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The scintigraphic appearance of an overuse injury at the insertion of the iliotibial band is described. This injury was depicted on three-phase bone scintigraphy as focally increased radionuclide concentration in the anterolateral tibial condyle (lateral tibial tubercle) where the iliotibial band inserts. Overuse injuries involving the insertion of the iliotibial band are uncommon and are not to be confused with a stress fracture or other bony lesion involving the lateral tibial condyle.

An athlete complained of chronic knee pain but had minimal findings on physical examination and initial equivocal radiographs. Subsequent tomograms of the knee suggested a patella stress fracture. Three-phase bone imaging confirmed a stress fracture of the inferior pole of the patella.

An exercise-related avulsion injury of the insertion of the pectineus muscle is described. The abnormality was detected on a 4-hour delayed bone scan. Symptomatic injuries of the adductor muscles are uncommon and are not to be confused scintigraphically with a stress fracture of the proximal femoral shaft.

Dipyridamole TI-201 imaging is an ideal alternative to exercise TI-201 scintigraphy in patients who are unwilling or unable to perform maximum exercise stress. The use of intravenous dipyridamole, alone or in combination with exercise, has not been approved for clinical practice by the Food and Drug Administration. Once approval is granted, the test will become a widely used and important component of the cardiac work-up. The indications, methodology, side effects, and utility of dipyridamole cardiac imaging in the clinical setting are discussed and a variety of examples presented.

Two adolescents with stress-related avulsion injury of the anterior iliac crest apophysis are presented. Increased tracer concentration in the anterior iliac crest area is present on the blood-pool and delayed images. Increased iliac crest activity was demonstrated on the radionuclide angiogram in one patient. Scintigraphic detection of this injury is useful when clinical findings are atypical, if objective evidence of a fracture is required, or when the fracture is not readily apparent radiographically.

Tl-201 exercise imaging in patients with left bundle branch block (LBBB) has proven to be indeterminate for significant left anterior descending (LAD) coronary artery stenosis because of the presence of immediate septal perfusion defects with redistribution on delayed images in almost all cases. Tl-201 redistribution occurs regardless of the presence or absence of LAD stenosis. Nineteen patients having LBBB were evaluated with dipyridamole Tl-201 SPECT. Fourteen of these subjects had normal dipyridamole Tl-201 SPECT imaging. Three patients had normal coronary angiograms. None of the remaining 11 patients with normal dipyridamole Tl-201 SPECT images was found to have clinical coronary artery disease in a 5-11 month follow-up period. Five patients had abnormal septal perfusion. Four underwent coronary angiography. One had a significant LAD stenosis. The single patient with septal redistribution who refused to undergo coronary angiography died shortly thereafter of clinical coronary artery disease. This preliminary work suggests that dipyridamole Tl-201 SPECT may be more useful for excluding LAD stenosis in patients with LBBB than Tl-201 exercise imaging.

Two intracerebral hemorrhages were detected because of vascular displacement on the radionuclide cerebral angiogram. The static brain images in both patients were normal.

The radionuclide cerebral angiogram using intravenous radiopertechnetate has been found to be of value in confirming the early diagnosis of stroke. The isotopic perfusion study is of value in detecting ischemic carotid and middle cerebral lesions. It can also provide a rapid means of demonstrating intracerebral hemorrhages. Nuclear angiography is not recommended for detection of vertebrobasilar artery disease unless a posterior cerebral artery occlusion is suspected.

Hepatic cavernous hemangiomas are benign tumors of the liver that are often an incidental finding. They are usually asymptomatic but may cause symptoms when traumatized, may bleed spontaneously, or may produce pain by virtue of their large size and mass effect. A retrospective analysis of the clinical presentation, liver function tests, and diagnostic imaging procedures in 20 patients with hepatic hemangiomas is presented and the literature is reviewed. The 20 patients had 27 mass lesions as seen on liver scintigraphy, computed tomography, or sonography. Technetium-99m-labeled red blood cell flow studies and blood pool scintigrams showed delayed filling of the mass lesions, diagnostic of hemangiomas. This finding was not encountered in any other type of lesion. A new diagnostic algorithm is proposed in which blood-flow and blood-pool scintigraphy play a more prominent role in the diagnostic workup. According to this algorithm, if liver function tests in a patient with hepatic mass are either normal or abnormal and suggestive of hepatocellular dysfunction, the patient should undergo hepatic blood-flow and blood-pool studies.

We have presented an unusual case of pyogenic liver abscess due to gamma streptococci group D, which remained undiagnosed for about seven months, and which ruptured spontaneously into subcutaneous tissue, resulting in self-cure. Despite the large hepatic abscess seen on liver scan and ultrasound, results of liver function tests remained normal. A mass seen on liver scan or ultrasound in patients with a malignancy does not necessarily indicate metastasis, and a more aggressive approach is required to treat a potentially curable disease.

A vertebral artery fistula was detected as increased neck vessel activity by rapid-sequential scintigraphy.

One hundred and one subjects (52 men, 49 women) with low probability coronary disease and normal resting left ventricular ejection fraction performed upright bicycle exercise to target without angina, ischemic ECG change, or segmental wall motion abnormality. Fifteen millicuries of Tc-99m pertechnetate were injected at rest and during peak exercise, and images were processed with first pass technique (RNA). The responses were not uniform. Group 1 was characterized by the resting end diastolic volume index (EDVI) usually greater than 80 ml/M2, a peripheral resistance drop (decreases R) of 0.20-0.50, an increase in cardiac index (increases CI) of 2.8-5.5 1/minute/M2, accompanied by decreasing EDVI and ESVI with exercise, stroke volume index (SVI) remaining essentially unchanged, and left ventricular ejection fraction (EF) usually increasing. Group 2 was characterized by the resting EDVI less than 80 ml/M2, and with the same decreases R and increases CI; EDVI, ESVI, SVI all increased and EF tended to decrease. Group 3 was characterized by decreases R greater than 0.50, increases CI greater than 5.5 1/minute M2, the exercise EDVI usually increasing, ESVI usually decreasing, SVI usually increasing, and EF usually increasing. There were no significant differences (alpha = 0.01) in exercise-related changes between men and women within each group.

Renal infarction is most frequently due to emboli from the heart or aorta. Other causes include atheromatous disease, renal artery aneurysm, vasculitis, hypotension, hypercoagulable states, aortic dissection, and major trauma. Most renal infarctions are segmental. The extent of disease is dependent upon the size and number of renal vessels involved, coexistent renal disease, and collateral circulation. Flank pain, fever, leukocytosis, hematuria, renal failure, or hypertension may suggest the diagnosis, but these findings are nonspecific and diagnosis will depend not only on history and physical examination, but also on the appropriate imaging tests. The type of treatment is dictated by the etiology of the infarction.

The scintigraphic findings are described of upper ureteral rupture seen incidentally on bone scan in a 30-year-old patient after retrograde pyelography. This case is presented to alert physicians to look for non-osseous abnormalities on the bone scan.