A new screening method for multidirectional shoulder instability on magnetic resonance arthrography: labro-capsular distance.

OBJECTIVE: To compare the capsular dimension as measured on magnetic resonance arthrography (MRA) between patients with multidirectional instability (MDI) of the shoulder and control subjects without instability. Ultimately, we aimed to develop an easy and reliable new screening method to assess MDI of the shoulder using MRA. MATERIALS AND METHODS: MRA images of patients with MDI of the shoulder (n = 25) during a 6-year period (February 2010 to May 2015) were retrospectively reviewed. A control group (n = 26) without instability was also identified. The capsular area was measured using a new screening method we termed labro-capsular (LC) distance. MRA images of the two groups were randomly mixed, and two orthopedic surgeon reviewers recorded anterior, posterior, and inferior LC distance measurements on axial and coronal images using a mid-glenoid cut. RESULTS: The inferior LC distance increased significantly in the patient group versus control group (P < 0.001), but there were no statistically significant differences in the anterior (P = 0.1165) and posterior (P = 0.5229) LC distances. An inferior LC distance >16.88 mm is most suggestive of MDI of the shoulder because of its high sensitivity (76 %) and specificity (96 %). CONCLUSION: The inferior LC distance can be easily and quickly measured and used as an effective clinical screening method for atraumatic MDI of the shoulder.

Late Onset Osteonecrosis of the Proximal Phalanx of the Great Toe in a Child.

Osteonecrosis, also known as avascular necrosis or osteochondrosis, refers to the death of bone tissue resulting from a to lack of blood supply. Osteonecrosis of the foot is most commonly seen in the talus and metatarsals and not as frequently in other bones. We report an extremely rare case of late-onset osteonecrosis of the proximal phalangeal head of the great toe in a 9-year-old male. Plain radiographs and computed tomography did not show any findings of osteonecrosis initially. However, because of persistent pain at the interphalangeal joint of the first toe and a decrease in the range of movement at the interphalangeal joint at 7 months after injury, the patient underwent additional examination with repeated radiographs and magnetic resonance imaging. We diagnosed late-onset osteonecrosis as a result of a subtle traumatic type I dislocation. Conservative treatment led to spontaneous recovery, leaving a bony fragment in the interphalangeal joint. To our knowledge, this is the first report of late-onset proximal phalangeal osteonecrosis after trauma in the great toe.

Enchondroma of the Foot.

The present study is a review of 20 patients with enchondroma of the foot treated from January 2005 to March 2012. All patients were examined clinically, followed by an evaluation of their enchondroma of the foot radiographically and an assessment of the outcome of their surgical intervention. The patients' sex and age, enchondroma location, findings from imaging studies such as plain radiography, computed tomography, and magnetic resonance imaging, clinical findings, operative findings, and treatment outcomes were recorded. The average postoperative follow-up period was 24 months. Eighty percent of the tumors were located in the proximal phalanx and 14 (70%) patients presented with pathologic fracture. The plain radiographs and computed tomography findings revealed 13 (65%) cases of internal calcification and 11 (55%) with endosteal scalloping. A periosteal reaction was seen only in 4 (20%) cases. Magnetic resonance imaging of 11 (55%) patients showed low T1-weighted and high T2-weighted signal intensity in all cases. Internal septa and nodules with low T2-weighted signal intensity were observed in 9 (82%) out of 11 cases, and adjacent soft tissue edema was noted in 9 (82%). All patients underwent curettage of the tumor and bone grafting as their surgical treatment. No recurrence or postoperative complications were observed during the 24-month follow-up period. Enchondroma of the foot most frequently involves the proximal phalangeal bone and is often associated with pathologic fracture. The unique clinical signs and characteristic radiographic images are easily recognized, making this a relatively easy diagnosis. With appropriate treatment, a good surgical outcome can be expected.

Initial experience of integrated PET/MR mammography in patients with invasive ductal carcinoma.

