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We report a case of a 49-year-old woman with a rare anomaly, intrathoracic renal ectopia. Her medical history includes a surgically corrected congenital diaphragmatic hernia, which can cause late presentations of diaphragmatic hernia in adult life. The Tc-MAG3 renogram demonstrated slower emptying of the dilated pelvis of the ectopic kidney than the normal kidney. The curve confirmed a delayed Tmax, followed by a distinct decline. These features are not indicative of a complete obstruction, but can result from partial obstruction, renal dysfunction with poor response to diuresis, pelvic dilatation (such as in our patient), or a combination.

Objective: Nuclear imaging can confirm pleuroperitoneal shunt as the cause of pleural effusion. No society guidelines exist for scintigraphic pleuroperitoneal shunt detection. Our institutional protocol was evaluated to determine optimal imaging time points for shunt detection., Methods: Pleuroperitoneal shunt studies over 4 years were blindly reviewed by 2 nuclear radiologists. Data from blinded review included presence or absence of pleuroperitoneal shunt, laterality of shunt and time points for shunt detection., Results: Chart review yielded 30 studies. Three cases were excluded because of improper injection. Imaging was positive for pleuroperitoneal shunt in 81% (22/27) of cases. In positive cases, activity was identified in the right hemithorax in 82% (18/22), left hemithorax in 9% (2/22), and bilaterally in 9% (2/22). One-hour imaging demonstrated 91% (20/22) of positive cases. The remaining 2 positive cases were negative at 1 hour but positive after 4 hours. No study was negative at 1 and 4 hours and positive at 24 hours. All negative cases (5/27) were confirmed on 24-hour imaging., Conclusions: The majority of positive pleuroperitoneal shunt examinations will demonstrate activity in the right hemithorax on 1-hour imaging. Although no case was negative at 1 and 4 hours and positive at 24 hours, imaging at 24 hours may still be necessary to confirm absence of shunt. Therefore, optimal imaging time points consist of early 1-hour and delayed 24-hour images if the 1-hour time point was negative. The 4-hour time point may be considered optional, thereby potentially optimizing patient safety and resource utilization.

A 5-year-old patient suffered Horner syndrome, which was caused by a neuroblastoma in the left apex of the lung shown on the initial I-MIBG scan. After the surgical resection and external radiation to the left lung field, a follow-up I-MIBG scan revealed significantly less MIBG activity in the left upper chest compared to the contralateral right upper chest.

Actinomycosis is a rare chronic granulomatous disease that runs an indolent course, predominantly seen in Asian countries. The present case highlights the findings of F-FDG PET/CT in cervicothoracic actinomycosis imitating lymphoma.

Whole-body 131I scan after total thyroidectomy is important in the evaluation of radioiodine avid metastatic foci in patients with differentiated thyroid carcinoma. False-positive uptakes are occasionally seen in the thoracic region which should be evaluated carefully and not mistaken as lung metastases. We report here 2 cases of abnormal focal thoracic uptake, 1 case of a pleuropericardial cyst and 1 case of focal bronchiectasis, that could potentially be confused with lung metastasis. Careful correlation with diagnostic CT and subsequent follow-up studies suggested that these were not metastatic lesions.

Extramedullary hematopoiesis refers to the presence of hematopoietic elements in locations other than the bone marrow medullary space. It occurs as a compensatory mechanism to impaired hematopoiesis resulting from a variety of pathological conditions. Because of the hazards of biopsy of a highly vascular hematopoietic mass, it is desirable to establish the diagnosis noninvasively. We report a case where 18F-fluoro-3'deoxy-L-thymidine PET/CT and 99mTc-SC scintigraphy were used as a noninvasive modality to diagnose extramedullary hematopoiesis.

A 57-year-old-male presented for whole-body PET with CT for restaging of lung cancer. Besides revealing postradiation changes, we noticed an unusual pattern of FDG uptake in the myocardium, with prominent metabolic uptake involving 4 chambers of the heart. Later that day, the patient was referred to the emergency department for increased heart rate, but otherwise asymptomatic. CT angiography was performed, which showed scattered filling defects in bilateral pulmonary arteries consistent with pulmonary embolism. The finding of prominent FDG uptake involving all cardiac chambers in this patient is likely related to heart strain caused by acute pulmonary embolism.

