs the second version of quantitative imaging of perfusion using a single subtraction (Q2TIPS) to quantify cerebral blood flow (CBF). We also discuss the effects of the parameters used in Q2TIPS on CBF values as measured with ASL-MRI.

Arterial spin-labeling MR imaging in Moyamoya disease compared with clinical assessments and other MR imaging findings.

PURPOSE: Our purpose was to identify the causal factors for the perfusion distribution obtained with ASL-MRI by comparing ASL-MRI with clinical information and other MRI findings in moyamoya disease. METHODS: Seventy-one patients with moyamoya disease underwent ASL-MRI and other MRI, including fluid-attenuated inversion recovery imaging (FLAIR) and three-dimensional time-of-flight magnetic resonance angiography (MRA) on 3.0-Tesla MRI system. Cerebral blood flow (CBF) values (ASL values) for the cerebral hemispheres (142 sides) were measured on CBF maps generated by ASL-MRI. Relationships between the ASL values and the following 9 factors were assessed: sex, family history, revascularization surgery, age at MR exam, age at onset, the steno-occlusive severity on MRA (MRA score), degree of basal collaterals, degree of leptomeningeal high signal intensity seen on FLAIR, and size of ischemic or hemorrhagic cerebrovascular accident lesion (CVA score). RESULTS: Patients with a family history had significantly higher ASL values than those without such a history. There were significant negative correlations between ASL values and age at MR exam, MRA score, and CVA score. CONCLUSIONS: ASL-MRI may have cause-and-effect or mutual associations with family history, current patient age, size of CVA lesion, and intracranial arterial steno-occlusive severity in Moyamoya disease.