The purpose of this study was to evaluate the feasibility of integrated fluorine-18-fluorodeoxyglucose positron emission tomography/magnetic resonance ((18)F-FDG PET/MR) mammography in invasive ductal carcinoma (IDC) patients. From August 2012 to March 2013, we enrolled 42 consecutive breast cancer patients who received whole- body PET/MR and subsequent PET/MR mammography by an integrated PET/MR scanner and were scheduled for surgery within 2 weeks after the of scan. On the whole body PET/MR, 2-point Dixon VIBE, coronal T1w image, axial T2w image, and post-contrast T1 sequences were acquired with simultaneous PET acquisition. For PET/MR mammography, T1w, T2w, and dynamic contrast-enhancement (DCE) sequences were acquired using a breast coil during simultaneous PET acquisition. We compared the detectability of the lesions between whole-body PET/MR and PET/MR mammography. Forty-eight IDC (1.89±1.19cm of width) were diagnosed in 42 women. Lesion conspicuity in (18)F-FDG PET was equivalent between whole-body PET/MR and PET/MR mammography; both PET/MR images showed 38 hypermetabolic masses. In the analysis of 10 IDC with <1.0cm wide lesions, only 1 IDC showed (18)F-FDG uptake, and 4 IDC were noted on whole-body PET/MR; however, all 10 IDC showed a depictable mass on PET/MR mammography. In the analysis of 38 IDC >1.0cm wide, 37 IDC showed (18)F-FDG uptake, and 38 IDC were detected on both whole-body PET/MR and PET/MR mammography. The overall sensitivity was 79.2% (38/48) on PET, 87.5% (42/48) on whole-body PET/MR, and 100% on PET/MR mammography. The SUV between whole-body PET/MR and PET/MR mammography showed strong and highly significant correlation (r=0.987, P<0.001). In conclusion, our results, although in a limited number of cases show that integrated PET/MR mammography is feasible and has the advantage of combining high-resolution breast images with metabolic images. Furthermore, PET/MR mammography could provide an accurate diagnosis in case of IDC that are less than 1cm in size.

Emphasis on the MR imaging findings of brown tumor: a report of five cases.

OBJECTIVE: Brown tumors are focal reactive osteolytic lesions that are encountered in patients with primary or secondary hyperparathyroidism, and these tumors have nonspecific magnetic resonance (MR) imaging findings. However, there are only a few reports on MR imaging of brown tumors. The purpose of this study is to describe the spectrum of MR imaging findings of brown tumors. MATERIALS AND METHODS: The MR imaging features of five patients with clinical and pathological evidence of brown tumor were retrospectively reviewed by two radiologists. The patients had primary hyperparathyroidism, which was confirmed as parathyroid adenoma (n = 2) and parathyroid carcinoma (n = 3). The MR images were evaluated for the presence of solid or cystic portions, the signal intensity of the lesions, the contrast enhancement pattern and the presence of cortex destruction and fluid-fluid levels. RESULTS: Twelve bone lesions were detected on the MR images of five patients; three lesions in two patients, four lesions in one patient, and one lesion in two patients. The tumor was solid in three lesions, mixed solid and cystic in four, and cystic in five. All the solid lesions were accompanied by mixed lesions. Discontinuity of the cortex and adjacent soft-tissue enhancement were seen in all the solid lesions. Fluid-fluid levels were seen in two cases within the cystic component of the mixed lesions and cystic lesions. CONCLUSIONS: The five patients with brown tumor demonstrated a wide spectrum of MR imaging findings. There are few lesions that are osteolytic on the radiographs and that show a short T2 on MR imaging, such as brown tumor. Multiple cystic or mixed lesions are the expected findings of brown tumors.

Incidental pituitary uptake on whole-body 18F-FDG PET/CT: a multicentre study.