Purpose: To assess the diagnostic value of dual-phase (99m)Tc sestamibi scintigraphy with neck and thorax single-photon emission computed tomography/computed tomography (SPECT/CT) in patients with primary hyperparathyroidism, and to analyze the relationships between SPECT/CT data and serum calcium or parathyroid hormone (PTH) concentrations., Materials and Methods: (99m)Tc sestamibi scintigraphy was performed in 94 consecutive patients. Images included early and delayed planar neck images and delayed neck and thorax SPECT/CT. Scintigraphy was scored positive or negative., Results: Fifty-nine sestamibi studies (63%) were positive. SPECT/CT demonstrated a single focus in 56 patients, in usual parathyroid sites in 80% of cases and in unusual sites in the remaining 20% (retrotracheal area, 7%; intrathyroidal, 9%; mediastinum, 4%), and double foci in 3. Serum calcium values were higher in patients with a positive scintigraphy than in those with a negative scintigraphy (2.80 vs. 2.66 mmol/L, P = 0.001) with similar figures for serum PTH values (129 vs. 107 pg/mL, P = 0.0649). In patients with a measurable parathyroid adenoma on integrated CT scan (n = 43), the greatest axial diameter of the adenoma was correlated to serum calcium (r = 0.405, P < 0.0071) or PTH concentrations (r = 0.589, P < 0.0001). Fifty-four patients underwent surgery, 45 with a positive, and 9 with a negative preoperative scintigraphy, resulting in a sensitivity of 92% (95% CI: 80-98) and a specificity of 83% (95% CI: 36-100)., Conclusions: Dual-phase (99m)Tc sestamibi scintigraphy with SPECT/CT enables to identify a parathyroid adenoma in about two-thirds of patients with primary hyperparathyroidism and allows the surgeon to plan appropriate surgery. The likelihood of scintigraphy to be positive is affected by calcium or PTH concentrations.

A 69-year-old man with remote gastric pull-up was evaluated with a 2-day stress-rest dypiridamole Tc-99m sestamibi myocardial perfusion imaging, where significant tracer uptake was noted in the posterior mediastinum related to enterogastric reflux of sestamibi. These ancillary findings were suggestive of a noncardiac etiology of the patient's atypical chest pain. This case highlights the value of examining the raw projection images for incidental findings that may be present during myocardial perfusion imaging.

Purpose: The purpose of this study was to determine if an FDG-PET study was able to visualize muscle uptake of the chest and abdomen in patients with chronic obstructive pulmonary disease (COPD)., Methods: This study included 25 patients with COPD and 25 patients without COPD who had undergone a FDG-PET study. The nonattenuation-corrected images were used to determine the degree of FDG uptake in the intercostals, subscapular, abdominal rectus, and abdominal oblique muscles. The intensity of uptake in the muscles was rated on a 4-point grading scale with 1 being less, 2 the same, 3 slightly more, and 4 markedly more intense than the sternum., Results: Thirteen patients with COPD demonstrated FDG activity in the intercostal muscles that was equal to or greater than the sternum and the tracer was demonstrated predominantly in the inferolateral chest wall (n = 8), the entire lateral chest wall (n = 2), the posteroinferior chest wall (n = 2), and the entire chest wall (n = 1). In all 13 patients with COPD who demonstrated FDG activity in the abdominal oblique muscles, the site of muscle activity was predominantly in the anteroinferior abdominal wall (n = 8), the lateral wall (n = 4), and the anterior wall (n = 1). In patients without known COPD, the frequency and intensity of uptake in the muscles were less than those with the disease., Conclusion: This study demonstrates the ability of FDG-PET imaging to assess muscle function in respiratory disorders and may prove to be of some value in further characterizing this disorder.

There are occasional reports of a hiatal hernia demonstrating thoracic uptake on I-131 scintigraphy. This is a cause of a potential false-positive appearance mimicking a pulmonary or mediastinal metastasis. Hiatal hernia is 1 of a number of causes of false-positive I-131 whole-body scans. Although previous case reports have demonstrated uptake to lie to the left of the midline, this case is slightly unusual in view of the midline appearance of the uptake. Although this appearance could be seen with mediastinal, pulmonary, or prevertebral metastases, hiatal hernia should be considered in the differential diagnosis of uptake in the thoracic midline on I-131 scintigraphy.

