Cerebral Infarction Mimicking Skeletal Metastases on Tc-99m MDP Bone Scintigraphy / 대한핵의학회잡지

A 60-year-old male with carcinoma of the prostate and cerebral infarction underwent a Tc-99m MDP bone scintigraphy for the evaluation of skeletal metastases. Bone scintigraphy (Fig. 1) showed multiple areas of increased uptake of Tc-99m MDP in the skull, spine, and ribs representing skeletal metastases. Two different patterns of uptake occurred in the skull region (Fig. 1A-C); one represents bony metastasis and the other represents cerebral infarction. The shape, size, location, intensity, and border of the increased uptake differed between the two lesions. An oval-shaped pattern with smaller size, greater intensity and more sharply defined border in the frontal region was consistent with bony metastasis. A rectangular-shaped pattern with larger size, lesser intensity and relatively indistinct border in the temporo-parieto-occipital region was consistent with cerebral infarction. Increased uptake of bone-seeking radiotracers in cerebral infarction has been reported previously.1-4) A suggested mechanism by which bone-seeking radiotracers accumulate in the necrotizing cerebral tissue is an alteration of the blood-brain barrier induced during cerebral infarction, which results in entry of the radiotracers into the extracellular space of the brain.4) Brain CT (Fig. 2) performed 7 days before and one month after the bone scintigraphy revealed lesions on the right temporo-parieto-occipital region consistent with acute hemorrhagic and chronic cerebral infarction, respectively.

Unusual Tc-99m MDP Uptake in the Keloid Developed after Subtotal Gastrectomy / 대한핵의학회잡지

A 63-year-old male who had subtotal gastrectomy for early gastric cancer three months ago underwent Tc-99m bone scintigraphy for the evaluation of skeletal metastases. He had no symptoms such as fever, tenderness, or wound discharge. On physical examination, the surgical scar along the midline of the upper abdomen had keloid formation and there was no radiographic evidence of calcification. Bone scintigraphy (Fig. 1A & 1B) demonstrated an unusual linear increased uptake along the midline of the upper abdomen that corresponded to the skin incision for subtotal gastrectomy. Usually, an incisional scar will not be visualized in Tc-99m methylene diphosphate (MDP) scintigraphy beyond two weeks after surgery.1) Upon reviewing the literature, there were only a few reports where localization of Tc-99m MDP in surgical scars were found two months after surgery.2) It was also reported that a few cases with Tc-99m MDP uptake in the keloid scar developed after surgery. Although there are several potential mechanisms that may explain the uptake of Tc-99m MDP in scar tissue, the primary mechanism in older scars is suggested to be a result of pathological calcification.2) Siddiqui et al3) suggested it could be due to microscopic calcification in small resolving hematomas. However, the primary mechanism in keloid scar is not well-known. We should obtain oblique or lateral views to differentiate the uptake in healing surgical scars from the artifactual uptake.

Tc-99m ECD Brain SPECT in Patients with Traumatic Brain Injury : Evaluating Distribution of Hypoperfusion and Assesment of Cognitive and Behavioral Impairment in Relation to Thalamic Hypoperfusion / 대한핵의학회잡지

PURPOSE: We evaluated the distribution of hypoperfusion in patients with traumatic brain injury (TBI) and the relationship of thalamic hypoperfusion to severity of cognitive and behavioral sequelae. MATERIALS AND METHODS: Tc-99m ECD SPECT and MRI were performed in 103 patients (M/F=81/22, mean age 34.7+/-15.4 yrs) from 0.5 to 55 months (mean 10.3 months) after TBI. The patients were divided into three groups showing no abnormalities (G1), focal (G2) and diffuse injury (G3) on MRI. Psychometric tests assessed 11 cognitive or behavioral items. In all patients, we evaluated the distribution of hypoperfused areas in SPECT, and in 57/103 patients, neuropsychological (NP) abnormalities in patients with thalamic hypoperfusion were compared with those of patients without thalamic hypoperfusion. RESULTS: The perfusion deficits were most frequently located in the frontal lobe (G1, 42.3%: G2 34.5%: G3 33.3%), temporal lobe (24~26%) thalami (21~22.4%), parietal and occipital lobe (< or =10%). Numbers of NP abnormalities in the cases of cortical hypoperfusion with or without concomitant thalamic hypoperfusion were following: the former 4.7+/-1.5 and the latter 3.2+/-1.4 in G1, 5.0+/-1.1 and 4.8+/-1.2 in G2, 6.8+/-1.8 and 6.3+/-1.1 in G3, respectively. This difference according to thalamic hypoperfusion was significant in G1 (p=0.002), but was not significant in G2 or G3. CONCLUSION: SPECT in patients with TBI had demonstrated hypoperfusion mostly involving the frontal, temporal and thalami. In normal group on MRI, frontal hypoperfusion was more prominent than that of any other group, Furthermore in this group, SPECT could predict severity of NP outcome by concomitant thalamic hypoperfusion with cerebral cortical abnormalities.

Percutaneous alcohol sclerotherapy for symptomatic congenital cysts

Twenty patients with symptomatic congenital cysts in the liver, kidney, thyroid, and lower neck underwent, ultrasound guided percutaneous aspiration through a drainage catheter with temporary instillation of 95% ethanol into the cyst. Our procedure was based on the method as described by Bean and Rodan(16) in 1985. Additionaly, two othe steps were odded to prevent the dilutional effect of residual cyst fluid. One was the preliminary washing of the cyst with alcohol. The other was to treat with 30% replacement of alcohol every 10 minutes during the treatment secession. Minot complications of transient temperature elevation and hziness occurred, butj no major complications were encountered. After the alcohol treatment follow up examinations were performed with computed tomography or ultrasonography at 6 weeks. 6 months. 9 months and 15 months. Although there was diminished size, recurrence was noted in 6 of twenty patients(30%) at 6 weeks and one of twenty patients(5%) at 6 months. There was no recurrence at 9 months and 15 months. The results indicated that percutaneous aspiration and alcohol sclerotherapy are safe and effective therapy for symptomatic congenital cysts.

An experimental study of gallbladder sclerosis with 10% phenol in rabbits

To evaluate a new reliable sclerosant of the gallbladder, we attempted gallbladder ablation with 10% phenol, and the results compared with those from using 95% ethanol which had been used previousy as gallbladder sclerosing agent in laboratory animals in other reports. After laparotomy, ligation of the cystic dusts with silk and cannulation of gallbladder with 18 gauge angiocatheter were done. Then, transcatheter administration of two different scleroing agents was performed in 8 rabbits respectively and normal saline in four rabbits as a control. Additionally, preliminary washing with each agent were implemented to prevent the dilutional effect of residual bile and bleeding. All animals survived without complication. Eight animals were used for each agent, four each being sacrified two weeks and six weeks after adminstration of sclerosing agents respectively. In our results, 10% phenol was more effective than 95% ethanol in denuding the gallbladder epithelium and promoting fibrosis of gallbladder wall, And it was relatively safe in regard to the dilutional effect of residual fluid and bleeding during procedure. Toxic effects on the liver evaluated by examination of histologic specimen were non-specific except for edematous swelling on some cases, which had also been observed on others including control group. 10% phenol can be considered to be a promosing sclerosant for gallbladder ablation, but further study of its toxicity is needed before its application on human gallbladder.