Tatsuhiko Nakasato

Virtual CT endoscopy of ossicles in the middle ear

The purpose of this study is to evaluate how virtual computed tomography (CT) endoscopy may help in assessing ossicles in the middle ear. Our series consisted of 96 ears of 68 consecutive patients with conducting hearing loss. All examinations were performed with a high-resolution spiral CT using axial and direct coronal planes of the temporal bone. Perspective virtual endoscopy was processed using the virtual endoscopic software. Superstructure of the stapes was difficult to evaluate on the virtual endoscopy; however, virtual endoscopy of the middle ear provides further information on the pathological conditions including congenital anomaly, posttraumatic, and inflammatory processes.

MRI of myositis ossificans circumscripta

Myositis ossificans circumscripta (or pseudomalignant osseous tumor of soft tissue) may be confused with malignant neoplasms if there is no clear history of trauma. Two cases are presented in which magnetic resonance imaging (MRI) clearly demonstrates disproportionally extensive abnormal signal intensity along the course of muscle fibers. Although the specificity of this finding is uncertain, MRI enhances the level of confidence in diagnosing myositis ossificans.

Virtual CT endoscopy in determining safe surgical entrance points for paranasal mucoceles.

The goal of this work was to evaluate virtual CT endoscopy for determining safe surgical entrance points for paranasal mucoceles. Twelve mucoceles in 11 cases were scanned with helical CT, and multiplanar reconstruction (MPR) and virtual endoscopic images were obtained. After a safe surgical entrance point was determined by MPR images, the entrance point was specified on the virtual endoscopic images. The combination of virtual endoscopic images and MPR images is a suitable method for determining a safe surgical entrance point for simple mucoceles.

Spontaneous temporomandibular joint herniation into the external auditory canal through a persistent foramen tympanicum (Huschke): radiographic features.

Persistent foramen tympanicum (Huschke) is an anatomical variation located in the anteroinferior portion of the external auditory canal. We present a case of symptomatic temporomandibular joint (TMJ) herniation into the external auditory canal though an enlarged osseous defect. The herniated retrodiscal TMJ tissue moved backward when the patients mouth was closed, and forward, when opened. Magnetic resonance imaging findings were useful for differentiating TMJ herniation from salivary fistula caused by an ectopic salivary gland.

Is ultrasound-guided central venous port placement effective to avoid pinch-off syndrome?

Purpose Ultrasound (US)-guided internal jugular vein access has been the standard practice of central venous port (CVP) placement. The subclavian vein (SCV) access has also been preferred, but has potential risk of pinch-off syndrome (POS). The purpose of this study was to examine the effect of US-guided SCV access to avoid POS in patients with CVP. Methods Included in this study were patients who had undergone CVP placement via the SCV. We mainly assessed the computed tomography (CT) findings from two different placement techniques of a CVP via the SCV: (i) venipuncture point described by the ratio between the distance from the venipuncture point to the sternoclavicular joint and the clavicular length; and (ii) presence of direct attachment of the catheter to the clavicle. Secondary outcome was POS rate associated with two different placement techniques of CVP via the SCV. Results A total of 237 patients were included in this study between August 2007 and January 2011. A total of 100 patients (42.2%) underwent CVP placement using the landmark technique while 137 patients (57.8%) underwent CVP placement by US guidance. CT revealed that the US-guided technique tended to be lateral SCV approach compared with the landmark technique (p<0.001). A total of four patients (1.7%) experienced POS, all of them in the landmark group. Conclusion Our results showed that the US-guided technique determines a more lateral SCV approach, with a reduced POS risk than the landmark venipuncture technique.

Radiotherapy and Concomitant Intra-Arterial Docetaxel Combined With Systemic 5-Fluorouracil and Cisplatin for Oropharyngeal Cancer: A Preliminary Report—Improvement of Locoregional Control of Oropharyngeal Cancer

PURPOSE To confirm the advantage of chemoradiotherapy using intra-arterial docetaxel with intravenous cisplatin and 5-fluorouracil. PATIENTS AND METHODS A total of 26 oropharyngeal cancer patients (1, 2, 2, and 21 patients had Stage I, II, III, and IVa-IVc, respectively) were treated with two sessions of this chemoradiotherapy regimen. External beam radiotherapy was delivered using large portals that included the primary site and the regional lymph nodes initially (range, 40-41.4 Gy) and the metastatic lymph nodes later (60 or 72 Gy). All tumor-supplying branches of the carotid arteries were cannulated, and 40 mg/m(2) docetaxel was individually infused on Day 1. The other systemic chemotherapy agents included 60 mg/m(2) cisplatin on Day 2 and 500 mg/m(2) 5-fluorouracil on Days 2-6. RESULTS The primary response of the tumor was complete in 21 (81%), partial in 4 (15%), and progressive in 1 patient. Grade 4 mucositis, leukopenia, and dermatitis was observed in 3, 2, and 1 patients, respectively. During a median follow-up of 10 months, the disease recurred at the primary site and at a distant organ in 2 (8%) and 3 (12%) patients, respectively. Three patients died because of cancer progression. Two patients (8%) with a partial response were compromised by lethal bleeding from the tumor bed or chemotherapeutic toxicity. The 3-year locoregional control rate and the 3-year overall survival rate was 73% and 77%, respectively. CONCLUSION This method resulted in an excellent primary tumor response rate (96%) and moderate acute toxicity. Additional follow-up is required to ascertain the usefulness of this modality.

