Technetium-99m RBC scintigraphy in the evaluation of small bowel leiomyoma

Hypervascularity and persistent uptake were demonstrated in a small bowel leiomyoma not actively bleeding at the time of Tc-99m RBC scintigraphy. The potential value of Tc-99m RBC scanning in the evaluation of benign small bowel tumors is discussed.     

A predominant pelvic gastrointestinal stromal tumor (GIST) mass observed on Tc-99m red blood cell gastrointestinal bleeding scintigraphy

A 51-year-old woman presented with recurrent bleeding per rectum. Her earlier endoscopies were negative. Tc-99m RBC GI bleeding scintigraphy was performed. It demonstrated an apparent hypervascular pelvic mass, and active small bowel bleeding. Based on scintigraphic finding of a predominant pelvic mass indicating tumor, CT of the abdomen and pelvis was performed for further gastrointestinal bleeding localization work up instead of an invasive angiography or endoscopy, which detected a small bowel tumor in the pelvis. A small bowel gastrointestinal stromal tumor was resected subsequently.     

Evaluation of active bleeding into hematomas by technetium-99m red blood cell scintigraphy before angiography

PURPOSE: To evaluate the utility of technetium-99m red blood cell (Tc-99m RBC) scintigraphy in the diagnosis of active hemorrhage into large intra-abdominal hematomas before arteriography. METHODS: This retrospective case series describes four patients (1 man and 3 women) with large abdominal wall and retroperitoneal hematomas confirmed by computed tomography who underwent Tc-99m RBC scintigraphy before angiography. Arterial transcatheter embolization was performed if active hemorrhage was found. RESULTS: Three of the patients had positive findings on Tc-99m RBC scans, which showed spreading of the labeled erythrocytes into the hematoma space. Positive scintigraphy was diagnostic for active hemorrhage and helped localize the bleeding sites. Angiography confirmed the diagnosis in all patients with positive scintigraphy and ruled out active bleeding in the patient with a negative Tc-99m-labeled RBC scan. CONCLUSION: Tc-99m RBC scintigraphy appears to be sensitive and accurate in detecting active hemorrhage into intra-abdominal hematomas.     

The spectrum of heterotopic gastric mucosa in children detected by Tc-99m pertechnetate scintigraphy

Meckel's diverticulum is the most common site of heterotopic gastric mucosa (HGM). Other sites include intestinal duplication and the small bowel proper. Tc-99m pertechnetate abdominal scintigraphy is used commonly to detect HGM. This article describes various scintigraphic patterns of HGM and reviews technical aspects of the procedure, with emphasis on pharmacologic enhancement.     

Intraperitoneal bleeding demonstrated by Tc-99m labeled red blood cell scintigraphy.

Tc-99m RBC scintigraphy is known to be useful for the evaluation of gastrointestinal bleeding. The authors describe a patient with a posttraumatic peritoneal tap in whom Tc-99m RBC imaging showed bleeding into the gastrointestinal wall and into the ascitic fluid.     

Tc-99m HMPAO scintigraphy in amiodarone-induced acute lung toxicity: comparison with Tc-99m DTPA inhalation scintigraphy

PURPOSE: This case demonstrates the use of Tc-99m HMPAO scintigraphy in amiodarone (AD)-induced lung toxicity. The aim of this presentation is also to discuss different scintigraphic modalities in the diagnosis and follow up in AD-induced lung toxicity. MATERIALS AND METHODS: A 77-year-old man, with a suspicious AD-induced acute lung toxicity, underwent Tc-99m DTPA aerosol inhalation scintigraphy and Tc-99m HMPAO scintigraphy. RESULTS: Rapid alveolar clearance of Tc-99m DTPA was found during AD therapy and increased lung uptake of Tc-99m HMPAO was also demonstrated. These findings supported the diagnosis AD lung toxicity. After cessation of therapy, Tc-99m DTPA alveolar clearance was decreased. Although there was some decrease in L/H and L/B ratios of Tc-99m HMPAO after 3 weeks of stopping therapy, Tc-99m HMPAO uptake in the lungs was still continued. This finding may be the result of ongoing pulmonary inflammation as a result of the long half-life of AD. CONCLUSION: Compared with Tc-99m DTPA aerosol inhalation scintigraphy, Tc-99m HMPAO scintigraphy may have a role in the diagnosis of AD lung toxicity. Nevertheless, there is a need for longitudinal studies investigating patients under AD therapy using follow-up Tc-9m HMPAO scintigraphy.     

