False-positive result of a captopril-enhanced radionuclide renogram in a child secondary to dehydration.

PURPOSE: Renovascular hypertension is an unusual cause of elevated mean arterial pressure in children. When suspected, angiotensin-converting enzyme inhibitor-enhanced renal scintigraphy is usually one of the initial studies done to evaluate patients. The accuracy of this test depends not only on patient selection but also on technical factors involved in performing the study. We report a case of a false-positive angiotensin-converting enzyme inhibitor-enhanced radionuclide renogram in a 5-year-old boy with hypertension. METHODS: Angiotensin-converting enzyme inhibitor-enhanced renal scintigraphy was performed and the result was interpreted as positive for bilateral renovascular disease. A review of the anesthesia record from the study revealed that the patient was hypotensive. A repeated study with adequate hydration and blood pressure stability was then done. RESULTS: The result of the second examination was interpreted as normal, without evidence of abnormal renovascular physiology. CONCLUSIONS: The cause of the initial false-positive result was determined to be dehydration with secondary hypotension. Dehydration, with secondary hypotension, can cause a diminished glomerular filtration rate and mimic bilateral renovascular physiology on angiotensin-converting enzyme inhibitor-enhanced renal scans.

Retro runner with ischial tuberosity enthesopathy.

In reviewing the literature, no studies were found reporting the use of retro running on flat and hilly terrain, which elicited enthesopathy (stress reaction) at the ischial tuberosity. Therefore, this case study of an atypical enthesopathy condition warrants careful scrutiny in order to generate future research. This case study describes the clinical management of a female runner with bilateral patellofemoral pain who self-initiated a program of backward running and stationary bicycling after reading an article about retro running in a runners' magazine. She subsequently developed ischial tuberosity enthesopathy verified by scintigraphy (bone scan). Her symptoms gradually resolved with physical therapy intervention. Eventually, she was able to forward jog 2 miles on flat surfaces without complaint of pain but did not resume retro running. This case not only suggests the need for further research in retro running kinetics and kinematics but highlights the proactive role health professionals must assume in injury prevention.

Scintigraphy in gastroesophageal reflux disease: a comparison to endoscopy, LESp, and 24-h pH score, as well as to simultaneous pH monitoring.

We compared scintigraphy to other reflux tests in 45 symptomatic patients. Sensitivity of 24-h pH score was 82%, endoscopy 64%, and LESp 33%. Scintigraphy was insensitive (36%), although 50% of patients with esophagitis had a positive test. Specificity and positive predictive value were good (all greater than or equal to 88%) in discerning patients with an abnormal 24-h pH score and esophagitis. We suggest scintigraphy as the first diagnostic test to confirm frequent reflux events (REs) and normal clearance in the subgroup of patients with severe endoscopic esophagitis, and manometry and 24-h pH monitoring when scintigraphy is negative. We also compared scintigraphy to simultaneously performed pH monitoring in detecting individual postprandial REs and their clearance. The two methods agreed in only 25% of total reflux events. Scintigraphy was superior at detection of reflux of buffered gastric contents and detection of additional REs during acid clearing intervals, whereas only the pH probe detected REs after gastric emptying. We conclude that scintigraphy has a limited role as a diagnostic test in gastroesophageal reflux disease, and much potential as a research tool, especially in combination with the pH probe.

Abnormalities of lymphatic drainage in lower extremities: a lymphoscintigraphic study.

