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BackgroundComputed diffusion-weighted imaging (DWI) (cDWI) is a computational technique that can be used to calculate a high b-value image from DWI acquired with at least two different lower b-valu...

Endosalpingiosis is characterized by the presence of glands lined by benign tubal-type epithelium outside the fallopian tube. It is usually an incidental finding and rarely occurs as a tumor-like mass lesion. Here, we describe the magnetic resonance imaging findings of endosalpingiosis that presented as a paraovarian multicystic lesion. It exhibited iso to low intensity on T1-weighted images and inhomogeneous high intensity on T2-weighted images. The septa presented relatively iso to slight high intensity on T2-weighted images and strong contrast enhancement on dynamic contrast-enhanced imaging. Endosalpingiosis should be considered as a differential diagnosis in cases of paraovarian multicystic lesions along the uterine serosa.

On conventional magnetic resonance imaging (MRI), hemangioblastomas typically appear as mural nodules with an adjacent surrounding cyst or a solid mass in the cerebellum. However, hemangioblastomas sometimes cannot be reliably distinguished using this imaging technique from other tumors, especially pilocytic astrocytomas and metastatic tumors, because of their similar imaging findings and locations. Herein, we report three cases of cerebellar hemangioblastomas and review their findings on conventional and advanced MRI, including diffusion-weighted imaging (DWI), dynamic susceptibility-weighted contrast-enhanced perfusion-weighted imaging (DSC-PWI), and magnetic resonance spectroscopy (MRS). Solid contrast-enhanced lesions of hemangioblastomas showed increased apparent diffusion coefficient values on DWI, increased relative cerebral blood volume ratio on DSC-PWI, and high lipid/lactate peak on MRS. Therefore, advanced MRI techniques can be helpful in understanding the pathological and metabolic changes of hemangioblastomas and may be useful for their characterization.

Background Both neuromelanin-sensitive magnetic resonance imaging (NmMRI) and 123I-FP-CIT single photon emission computed tomography (SPECT) (DaTSCAN) assist the diagnosis of Parkinson’s disease (PD). However, there have been few studies investigating a correlation between them. Purpose To correlate the utility of NmMRI and DaTSCAN and to evaluate the relationship between both imaging findings and the Unified PD rating scale part III (UPDRS III) score for the diagnosis and management of PD. Material and Methods Seventeen patients with PD who underwent both NmMRI and DaTSCAN were included. We measured the volume of the neuromelanin-positive substantia nigra pars compacta (SNc volume) on NmMRI and measured the specific binding ratio (SBR) on DaTSCAN. The asymmetry index (AI) of the SNc volume and SBR were also calculated. We evaluated the relationship between the UPDRS III score and the SNc volume and SBR, respectively. Results The SNc volume showed a significant correlation with the SBR. The AIs of them also showed a significant correlation. Both the mean of the bilateral SBR and the mean of the bilateral SNc volume showed significant negative correlations with the UPDRS III score. However, the correlation between the SBR and the UPDRS III score was stronger than that between the SNc volume and the UPDRS III score. Conclusion Both NmMRI and DaTSCAN are helpful for PD diagnosis. However, we conclude that DaTSCAN is more suitable for the evaluation of the clinical motor severity and would be more useful for the management of PD patients than NmMRI.

Secondary ovarian involvement by renal cell carcinoma rarely occurs. Here, we describe the computed tomography and magnetic resonance imaging findings of bilateral ovarian metastases from renal cell carcinoma that demonstrated heterogeneous strong contrast enhancing tumors with flow voids around and within the tumors. In addition, the apparent diffusion coefficients of the malignant tumors were high. These findings were similar to those of renal cell carcinomas at primary and other metastatic sites.

Background Multiple system atrophy, cerebellar type (MSA-C) sometimes shows asymmetrical findings on magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). Purpose To assess the frequency and clinical significance of asymmetrical MRI and 99mTc-ethyl cysteinate dimer perfusion (ECD) SPECT findings of the cerebellum, middle cerebellar peduncle (MCP), and pons in MSA-C patients. Material and Methods We retrospectively reviewed 28 patients with MSA-C who underwent MRI and 99mTc-ECD SPECT and evaluated laterality of atrophy and signal changes on MRI, and laterality of perfusion on 99mTc-ECD SPECT transversely and longitudinally. Results Laterality was identified for 64%, 61%, and 21% of atrophy in the cerebellum, MCP, and pons, respectively, on MRI and for 71% of atrophy in the cerebellum on perfusion SPECT. Concerning comparisons between the latest MRI and SPECT findings, laterality of cerebellar/MCP atrophy on MRI and decreased cerebellar perfusion on SPECT was matched in 57%, mismatched in 11%, and absent in 25% of patients. On past images, MRI and SPECT showed matched laterality in 33%, mismatched laterality in 27%, no laterality in 13%, and SPECT precedent laterality in 27% of patients. Including the latest and past images, asymmetrical changes were observed in 75% of patients. We could not identify any correlation between laterality of image findings and cerebellar symptoms in most patients. Conclusion Asymmetrical changes on MRI and perfusion SPECT are common in MSA-C patients. Perfusion SPECT is useful for diagnosing MSA-C in the early stages from a functional perspective.

