Masanari Shiigai

Postmortem Computed Tomography Findings as Evidence of Traffic Accident-Related Fatal Injury

PurposeMost traumatic deaths in Japan are due to nonpenetrating injuries, especially those that result from traffic accidents; however, the autopsy rate of traffic accident-related deaths is only about 5%. We investigated the diagnostic ability of postmortem computed tomography (PMCT) in cases of fatal trauma after traffic accidents.Materials and methodsOur subjects were 78 subjects (59 males, 19 females; mean age 50 years, range 15–87 years) who were brought to our institution in cardiopulmonary arrest on arrival after traffic accidents and died despite resuscitation attempts. PMCT findings of damage to the head, neck, thorax, abdomen, and pelvis were classified into three grades according to the Abbreviated Injury Scale (AIS) severity: A: 1 (minor), 2 (moderate); B: 3 (serious), 4 (severe), 5 (critical); C: 6 (maximum).ResultsThe percentage ratio of A/B/C in 78 head injuries was 32/60/8, in 41 neck injuries 83/5/12, in 76 thorax injuries 5/38/57, in 76 abdominal injuries 70/24/7, and in 76 pelvic injuries 79/21/0, respectively.ConclusionPMCT can detect or presume fatal trauma when diagnosing the cause of death after traffic accidents

Moyamoya disease: evaluation of postoperative revascularization using multiphase selective arterial spin labeling MRI.

Purpose The purpose of this study was to evaluate cerebral blood flow through the bypass in operated patients with Moyamoya disease using multiphase selective arterial spin labeling (ASL) technique. Materials and Methods Fifteen surgically treated cerebral hemispheres from 11 patients with Moyamoya disease were included. Selective ASL examinations were performed during the early postoperative period (mean, 5.5 days) on 4 hemispheres and late postoperative period (mean, 332.7 days) on 15 hemispheres. The labeling slab was positioned at the bypassed external carotid artery and 5 slices in each of the 10 sequential phases were acquired using a 3-T scanner. Results Two of 4 early postoperative ASL examinations and all late postoperative ASL examinations demonstrated blood flow through the bypass. The remaining 2 early postoperative ASL examinations showed absence of blood flow; however, blood flow improved on follow-up examinations. Conclusion Multiphase selective ASL technique can provide information about the dynamics of postoperative blood flow through the bypass in Moyamoya disease.

Assessment of Uterine and Ovarian Arteries before Uterine Artery Embolization: Advantages Conferred by Unenhanced MR Angiography

PURPOSE To clarify the benefits of unenhanced magnetic resonance (MR) angiography in planning uterine artery embolization (UAE). MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and the informed consent requirement was waived. Fifty-five consecutive women (mean age, 42 years; age range, 26-52 years) who underwent UAE for symptomatic uterine fibroids were placed chronologically into groups 1, 2, or 3, which were composed of 20, 22, and 13 patients, respectively. Digital subtraction angiography was performed in groups 1 and 2 but not in group 3. In the 35 patients in groups 2 and 3, unenhanced MR angiography was performed before UAE, and two independent radiologists assessed the results. The parameters indicating performance of UAE were compared among the three groups with the Tukey test. RESULTS Forty-five patients underwent routine UAE (19, 16, and 10 patients in groups 1, 2, and 3, respectively). Sixty-eight (97%) of 70 uterine artery origins were demonstrated clearly at MR angiography. Among five ovarian arteries detected at MR angiography, collateral supply was confirmed in four (80%). The assessment of MR angiographic results and discontinuation of digital subtraction angiography led to a reduction in the mean performance time (from 96.2 minutes to 51.9 minutes [P = .004]), fluoroscopy time (from 28.5 minutes to 17.8 minutes [P = .036]), dose-area product (from 109.8 Gy.cm(2) to 25.4 Gy.cm(2) [P < .001]), and contrast medium volume (from 103.8 mL to 40.8 mL [P < .001]). CONCLUSION Unenhanced MR angiography provides useful information regarding uterine and ovarian arteries before UAE.

Detection of hepatic metastases using ferucarbotran‐enhanced MR imaging: Feasibility and diagnostic accuracy of three‐dimensional sensitivity‐encoding water‐excitation multishot echo‐planar sequence (3D‐SWEEP)

To evaluate the diagnostic accuracy of a ferucarbotran‐enhanced three‐dimensional sensitivity‐encoding water‐excitation multishot echo‐planar sequence (3D‐SWEEP) for detecting hepatic metastases compared to a T2*‐weighted fast field‐echo (FFE) sequence.

Assessment of the uterine artery before uterine arterial embolization: comparison of unenhanced 3D water-excitation sensitivity-encoding time-of-flight (WEST) and gadolinium-enhanced 3D sensitivity-encoding water-excitation multishot echo-planar (SWEEP) MR angiography.

To compare unenhanced 3D water‐excitation sensitivity‐encoding time‐of‐flight (WEST) and gadolinium‐enhanced 3D sensitivity‐encoding water‐excitation multishot echo‐planar (SWEEP) MR angiography (MRA) with regard to conspicuity of uterine arteries in correlation with digital subtraction angiography (DSA).