Protein-losing enteropathy detected on Tc-99m HSA and Tc-99m MDP scintigraphy

The authors describe a patient with protein-losing enteropathy in whom abnormal intestinal accumulation of tracer occurred during Tc-99m human serum albumin scintigraphy. Abnormal leakage of the radiotracer was observed in the left upper abdomen and was confirmed by Tc-99m MDP scintigraphy. Both Tc-99m HSA scintigraphy and Tc-99m MDP scintigraphy are useful in the detection of protein-losing enteropathy.     

Localization of small bowel bleeding by arterial injection of Tc-99m-labeled RBC

A 79-year-old man with melena was suspected of having small bowel bleeding because upper and lower endoscopic findings were negative. Technetium-99m-labeled red blood cell (Tc-99m-RBC) scintigraphy was performed by arterial injection of a radiotracer from the superior mesenteric artery (SMA) after angiography. Extravasation was seen in the ileum by scintigraphy although angiography was negative. Scintigram 2 minutes after arterial injection was consistent with the late capillary phase of balloon occluded angiography. This comparison provided a better anatomical distinction. Tc-99m-RBC scintigraphy by arterial injection through the SMA identified the bleeding site in the small bowel more accurately than conventional intravenous Tc-99m-RBC scintigraphy.     

Detection of cecal adenocarcinoma by Tc-99m pertechnetate scintigram

A 23-year-old male presented with occult gastrointestinal bleeding and iron deficiency anemia. A Tc-99m pertechnetate abdominal scan was positive and surgery revealed an adenocarcinoma of the cecum. No Meckel's diverticulum was identified. This is the first reported association of an abnormal Tc-99m pertechnetate scan in adenocarcinoma. Carcinoma of the right colon should be considered in any patient with a positive pertechnetate scan for Meckel's diverticulum and suggestive clinical features.     

Tc-99m sulfur colloid and Tc-99m tagged red blood cell methods are comparable for detecting lower gastrointestinal bleeding in clinical practice

PURPOSE: The objective of this study was to determine whether the Tc-99m red blood cells (Tc-99m RBC) method has a true advantage over the Tc-99m sulfur colloid (Tc-99m SC) technique in a busy clinical practice for detecting and localizing lower gastrointestinal bleeding sites. METHODS: Three hundred fifty-nine consecutive gastrointestinal bleeding studies performed during the past 4 years were reviewed retrospectively. One hundred ninety-three scans were obtained with Tc-99m SC (scan duration, 30 minutes) and 138 studies were performed after the administration of Tc-99m RBC (scan duration, 1 hour). In addition, 28 examinations with Tc-99m SC were followed immediately by Tc-99m RBC scans for a duration of several hours. The results of the two methods were analyzed and the performance of the two techniques was compared. RESULTS: Among 193 scans performed using the Tc-99m SC method, 47 (24.4%) successfully identified the location of the bleeding site, whereas in 138 scans performed using Tc-99m RBC, 38 (27.5%) were successful for this purpose. In the remaining 28 scans in which the Tc-99m SC scan was followed by the Tc-99m RBC study, only 4 (14.3%) positive bleeding sites were identified after a prolonged imaging period. DISCUSSION: The theoretical advantages of the Tc-99m RBC technique compared with the Tc-99m SC method cannot be substantiated by this study. Our findings suggest that the efficacy of these two methods is nearly equal at a practical level. CONCLUSION: The simpler and cost-effective Tc-99m SC method is as efficient as the Tc-99m RBC method when the scanning time is limited to 1 hour and optimal imaging and interpretation schemes are used.     

The role of Tc-99m RBC scintigraphy in the differential diagnosis of orbital cavernous hemangioma

The cavernous hemangioma is the most common benign orbital tumor in adults. Its presentation is during the forth to fifth decades with a slowly progressive unilateral proptosis. Intraconal cavernous hemangiomas may be difficult to differentiate from other intraconal lesions such as schwannomas, meningiomas and hemangiopericytomas. We report a case of orbital cavernous hemangioma diagnosed by Tc-99m RBC scintigraphy. Tc-99m RBC scintigraphy revealed a typical scintigraphic pattern in which there is intense focally increased uptake on the delayed image. We conclude that Tc-99m RBC scintigraphy can be a useful method in the differential diagnosis of orbital cavernous hemangioma as in hepatic hemangioma.     