Chronic lower-leg edema in patients with venous disorders was studied by means of lymphoscintigraphy. Lymphatic patterns of flow were evaluated prospectively in 26 patients with technetium 99m antimony trisulfide colloid injected subcutaneously in the interdigital web spaces on the feet. Most patients in this study had postphlebitic syndrome, and all of these patients had abnormal lymphoscintigraphic flow patterns. Nine had evidence of lymphatic obstruction, and one had an enhanced flow pattern. Three patients had veins used for distal arterial bypass, and all these veins showed decreased lymphatic flow. Two patients with Klippel-Trenaunay syndrome (congenital varicose veins associated with limb elongation, a capillary nevus, and an abnormal deep venous system) had obstruction to lymphatic flow, and two others had normal and enhanced patterns. Normal studies were seen in four of five patients who had veins used for coronary artery bypass grafting. The finding of decreased lymphatic flow in patients appears to be the result of the length of time from an episode of deep venous thrombosis, the occurrence and number of episodes of cellulitis and lymphangitis, and mobilization of the vein for use in distal arterial bypass surgery. This study shows that the edema attributed previously to primary venous disorders may have a significant lymphatic component. The degree of lymphatic obstruction can be determined by lymphoscintigraphy with technetium-labeled antimony trisulfide colloid.

Preoperative indium-labeled white blood cell scintigraphy in suspected osteomyelitis of the axial skeleton.

The cases of six patients with suspected osteomyelitis of the axial skeleton who underwent preoperative indium-labeled white blood cell scintigraphy (In-WBC) were reviewed retrospectively. Five of these patients had undergone previous spinal surgery, and all six patients complained of back pain. Four of these six patients were proven to have osteomyelitis by culture and histopathology. The sensitivity, specificity, and accuracy of In-WBC scintigraphy in detecting osteomyelitis of the axial skeleton was 25%, 50%, and 33%, respectively. Our preliminary experience in six patients with suspected osteomyelitis of the axial skeleton suggests that In-WBC scintigraphy is neither sensitive nor specific in predicting infection.

In-111-labeled white blood cell uptake in noninfected closed fracture in humans: prospective study.

Since indium-111 white blood cell (In-111 WBC) scintigraphy is often used to evaluate for osteomyelitis in bone fractures, it is important to know if noninfected fractures have In-111 WBC uptake. Twenty-seven noninfected closed fracture sites in 19 patients were prospectively evaluated with technetium-99m methylene diphosphonate bone scintigraphy and In-111 WBC scintigraphy. In-111 WBC uptake was present in 41% of the 27 sites. In the 11 positive sites, the In-111 WBC uptake was 1+ (definite but minimal) in 55%, 2+ (moderate) in 36%, and 3+ (marked) in 9%. The visual intensity of the radioactive uptake on In-111 WBC scintigrams relative to that on bone scintigrams was less in 82%, equal in 9%, and greater in 9%. The visual size of the area of uptake on In-111 WBC scintigrams and bone scintigrams was smaller in 36%, equal in 55%, and greater in 9%. Factors that may help distinction of In-111 WBC uptake due to fracture alone from infection associated with fracture are discussed.

Diagnosis of infection by preoperative scintigraphy with indium-labeled white blood cells.

Scintigraphy with indium-labeled white blood cells has been reported to be sensitive and specific in the diagnosis of low-grade sepsis of the musculoskeletal system. We reviewed the records of fifty patients who had suspected osteomyelitis or suspected infection about a total joint prosthesis and who underwent scintigraphy with technetium-99m methylene diphosphonate and scintigraphy with indium-111 oxine-labeled white blood cells before an open surgical procedure. Any patient who received preoperative antibiotics was not included in the study. For all of the patients, gram-stain examination of smears, evaluation of a culture of material from the operative site, and histological examination were done. The patients were divided into two groups. Group I was composed of twenty-four patients, each of whom had a prosthesis in place and complained of pain. Group II was composed of twenty-six patients for whom a diagnosis of chronic osteomyelitis had to be considered. With the indium scans alone, there was only one false-negative result (in Group II), but there were eighteen false-positive results (eight patients in Group II and ten patients in Group I). Although scintigraphy with indium-labeled white blood cells is quite sensitive, it is not specific in detecting chronic osteomyelitis; a negative scan should be considered highly suggestive that osteomyelitis is not present. Specificity can be increased by interpreting the indium scan in conjunction with the technetium scan.