A Modified Metallic Coil Embolization Technique for Pulmonary Arteriovenous Malformations Using Coil Anchors and Occlusion Balloon Catheters

PurposeTo evaluate the feasibility and efficacy of a modified metallic coil embolization technique for pulmonary arteriovenous malformations (PAVMs) using coil anchors and occlusion balloon catheters.MethodsFive consecutive female patients with 6 PAVMs were included in the present study. One of the 6 PAVMs was of the complex type with four feeding arteries. An occlusion balloon catheter was inserted into the feeding artery as close to the venous sac as possible. The coil anchor, which was a simple W-shaped bent stainless steel wire with two markers at each end, was deployed prior to embolization to prevent the systemic migration of embolic materials. Then, metallic coils were deployed around the coil anchors under inflow stoppage using the inflated occlusion balloon catheter. In the complex-type PAVM, the main feeder was occluded by this technique and the other three small feeders were embolized with metallic coils only.ResultsIn all 5 cases, occlusion balloon catheters could be inserted into the feeding arteries just proximal to the venous sacs, coil anchors were easily deployed, and complete occlusion was achieved without any migration of metallic coils or paradoxical embolism during the procedure.ConclusionsThe modified metallic coil embolization technique with coil anchors and occlusion balloon catheters was feasible and considered to be useful in preventing procedure-related complications.

Proton magnetic resonance spectroscopy findings of hemangioblastoma.

We report a case of proton magnetic resonance spectroscopy (MRS) of hemangioblastoma in a 56-yearold man with a history of hyperlipidemia who was suffering from an equilibrium disorder. Proton MRS revealed a high mobile lipids (Lip) peak between 0.9 and 1.4 ppm, which was compatible with histologically proven lipids in the tumor. No lactate peak was recognized. The creatine/phosphocreatine peak was low. Choline-containing compounds were increased. The N-acetylaspartate peak was absent, which indicated that the tumor is of nonneurogenic origin. Combined with the absence of the necrotic component on magnetic resonance imaging, this Lip peak on proton MRS could be the characteristic pattern of hemangioblastoma. These unique results of proton MRS can play an important role in the differential diagnosis of intracranial hemangioblastoma. However, further investigations are required to establish the typical characteristics of proton MRS of hemangioblastoma.

Reduction en masse of inguinal hernia: MDCT findings of two cases

Reduction en masse of inguinal hernia is an extremely rare complication arising from manual reduction of a hernia. The hernial content remaining in the hernia sac returns above the inguinal canal but remains in the abdominal wall. Accurate preoperative diagnosis of reduction en masse of inguinal hernia is challenging because the hernia appears to be reduced upon physical examination. We experienced two cases of reduction en masse. In both cases, multidetector row computed tomography revealed a closed loop obstruction near the inguinal fossa. In addition, we observed a continuous tract of the hernia sac to the inguinal canal and prominent peritoneal thickening suggestive of the hernia sac.

Pararenal Lymphatic Cyst Infection Caused by Helicobacter cinaedi.

A 43-year-old man was referred to our hospital for an acute-onset fever and left flank pain. He had been previously diagnosed with lymphangioma, and abdominal computed tomography showed pararenal cysts with fat stranding around the left kidney, of which infection was subsequently confirmed on magnetic resonance imaging. Gram-negative spiral bacilli were isolated from two sets of blood cultures, and Helicobacter cinaedi was identified using 16S rRNA sequencing. The patient was successfully treated with ceftriaxone therapy without recurrence. A multilocus sequence typing analysis indicated the current H. cinaedi strain differed from previous strains isolated in Japan.

Usefulness of Subtraction of 3D T2WI-DRIVE from Contrast-Enhanced 3D T1WI: Preoperative Evaluations of the Neurovascular Anatomy of Patients with Neurovascular Compression Syndrome

BACKGROUND AND PURPOSE: High-resolution 3D MR cisternography techniques such as 3D T2WI–driven equilibrium radiofrequency reset pulse (DRIVE) are used preoperatively to assess neurovascular anatomy in patients with neurovascular compression syndrome, but contrast between vessels and cranial nerves at the point of neurovascular contact is limited. The postprocessing technique subtraction of 3D T2WI-driven equilibrium radiofrequency reset pulse from contrast-enhanced 3D T1WI (sDRICE) provides both high spatial resolution and excellent contrast in depicting the neurovascular contact. We evaluated the usefulness of sDRICE compared with 3D T2WI-DRIVE. MATERIALS AND METHODS: Twelve patients who underwent microvascular decompression for hemifacial spasm or trigeminal neuralgia were examined preoperatively with 3D T2WI-DRIVE and sDRICE. Two neuroradiologists retrospectively analyzed and scored lesion conspicuity, defined as the ease of discrimination between offending vessels and compressed nerves or the brain stem at the neurovascular contact. They also quantitatively analyzed the contrast and contrast-to-noise ratio at the neurovascular contact. RESULTS: The lesion conspicuity scores of sDRICE images were significantly higher than those of 3D T2WI-DRIVE for all 12 patients (P = .006) and the 6 cases of hemifacial spasm (P = .023) but were not significantly higher in the 6 trigeminal neuralgia cases alone (P = .102). For all 12 patients, the contrast-to-noise ratio between the offending vessels and the brain stem and between the vessels and nerves on sDRICE images was significantly higher than that on 3D T2WI-DRIVE (P = .003 and P = .007, respectively). Among these structures, the contrast values were also significantly higher on the sDRICE than on the 3D T2WI-DRIVE (P < .001) images. CONCLUSIONS: The postprocessing technique sDRICE is useful to evaluate neurovascular anatomy and to improve contrast and the contrast-to-noise ratio in patients with neurovascular compression syndrome.