MR sialography using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences

We describe our preliminary experience with the half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences for MR imaging of the salivary gland ducts. In the majority of patients, the main parotid and/or submandibular gland ducts and large branches within the glands were detectable on MR images obtained in 2 seconds per section and within 3 minutes for the entire examination. MR sialography using HASTE sequences can be combined with conventional MR studies for the salivary glands.

Mesenteric schwannoma

Schwannoma is a benign neurogenic tumor arising from the sheath of peripheral nerves. It occurs very rarely in the mesentery, where it is difficult to diagnose. Herein we describe a case in which contrast-enhanced CT and gadolinium-DTPA-enhanced MR showed a locally enhanced well-defined tumor with a cystic component just anterior to the duodenum. These findings corresponded well to the resected specimen.

Acute traumatic injury of the distal descending aorta associated with thoracic spine injury

A rare case of traumatic injury of the distal descending aorta associated with thoracic spine injury is reported. A 21-year-old man was admitted after a traffic accident. Thoracic CT and angiography demonstrated a false aneurysm of the distal descending aorta and a compression fracture of the eleventh thoracic vertebra. At emergency surgery, a transverse linear tear at the level of the aortic hiatus was confirmed and repaired.

MR of denervated tongue: temporal changes after radical neck dissection

PURPOSE

The purpose of this study was to evaluate the temporal changes of MR imaging in the denervated tongue after a radical neck dissection.

METHODS

One hundred seventy-four consecutive MR studies in 116 patients with radical neck dissections for malignant tumors of the head and neck were evaluated retrospectively. Patients with tumors involving the tongue or hypoglossal nerve were not included in this study.

RESULTS

Abnormal signal intensity and/or hemiatrophy on the side of the tongue operated on was seen in 22 patients who had hypoglossal paralysis after radical neck dissection. The denervated side of the tongue appeared hypointense to hyperintense relative to the normal side on T1-weighted images and hyperintense on T2-weighted images. Signal intensity ratios of the abnormal to normal muscles were 0.9-1.6 on T1-weighted images and 1.3-2.8 on T2-weighted images. High signal intensity on T1-weighted images appeared 5 months or more after the dissection, whereas on T2-weighted images, the most prominent increases in signal intensity appeared in the first several months after denervation. Hemiatrophy of the tongue was observed on MR images obtained more than 6 months after surgery.

CONCLUSION

MR findings in the denervated tongue are compatible with histologic changes and are characterized by an enlarged extracellular fluid space or fatty infiltration. The pattern of signal intensity and the degree of hemiatrophy suggest the duration of denervation.

Use of fluid-attenuated inversion recovery (FLAIR) pulse sequences in perinatal hypoxic-ischaemic encephalopathy

The purpose of this study was to evaluate the usefulness of fluid-attenuated inversion recovery (FLAIR) techniques in patients with perinatal hypoxic-ischaemic encephalopathy. 13 patients with a history of perinatal hypoxic-ischaemic encephalopathy (age range 1 month to 3.6 years) underwent T1 and T2 weighted spin echo and FLAIR imaging with a 1.5 T superconducting unit. FLAIR images were qualitatively evaluated in comparison with T1 and T2 weighted images by three experienced radiologists. Quantitative analysis (contrast and contrast-to-noise ratio) was also performed. FLAIR images were preferred to T1 and T2 weighted images in the demonstration of periventricular leukomalacia (PVL), cystic PVL and subcortical lesions near the brain surface. On T1 and T2 weighted images, almost all lesions were demonstrated as hypointense or hyperintense areas, respectively. However, FLAIR images could differentiate cystic lesions by their signal intensities. FLAIR images were not diagnostic in two cases with PVL. In conclusion FLAIR sequences provide useful information in patients with perinatal hypoxic-ischaemic encephalopathy.

Totally occluded iliac arteries: long-term results of percutaneous transluminal angioplasty

PURPOSE

To evaluate the initial and long-term results of percutaneous transluminal angioplasty (PTA) for totally occluded iliac arteries.