Rim sign in Tc-99m sulfur colloid hepatic scintigraphy

A case of pericholecystic hyperperfusion on Tc-99m sulfur colloid (SC) flow images with a pericholecystic rim of increased activity (PCHA) on delayed planar and single-photon emission computed tomography images of the liver was seen in a patient with a history of multiple renal transplants admitted with cramping right lower quadrant abdominal pain. Laparotomy performed 5 days after the scan revealed an acutely perforated gangrenous gallbladder and occluded cystic duct. The secondary findings of gallbladder hyperperfusion and PCHA or "rim sign" have been frequently reported with Tc-99m IDA hepatobiliary imaging. These secondary findings in conjunction with a nonvisualized gallbladder on an IDA scan suggest a complicated or advanced stage of acute cholecystitis and usually require urgent surgical intervention. The rim sign on Tc-99m SC scintigraphy also likely indicates the same grave diagnosis.     

Comparison of Tc-99m EC and Tc-99m DTPA captopril scintigraphy to diagnose renal artery stenosis.

PURPOSE: Although, captopril scintigraphy is a well established method to detect renovascular hypertension, the optimal radiopharmaceutical for this test remains to be determined. Recently, Tc-99m ethylenedicysteine (Tc-99m EC) appeared as an alternative agent for captopril scintigraphy. The aim of this study was to compare the diagnostic accuracy of Tc-99m EC with Tc-99m DTPA, which is a well-established renal radiopharmaceutical for the captopril test. METHODS: Nineteen hypertensive patients who had various degrees of renal artery stenosis on angiography were included in the study. All patients had baseline and captopril Tc-99m EC and Tc-99m DTPA scintigraphy within a 1-week period. The results were compared with angiography and in eight patients with changes in blood pressure after revascularization. The images were interpreted without knowledge of the angiography and revascularization data as low, intermediate, or high probability for hemodynamically significant renal artery stenosis, which was defined as an area of stenosis exceeding 50%. RESULTS: Tc-99m EC and Tc-99m DTPA study results were in agreement in 16 of the 19 patients. In two patients with branch artery stenosis, Tc-99m EC was definitely superior to Tc-99m DTPA and correctly identified the probability of stenosis on scintigraphy. On kidney analysis, Tc-99m EC had a slightly greater diagnostic sensitivity compared with Tc-99m DTPA (79% vs. 68%; P > 0.05 by the chi-squared test) but equal specificity (93% for both agents). Both Tc-99m EC and Tc-99m DTPA showed the same accuracy in predicting the outcome after revascularization in all but one patient with branch artery stenosis, in whom Tc-99m EC accurately predicted a successful outcome of the intervention but Tc-99m DTPA did not. Tc-99m EC had better renal uptake in patients with decreased renal function and provided more dramatic evidence of renogram changes after captopril intervention, which resulted in more confident interpretation. CONCLUSIONS: There is no significant difference between Tc-99m EC and Tc-99m DTPA captopril scintigraphy for detecting renal artery stenosis. However, because of the better imaging characteristics and more confident interpretation provided by the dramatic changes in the degree of renogram abnormality after captopril intervention, Tc-99m EC captopril scintigraphy should be used, particularly in patients with decreased renal function or branch artery stenosis.     

Assessment of viable splenic tissue in massive splenic infarction with a Tc-99m heat-damaged RBC scan

A 59-year-old man with essential thrombocytosis was examined for abdominal pain. Splenic infarction was diagnosed on a computed tomographic scan. The Tc-99m heat-denatured RBC scan showed viable splenic tissue that was not evident on the computed tomographic scan or Tc-99m sulfur colloid scintigraphy.     

Features of hepatic cavernous hemangioma on planar and SPECT Tc-99m-labeled red blood cell scintigraphy.

PURPOSE: To determine the value and diagnostic accuracy of planar and SPECT Tc-99m-labeled red blood cell (Tc-99m RBC) scintigraphy in the investigation of suspected hepatic cavernous hemangioma as found on ultrasound. PATIENTS AND METHODS: One hundred patients, 89 women (89%) and 11 men (11%), between 22 and 67 years old (mean age, 38 years) were evaluated for liver masses found on abdominal ultrasound. All the patients had previous Tc-99m RBC scintigraphy. The size of the lesions ranged from 1 to 9 cm. The final diagnosis was reached through cytologic biopsy, or histopathologic tests (or all of these). RESULTS: One hundred thirty lesions were found. With regard to the distribution of the lesions, 116 (89%) were single; 14 (3%) were multiple, with 118 (91%) in the right lobe and 12 (9%) in the left lobe; 83 (64%) were posterior; and 47 (36%) were anterior. With respect to the pattern of radioactivity fill-in, 86 (66%) lesions were typical and 44 (34%) were atypical. The results of Tc-99m RBC scintigraphy showed sensitivity, specificity, and positive and negative predictive and accuracy values of 97%, 83%, 98%, 77%, and 96% respectively. The use of SPECT improved the sensitivity value by 11% for lesions of 1 to 2 cm. CONCLUSIONS: Tc-99m RBC scintigraphy is the noninvasive technique most helpful in the diagnosis of hepatic hemangioma, especially in those at risk for lesion rupture or bleeding. SPECT should be performed whenever planar imaging fails to show the lesion by 2 hours. The use of ultrasound should precede scintigraphy for two important reasons: the size and the location of the lesion. Location of the lesion (anterior or posterior) is important for optimal gamma camera acquisition parameters. Lesions less than 1 cm are cannot be detected because they are beyond the limit of spatial resolution of the gamma camera we used.     

