Yeh-You Shen

Comparison technetium of Tc-99m disofenin cholescintigraphy with ultrasonography in the differentiation of biliary atresia from other forms of neonatal jaundice

Technetium Tc-99m disofenin cholescintigraphy (CS) and ultrasonography (US) are two major clinical methods used in differentiating biliary atresia (BA) from neonatal jaundice. To compare the diagnostic utility of these two modalities, 66 patients with neonatal cholestasis (15 BA, 3 choledochal cyst (CC), 32 neonatal hepatitis, 13 prolonged jaundice, 2 total parenteral nutrition, and 1 sepsis) underwent Tc-99m disofenin CS and US. The diagnostic sensitivity, specificity, and accuracy of CS in differentiating BA from other forms of neonatal jaundice was 100%, 87.5%, and 90.5%, respectively, and for US 86.7%, 77.1%, and 79.4%, respectively. Tc-99m disofenin CS after premedication with phenobarbital and cholestyramine is a convenient and reliable method of differentiating BA from neonatal hepatitis, with a diagnostic accuracy superior to that of US. However, US is the initial imaging procedure of choice in patients presenting with jaundice to rule out anatomic anomalies such as CC.

Regional cerebral blood flow in patients with systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) with or without definite neuropsychiatric symptoms/signs were studied. Technetium‐99m (Tc‐99m) hexamethylpropylenamine (HMPAO) brain images were used to detect basal ganglion and cerebral cortex regional cerebral blood flow (rCBF) in patients with SLE with brain involvement. One hundred nine female patients with SLE were investigated using Tc‐99m HMPAO brain images with fan‐beam single‐photon emission computed tomography (SPECT) and surface three‐dimensional (3D) display. These patients were separated into 2 subgroups: group 1, 74 cases with definite neuropsychiatric symptoms/signs; and group 2, 35 cases without any neuropsychiatric symptoms/signs. Fan‐beam SPECT demonstrated unilateral or bilateral hypoperfusion of basal ganglia or thalamus in 22% and 9% of patients in groups 1 and 2, respectively. Local hypoactivity anomalies were found in the brain cortex of 89% and 20% of patients in groups 1 and 2, respectively, using surface 3D display of the brain. In either group 1 or group 2 patients, parietal and frontal lobes are the most common areas and cerebellum and thalamus are the least common areas of brain involvement, respectively. This study suggests that in comparison with traditional brain imaging techniques, Tc‐99m HMPAO brain imaging with fan‐beam SPECT in combination with surface 3D display may provide objective information for detection of anomalies of rCBF in patients with SLE.

The role of dopamine transporter imaging agent [99mTc]TRODAT-1 in hemi-parkinsonism rat brain.

This study aims to investigate the relationship between the determination of dopamine level by high performance liquid chromatography (HPLC) with electrochemical detection (ECD) and the detection of dopamine transporter (DAT) counts using autoradiography with DAT image agent [99mTc]TRODAT-1. For striatal lesions, pretreatment of 6-hydroxydopamine (6-OHDA) in the medial forebrain bundle shows that autoradiogaphic labeling of striatum region is reduced to near-background level. Using HPLC with ECD, unilateral 6-OHDA treatment is associated with significant (p < 0. 0002) reductions of dopamine levels. For the striatum of the 6-OHDA-lesioned side, dopamine content and DAT counts are reduced to 97% and 90%, respectively. Thus, our observation indicates a potential of using [99mTc]TRODAT-1 for the evaluation of animal DAT.

Superscan in patients with nasopharyngeal carcinoma

Bone scintigraphy plays an important role in the early detection of bone metastases in patients with nasopharyngeal carcinoma and serial scans may aid the clinician to assess the therapeutic response. A superscan is a pattern described as abnormal bone scan, indicating extensive bony metastases associated with various neoplastic diseases. Bone scans from 407 patients with nasopharyngeal carcinoma were reviewed retrospectively. Only six superscans (1.5%) were found. The appearance of a superscan is frequently accompanied by an abnormal titer of serological markers IgG-VCA and IgA-VCA, liver metastases, and poor survival. Although a superscan rarely occurs in nasopharyngeal carcinoma, its appearance may represent a poor prognosis in these patients.

