Lobar primary pulmonary lymphoma: iodine-123-iodoamphetamine and thallium-201-chloride scintigraphic findings.

A case of primary pulmonary malignant lymphoma (PML) was evaluated by 123I-IMP scintigraphy and 201TlCl SPECT. Radiography and CT showed a so-called lobar consolidation on the chest that was difficult to differentiate from other benign conditions. However, 123I-IMP scintigraphy showed a defect corresponding to the lesion both in the early and delayed images, and 201TlCl SPECT showed a higher retention index than that of benign disorders. Both results were highly suggestive of malignancy. These scintigraphies can help differentiate PML from benign lesions and other malignant pulmonary tumors.

Technetium-99m-HMPAO as a marker of chemical and irradiation lung injury: experimental and clinical investigations.

UNLABELLED: We evaluated the ability of 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) to serve as a sensitive marker of lung injury. METHODS: Two experimental rabbit models of minimal lung injury were designed using injections of a low dose (0.05 ml/kg) of oleic acid or 50 Gy of irradiation. In addition, we clinically investigated whether patients who received chemotherapy (n = 14) or radiotherapy (n = 13) for lung cancer showed high uptake of 99mTc-HMPAO in the lungs. RESULTS: Despite the minimal endothelial lesions visualized by electron microscopy (edematous changes and blebbing), in both animal models, the lungs showed high uptake of 99mTc-HMPAO, which occurred rapidly within 1 min after injection. Clinically, the mean lung-to-liver ratio of 99mTc-HMPAO activity in the patients who received chemotherapy (0.649 +/- 0.185, p < 0.01) was significantly higher than that of the controls (n = 16; 0.387 +/- 0.108), and all 12 patients who received more than 30 Gy of irradiation showed abnormal uptake in the irradiated lungs, despite the lack of abnormal opacities on chest CT. CONCLUSION: These findings suggest that 99mTc-HMPAO has the potential to be a sensitive marker of chemical and irradiation lung injury.

Iodine-123-MIBG imaging in pheochromocytoma with cardiomyopathy and pulmonary edema.

We encountered a patient with pheochromocytoma associated with a catecholamine-induced cardiomyopathy that developed recurrently bilateral and unilateral pulmonary edema. The diagnosis of pheochromocytoma was made by elevated plasma catecholamine levels and the intense tumor [123I]MIBG uptake and was confirmed at the time of surgery. The patient showed reduced myocardial [123I]MIBG uptake with left ventricular dysfunction, and endomyocardial biopsy findings were consistent with the diagnosis of catecholamine-induced cardiomyopathy. After tumor resection, plasma levels of catecholamine were normalized, and pulmonary edema never recurred, although cardiac dysfunction did not show an improvement on echocardiography. Myocardial and lung [123I]MIBG uptake increased when compared to uptake levels on preoperative scans, but myocardial uptake was still below normal. These findings indicated that over-secreted catecholamines influenced both the heart and lungs. Pheochromocytoma can induce cardiac and lung injuries, and [123I]MIBG scanning may contribute not only to tumor characterization but also to assessing and monitoring the influence of catecholamines on the heart and lungs.

Dynamic pulmonary SPECT of xenon-133 gas washout.

UNLABELLED: A triple-detector SPECT data acquisition mode of "continuous repetitive rotation acquisition" was applied to dynamic pulmonary SPECT with 133Xe gas. METHODS: Subjects included 7 healthy volunteers, 22 patients with a space-occupying mass lesion, 22 with obstructive lung disease and 10 with restrictive lung disease. Following rebreathing of 133Xe, equilibrium and washout SPECT images during spontaneous breathing were acquired every 30 sec for 5-7 min. Regional 133Xe washout was assessed by the real half-time (T1/2) and mean transit time (MTT) images. RESULTS: SPECT and MTT images represented a gravity-induced gradient of ventilation in normal lungs and detailed the distribution of heterogeneous 133Xe washout in patient's lungs with or without abnormalities on chest x-ray CT. The T1/2 (111.4 +/- 26.4 sec) and its coefficient of variation (0.36 +/- 0.13) in obstructive lung diseases were significantly different from those (56.8 +/- 3.9 sec and 0.16 +/- 0.15) in restrictive lung diseases (p < 0.001, p < 0.05, respectively). Comparison of SPECT and planar studies assessed in 19 patients revealed superiority of SPECT in detecting ventilatory abnormalities and a high correlation of T1/2 between the two studies ( r= 0.977, p < 0.001). CONCLUSION: This modality has excellent potential for elucidating the distribution and nature of ventilatory abnormalities.

