Shuji Sakai

Early Postoperative Screening by Contrast-Enhanced CT and Prophylactic Embolization of Detected Pseudoaneurysms Prevents Delayed Hemorrhage after Partial Nephrectomy

PURPOSEnTo evaluate retrospectively whether prophylactic embolization of pseudoaneurysms detected on early postoperative screening with computed tomography (CT) after partial nephrectomy can prevent delayed hemorrhage.nnnMATERIALS AND METHODSnBetween January 2012 and May 2014, early postoperative contrast-enhanced CT was performed 3-5 days after partial nephrectomy in 312 patients (group A); CT was not performed in 65 patients (group B) because of renal insufficiency or contrast medium allergy. If pseudoaneurysms were detected on CT in group A, prophylactic embolization was performed. The frequency of delayed hemorrhage occurring more than 3 days after surgery in group A was compared with group B and with 212 patients (group C) who underwent partial nephrectomy between January 2010 and December 2011 without early postoperative CT. Changes in estimated glomerular filtration rate at discharge were compared among the groups.nnnRESULTSnProphylactic embolization of pseudoaneurysms was performed in 26 patients (8%) in group A. Frequency of delayed hemorrhage in group A (0.6%) was significantly lower than in groups B (4.6%; P = .038) and C (4.7%; P = .005). No major complications attributable to prophylactic embolization were observed. The decrease in estimated glomerular filtration rate in group A (-2% ± 13%) was smaller than that in group B (-8% ± 13%; P < .001) and not worse than that in group C (-4% ± 14%; P = .108).nnnCONCLUSIONSnProphylactic embolization of pseudoaneurysms detected on early postoperative CT can prevent delayed hemorrhage after partial nephrectomy, without major complications.

Usefulness of 4D-CTA in the detection of cerebral dural sinus occlusion or stenosis with collateral pathways.

In time-resolved CT angiography (4D-CTA), it is of substantial merit to detect the veins and sinuses of the whole brain with the simultaneous demonstration of the natural drainage flow in order to find occlusion or stenosis of the dural sinuses with collateral pathways. As preoperative information for patients with brain tumors, it is important to detect feeding arteries, incidentally found aneurysms or other vascular lesions, and to detect patency of the dural sinuses and the important cortical veins, whether they are compressed by tumors or not. On the other hand, cerebral venous thrombosis (CVT) may occur in patients due to various causes, which has not been unusual in recent years. For patients with acute symptomatic or chronic non-symptomatic CVT, identification of dural sinus occlusion (DSO) or dural sinus stenosis (DSS) and compensatory collateral pathways is necessary for suitable thrombolytic therapy or careful investigation to avoid further CVT. This study reviews our experiences in 116 cases of 4D-CTA for 90 patients with brain tumors and 26 other patients including 11 with arteriovenous malformation, and four with acute CVT and other conditions. 4D-CTA presented DSO/DSS with compensatory venous collateral pathways, which was helpful to detect the severity of the venous abnormality, and see whether it was compressed by brain tumors, or due to other causes in patients with symptomatic or non-symptomatic CVT. 4D-CTA is a useful non-invasive diagnostic tool to detect cerebral venous abnormalities as an alternative to DSA.

Successful Adrenal Venous Sampling by Non-experts with Reference to CT Images

PurposeTo establish technical success rates and safety of adrenal venous sampling (AVS) performed by non-experts with reference to CT images.Materials and Methods104 AVS procedures with adrenocorticotropic hormone stimulation were performed for patients with suspected primary aldosteronism. One of three radiology residents with 2nd, 5th, and 5th grade experience undertook the procedure under the guidance of an experienced, board-certified interventional radiologist with reference to contrast-enhanced CT images obtained in 102 cases. Successful catheterization of the adrenal veins was assessed using three criteria: an adrenal venous cortisol concentration of more than 200xa0μg/dL (criterion A); an adrenal vein/inferior vena cava cortisol ratio of more than 5:1 (criterion B); and an adrenal vein/inferior vena cava cortisol ratio of more than 10:1 (criterion C).ResultsThe operators were aware of the anatomy of the left adrenal veins in 102 cases (98xa0%) and of the right adrenal veins in 99 cases (95xa0%) prior to the procedure. CT identified the correct position of the right adrenal vein orifice in 82 of 99 cases (83xa0%). The overall technical success rates for AVS from the right adrenal vein according to criteria A, B, and C, were 96, 96, and 94xa0%, respectively. Those for the left adrenal vein were 97, 98, and 94xa0%, respectively. No significant differences in success rates were observed between the operators (pxa0=xa00.922–0.984). No major complications, including adrenal vein rupture, were observed.ConclusionsWhen CT images are used to guide AVS, the procedure can be performed successfully and safely even by non-experts.