METHODS

Fifty-four occluded iliac arteries in 54 patients were treated by PTA. The mean length of the occlusions was 8.0 cm (range 0.5-24.0 cm). Patients were followed for a maximum of 124 months (mean, 56 months).

RESULTS

The initial success rate was 57% (31 of 54). On follow-up study, two arteries were reoccluded, and six showed evidence of restenosis. These recurrences were observed within 20 months after PTA. The long-term results obtained by Kaplan-Meier life-table analysis revealed a 71% primary patency rate and 93% secondary patency rate for 124 months. Thirteen arteries were treated by surgical intervention, while the other arteries with unsuccessful PTA were followed conservatively because of a high risk for surgery or patients' refusal to have surgery. Major complications were recorded in 7% (4 of 54) of cases: thrombosis requiring emergent bypass surgery in one artery, and distal embolization requiring thromboembolectomy in three.

CONCLUSION

Although the procedure is difficult, the long-term results suggest that PTA is an effective method and a treatment of choice for totally occluded iliac arteries.

Free groin flap for reconstruction of the tongue and oral floor

The authors report the use of free groin flaps to close intraoral defects in 24 patients following ablative tongue cancer surgery. The lateral thin portion of the flap was used for tongue reconstruction, and the deepithelialized medial thick portion for filling the mandibular defect and for covering the important vessels in the neck. In lean patients, if the medial deepithelialized portion was too thin for adequate coverage, the proximal sartorius muscle was included to prevent postoperative orocervical fistula. The advantages of the groin flap in reconstructing the tongue and oral floor after hemiglossectomy include the following: (1) a suitable amount of tissue is available for both the tongue and oral floor; (2) the important vessels in the neck may be protected with the flap; (3) the proximal sartorius muscle can be included with the flap, if necessary; (4) donor-site morbidity is less than with other flaps; and (5) flap elevation can be done concurrently with the hemiglossectomy and radical neck dissection.

The effect of starvation on brain carnitine concentration in neonatal rats

BACKGROUND

We examined carnitine concentrations in fasted neonatal rat brain to evaluate the effect of starvation on fatty acid metabolism.

METHODS

The free- and acylcarnitine concentrations in neonatal rat brain and heart were determined after a 72-hour starvation period from the 3rd to 6th postnatal day. They were also determined in rats at 3 and 6 days of age fed normally by the mother rats as controls.

RESULTS

In the brain, the mean free carnitine concentration in the fasted group showed an increase similar to that in normal rats and there was no difference between the fasted and 6-day-old control rats. However, the mean acylcarnitine concentration was significantly higher in the fasted group than in the control group at both 3 and 6 days of age. Almost all of the increased acylcarnitine in the fasted group was short-chain acylcarnitine. In the heart, there was no difference in the mean free carnitine concentration between the fasted group and control group at 6 days of age. The 6-day-old rats in both the fasted and control groups showed higher levels compared to 3-day-old rats in the control group. The mean acylcarnitine concentration in the fasted group was not different from that in control group at 6 days of age, while the amount of short-chain acylcarnitine was less than that in the control group at 6 days of age.

CONCLUSIONS

These findings suggest that in the brain, carnitine is accumulated as a result of redistribution during starvation, and is utilized for energy supply by fatty acid oxidation.

Ethanol sclerosis: one of the best treatments for thymic cyst in very elderly patients?

An 83-year-old female patient with a giant thymic cyst that was successfully treated by percutaneous aspiration and ethanol injection. The patient had complained of coughing and chest discomfort for several years. A chest X-ray film revealed the shadow of a large abnormal mass in the anterior mediastinum. We diagnosed it as a thymic cyst. The patient refused surgery because of her age. We chose a less invasive therapy, namely, ethanol sclerosis of the cyst. The cyst was successfully treated without any complications, and no recurrence was found at the one-year follow-up. This therapy may be one of the best treatments for thymic cysts, especially in very elderly patients.