Thallium-201 SPECT and technetium-99m-phytate subtraction liver imaging in the evaluation of pancreatic cancers.

UNLABELLED: We preliminarily evaluated the usefulness of 201Tl SPECT in the investigation of pancreatic cancers. METHODS: The subjects included 32 patients with malignant tumors, 16 with benign disorders and 10 controls. SPECT was performed 10 min after the injection of 148-222 MBq of 201Tl; subjects had fasted to minimize intestinal activity. In addition, subtracted SPECT using 99mTc-phytate to separate the boundary of abnormal uptake from liver activity was carried out in 14 patients. RESULTS: Thallium-201 did not accumulate in the pancreatic bed of the controls. In contrast, 29 of the 32 patients with malignant tumors showed positive phytate uptake with a sensitivity of 90.6% in the detection of malignancy. Of the 16 benign disorders, only four patients showed abnormal uptake; however, the mean value of the lesion-to-hepatic ratio (0.43 +/- 0.06; range, 0.35-0.51), as an index of the degree of uptake, was lower than that in positive malignant tumors (0.72 +/- 0.16; range, 0.53-1.28). Thallium-201 activity per milligram of resected cancer tissue in two patients was 2-3 times greater than in normal tissue. Follow-up 201Tl SPECT in the five treated patients demonstrated similar alterations between 201Tl uptake and tumor markers. CONCLUSION: Our results suggest that 201Tl SPECT may have clinical potential in the investigation of pancreatic cancers.

Bone scintigraphy in growth hormone-secreting pulmonary cancer and hypertrophic osteoarthropathy.

Hypertrophic osteoarthropathy was detected in a 55-yr-old man with pulmonary squamous-cell cancer by bone scintigraphy using 99mTc-hydroxy methylene diphosphonate (HMDP). Intense symmetrical uptake was demonstrated in the distal portions of the long bones as was the parallel tract sign, accompanied by markedly elevated serum growth hormone levels. After chemoradiotherapy for pulmonary cancer, the arthralgia disappeared and scintigraphic findings and serum growth hormone levels improved, suggesting that ectopic production of growth hormone in the pulmonary tumor had been associated with hypertrophic osteoarthropathy. These findings indicate that bone scintigraphy is useful for detecting hypertrophic osteoarthropathy, and assessing alterations in hypertrophic osteoarthropathy activity post-treatment.

Three-dimensional surface display of dynamic pulmonary xenon-133 SPECT in patients with obstructive lung disease.

UNLABELLED: To better perceive abnormal regional ventilation in patients with obstructive lung disease, a three-dimensional display was applied to dynamic pulmonary 133Xe SPECT. METHODS: Dynamic SPECT was performed using a triple-detector SPECT system in 30 patients with obstructive disease, 13 patients with restrictive disease and 7 normal subjects. After reconstructing color-illuminated, surface-rendered three-dimensional images of equilibrium and 3-min washout (WO3), a single three-dimensional fusion display was created from these two different time-course image sets in which a three-dimensional WO3 image indicating 133Xe retention was transparently visible through three-dimensional equilibrium image delineating lung contours. The three-dimensional equilibrium and WO3 images were created by a 25% threshold of the 133Xe maximal pixel activity (MPA) in equilibrium data. Besides, a three-dimensional WO3 image with a 18% threshold [mean + 2 s.d. ratios (%) of the MPA in WO3 data to that in equilibrium data in normal subjects] was used for assessing the presence of retention compared to normal lungs. RESULTS: The 18% threshold three-dimensional WO3 image showed abnormal retention in obstructive diseases but not in restrictive diseases. The three-dimensional fusion display provided an overview of localized retention in obstructive diseases and enhanced the perception of their spatial relationships and extent compared to those on multislice tomograms. The extent of retention correlated well with %FEV1 (r = 0.813) and 133Xe clearance-time (T(1/2)) (r = 0.912). CONCLUSION: This topographic modality for 133Xe SPECT is helpful for the better perception of anatomic distributions of 133Xe retention and interstudy comparisons of ventilation abnormality in patients with obstructive disease.

Ca2+,Mg2+-ATPase of microsomal membranes from bovine aortic smooth muscle: effects of Sr2+ and Cd2+ on Ca2+ uptake and formation of the phosphorylated intermediate of the Ca2+,Mg2+-ATPase.