Application of 18F-FDG PET/CT in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy occurring worldwide, with particularly high frequencies in Southern China, Hong Kong, Singapore and Taiwan. Imaging is vital for detection, staging, and treatment. 2-[Fluorine-18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) has been shown to be a valuable imaging tool in patients for initial staging and restaging diagnosis of NPC. Dual-modality positron emission tomography/computed tomography (PET/CT) provides the technical basis for intrinsically aligned functional and morphologic data sets. The false-negative and false-positive rate may be decreased by using combined FDG-PET/CT. FDG-PET/CT may be as a standard clinical imaging modality in the staging of NPC and in the detection of recurrent disease after radiotherapy. It could provide valuable information in localizing primary tumor in patients with neck nodal metastases from an unknown primary tumor.

Skull meningioma demonstrated with Tc-99m tetrofosmin SPECT

A 47-year-old woman had a protruding mass in the left parietal region of the skull. The mass was clearly demonstrated by Tc-99m tetrofosmin skull SPECT. Craniotomy was performed and the pathologic examination revealed it to be an intraosseous meningioma.

Discrepancy between 24-hour I-131 and 30-minute Tc-99m tetrofosmin thyroid imaging in thyroiditis

1-131 and Tc-99m tetrofosmin thyroid imaging were performed in two patients with thyroiditis. One patient had subacute thyroiditis and the other had Hashimatos thyroiditis. 1-131 imaging showed no thyroid visualization in the patient with subacute thyroiditis and poor visualization in the patient with Hashimatos thyroiditis. Thyroid imaging with Tc-99m tetrofosmin was successful in both cases.

Huge primary soft tissue sarcoma of the breast on bone scan.

A 54-year-old woman had a primary breast sarcoma with rapid enlargement in 3 months. The mass became so huge that it was more than 20 cm in diameter and occupied the entire right breast on presentation. Extraosseous uptake was present in this mass and demonstrated a unique picture, mimicking the posture of a racing driver who holds a helmet under the armpit, on the bone scan.

Incidental Pituitary Macroadenoma Detected In FDG-PET: Three Cases Report

Intense 18F-fluorodeoxyglucose(FDG)uptake in the suprasellar region is suggestive of pituitary adenoma by its relative high prevalence. Three cases of pituitary macroadenoma were identified in consecutive 1,166studies of FDG-PET from non-selective 1,140 examinees(subtract repeat scans, and exclude scans for heart only).The prevalence in this mixed-age population is 0.26%.Subsequent workup revealed nonfunctioning macroadenoma ranging in size from 1.5cm to3.3cm,and at least one case behaves aggressively by its repeat recurrence. The therapeutic options are not standardized, one went for transphenoid hypophysectomy, another one is in conservative approach due to other more debilitating disease, and the recurrence case is pending for gamma knife treatment option after recent operation to relieve the optical symptoms There fore, the clinical importance is determined mainly by the size in anatomic image for local invasion potentials, evaluating the functional status and to rule out jeopardy from other much rare malignancy. Clinical approach may be based on incidentaloma that may usually follow a benign course, and baseline evaluation and observation over time can be the initial steps

Reappraisal of scrotal scintigraphy in evaluation of varicocoeles

Varicocoeles could be classified into stop-type and shunt-type. In stop-type varicocoeles, only the internal spermatic (testicular) vein is dilated and needs to be ligated. In shunt-type, both internal spermatic vein and external spermatic (cremasteric) vein are dilated due to incompetence of the cremasteric system and both venous systems require ligation. Two-phase (flow and static) scrotal scintigraphy was performed on 92 patients preoperatively. Forty-three patients in whom the testicular and cremasteric veins could be verified during operation were included in this study. All 43 patients had unilateral varicocoeles and had abnormal blood pooling in the affected spermatic cord and hemiscrotum. In the blood flow study, 22 of 27 shunt-type varicocoeles had abnormal flow in the spermatic cord whereas only one out of 16 stop-type varicocoeles had increased blood flow. No difference in the results of semen analysis was found between the two groups of patients. Two-phase scrotal scintigraphy provides a noninvasive evaluation of shunting of the retrograde venous flow from the internal spermatic to the external spermatic vein. Understanding this pathophysiological change would be of benefit in the decision making about a surgical approach to varicocoeles.