Splenosis is defined as the autotransplantation of splenic tissue to abnormal locations after splenic injury. Although abdominal splenosis is the most common form and is usually discovered at laparotomy, thoracic splenosis is less common and occurs as an asymptomatic peripheral pulmonary nodule, incidentally discovered on a routine chest radiograph. Given the long interval between the initial trauma and its discovery, thoracic splenosis is rarely considered in the differential diagnosis of left-sided, pleural-based pulmonary nodules or masses. The diagnosis is often a result of surgery. The authors report an additional case of thoracic splenosis, review the literature, and discuss nonsurgical diagnostic methods.

Extramedullary hematopoiesis is of special interest to physicians because of its relation to hematologic disease. Because it normally remains asymptomatic, sites are typically found by chance. Effective diagnosis involves a specific, reliable, whole-body and low-cost method of screening. Although radiologic methods such as computed tomography and magnetic resonance imaging can only suggest the presence of extramedullary hematopoiesis, apart from invasive and therefore risky biopsy procedures, only scintigraphy can detect and confirm the nature of hematopoietic tissue. Although radioactive tracers commonly in use partly lack the demands for specific diagnosis, Tc-99m-labeled antibodies (NCA-95) seem to combine the advantages of different scintigraphic approaches. Two patients with dyserythropoetic anemia and paravertebrally situated pelvic and thoracic tumor masses were studied for extramedullary hematopoiesis. Planar and SPECT images were obtained 6 and 24 hours after injection of 800 to 850 MBq (22 to 23 mCi) Tc-99m-labeled monoclonal antibodies (BW 250/183). In both patients, tracer accumulated in the masses, thereby revealing hematopoietic tissue. Biopsy confirmed these findings. By using Tc-99m-labeled monoclonal antibodies to detect extramedullary hematopoiesis, the demands of diagnosis were met. As an alternative to invasive diagnostic procedures, this tracer combines the advantages of other radioactive substances previously used, such as radioiron, In-111 chloride, and Tc-99m colloids. This low-cost agent is readily available and when applied, reliable, and delivers whole-body images free of additional uptake in the liver or spleen.

Extramedullary plasmacytoma is a rare form of plasma cell tumor occurring in a wide variety of organs and tissues. Most tumors occur in the head and neck, involving the nasal cavity, paranasal sinuses, and upper airway. Tl-201 and Ga-67 scan findings in a patient with extramedullary plasmacytoma in the right side of the chest wall are presented. Only a few publications have described Tl-201 or Ga-67 uptake in extramedullary plasmacytoma. This is the first report of both Tl-201 and Ga-67 uptake in an extramedullary (or intramedullary) plasmacytoma.

This case report clearly illustrates defined simultaneous cerebrospinal fluid leaks at the cervicothoracic and upper lumbar areas. A 53-year-old woman without a remarkable medical history was hospitalized for sudden onset of severe headache. The headache lasted more than 1 week and standing or sitting positions exaggerated the symptoms, although it was relieved when the patient was recumbent. Radionuclide cisternography was performed using 150 MBq (4 mCi) Tc-99m DTPA. It revealed two cerebrospinal fluid leaks from the cervicothoracic junction bilaterally and the left side of the upper lumbar area. Epidural blood patching was tried at the lumbar level (L1-L2) and showed only a transient effect. A second trial of this method at the level of C7-T1 performed 2 days later resulted in immediate improvement of the symptoms without recurrence. The simultaneous cerebrospinal fluid leaks were detected successfully with radionuclide cisternography using Tc-99m DTPA, which provided a useful guideline for treatment despite the limitations of delayed scanning.

Cardiac function is commonly evaluated in patients with cancer in most nuclear medicine departments. At their dedicated cancer facility, the authors routinely perform a dynamic right anterior oblique first-pass study and a 4-minute left anterior oblique static planar study in addition to the routine equilibrium gated scanning in appropriate projections. Here they show the range of noncardiac disease encountered using this protocol. Useful unexpected information can be obtained from left ventricular ejection studies, and further data may be gained from these simple additions to this common test.