The effects of various divalent cations on the Ca2+ uptake by microsomes from bovine aortic smooth muscle were studied. High concentrations (1 mM) of Co2+, Zn2+, Mn2+, Fe2+, and Ni2+ inhibited neither the Ca2+ uptake by the microsomes nor the formation of the phosphorylated intermediate (E approximately P) of the Ca2+,Mg2+-ATPase of the microsomes. The cadmium ion, however, inhibited both the Ca2+ uptake and the E approximately P formation by the microsomes. Dixon plot analysis indicated Cd2+ inhibited (Ki = 135 microM) the Ca2+ dependent E approximately P formation in a non-competitive manner. The inhibitory effect of Cd2+ was lessened by cysteine or dithiothreitol. The strontium ion inhibited the Ca2+ uptake competitively, while the E approximately P formation increased on the addition of Sr2+ at low Ca2+ concentrations. At a low Ca2+ concentration (1 microM), Sr2+ was taken up by the aortic microsomes in the presence of 1 mM ATP. It is thus suggested that Sr2+ replaces Ca2+ at the Ca2+ binding site on the ATPase.

Experimental evaluation of the usefulness of 201Tl-chloride scintigraphy for monitoring radiotherapeutic effects.

The level of Na(+)-K+ adenosine triphosphatase (ATPase) has been demonstrated to be correlated with tumour growth potential, and accelerated active transport of K+ carried out by Na(+)-K+ ATPase is said to be a trigger of 201Tl affinity for malignant tumour cells. Therefore, 201Tl scintigraphy appears to be a good indicator for evaluation of changes of tumour proliferative potential after treatment. In the present study, the usefulness of 201Tl scintigraphy for monitoring radiotherapeutic effects was evaluated in VX-2 tumours irradiated with variable doses (10-40 Gy of radiation). Changes in 201Tl uptake were compared with tumour growth, and 201Tl uptake on day 7 after irradiation was compared with tumour bromodeoxyuridine (BrdU) uptake, which reflects DNA synthesis. All the treated tumours showed dose-dependent diminished 201Tl uptake, accompanied by either dose-dependent tumour growth delay or tumour regression/resolution. The diminished 201Tl uptake had already appeared on day 7 after irradiation, accompanied by diminished BrdU uptake, although, at this time, the tumour volumes were increased, or were not significantly decreased compared to pre-irradiation. Moreover, the 20 Gy tumours demonstrated two different tumour growth patterns, each accompanied by a different degree of reduction of 201Tl uptake. These findings suggest that the degree of reduction of tumour 201Tl uptake following irradiation can reflect the degree of suppressed proliferative activity in the treated tumours, and that assessment of altered 201Tl uptake at a relatively early time following irradiation allows prediction of subsequent tumour growth, regardless of the tumour volume.

Difference in 201Tl accumulation on single photon emission computed tomography in benign and malignant thoracic lesions.

The difference in 201Tl-chloride (201Tl) accumulation on single photon emission computed tomography (SPECT) between 58 benign (58 cases) and 48 malignant (46 cases) thoracic lesions, each of more than 20 mm in diameter was investigated. In the 34 benign and 48 malignant lesions depicted in both early (15 min) and delayed (3 h) images there was no significant difference in the mean early and delayed uptake ratios of lesion to normal contralateral lung between benign and malignant. However, the retention index in the lesion derived from (delayed ratio--early ratio)/(early ratio) x 100% showed a significant difference (benign -4.30 +/- 13.6% versus malignant 23.3 +/- 18.9%, P < 0.01), indicating the poor 201Tl retention in the benign lesions. Using the criteria of nondepiction in the delayed image or a negative retention index, 81.1% accuracy and 95.2% predictive value for diagnosis of benign lesions were obtained. Thus, 201Tl SPECT appears to have potential usefulness in the diagnosis of benign thoracic lesions.

Altered regional clearance of 99Tcm-DTPA in radiation pneumonitis.

99Tcm-diethylene triaminepenta-acetic acid (99Tcm-DTPA) lung scintigrams were investigated in 11 patients with radiation pneumonitis to assess the alteration of clearance of this small solute. Thirty minutes after the injection of 99Tcm-DTPA, all 11 patients showed abnormal accumulation. This uptake was seen in the areas with reduced 99Tcm-macroaggregated albumin activity. The curves of the lung/heart ratios obtained after 1 min after injection of 99Tcm-DTPA in areas showing abnormal accumulation were of three types. Comparison of the slope for the initial 5 min of the lung/heart curves between the abnormal accumulation sites and the contralateral non-irradiated lung revealed a significant difference. The uptake ratio (the mean counts of the last frame divided by initial peak count) was related to the degree of abnormal accumulation in the radiation pneumonitis. Moreover, study of rabbits with radiation pneumonitis revealed similar behaviour by 99Tcm-DTPA as observed clinically. This simple and rapid method may be useful in detecting and monitoring the altered regional kinetics of 99Tcm-DTPA in radiation pneumonitis.