MR evaluation of radiation otomastoiditis

PURPOSE

The purpose of this study was to evaluate the incidence of radiation otomastoiditis, on using T2-weighted magnetic resonance (MR) imaging, in relation to radiation fields, doses, intervals, and clinical symptoms after radiotherapy that included the temporal bone in the fields.

METHODS AND MATERIALS

We performed follow-up MR examinations at various intervals after radiotherapy including the temporal bones for 270 ears of 114 patients with various diseases of the head and neck and intracranial regions. The middle ear and mastoid air cells on T2-weighted images were scored as follows; showing no high signal intensity, a local high signal intensity area, or a high signal intensity area occupying the entire middle ear and all mastoid air cells. The radiation fields as depicted on the lateral simulator films classed as anterior to the clival line, posterior to the clival line, or both.

RESULTS

The incidence of radiation otomastoiditis depicted on T2-weighted MR images increased in the patients who had received irradiation doses of 50 Gy or more. In the patients with doses of less than 50 Gy, the incidence was 18% within 6 months following radiotherapy, 13% at between 6 and 12 months, and 8% after 12 months, whereas it was more than 50% at any period after radiotherapy in the patients with 50 Gy or more. The incidence of radiation otomastoiditis was quite high in the patients whose radiation fields included region both anterior and posterior to the clival line.

CONCLUSION

The incidence of radiation otomastoiditis as demonstrated on T2-weighted MR images is increased at irradiation doses of 50 Gy or more. To reduce the incidence of severe radiation otomastoiditis, the irradiation fields of the temporal bone when the dose is 50 Gy or more should be limited to as small as possible. The clival line is considered to be a good landmark in reducing the irradiation field when doses of 60-70 Gy are delivered in curative radiotherapy.

Relationship between progressive microvascular damage and intramyocardial hemorrhage in patients with reperfused anterior myocardial infarction: myocardial contrast echocardiographic study

BACKGROUND

Recent studies indicated that ischemic microvascular damage may be reversible or progressive after coronary reflow. Intramyocardial hemorrhage is a phenomenon that reflects severe microvascular injury. We examined the relationship between temporal changes in microvascular perfusion patterns detected by myocardial contrast echocardiography (MCE) and intramyocardial hemorrhage detected by magnetic resonance imaging (MRI) in patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

The study population consisted of 24 patients with anterior AMI. All patients underwent MCE shortly after reflow and in the chronic stage (a mean of 31 days after reflow). Wall motion score (WMS) was determined as the sum of 16 segmental scores (dyskinetic/akinetic=3 to normal=0) at days 1 and 31. Gradient-echo acquisition and gadolinium-DTPA-enhanced spin-echo MRI were performed within 10 days after reflow. In MCE shortly after reflow, 16 patients (67%) showed contrast enhancement and the other 8 patients (33%) showed a sizable contrast defect. In the chronic stage, a persistent contrast defect was observed in 7 of 8 patients with a contrast defect shortly after reflow. Consistent contrast enhancement was observed in 12 of 16 patients (75%) with contrast enhancement shortly after reflow, indicating that a contrast defect newly appeared in 4 patients (25%). Intramyocardial hemorrhage was detected in 9 patients (38%): 5 of 7 patients with a persistent contrast defect and in all 4 patients with a new appearance of a contrast defect during the chronic stage. The patients without hemorrhage showed a significant improvement in WMS compared with patients with hemorrhage at day 31 (5+/-5 versus 19+/-6, P<.0005).

CONCLUSIONS

These results suggest that irreversible microvascular damage to the ischemic myocardium may cause intramyocardial hemorrhage after reflow, associated with impaired recovery of left ventricular function. Contrast enhancement within the risk area shortly after reflow does not necessarily indicate long-term microvascular salvage.

