Takanori Higashino

Quantitative assessment of regional pulmonary perfusion in the entire lung using three-dimensional ultrafast dynamic contrast-enhanced magnetic resonance imaging: Preliminary experience in 40 subjects.

To assess regional differences in quantitative pulmonary perfusion parameters, i.e., pulmonary blood flow (PBF), mean transit time (MTT), and pulmonary blood volume (PBV) in the entire lung on a pixel‐by‐pixel basis in normal volunteers and pulmonary hypertension patients.

Primary pulmonary hypertension: 3D dynamic perfusion MRI for quantitative analysis of regional pulmonary perfusion.

OBJECTIVE The purpose of this study was to determine whether quantitative pulmonary perfusion parameters obtained from 3D dynamic contrast-enhanced MR perfusion data can be used to assess the severity of primary pulmonary hypertension (PPH) as indicated by pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (MPAP). CONCLUSION Three-dimensional dynamic contrast-enhanced MRI has potential for assessment of disease severity as indicated by PVR and MPAP in patients with PPH.

Whole-body MR imaging vs. FDG-PET: Comparison of accuracy of M-stage diagnosis for lung cancer patients†

To conduct a prospective comparison of the accuracy of whole‐body MR imaging and positron emission tomography (PET) with fluorine‐18 deoxyglucose (FDG) (FDG‐PET) to assess the M‐stage in lung cancer patients.

Prognostic value of dynamic MR imaging for non-small-cell lung cancer patients after chemoradiotherapy.

To determine the prognostic value of dynamic MRI for non‐small‐cell lung cancer (NSCLC) patients after chemoradiotherapy.

Time-resolved contrast-enhanced pulmonary MR angiography using sensitivity encoding (SENSE)

To evaluate the relationship between gadolinium concentration and signal‐to‐noise ratio (SNR) on sensitivity encoding (SENSE) images, and determine the appropriate bolus injection protocol for visualizing pulmonary circulation.

Assessment of bolus injection protocol with appropriate concentration for quantitative assessment of pulmonary perfusion by dynamic contrast‐enhanced MR imaging

To determine the appropriate concentration for quantitative assessment of dynamic contrast‐enhanced pulmonary MR imaging.

Esophageal magnetic resonance fluoroscopy: Optimization of the sequence

Objective The purpose of this study was to try to delineate the esophageal passage under dynamic conditions and to determine optimum settings for esophageal magnetic resonance (MR) imaging. Methods Ten healthy volunteers underwent MR fluoroscopy with two T1-weighted sequences: turbo field echo (TFE) and T1-weighted fast field echo (T1-FFE). These sequences were compared for signal-to-noise ratios (SNRs) and image quality. To determine the optimum slice thickness, an additional 10 healthy volunteers underwent MR fluoroscopy. Results obtained for slice thicknesses of 25, 35, 45, and 55 mm were compared for delineated length of the esophagus and image quality. Results The T1-FFE sequences provided higher SNRs and better image quality than the TFE sequences (T1-FFE: 89.4 ± 28.0, TFE: 52.4 ± 16.7; P < 0.001). Artifacts were less prominent and delineation of the esophageal wall was better on the T1-FFE images. The delineation of the esophageal wall was best with a 35-mm slice thickness, although delineated length was the longest with a 55-mm slice thickness. Conclusion This study showed T1-FFE to be a more suitable sequence than TFE and that the 35-mm slice thickness was the optimum slice thickness for esophageal MR fluoroscopy.

Bilateral popliteal artery entrapment syndrome: reemphasis on reading axial tomograms

A 33-year-old man with bilateral popliteal artery entrapment syndrome (PAES) presented with right calf claudication. He underwent radiological studies including conventional arteriography, multidetector row CT (MDCT), and magnetic resonance imaging (MRI) of the lower extremities. He had been fine since birth and athletic in his school days. Axial tomographic images by MDCT and MRI at the popliteal fossa bilaterally showed an anomalous medial head of the gastrocnemius muscle between the popliteal artery and vein, resulting in right popliteal artery occlusion and leading to the diagnosis of bilateral PAES type II. MDCT or MR facilitates noninvasive computer-aided arteriography and is often utilized for screening patients with claudication for peripheral arterial diseases. However, axial tomograms are more essential for confirming PAES than arteriography, and radiologists should continue to look for possible abnormalities on popliteal fossa tomograms because early diagnosis of PAES allows better choices and outcomes of treatment.

Cerebral air embolism as a complication of computed tomography-guided marking of the lung: depiction of air inflow route from a pulmonary vein to the left atrium.

Air embolism in the arterial system is a very rare but potentially fatal complication of percutaneous transthoracic needle biopsy or marking. We report a case of a patient with interstitial pneumonia associated with Sjögren syndrome, who presented with systemic arterial air embolism as a complication of computed tomography-guided marking of the lung. The air inflow route was depicted clearly on computed tomography from the peripheral pulmonary vein that crossed the needle pathway to the left atrium.

Flow-preserved coil embolization using a side-holed indwelling catheter for common hepatic artery pseudoaneurysm: report of three cases

We report three cases of hepatic artery pseudoaneurysm, which were all treated successfully using a combination of coil embolization and a side-holed 5F indwelling catheter for maintaining minimal hepatic artery blood flow with exclusion of the pseudoaneurysm. The tip of an infusion catheter was placed in the right hepatic artery and a side hole was positioned at the celiac axis. Coil embolization was then performed from the proper to the common hepatic artery using detachable coils. Hemostasis was achieved in all patients, with a final angiogram showing the hepatic arteries through the indwelling catheter. One major hepatic infarction and one focal liver abscess caused by reflux cholangitis manifested on postoperative days (PODs) 11 and 87, respectively. All patients survived and the indwelling catheter was removed on POD 136–382 without complication.