Assessment of Cerebrospinal Fluid Flow Patterns Using the Time-Spatial Labeling Inversion Pulse Technique with 3T MRI: Early Clinical Experiences

CSF imaging using the time-spatial labeling inversion pulse (time-SLIP) technique at 3T magnetic resonance imaging (MRI) was performed to assess cerebrospinal fluid (CSF) dynamics. The study population comprised 15 healthy volunteers and five patients with MR findings showing expansive dilation of the third and lateral ventricles suggesting aqueductal stenosis (AS). Signal intensity changes were evaluated in the tag-labeled CSF, untagged brain parenchyma, and untagged CSF of healthy volunteers by changing of black-blood time-inversion pulse (BBTI). CSF flow from the aqueduct to the third ventricle, the aqueduct to the fourth ventricle, and the foramen of Monro to the lateral ventricle was clearly rendered in all healthy volunteers with suitable BBTI. The travel distance of CSF flow as demonstrated by the time-SLIP technique was compared with the distance between the aqueduct and the fourth ventricle. The distance between the foramen of Monro and the lateral ventricle was used to calculate the CSF flow/distance ratio (CD ratio). The CD ratio at each level was significantly reduced in patients suspected to have AS compared to healthy volunteers. CSF flow was not identified at the aqueductal level in most of the patients. Two patients underwent time-SLIP assessments before and after endoscopic third ventriculostomies (ETVs). CSF flow at the ETV site was confirmed in each patient. With the time-SLIP technique, CSF imaging is sensitive enough to detect kinetic changes in CSF flow due to AS and ETV.

Pulmonary Paragonimiasis: The Detection of a Worm Migration Track as a Diagnostic Clue for Uncertain Eosinophilic Pleural Effusion

A 38-year-old woman with sustained right chest pain was referred to our hospital. She showed pleural effusion and peripheral blood eosinophilia. Thoracentesis revealed eosinophilic pleural effusion in which the smear, culture and cytological examinations were all negative. Although she had no notable dietary history, chest CT revealed linear opacities, which suggested the migration tracks of paragonimiasis. The diagnosis was confirmed using enzyme-linked immunosorbent assays, which showed elevated Paragonimus westermani and Paragonimus miyazakii antibody levels. After the initiation of praziquantel therapy, all clinical findings were promptly improved. The detection of a migration track may therefore be useful in the diagnosis of paragonimiasis.

The role of 4D CT angiography for preoperative screening in patients with intracranial tumors

Introduction Four-dimensional computed tomography angiography (4D CTA) is now becoming an often used diagnostic imaging modality for the assessment of patients with intracranial tumors. The purpose of this study was to demonstrate the utility of 4D CTA for preoperative screening in patients with intracranial tumors as well as to examine the correlation between perfusion data and grading of gliomas. Methods We performed preoperative screening using 320-row detector CT scanner in 186 patients with intracranial tumors, and 115 patients were finally included in the study. Time-resolved subtracted maximum intensity projection images and volume-rendered images were reconstructed to evaluate vascular structures, tumor staining and incidental lesions. We also evaluated the perfusion functional map for gliomas to find correlations between their vascularity and tumor grading. Results We evaluated gliomas in 70 patients, meningiomas in 29, and other tumors in 16. Patients with gliomas of a pathologically higher grade showed high cerebral blood volume (pu2009<u20090.05). Tumor staining was observed on MIP images for 12 meningiomas, 4 gliomas, and 3 other tumors. Fifty patients showed a mass effect on vascular structures, seven had cerebral venous sinus obstruction, and two had aneurysms. No iatrogenic accidents with the CT procedure were reported. Conclusions The 4D CTA technique is effective and safe for depicting vascular structures such as arteries, veins, tumor-related vessels, and direct and indirect anatomical complications such as vascular obstruction or vascular compression. This information is useful for preoperative screening. Although 4D CTA also provides perfusion data correlating with the tumor vascularity and grading of gliomas, its clinical value remains limited.

Subpial Hematoma and Extravasation in the Interhemispheric Fissure with Subarachnoid Hemorrhage

A recent report on computed tomography (CT) findings of contrast extravasation in subarachnoid hemorrhage (SAH) with Sylvian hematoma suggests that the occurrence of the hematoma is secondary to bleeding in the subpial space. Our patient was in his sixties and was admitted to the hospital because of loss of consciousness (Glasgow Coma Scale E4V1M4). SAH was diagnosed in plain head CT, and growing hematomas were observed in the Sylvian and interhemispheric fissures following a subarachnoid hemorrhage. CT angiography (CTA) using a dual-phase scan protocol revealed contrast extravasation in both the fissures in the latter phase, and hematoma in the interhemispheric fissure contained multiple bleeding points. This case indicates that the occurrence of subpial hematoma such as Sylvian hematoma can be a secondary event following subpial bleeding from damaged small vessels elsewhere in the cranium. Instead of four-dimensional (4D) CT, the dual-phase CTA technique may help detect minor extravasations with usual helical CT scanner.