Thirty-one men (age range, 46-76 years; mean age, 64.8 years) with intrathoracic masses suggesting possible malignancy on the basis of chest radiography or CT underwent preoperative Tc-99m MIBI SPECT examinations. Diagnosis was confirmed on pathologic examinations of samples obtained either at thoracotomy, esophagectomy, or by biopsy. Twenty-five patients had primary lung cancer, including squamous cell carcinoma, large cell carcinoma, adenocarcinoma, and small cell carcinoma. Two patients had lymphomas with spread to the mediastinum, and three patients had extrathoracic primary cancers (one squamous cell carcinoma of esophagus, one squamous cell carcinoma originating from a head and neck tumor, and one metastatic mediastinal leiomyosarcoma). One patient with a tuberculoma had negative results of the Tc-99m MIBI examination. Tc-99m MIBI had a 86.7% sensitivity rate, a 0% false-positive rate, and a 100% positive predictive value to detect malignant intrathoracic masses. There was a 13% false-negative rate, however, suggesting that MIBI-SPECT may underdiagnose malignant lesions. SPECT findings of these 31 patients can be classified as 1) mass with increased uptake, n = 23; 2) ring-like appearance of increased uptake, n = 3; 3) mass with absent uptake, n = 4; and 4) photon-deficient mass, n = 1. Absent uptake in patients with mass lesions could be explained by necrosis of the lesion (caseation necrosis or massive tumor necrosis with or without bleeding). Most malignant intrathoracic masses are Tc-99m MIBI avid and may be detected with a high degree of sensitivity and with an excellent positive predictive value. A positive MIBI scan may help in the clinical diagnosis of malignancy. The use of Tc-99m MIBI could serve not only as a tumor imaging agent, but also may be used to determine the extent of spread and potentially the chemotherapeutic responsiveness of a tumor.

Hyperparathyroidism (HPT) is one of the most prevalent endocrine diseases, for which the only effective treatment is surgery. The use of imaging techniques in the preoperative localization of the hyperfunctioning glands is the subject of controversy. The purpose of this paper is to assess the use of double-phase scintigraphy with Tc-99m sestamibi in the localization of lesions causing HPT. We used scintigraphy to preoperatively examine 41 patients, 31 of whom had primary HPT and 10 with secondary HPT. We acquired two anterior view planar images of the neck and chest 10 minutes and 3 hours after injection of Tc-99m sestamibi. Final diagnosis, determined with biopsy, was adenoma in 26 patients, 24 of whom had a positive scintigraphic study (sensitivity 92%), with only two false negative results. In the 14 cases of parathyroid hyperplasia, scintigraphy was also positive, and 62% (30/48) of the excised glands were identified by Tc-99m sestamibi. The radioisotope study was of particular interest in the six patients who previously had undergone surgery, since all the studies were positive; in two patients, additional diseased glands were located in the neck, and an ectopic adenoma was found in the remaining four patients. A fifth ectopic lesion was also sestamibi-positive and, in this case, the scintigraphic result was a direct indication for mediastinal surgery. There were no false positive results, even in patients with multinodular goiter. We conclude that, due to its high sensitivity and the ease with which it is performed, double-phase scintigraphy with Tc-99m sestamibi is the preferred technique for the preoperative localization of diseased glands in patients with HPT, especially in cases of parathyroid adenoma, including those with aberrant location. Its use is of particular interest in patients who previously have undergone surgery.

Multiple cardiac pacing wires present a potential source of thrombosis and infection within veins and cardiac chambers. A case is presented where persistent infection involved thrombus on cardiac pacing wires in and around the right subclavian and brachiocephalic veins, which proved difficult to localize and treat. Early Ga-67 and Tc-99m labeled white blood cell imaging were negative but, when the latter test was repeated after 5 weeks, the septic focus was identified. Treatment with antibiotic therapy combined with surgical removal of the infected thrombus and both pacing wires was effective in eradicating infection. Failure to demonstrate an infection focus early in the course of the illness may have related to the size of the infection focus; however, in a later phase of the illness, Tc-99m labeled white blood cell imaging proved helpful in localizing focal infection associated with pacemaker wires.

Ga-67 SPECT has been shown to be more sensitive than planar imaging in several pediatric and adult studies. With multidetector SPECT cameras, SPECT imaging of multiple sites and volumes rendered images are possible. This study was performed to determine if SPECT of the chest, abdomen, and pelvis can be substituted for planar imaging of the same body regions. Fifty-one Ga-67 studies in 36 patients with lymphoma (29 patients) and inflammation (7 patients) were reviewed. Ga-67 SPECT of the chest, abdomen, and pelvis was compared with planar images of the same body regions. There were 52 abnormal sites on SPECT and 42 on planar imaging. Ten sites were positive only on SPECT; five of these sites were seen on SPECT because of improved three-dimensional separation of sites of gallium uptake. In the limited number of cases in this study, duplicate planar and SPECT imaging of the same volume was unnecessary.