PURPOSE: The purpose of this study was to determine the incidence of incidental pituitary uptake on whole-body 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and to investigate its clinical significance. METHODS: The files of 40,967 patients who underwent whole-body FDG PET/CT were retrospectively reviewed. Quantification of pituitary metabolic activity was obtained by using the maximum standardized uptake value (SUVmax). Hormone assays and pituitary MRIs were performed to assess pituitary lesions. RESULTS: Focally increased pituitary FDG uptake on PET/CT was found in 30 of 40,967 patients, accounting for an incidence of 0.073%. The mean SUVmax of 30 patients was 8.9±6.6 (range: 3.2-32.6). Histological diagnosis was obtained in three patients and included two growth hormone-secreting adenomas and one non-functioning adenoma. Hormone assays were performed on serum samples from 11 patients, 2 of whom were shown to have hypersecretion of pituitary hormone. MRI was performed on 19 patients. Abnormal MRI findings suggesting a pituitary mass were found in 18 of 19 cases (94.7%). The mean SUV(max) calculated without correction for partial volume effect for macroadenomas was significantly higher than the SUVmax for microadenomas (11.5±8.4 vs 4.8±1.3; p<0.05). There were no cases diagnosed with metastasis to the pituitary gland during clinical follow-up. CONCLUSION: Incidental pituitary FDG uptake was a very rare finding. Cases with incidental pituitary FDG uptake were diagnosed primarily with clinically non-functioning adenomas, and there were also a few functioning adenomas. Further evaluations, including hormone assays and pituitary MRI, are warranted when pituitary uptake is found on FDG PET/CT.

Primary cutaneous Ewing's sarcoma/primitive neuroectodermal tumor manifesting numerous small and huge ulcerated masses: its complete remission by chemotherapy and magnetic resonance imaging findings.

Extraskeletal Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET) are widely regarded as clinically and histologically identical tumors which consist of small blue round cells. Extraskeletal ESs/PNETs usually occur in the deep soft tissues of the paraspinal region, chest wall, or lower extremities. However, superficially located cases, so-called cutaneous ESs/PNETs, are exceedingly rare, and the vast majority of the reported cases present as a single small mass. We present magnetic resonance imaging (MRI) findings and clinical course of a unique case of primary cutaneous ES/PNET presenting as numerous huge masses with severe ulceration on them.

Epidermoid cyst appearing as a malignancy-mimicking subcutaneous lesion on ultrasonography.

PURPOSE: It is challenging to diagnose epidermoid cysts on ultrasonography; except in typical, benign-appearing cases. The purpose of this study was to include epidermoid cysts in the differential diagnosis of diverse subcutaneous lesions, especially malignancy-mimicking lesions, as seen on ultrasonography. METHODS: We reviewed 19 cases of pathologically confirmed epidermoid cysts in 19 patients (male, 8; female, 11). Three radiologists, who were blinded to the pathology data, classified (by consensus) these epidermoid cysts as benign or malignancy-mimicking lesions, according to generally accepted ultrasonographic criteria, including the margin, shape, echotexture, and transitional zone with surrounding tissue, and also including the growth pattern and adjacent tissue change. The ultrasonographic data were then correlated with the pathology results regarding the ruptured or unruptured status of the cysts. RESULTS: Epidermoid cysts have been noted as showing a wide-spectrum of findings on ultrasonography. Twelve of our cases showed benign ultrasonographic features: six cases had typical, benign ultrasonographic features with unruptured status; two cases with ruptured status did not have clear ultrasonographic features, although we decided by consensus that there were benign ultrasonographic features; and four cases with unruptured status had peculiar internal echogenicities, described as "internal rod-like contents", that could be considered to be a variation of the typical ultrasonographic finding of epidermoid cysts. Seven cases showed malignancy-mimicking ultrasonographic features; all seven of these had ruptured status. CONCLUSION: The diagnosis of ruptured epidermoid cysts should be included in the differential diagnosis of malignancy-mimicking subcutaneous lesions. The internal rod-like contents can be regarded as another typical ultrasonographic finding of epidermoid cysts.