Three-dimensional surface displays of perfusion SPET in the evaluation of patients with pulmonary emphysema for thoracoscopic lung volume reduction surgery.

A modified, three-dimensional display was applied to 99Tcm-macroaggregated albumin (99Tcm-MAA) SPET to help assess the effect of thoracoscopic lung volume reduction surgery (LVRS) on regional lung perfusion. Surface-rendered three-dimensional images for 99Tcm-MAA and xenon-133 (133Xe) equilibrium (EQ) SPET were obtained in 11 patients with pulmonary emphysema before and after LVRS. A single three-dimensional fusion display of both images was then reconstructed, and the perfused lungs were transparently visible through the lung contours delineated by the three-dimensional 133Xe EQ image. The extent of preserved perfusion in the lung (the perfusion index) was estimated using the ratio (%) of the total pixel numbers of the segmented perfusion data to those of the 133Xe lung volume data. The three-dimensional fusion display provided an overview of the distribution of hypoperfusion in the lungs with geometric realism and enhanced the perception of anatomic size and configuration compared with multiple tomograms and three-dimensional perfusion images without superimposition of three-dimensional 133Xe image. Post-operatively, it displayed restored perfusion in the remaining lungs, and changes in the perfusion index correlated with %FEV1 (r = 0.731, P = 0.0001) more closely than the perfusion data alone (r = 0.593, P < 0.01). This method is useful for directing LVRS and assessing its effectiveness, as it provides precise tomographic information on regional perfusion.

Evaluation of abnormal regional ventilation in patients with lung cancer using three-dimensional display of dynamic 133Xe SPET.

Preliminary studies were carried out of regional ventilation in lung cancer using three-dimensional (3D) display of dynamic pulmonary 133Xe single photon emission tomography (SPET). Transaxial equilibrium and washout images were obtained from SPET data acquired with an acquisition time of 30 s using a triple-detector SPET system in 39 patients with lung cancer. After reconstructing colour-illuminated, surface-rendered 3D images of equilibrium and 3-min washout (WO3), a single 3D fusion display was created from these two different time-course image sets, in which the 3D WO3 image indicating 133Xe retention was visible through the 3D equilibrium image delineating lung contours. The extent of retention was assessed using the 133Xe retention index, defined as the ratio of summed pixels of the segmented WO3 data to those of the segmented equilibrium data. 133Xe SPET was highly sensitive and specific for the presence of regional ventilation abnormalities associated with endobronchial tumour or bronchial compression due to enlarged lymph nodes. These abnormalities were demonstrated irrespective of the presence or absence of secondary changes distal to the tumour on the chest computed tomography scan. The geometrically realistic 3D fusion display enhanced anatomic localization of the regional ventilation abnormalities compared to the information from multislice tomograms, and the 133Xe retention index correlated well with %FEV1 (r = 0.828). This topographic 3D display for 133Xe SPET allows better perception of anatomic localization and extent of 133Xe retention. It will be useful for assessing regional ventilatory function in patients with lung cancer.

I-123 IMP scintigraphy in two patients with primary pulmonary malignant lymphoma.

123I-IMP lung scintigraphy was performed in two patients with primary malignant lymphoma, whose radiographic features were difficult to differentiate from inflammatory or atelectatic lesions. 123I-IMP scans revealed a defect in the lesions on the delayed (24 hr) image, suggesting a tumorous lesion. 123I-IMP scan may contribute to differential diagnosis of this rare tumorous entity from benign disorders having a different appearance.

Demonstration of inguinal hernia by means of peritoneal 99mTc-MAA scintigraphy with a load produced by standing in a patient treated by continuous ambulatory peritoneal dialysis.

A 45-year-old man receiving continuous ambulatory peritoneal dialysis developed scrotal swelling and edema which was aggravated in the standing position. Physical examination failed to find inguinal hernia and although ultrasonography revealed the patent had processus vaginalias, it failed to prove its continuity to the peritesticular space of the tunica vaginalis. Peritoneal scintigraphy with intraperitoneal instillation of 99mTc-Macroaggregated albumin followed by standing clearly demonstrated the connection. The use of the standing load makes possible faster visualization of a positive finding and more accurate diagnosis than examination in the supine position.

201Tl SPECT as an indicator for early prediction of therapeutic effects in patients with non-small cell lung cancer.