A case study is presented in which three types of images from a Ga-67 study are compared. The Ga-67 study was performed on a patient with fever of unknown origin (FUO). Planar and SPECT images were obtained. Planar data were presented as standard 2-D images on radiographic film. The SPECT data were used to generate two sets of images: standard 2-D multiple 'slice' images presented on radiographic film and a rotating 3-D synthetic reprojection displayed on a computer monitor. Compared to the planar and SPECT images, three sites of inflammation and the path of an oblique sinus tract were best seen in the 3-D synthetic reprojection. Recognition of anatomic structures and their spatial relationships was most readily apparent when viewing the 3-D synthetic reprojection, and this method of display facilitated the rapid recognition of abnormal findings.

After a motor vehicle accident, an 18-year-old woman reported cough and dyspnea. A chest radiograph revealed an intrathoracic mass blending with the cardiac shadow. Hepatobiliary imaging showed that this was due to herniation of the left hepatic lobe and a portion of the right lobe and gallbladder into the right hemithorax.

A 69-year-old woman presented with non-Hodgkin's lymphoma of the right ilioinguinal region in whom bilateral uptake of Ga-67 in hilar lymph nodes was noted on thoracic SPECT. There were no Ga-67 abnormalities elsewhere within the thorax, and a chest CT scan was also normal. The patient received radiotherapy to the inguinal region and remained in clinical remission for 28 months following treatment. She subsequently relapsed at a number of peripheral lymph node sites, but not in the chest. The authors postulate that isolated hilar uptake of Ga-67 SPECT may not be clinically significant in some untreated patients with lymphoma. This scintigraphic finding should be interpreted cautiously, particularly when other chest imaging studies remain negative.

Diffusely increased radioactivity in the thoracoabdominal region (lower thorax and/or upper abdomen) occasionally has been observed when performing Tc-99m phosphonate bone studies. To assess the significance of activity in this finding, 1100 bone scintigrams were reviewed and the clinical data and other diagnostic imaging procedures were evaluated in these cases. With the exclusion of Tc-99m sulfur colloid liver-spleen scans 18 patients were found to have mild but diffuse increased radioactivity in the thoracoabdominal region either on the right or left. Clinical findings in these cases with abnormal uptakes were pleural effusions (six cases), hepatic colonic metastases (six cases), splenic metastases from bronchogenic carcinoma (one case), abdominal and peritoneal colonic metastases (one case), a massive metastatic squamous cell carcinoma (from lung) in the right lower chest (one case), and defective radiopharmaceuticals (three cases). Since the defective radiopharmaceuticals contained 5% of hydrolyzed reduced Tc-99m colloid by thin-layer chromatography, each of three patients received approximately 740 mu Ci of Tc-99m sulfur colloid. Factors to be considered in the interpretation of diffuse thoraco-abdominal activity from a bone agent should include splenic or hepatic metastases, a Tc-99m sulfur colloid splenic or hepatic metastases, a Tc-99m sulfur colloid study within the previous 24 hours, pleural effusion, faulty radiopharmaceuticals, and abdominal and peritoneal colonic metastases.

Fifty-two patients with proven primary lung cancer who were referred for mediastinoscopy were prospectively studied with Tc-99m glucoheptonate and Ga-67 citrate thoracic scintigraphy. Primary lung tumors concentrated Ga-67 in 92% of cases, compared to 88% for Tc-99m glucoheptonate. Mediastinoscopy confirmed the presence of mediastinal metastases in 23 patients. The sensitivity of Tc-99m glucoheptonate and Ga-67 scans for mediastinal involvement detection is respectively 52% and 83%, for a specificity of 100% (Tc-99m glucoheptonate) and 88% (Ga-67). Twenty-nine patients underwent thoracotomy after a negative mediastinoscopy. Hilar metastatic involvement was present in eight patients. The sensitivity and the specificity for detection of hilar involvement were respectively 63% and 95% for Tc-99m glucoheptonate and 88% and 78% for Ga-67. Although more specific than Ga-67 scan, Tc-99m glucoheptonate thoracic imaging cannot be recommended in the staging of lung cancer because of its low sensitivity in the detection of intrathoracic metastatic spread of primary lung carcinoma.