Background Recently, a newly developed fast-kV switching dual energy CT scanner with a gemstone detector generates virtual high keV images as monochromatic imaging (MI). Each MI can be reconstructed by metal artifact reduction software (MARS) to reduce metal artifact. Purpose To evaluate the degree of metal artifacts reduction and vessel visualization around the platinum coils using dual energy CT with MARS. Material and Methods Dual energy CT was performed using a Discovery CT750 HD scanner (GE Healthcare, Milwaukee, WI, USA). In a phantom study, we measured the mean standard deviation within regions of interest around a 10-mm-diameter platinum coil mass on MI with and without MARS. Thirteen patients who underwent CTA after endovascular embolization for cerebral aneurysm with platinum coils were included in a clinical study. We visually assessed the arteries around the platinum coil mass on MI with and without MARS. Results Each standard deviation near the coil mass on MI with MARS was significantly lower than that without MARS in a phantom study. On CTA of a clinical study, better visibility of neighboring arteries was obtained in 11 of 13 patients on MI with MARS compared to without MARS due to metal artifact reduction. Conclusion: Dual energy CT with MARS reduces metal artifact of platinum coils, resulting in favorable vessel visualization around the coil mass on CTA after embolization.

The aim of this study was to investigate the spatiotemporal characteristics of rhythmic, stationary basketball bouncing in skilled and unskilled adult basketball players. Skilled ( n = 12) and unskilled ( n = 11) basketball players were asked to bounce a basketball every 700 msec, in as temporally stable and spatially accurate a manner as possible, while keeping their eyes fixed straight ahead. Spatial analyses revealed a lower variability of the ball bouncing point and less deviation from a target point in the performance of skilled players compared to unskilled players. Temporal analyses revealed no significant difference in variability of the interbounce interval in skilled versus unskilled players. However, skilled players had longer and more consistent contact time between hand and ball compared to the unskilled players. These results suggest that longer and more consistent hand contact with the ball play an important role in spatial control of basketball bouncing position.

Ovarian stromal hyperthecosis is characterized by diffuse distribution of luteinized stromal cells accompanied by varying degrees of stromal hyperplasia. We report a case of ovarian stromal hyperthecosis with particular regard to magnetic resonance (MR)–pathologic correlation. At initial MR imaging, the central areas of the bilateral ovarian masses showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images, while the peripheries of the bilateral masses showed isointensity to myometrium on T1-weighted images and heterogeneous signal intensities on T2-weighted images. At 15 days after the initial MR imaging examination, a second MR imaging demonstrated shrinkage of the bilateral ovarian masses. Change in the peripheries to predominantly isointensity to myometrium on the T2-weighted images was also observed. The patient underwent bilateral oophorectomy. Microscopic examination revealed scattered nests of lutein cells on a background of densely proliferated ovarian stroma with minimal collagen production in both ovaries. Edema was occasionally seen in the outer portion but was marked in the central zone of the ovaries, particularly on the left. The final pathologic diagnosis was stromal hyperthecosis. With regard to MR–pathologic correlation, the MR findings in the peripheries of the bilateral masses (isointensity relative to myometrium on both T1- and T2-weighted imaging) showed the characteristics of stromal hyperthecosis.

Postmortem magnetic resonance (MR) images were correlated with the histological findings in two autopsy-proven cases of Wallerian degeneration of the corticospinal and corticopontine tracts associated with cerebral embolic infarction. T2 hyperintensities seen in Wallerian degeneration showed vacuolation of myelin in the early stage, and marked loss of myelin and axons with macrophages in the subacute and chronic stages. Similar T2 hyperintensities seen in the different stages of Wallerian degeneration reflect different histological findings.

The purpose of this study was to investigate tapping speed asymmetry in 13 right-handed drummers and 13 right-handed nondrummers. The participants executed single-hand tapping with a stick as fast as possible for 10 sec. with the left and right hand. There was no significant difference in the tapping speed of the right hand between the drummers and the nondrummers, whereas in the left hand, the drummers tapped significantly faster than the nondrummers. Drummers showed less tapping speed asymmetry than nondrummers. These results suggest that the tapping speed of the nonpreferred hand progressed nearly to the level of the preferred hand through daily drum training.