Determining the factors influencing the symptoms related to naviculo-medial cuneiform coalition.

PURPOSE: We aimed to determine the factors that influence the symptoms of naviculo-cuneiform (NC) coalition using radiography and computed tomography (CT). METHODS: We retrospectively reviewed the radiographic and CT findings of 37 NC coalition cases. The existence of a large pit (depth >3 mm), irregular articular surface, joint space narrowing, dorsal bony spur, subchondral sclerosis, multiple subchondral bony cysts, and intra-articular loose body were evaluated on radiographs or CT. The size of the largest subchondral bony cyst was also measured using CT. All cases were divided into two subgroups according to the symptoms. Fisher's exact test was used to distinguish the factors influencing the symptoms. RESULTS: Twenty-three and fourteen feet were enrolled into the symptomatic and asymptomatic groups, respectively. The rates of the large pit on either radiograph (47.83 vs. 21.43%) or CT (65.22 vs. 28.57%) were significantly different between both groups ( p = 0.001). The mean size of the largest subchondral bony cyst on CT was also significantly greater in the symptomatic group (4.25 vs. 1.53 mm, p = 0.005). CONCLUSION: A large deep pit and huge subchondral bony cyst on the radiograph or CT can be related to symptoms for the patient with NC coalition. A CT is highly recommended for a more accurate evaluation in patients with NC coalition.

MR imaging manifestations of skin tumors.

In this study, we evaluated MR imaging findings of skin tumors and categorized them into four types: (1) discrete mass lesions of the dermis and epidermis, (2) mass lesions of the subcutis with or without abutment to the skin, (3) diffuse or localized skin thickening without a true mass, and (4) a skin mass with bone destruction. The categorization of MR images may be useful in the differential diagnosis of skin tumors.

The clinical efficacy of (18)F-FDG-PET/CT in benign and malignant musculoskeletal tumors.

OBJECTIVE: Most of the current clinical data on the role of 2-[(18)F]fluoro-2-deoxy-D -glucose positron emission tomography ((18)F-FDG-PET) in musculoskeletal tumors come from patients studied with PET and less frequently with hardware fusion PET/computed tomography (CT). And the number of cases in each report is too small to clarify the exact clinical efficacy of PET or PET/CT. This prompted us to analyze our experience with (18)F-FDG-PET/CT in a relatively large group of patients with musculoskeletal tumors. METHODS: (18)F-FDG-PET/CT was performed on 91 patients from May 2004 to June 2007. The final diagnosis was obtained from surgical biopsy in 83 patients (91%) and clinical follow-up in 8 (9%). We analyzed the characteristics and amount of (18)F-FDG uptake in soft tissue and bone tumors, and investigated the ability of (18)F-FDG-PET/CT to differentiate malignant from benign tumors. The cutoff maximum standardized uptake value (SUV(max)) was calculated using the receiver-operation characteristic curve method. Sensitivity, specificity, and diagnostic accuracy were calculated with cutoff SUV(max) and the final diagnosis. Unpaired t test was used for the statistical analysis. RESULTS: Final diagnosis revealed 19 benign soft tissue tumors (mean SUV(max) 4.7), 27 benign bone tumors (5.1), 25 malignant soft tissue tumors (8.8), and 20 malignant bone tumors (10.8). There was a significant difference in SUV(max) between benign and malignant musculoskeletal tumors in total (P < 0.002), soft tissue tumors (P < 0.05), and bone tumors (P < 0.02). Sensitivity, specificity, and diagnostic accuracy were 80%, 65.2%, and 73% in total with cutoff SUV(max) 3.8, 80%, 68.4%, and 75% in the soft tissue tumors with cutoff SUV(max) 3.8, and 80%, 63%, and 70% in the bone tumors with cutoff SUV(max) 3.7. CONCLUSIONS: (18)F-FDG-PET/CT reliably differentiated malignant soft tissue and bone tumors from benign ones, although there were many false-positive and false negative lesions. Further studies with all kinds of musculoskeletal tumors in large numbers are needed to improve the diagnostic accuracy of (18)F-FDG-PET/CT.