A large renal pelvic diverticulum,presenting incomplete excretion during tc-99m mag-3 scintigraphy and tracer accumulation on tc-99m dmsa scintigraphy; a case report

This case report illustrates the dynamic and static renal scintigraphic images of a patient with an unusual large diverticulum of the renal pelvis. The initial diagnosis by intravenous pyelography (IVP) and ultrasonographic (US) examination was a renal pelvic diverticulum of the left kidney, and the patient was referred to the nuclear medicine department for exploration of the effect of the pelvic diverticulum on renal functions. We performed dynamic renal scintigraphy with technetium-99m (Tc-99m) labeled mercaptoacetyl triglycine (MAG-3) and static renal scintigraphy with Tc-99m labeled dimercaptosuccinic acid (DMSA). In dynamic renal scintigraphy, bilaterally normal concentration function was observed. While right kidney excretion function was normal, an incomplete excretion pattern was seen on the left side. Complete urinary flow obstruction occurred approximately at the 10th minute of the acquisition, which did not seem to respond to the i.v. furosemide application. However, when only the renal cortex was included in the region of interest, the obstructive pattern disappeared. In static renal scintigraphy, a large renal pelvic diverticulum localized antero-medially was clearly visualized in the left-anterior oblique projection, most probably due to accumulation of radiopharmaceutical inside it. This case showed that a renal pelvic diverticulum should be thought of when an incomplete excretion pattern is seen on dynamic renal scintigraphy. Using only a cortical region of interest may also help to distinguish other types of obstructive pattern from diverticulum. Additionally, Tc-99m DMSA scintigraphy may show diverticulum localization with antero-oblique projections in addition to routine projections.     

Glucagon in the scintigraphic diagnosis of small-bowel hemorrhage by Tc- 99m-labeled red blood cells

Twelve patients undergoing scintigraphy with Tc-99m-labeled red blood cells (RBC) exhibited abnormal small-bowel activity and were given glucagon to assess its role in detecting bleeding from the small bowel. Six demonstrated focal accumulation of activity which was not identified prior to glucagon. Endoscopy, barium studies, angiography, and colonoscopy located the small-bowel bleeding site in 4 patients; in the other 2, studies of the colon failed to show the bleeding site and the origin was presumed to be the small bowel. The authors suggest that intravenous glucagon can be beneficial as an adjuvant to Tc-99m-RBC when diagnosing bleeding from the small bowel.     

Discordant splenic uptake of Tc-99m colloid and Tc-99m denatured RBC in candidiasis-endocrinopathy syndrome

We report discordant splenic uptake of Tc-99m colloid and Tc-99m heat-denatured red blood cells (RBC) which occurred in a 21-year-old female with candidiasis-endocrinopathy syndrome. Tc-99m colloid liver-spleen imaging showed no splenic uptake, suggesting the presence of functional asplenia. A subsequent Tc-99m heat-denatured RBC study clearly revealed a small spleen with preserved sequestrating function. These results may demonstrate that the qualitative dissociation of splenic functions in processing colloid and denatured RBC in functional asplenia: the sequestration function remains while the reticuloendothelial system is impaired.     

Visualization of bladder diverticulum during Tc-99m DTPA renal scintigraphy

An eight-year-old boy with recurrent urinary infection underwent Tc-99m DTPA renal scintigraphy for the evaluation of renal function. Stasis of the tracer was observed in the pelvocalyceal systems of both kidneys. Intravenous diuretic was administered to evaluate a possible mechanical obstruction. During the course of the study, a well-defined, round area of activity extended from the bladder which was subsequently confirmed to be a diverticulum on voiding cystourethrogram and at surgery.     

A horseshoe kidney detected incidentally by Tc-99m DISIDA hepatobiliary scintigraphy

Horseshoe kidney is a common renal fusion anomaly that is usually asymptomatic in adults. A horseshoe kidney was detected incidentally on Tc-99m DISIDA hepatobiliary scintigraphy performed to evaluate acute cholecystitis. The diagnosis was first suggested on hepatobiliary scintigraphy and confirmed by computed tomography.