Myeloperoxidase-specific anti-neutrophil cytoplasmic autoantibodies -- related scleroderma renal crisis treated with double-filtration plasmapheresis

A 46-year-old female patient who was diagnosed with systemic sclerosis (SSc) developed rapidly progressive renal failure without elevation of blood pressure or plasma renin concentration. Renal biopsy revealed necrotizing crescentic glomerulonephritis (pauci-immune type) and the myeloperoxidase-specific anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA) titer was found to be elevated to 669 EU/ml. Methylprednisolone (MP) pulse therapy followed by prednisolone (PSL) and mizoribine (MZR) did not suppress the progression of renal failure. Therefore, we started double-filtration plasmapheresis (DFPP) which effectively removed MPO-ANCA and prevented renal failure despite the relatively low dose of immunosuppressive agents.

Percutaneous microwave coagulation therapy: an experimental study

PURPOSE

Microwave coagulation therapy (MCT) is a surgical alternative for inoperable hepatocellular carcinomas (HCCs). We have recently developed a percutaneous method for using MCT under ultrasound guidance. The purpose of this study was to investigate the feasibility of percutaneous MCT (PMCT) in an animal model and correlate the ultrasound findings with histological results.

MATERIALS AND METHODS

Microwaves were administered for 30, 45, 60 and 90 seconds to 12 cadaveric porcine livers in vivo one hour after sacrificing them, to determine the most suitable coagulation time for the percutaneous method. The cadaveric livers were then subjected to histologic evaluation. The temperature around the electrode was measured in both cadaveric and living livers during PMCT. Ultrasound-guided MCT was also performed in nine rabbits. The histological findings after PMCT were evaluated in the cadaveric and living livers, and the areas of coagulation necrosis were correlated with the ultrasound findings.

RESULTS

After microwave emission, coagulation necrosis of a spindle shape occurred primarily from the base of the electrode. The maximum area of coagulation was obtained at 60 seconds. The maximum temperature of cadaveric liver under PMCT was 95 degrees at 3 mm from the electrode; that of living liver was 85.1 degrees at 5 mm. Ultrasound revealed hyperechoic areas after PMCT in both cadaveric and living livers. On microscopy, parenchymal necrosis of the liver was observed only in living livers one month after MCT. Hyperechoic areas measured with ultrasound were significantly larger than the actual necrotic areas (p < 0.01), probably due to air bubbles which developed within the tissue.

CONCLUSIONS

PMCT completely coagulated the liver tissue around the electrode. These preliminary results indicate that PMCT should be an effective treatment for hepatic neoplasms. In terms of clinical application, the hyperechoic areas observed during PMCT appear to be considerably larger than the areas actually treated.

Percutaneous microwave coagulation therapy in liver tumors. A 3-year experience

PURPOSE

Percutaneous microwave coagulation therapy (PMCT) is an interventional alternative for inoperable malignant liver tumors. In this paper, we report the results of our 3-year experience of PMCT in order to establish suitable indications for this treatment.

MATERIAL AND METHODS

We studied a total of 27 inoperable liver tumors in 24 patients. Histology of the tumors showed 20 hepatocellular carcinomas (HCCs) (13 well differentiated, 4 moderately differentiated, and 3 poorly differentiated) and 7 metastases. These tumors were treated by PMCT and were followed for 4-40 months (average 18 months). Under US guidance, the tumors were coagulated by microwaves emitted from an electrode. The changes of tumor size after PMCT were evaluated by CT. When the tumors disappeared or were reduced in size after treatment, PMCT was regarded as effective. Complications from PMCT were also evaluated. The patient survival rate was obtained by means of the Kaplan-Meier method.

RESULTS

In tumors of 30 mm or less, treatment response was obtained in 70% of cases, while 55% of tumors larger than 30 mm responded. The tumor became smaller or disappeared in 85% of the well differentiated HCCs, and in 25% of the moderately differentiated HCCs, but none of the poorly differentiated HCCs responded. In metastatic tumors, PMCT was effective in 57% of cases. Slight pain (24%), fever (20%) and subcutaneous hematoma (8%) were experienced immediately after PMCT. In 2 poorly differentiated HCCs, needle tract seeding was observed. No case of liver dysfunction was seen after PMCT. The overall survival rate was 83.1% at 1 year and 68.7% at 2 years.

CONCLUSION

Good therapeutic results were achieved with PMCT in lesions of 30 mm or less, and in well differentiated HCCs.