Beta-amyloid imaging in dementia.

Alzheimer's disease (AD) is a neurodegenerative disorder associated with extracellular plaques, composed of amyloid-beta (Aß), in the brain. Although the precise mechanism underlying the neurotoxicity of Aß has not been established, Aß accumulation is the primary event in a cascade of events that lead to neurofibrillary degeneration and dementia. In particular, the Aß burden, as assessed by neuroimaging, has proved to be an excellent predictive biomarker. Positron emission tomography, using ligands such as 11C-labeled Pittsburgh Compound B or 18F-labeled tracers, such as 18F-florbetaben, 18F-florbetapir, and 18F-flutemetamol, which bind to Aß deposits in the brain, has been a valuable technique for visualizing and quantifying the deposition of Aß throughout the brain in living subjects. Aß imaging has very high sensitivity for detecting AD pathology. In addition, it can predict the progression from mild cognitive impairment to AD, and contribute to the development of disease-specific therapies.

Breast-specific gamma imaging of invasive breast cancer: Clinicopathologic factors affecting detectability and correlation with mammographic findings.

PURPOSE: To investigate the factors affecting detectability of invasive breast cancers on BSGI. MATERIAL AND METHODS: We evaluated BSGI, mammography and pathologic reports of 89 patients with invasive breast cancers. RESULTS: 87.6% were visible on BSGI. Cancer in old or postmenopausal women were more visible on BSGI (p = 0.003, 0.046). Cancers ≥ 1.0 cm in size were significantly more visible on BSGI than those <1 cm in size (p = 0.002). Cancers in fatty breasts were more visible than those in dense breasts (p = 0.042). CONCLUSION: Invasive cancers in older, postmenopausal patients, cancers with size ≥1.0 cm, and those with fatty breast are better visualized by BSGI, than those in younger, premenopausal patients, with size <1.0 cm and dense breast.

Evaluation of hepatic function with (99m)Tc-galactosylated serum albumin scintigraphy in patients with malaria: comparison with (99m)Tc-colloid scintigraphy and liver ultrasonography.

OBJECTIVE: Malarial parasites injected by the mosquito rapidly target hepatocytes, and hepatomegaly is commonly observed during the progress of the disease in malaria patients. To evaluate the degree of hepatic damage and functional status of hepatocytes in malaria patients, we performed liver scintigraphy using (99m)Tc-galactosylated serum albumin (GSA) prospectively and the findings were compared with those of (99m)Tc-colloid scintigraphy, ultrasonography and clinical results in the same subject. METHODS: Eight malaria patients (all male, mean age 22 years) confirmed to be infected with Plasmodium vivax underwent (99m)Tc-GSA liver scintigraphy, followed by liver ultrasonography and (99m)Tc-colloid scintigraphy using phytate within 3 days. For hepatocyte scintigraphy, anterior images of cardiac blood-pool and liver were continuously acquired for 30 min after injection of 185 MBq (99m)Tc-GSA (3 mg). In addition to visual interpretation of the images, quantitative measurement of hepatic function was performed with several functional parameters, such as hepatic uptake index (LHL15), blood clearance index (HH15) and modified receptor index (LHL/HH) calculated from the radioactivity of the liver and heart. (99m)Tc-colloid images were assessed and graded visually. Severity of hepatic dysfunction or reticuloendothelial system activation was classified as normal, mild, moderate and severe on GSA or colloid images. RESULTS: Hepatomegaly was observed in five and splenomegaly in seven of the eight patients. Serum levels of transaminase and alkaline phosphatase were mildly elevated in two. Visual assessment of GSA scintigraphy revealed normal findings in all subjects, except for mild increases in size. The mean values of LHL15, HH15 and LHL/HH were 0.928+/-0.014, 0.537+/-0.031 and 1.732+/-0.106, respectively. They were graded as normal in five, and near-normal to mild dysfunction in three subjects. In contrast, (99m)Tc-colloid scintigraphy revealed abnormal findings in all of the subjects, and graded as moderate in three or severe reticuloendothelial system activation in five subjects. Liver ultrasonographic findings were normal for all subjects except mild hepatomegaly. CONCLUSIONS: Malaria-induced injury of the hepatocyte is likely to be minimal whereas hepatomegaly is commonly seen during disease process. This suggests that hepatic damage in malarial infection is mainly due to involvement of the reticuloendothelial system. (99m)Tc-GSA scintigraphy can be used in differentiating hepatocellular damage from reticuloendothelial system involvement in patients with infectious disease showing hepatomegaly.

