Biomedical subjects

J I Chung

Publications and source records attributed to J I Chung.

4 recordsLinked to original sources

PubMed2005

Combined spinal intramedullary arteriovenous malformation and lipomyelomeningocele.

Combined spinal arteriovenous malformation and lipomyelomeningocele are extremely rare. We present a rare combined case of a lipomyelomeningocele with an intramedullary arteriovenous malformation (AVM) occurred at the L3-L4 level in a 30-year-old man who suffered from low back pain radiating to the lower extremities, dysuria, and frequency for 5 years. The MR studies showed an intradural mass with high-signal intensity on both T1-weighted and T2-weighted images, intermingled with multiple signal-void structures. The mass extended extradurally toward a subcutaneously forming fatty mass on the patient's back. Spinal angiography showed an AVM supplied by the radiculopial branches of the lumbar arteries and drained by tortuous, dilated, perimedullary veins. Endovascular embolization and surgical resection were performed.

Adult↗

PubMed1997

Posterior interosseous free flap: various types.

The posterior interosseous artery is located in the intermuscular septum between the extensor carpi ulnaris and extensor digiti minimi muscles. The posterior interosseous artery is anatomically united through two main anastomoses: one proximal (at the level of the distal border of the supinator muscle) and one distal (at the most distal part of the interosseous space). In the distal part, the posterior interosseous artery joins the anterior interosseous artery to form the distal anastomosis between them. The posterior interosseous flap can be widely used as a reverse flow island flap because it is perfused by anastomoses between the anterior and the posterior interosseous arteries at the level of the wrist. The flap is not reliable whenever there is injury to the distal forearm or the wrist. To circumvent this limitation and to increase the versatility of this flap, we have refined its use as a direct flow free flap. The three types of free flaps used were (1) fasciocutaneous, (2) fasciocutaneous-fascia, and (3) fascia only. Described are 23 posterior interosseous free flaps: 13 fasciocutaneous flaps, 6 fasciocutaneous-fascial flaps, and 4 fascial flaps. There were 13 sensory flaps using the posterior antebrachial cutaneous nerve. The length and external diameter of the pedicle were measured in 35 cases. The length of the pedicle was on average 3.5 cm (range, 3.0 to 4.0 cm) and the external diameter of the artery averaged 2.2 mm (range, 2.0 to 2.5 mm). The hand was the recipient in 21 patients, and the foot in 2. All 23 flaps covered the defect successfully.

Adult↗

PubMed1995

Evaluation of embolization effect of hepatocellular carcinoma by hepatic arterial flow study with Tc-99m MAA SPECT.

The degree of hepatocellular carcinoma vascularity in eight patients was assessed with Tc-99m MAA radionuclide angiography before and after treatment. For chemoembolization therapy, lipiodol and doxorubicin hydrochloride were administered intraarterially along with Gelfoam particles. The ratio of radioactivity in the hepatocellular carcinoma compared to that in the surrounding uninvolved tissue before therapy was 6.5-19.0 with a mean of 12.0. After therapy, the ratio dropped to 0.5-1.3. Because survival improved significantly after the therapeutic regimen used in these patients, radionuclide Tc-99m MAA angiography appears to be an accurate method for demonstrating successful embolization of the vascular supply in hepatocellular carcinoma.

Adult↗

PubMedDate not supplied

Transient MR signal changes in patients with generalized tonicoclonic seizure or status epilepticus: periictal diffusion-weighted imaging.

BACKGROUND AND PURPOSE: Our purpose was to investigate transient MR signal changes on periictal MR images of patients with generalized tonicoclonic seizure or status epilepticus and to evaluate the clinical significance of these findings for differential diagnosis and understanding of the pathophysiology of seizure-induced brain changes. METHODS: Eight patients with MR images that were obtained within 3 days after the onset of generalized tonicoclonic seizure or status epilepticus and that showed seizure-related MR signal changes had their records retrospectively reviewed. T1- and T2-weighted images were obtained of all eight patients. Additional diffusion-weighted images were obtained of five patients during initial examination. After adequate control of the seizure was achieved, follow-up MR imaging was performed. We evaluated the signal changes, location of the lesions, and degree of contrast enhancement on T1- and T2-weighted images and the signal change and apparent diffusion coefficient (ADC) on diffusion-weighted images. We also compared the signal changes of the initial MR images to those of the follow-up MR images. RESULTS: The initial MR images revealed focally increased T2 signal intensity, swelling, and increased volume of the involved cortical gyrus in all eight patients. The lesions were located in the cortical gray matter or subcortical white matter in seven patients and at the right hippocampus in one. T1-weighted images showed decreased signal intensity at exactly the same location (n = 6) and gyral contrast enhancement (n = 4). Diffusion-weighted images revealed increased signal intensity at the same location and focally reduced ADC. The ADC values were reduced by 6% to 28% compared with either the normal structure opposite the lesion or normal control. Follow-up MR imaging revealed the complete resolution of the abnormal T2 signal change and swelling in five patients, whereas resolution of the swelling with residual increased T2 signal intensity at the ipsilateral hippocampus was observed in the other two patients. For one of the two patients, hippocampal sclerosis was diagnosed. For the remaining one patient, newly developed increased T2 signal intensity was shown. CONCLUSION: The MR signal changes that occur after generalized tonicoclonic seizure or status epilepticus are transient increase of signal intensity and swelling at the cortical gray matter, subcortical white matter, or hippocampus on periictal T2-weighted and diffusion-weighted images. These findings reflect transient cytotoxic and vasogenic edema induced by seizure. The reversibility and typical location of lesions can help exclude the epileptogenic structural lesions.

Adolescent↗