Percutaneous transluminal angioplasty for carotid artery stenosis in Takayasu arteritis: persistent benefit over 10 years

A 66-year-old man was admitted to our hospital with right hemiplegia due to a cerebral infarction associated with Takayasu arteries. We successfully performed percutaneous transluminal angioplasty for stenoses of the innominate and right common carotid arteries. Improvement of the stenotic lesions persisted over 10 years.

CT and MR findings of denervated tongue after radical neck dissection

PURPOSE

To describe the CT and MR findings in the denervated tongue after a radical neck dissection.

METHODS

We retrospectively evaluated the radiologic findings in seven patients who had hypoglossal paralysis following radical neck dissection. None of the patients had clinical or radiologic evidence of tumor recurrence.

RESULTS

The side of the tongue operated on showed low density on CT scans. At MR imaging, denervated tongues were clearly seen as hyperintense relative to muscle on T2-weighted images; on T1-weighted images, the signal was hypointense to hyperintense, representing increased extracellular water or fatty degeneration.

CONCLUSION

In patients who have undergone a neck dissection for a malignant process, abnormal imaging findings in the tongue not only might indicate a recurrence of tumor involving the hypoglossal nerve but also suggest the possibility of postoperative change. Our findings emphasize the importance of the denervated tongue in differentiating inflammatory from neoplastic diseases of the the tongue.

The effect of azelastine on acute radiation dermatitis in mice models

PURPOSE

In our previous report we described the clinical value of azelastine, an oral antiallergic agent, as an inhibitor of radiation dermatitis. Here we studied the effect of azelastine on normal skin and tumor size after irradiation in a mouse model.

METHODS AND MATERIALS

The modifying effects of azelastine on both the degree of radiation dermatitis and antitumoral effect of radiation therapy were investigated in the normal skin as well as in SCC VII tumors of C3H/He mice. The right hind legs, with or without tumors, were irradiated with 20-60 Gy at 0.62 Gy/min. Azelastine was administered via the mouse chow, and acute skin reactions and tumor growth curves were compared between the azelastine and control groups.

RESULTS

The acute skin reactions of the azelastine group were significantly less prominent than those of the control group (p < 0.01). At a dose of 40 Gy the dose modification factors were 1.19-1.25. The tumor growth curves of the azelastine and control groups were almost identical, indicating that the treatment response of irradiation was not affected by administration of azelastine.

CONCLUSIONS

Application of azelastine reduces the degree of acute radiation dermatitis without affecting the antitumoral effect of radiation therapy.

Role of dynamic MRI in the evaluation of head and neck cancers treated with radiation therapy

PURPOSE

To study the usefulness of dynamic magnetic resonance imaging in the evaluation of head and neck cancers treated with radiation therapy.

METHODS AND MATERIALS

Seventy-six patients (58 males and 18 females; ages 20-82) with head and neck cancers (10 nasopharyngeal carcinomas, 22 mesopharyngeal carcinomas, 10 hypopharyngeal carcinomas, 16 oral cavity carcinomas, 11 lingual carcinomas, and 7 laryngeal carcinomas) were treated by radiation therapy combined with concomitant low-dose cisplatinum. Magnetic resonance imaging (MRI) was performed before and 2 weeks after the irradiation in all cases. After bolus administration of gadopentetate dimeglumine (Gd-DTPA) (0.1 mmol kg), images were obtained every 30 s (repetition time 200 ms, echo time 16 ms) using a 1.5 or 0.5-T superconductive unit. Biopsy or surgery was performed after radiation therapy and the histologic findings were correlated with the MRI findings (T1, T2, dynamic, and enhanced T1).

RESULTS

Complete remission, partial response, and no response were obtained in 18, 36, and 7 cases, respectively. Dynamic MRI correctly diagnosed 17 of the 18 complete remission cases, 33 of the 36 partial response cases, and all of the 7 no-response cases. The accuracy of dynamic MRI, T1-weighted image, T2-weighted image, and Gd-enhanced T1-weighted image was 94.4%, 68%, 82%, and 86%, respectively.