A case of silent giant cell arteritis involving the entire aorta, carotid artery and brachial artery screened by integrated PET/CT.

We report a case of giant cell arteritis involving the aorta and several large arteries identified by integrated positron emission tomography (PET)/computed tomography (CT) obtained in a patient with a high erythrocyte sedimentation rate (ESR). A 63-year-old man with anemia and a high ESR noted on a regular medical examination was transferred to our department. The patient complained of only a low-grade general weakness for several months; there were no specific symptoms or signs. A PET was recommended. The image showed strong (18)F-fluorodeoxyglucose ((18)F-FDG) uptake at the ascending aorta, aortic arch, descending aorta, thoraco-lumbar aorta, brachial artery, and the carotid artery wall, bilaterally. Suspicious for large-vessel vasculitis, a temporal artery biopsy was performed, which confirmed giant cell arteritis. After treatment with prednisolone, the high ESR and anemia resolved, and (18)F-FDG uptake decreased on follow-up integrated PET/CT.

Quantitative assessment of simultaneous F-18 FDG PET/MRI in patients with various types of hepatic tumors: Correlation between glucose metabolism and apparent diffusion coefficient.

PURPOSE: Metabolism and water diffusion may have a relationship or an effect on each other in the same tumor. Knowledge of their relationship could expand the understanding of tumor biology and serve the field of oncologic imaging. This study aimed to evaluate the relationship between metabolism and water diffusivity in hepatic tumors using a simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI) system with F-18 fluorodeoxyglucose (FDG) and to reveal the metabolic and diffusional characteristics of each type of hepatic tumor. METHODS: Forty-one patients (mean age 63 ± 13 years, 31 male) with hepatic tumors (18 hepatocellular carcinoma [HCC], six cholangiocarcinoma [CCC], 10 metastatic tumors, one neuroendocrine malignancy, and six benign lesions) underwent FDG PET/MRI before treatment. Maximum standard uptake (SUVmax) values from FDG PET and the apparent diffusion coefficient (ADC) from the diffusion-weighted images were obtained for the tumor and their relationships were examined. We also investigated the difference in SUVmax and ADC for each type of tumor. RESULTS: SUVmax showed a negative correlation with ADC (r = -0.404, p = 0.009). The median of SUVmax was 3.22 in HCC, 6.99 in CCC, 6.30 in metastatic tumors, and 1.82 in benign lesions. The median of ADC was 1.039 × 10-3 mm/s2 in HCC, 1.148 × 10-3 mm/s2 in CCC, 0.876 × 10-3 mm/s2 in metastatic tumors, and 1.323 × 10-3 mm/s2 in benign lesions. SUVmax was higher in metastatic tumors than in benign lesions (p = 0.023). Metastatic tumors had a lower ADC than CCC (p = 0.039) and benign lesions (p = 0.004). HCC had a lower ADC than benign lesions, with a suggestive trend (p = 0.06). CONCLUSION: Our results indicate that SUVmax is negatively correlated with ADC in hepatic tumors, and each group of tumors has different metabolic and water diffusivity characteristics. Evaluation of hepatic tumors by PET/MRI could be helpful in understanding tumor characteristics.