This study retrospectively investigated the good parameters on thallium-201 chloride (201Tl) SPECT for early assessment of the therapeutic effects in patients with non-small cell lung cancer. Based on tumor response as determined by chest CT scan about 9 weeks after the end of irradiation with adjuvant chemotherapy, the subjects were divided to the responder group (tumor regression > 50%, n = 13) and non-responder group (tumor regression < 50%, n = 13). 201Tl SPECT was performed before and at the halfway through the course of therapy (average tumor dose, 27.4 Gy +/- 4.5) in all the patients. SPECT was conducted twice 15 min (early scan) and 120 min (delayed scan) after intravenous injection of 148 MBq (4 mCi) of 201Tl. Tumor-to-contralateral normal lung tissue count ratios on both scans were calculated as early and delayed uptake ratios (EUR and DUR), and a retention index (RI) was also derived from these ratios. In the responder group, a significant decrease in DUR and RI halfway through the therapy was observed compared to pretreatment (2.6 +/- 0.6 vs. 3.5 +/- 1.0; p < 0.01, and -2.3% +/- 25.5 vs. 37.4% +/- 17.8; p < 0.001, respectively), even though EUR did not change significantly (N.S.). By contrast, in the non-responder group, there were no significant changes in any of these parameters (N.S.). When comparing DUR and RI for the two groups halfway through the therapy, DUR and RI were significantly lower in the responder group (both; p < 0.01), but no significant difference was noted in EUR (N.S.), and the percent reduction in tumor size did not correlate with the percent decrease in DUR or RI (N.S.). These results indicate that the extent of decrease in DUR and RI after therapy can be a useful parameter for early assessment of the therapeutic effects in patients with non-small cell lung cancer.

Inflammatory pseudotumor of the lung: a case report.

A case of inflammatory pseudotumor of the lung is reported. A 24-year-old male was referred for further examination of an abnormal shadow on chest radiography performed during a mass survey. Medical imaging data, including CT study, led to a diagnosis of benign tumor of the right lung. After right middle lobectomy, the lesion was diagnosed as inflammatory pseudotumor on the basis of histopathological study.

Characterization of hepatic adenoma with atypical appearance on CT and MRI by radionuclide imaging.

The appearance of hepatic adenomas on CT and MRI are highly variable because of their varied histopathology, and images of adenomas are at times indistinguishable from those of other hepatic tumors. The authors present two patients with hepatic adenomas with extremely atypical CT and MRI manifestations demonstrating a "nodule-in-nodule" appearance. Radionuclide imaging in both patients showed decreased Ga-67 uptake in the adenomas compared to normal liver, negative colloid (Tc-99m phytate) uptake in the adenomas, and early uptake and subsequent retention of Tc-99m PMT. This correctly characterized the unique histopathologic features of the resected tumors. Radionuclide imaging using a combination of radiotracers may play an important role in aiding the diagnosis of this rare benign tumor, despite variable CT and MRI appearances.

Radionuclide angiography and ventilation/perfusion studies in two patients with systemic arterial supply to the basal segment of the left lung.

The findings of radionuclide studies in two adult men with systemic arterial supply to the basal segment of the left lung without sequestration are reported. Radionuclide angiography with Tc-99m human serum albumin-diethylenetriamine showed that the lung was perfused by the systemic circulation rather than by the pulmonary artery. Ventilation and perfusion scans with Xe-133 and Tc-99m MAA showed a V/Q mismatch in this area, suggesting the presence of normal bronchial communication without a pulmonary arterial supply. These results also suggest the presence of a left-to-left shunt in the well-ventilated lung in this area. MRI and conventional angiography showed an aberrant artery arising from the descending thoracic aorta, supplying the basal segment of the left lung without a pulmonary artery. In both patients, left lower lobectomy showed normal alveobronchial structures without sequestration. Radionuclide angiography and ventilation/perfusion imaging appear to be reliable noninvasive methods for diagnosing this rare anomaly with a left-to-left shunt.

Radionuclide imaging in emphysema after lung volume reduction surgery.

Three dimensional (3D) surface displays of dynamic Xe-133 and Tc-99m MAA SPECT were performed to evaluate regional lung function in two patients with pulmonary emphysema before and after thoracoscopic lung volume reduction surgery. The 3D displays were reconstructed using a color-illuminated, surface-rendering technique. For the Xe-133 studies, a fusion display of 3D equilibrium (EQ) and 3-minute washout (WO) images was used to show the distribution of Xe-133 retention, which were transparently seen within the entire lung contours delineated by the EQ image. In both patients, these 3D displays allowed an overview of the localized poorly functioning lungs with Xe-133 retention or reduced perfusion with geometric realism. The location and extent were more easily comprehended on the displays compared to the slice-by-slice presentations of tomograms. Postoperatively, the displays efficiently revealed restored function in the remaining lungs. The 3D surface displays of the two SPECT procedures providing topographic information of regional lung function appears to contribute to the treatment strategy of this surgery.