CONCLUSION

Dynamic MRI proved to be useful in the evaluation of the radiation therapy of head and neck cancers.

[Diagnostic imaging of "body packers"]

Drug smuggling by intra-abdominal concealment, so called "body packing," has recently increased, even in Japan. Because of fatal drug intoxication and other adverse side effects, it is important to make a radiological diagnosis of body packers as soon as possible. A retrospective analysis of the images of plain abdominal radiography, computed tomography (CT) and ultrasound (US) was performed in twenty-three body packers to evaluate the imaging characteristics of three drugs (cannabis, cocaine and heroin). Cannabis (16 patients) and cocaine (5 patients) packages were demonstrated as well-demarcated rectangular-shaped high-density shadows surrounded by gas halo ("double condom sign") in abdominal plain radiographs and CT. Heroin packages (2 patients) were demonstrated as obscure shadows and were difficult to identify on plain radiographs, because they resembled stool masses. US was performed in one cannabis patient because of the refusal of radiological examination, and packages were demonstrated as round echogenic structures with dorsal echo extinctions. In conclusion, abdominal plain radiography, CT and US represent valuable diagnostic modalities in the assessment of body packers.

Short communication: the value of embolization therapy in painful osseous metastases from hepatocellular carcinomas; comparative study with radiation therapy

We evaluated the therapeutic effect of transcatheter arterial embolization therapy (TAE) for painful osseous metastases from hepatocellular carcinoma (HCC) in comparison with radiation therapy (RT). TAE using gelatin sponge particles was performed for seven lesions in seven patients. Selective catheterization and embolization were successfully performed in all lesions. Within 10 days after TAE, complete pain relief (CR), partial relief (PR) and no relief (NR) were attained in 57%, 29% and 14%, respectively. RT was used to treat 34 lesions in 22 patients. The dose fractionation schedules were in the range 28.0-50.4 Gy, with 1.8-4.0 Gy per fraction. CR, PR and NR were attained in 47%, 47% and 6%, respectively. There were no serious complications related to these treatments. Both TAE and RT are effective and the treatment of choice should be selected on an individual basis.

Effect of iomeprol on renal function immediately after abdominal angiography

PURPOSE

To investigate the acute renal effects of 2 osmolality levels of iomeprol in a double-blind, randomized, parallel-group study.

MATERIAL AND METHODS

Ten patients received iomeprol 300 mg I/ml, and a further 10 received iomeprol 400 mg I/ml intraarterially at routine abdominal angiography. The mean volume of contrast medium administered was 227.3+/-59.3 ml in the iomeprol 300 group and 221.5+/-30.9 ml in the iomeprol 400 group.

RESULTS

The urinary minute volume increased immediately after angiography, but tended to return to baseline 120 min after the examination. No significant decrease in creatinine clearance occurred; however, the fraction excretion of sodium increased immediately after angiography. The lysosomal enzyme N-acetyl-beta-glucosaminidase and the proximal tubular brush border enzyme gamma-glutamyl transferase increased up to 120 min after the procedure. Free water clearance was negative during each study period. No statistical differences in any parameter were evident between these 2 groups.

CONCLUSION

These results suggest that osmotic diuresis and its acute effect on proximal tubular function are induced by the administration of iomeprol, but that these changes are reversible.

Ethanol sclerosis can be a safe and useful treatment for pericardial cyst

We report the case of a 41-year-old man with a pericardial cyst treated by percutaneous aspiration and ethanol injection. He was referred to our hospital because of electrocardiographic abnormality. On admission, chest x-ray revealed a large pericardial cyst in the right cardiophrenic angle. The cyst was examined by echocardiography, computed tomography, and cytological analysis of aspiration fluid from the cyst. Ethanol sclerosis was applied for treatment of the cyst, which had continued to increase in size. There was no recurrence of the cyst 6 months after the treatment. Percutaneous ethanol sclerosis can be the first choice of treatment for pericardial cyst.