Prognostic value of preoperative 18F-FDG PET/CT in papillary thyroid cancer patients with a high metastatic lymph node ratio: a multicenter retrospective cohort study.

OBJECTIVE: Metastatic lymph node ratio (MLNR) is a known significant predictor of disease-free survival in differentiated thyroid cancer. The authors investigated the ability of preoperative fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT to predict recurrence after surgery with radioactive iodine therapy considering MLNR. PATIENTS AND METHODS: A total of 274 patients who underwent preoperative PET/CT and surgery with radioactive iodine therapy were enrolled. The tumor-to-liver uptake ratio on PET/CT was calculated by dividing the maximum standardized uptake value of a primary lesion by the mean standardized uptake value of the normal liver. High F-FDG uptake was defined as tumor-to-liver uptake ratio more than the median cutoff value (2.1). MLNR was calculated by dividing the number of metastatic lymph nodes (LNs) by the number of cervical LNs removed. A high MLNR was also defined as one more than a threshold value (0.4), identified by plotting Kaplan-Meier survival curves and comparing them using the log-rank test. The prognostic significances of clinicopathologic variables were analyzed. RESULTS: Fifteen (5.5%) patients developed recurrence in the thyroid bed or in cervical LNs. Cox regression analysis showed that a high MLNR was significantly associated with a worse disease-free survival (odds ratio 6.95; 95% confidence interval: 2.36-20.47; P<0.001). A subgroup analysis of 70 patients with a high MLNR showed that only high F-FDG uptake was significantly associated with a worse disease-free survival (odds ratio 5.77; 95% confidence interval: 1.22-27.16; P=0.027). CONCLUSION: High F-FDG uptake of primary lesion on preoperative PET/CT has selective prognostic value according to the extent of metastatic LNs (MLNR>0.4).

Direct comparison of adenosine and adenosine 5'-triphosphate as pharmacologic stress agents in conjunction with Tl-201 SPECT: Hemodynamic response, myocardial tracer uptake, and size of perfusion defects in the same subjects.

BACKGROUND: Adenosine 5'-triphosphate (ATP), a potent and inexpensive coronary vasodilator, was introduced as a pharmacologic stress agent for thallium 201 single photon emission computed tomography (SPECT). However, there has been no direct comparison of ATP and adenosine as myocardial stressors in the same subjects. METHODS AND RESULTS: Thirty-six patients underwent consecutive Tl-201 SPECT imaging with adenosine and ATP in a randomly assigned order. There were no changes in clinical status and no invasive procedures were performed between the two tests. The hemodynamic response and side effects were monitored, and myocardial tracer uptake was assessed by use of a visual grading system and quantitative analysis via a CEqual map. The hemodynamic changes and adverse effects did not differ significantly between the two groups. There were no changes in the detection of any perfusion defect on a per-subject basis, except in one. The exact agreement rate for the visual grading of the myocardial tracer uptake was 84.8%. However, the average extent of the perfusion defect and the severity score were higher with adenosine. CONCLUSION: The hemodynamic changes and the degree of myocardial uptake were similar between the adenosine and ATP infusion. However, quantitative analysis by use of a CEqual map revealed smaller perfusion defects and lower severity scores in subjects undergoing Tl-201 SPECT with ATP.

Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings of Post Traumatic Lymphangioma in a Young Adult Male.

The authors report the case of a 34-year-old male, who underwent a fluorine-18 fluoro deoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) scan 7 years after trauma for the evaluation of multifocal masses in the right iliac and right inguinal areas. CT findings showed multifocal low density masses and 18F-FDG PET revealed slightly increased uptake (maximum standardized uptake value [SUVmax] 3.1). These findings did not exclude the possibility of a benign or malignant lesion. To achieve differential diagnosis, partial surgical excision was performed and a pathologic examination subsequently revealed lymphangioma. Here, the authors describe the 18F-FDG PET/CT findings of a rare case of lymphangioma resulting from trauma.