Selection of peripheral intravenous catheters with 24-gauge side-holes versus those with 22-gauge end-hole for MDCT: A prospective randomized study

PURPOSE To compare the 24-gauge side-holes catheter and conventional 22-gauge end-hole catheter in terms of safety, injection pressure, and contrast enhancement on multi-detector computed tomography (MDCT). MATERIALS & METHODS In a randomized single-center study, 180 patients were randomized to either the 24-gauge side-holes catheter or the 22-gauge end-hole catheter groups. The primary endpoint was safety during intravenous administration of contrast material for MDCT, using a non-inferiority analysis (lower limit 95% CI greater than -10% non-inferiority margin for the group difference). The secondary endpoints were injection pressure and contrast enhancement. RESULTS A total of 174 patients were analyzed for safety during intravenous contrast material administration for MDCT. The overall extravasation rate was 1.1% (2/174 patients); 1 (1.2%) minor episode occurred in the 24-gauge side-holes catheter group and 1 (1.1%) in the 22-gauge end-hole catheter group (difference: 0.1%, 95% CI: -3.17% to 3.28%, non-inferiority P=1). The mean maximum pressure was higher with the 24-gauge side-holes catheter than with the 22-gauge end-hole catheter (8.16±0.95kg/cm2 vs. 4.79±0.63kg/cm2, P<0.001). The mean contrast enhancement of the abdominal aorta, celiac artery, superior mesenteric artery, and pancreatic parenchyma in the two groups were not significantly different. CONCLUSION In conclusion, our study showed that the 24-gauge side-holes catheter is safe and suitable for delivering iodine with a concentration of 300mg/mL at a flow-rate of 3mL/s, and it may contribute to the care of some patients, such as patients who have fragile and small veins. (Trial registration: UMIN000023727).

A New Method Using J-Type Long Sheath for Implantation of Indwelling Catheters for Trans-femoral Hepatic Arterial Infusion

PurposeFor implantation of a catheter-port system for hepatic arterial infusion chemotherapy, catheterization via the femoral artery is occasionally difficult. The purpose of this study was to determine the usefulness of a J-type long sheath, which facilitates difficult trans-femoral catheterization.Materials and MethodsWe applied this technique to 15 patients for difficult trans-femoral catheterization for catheter-port system placement.ResultsWe successfully implanted a catheter-port system in all patients using this technique without significant complications.ConclusionWe emphasize that our new technique using a J-type long sheath seems to be a reasonable option when trans-femoral catheterization is difficult.

Normal sonographic findings of the infant temporal lobe in coronal sections

Coronal sonograms of the temporal lobe of the infant brain were obtained using a real time sector scanner with a 5.0 MHz transducer probe. The precise normal anatomy in the coronal sections was determined by correlating with corresponding brain specimens. It was revealed that the spatial arrangement of structures in the medial part of the temporal lobe, i.e. the hippocampal formation and the inferior horn, varied in the three different planes. In the plane through the anterior part of the temporal lobe, these structures were seen as a horizontal lamellar configuration, whereas in the plane through the middle part these structures were depicted as a typical interfolded arrangement. However, the hippocampal formation was barely visible in the plane through the posterior part.

Minor ossicular anomalies in the middle ear: role of submillimeter multislice computed tomography.

Objective The objective was to elucidate clinical effectiveness of submillimeter multislice 2- and 3-dimensional computed tomography (CT) for diagnosis of congenital middle ear anomaly. Materials and Methods Preoperative CT and operative findings were retrospectively analyzed in 36 ears of 33 patients. The distance between the malleal handle (MH) and the incus long process (ILP) was measured in 28 normal ears. Results Mean ± SD MH-ILP distance in normal ears was 1.8 ± 0.3 mm. In patients with middle ear anomaly, overall specificity, accuracy, and positive and negative predictive values were 99.7%, 98.7%, 91.7%, and 99.1%, respectively. Overall sensitivity was 82.1%, with relatively low sensitivities for detecting fused incudomalleolar joint, lenticular process defect, stapedial footplate defect, and oval window atresia and high sensitivities (80%–100%) for stapedial crural anomaly and certain fibrous connections. Conclusions Submillimeter CT improved detectability of anomalies of the stapedial superstructure; however, it is still difficult to identify abnormalities of the footplate.