Circulating KL-6 levels in patients with drug induced pneumonitis.

BACKGROUND: The circulating level of KL-6/MUC1 is a sensitive marker for various interstitial lung diseases. Previous case reports have suggested that KL-6 may also be increased in some patients with drug induced pneumonitis. A study was undertaken to determine whether serum KL-6 could be a marker for particular types of drug induced pneumonitis. METHODS: The findings of high resolution computed tomographic (HRCT) chest scans of 30 patients with drug induced pneumonitis were reviewed separately by two independent observers. The pneumonitis was classified into four predominant patterns: widespread bilateral consolidation (diffuse alveolar damage, DAD; n=7), fibrosis with or without consolidation (chronic interstitial pneumonia, CIP; n=11), consolidation without fibrosis (bronchiolitis obliterans organising pneumonia or eosinophilic pneumonia, BOOP/EP; n=8), and diffuse ground glass opacities without fibrosis (hypersensitivity pneumonitis, HP; n=4). Serum KL-6 levels were measured by a sandwich enzyme linked immunosorbent assay. RESULTS: The overall sensitivity of serum KL-6 in detecting drug induced lung disease was 53.3%, which was lower than its sensitivity in detecting other interstitial lung diseases. However, the KL-6 level was increased in most patients with a DAD or CIP pattern (16/18; 88.9%) and was closely correlated with their clinical course. In contrast, serum KL-6 levels were within the normal range in all patients with a BOOP/EP or HP pattern. CONCLUSIONS: Particular patterns detected by HRCT scanning, such as DAD and CIP but not the BOOP/EP or HP patterns, are associated with increased circulating KL-6 levels in drug induced pneumonitis. Serum KL-6 levels may reflect the clinical activity of the particular disorders.

Reproducibility of the brain perfusion index for measuring cerebral blood flow using technetium-99m compounds.

We previously developed an alternative method for estimating the brain perfusion index (BPI) using technetium-99m compounds and spectral analysis (SA) for quantification of cerebral blood flow (CBF). In this study, we investigated the reproducibility of the BPI values obtained by SA (BPIS) using a double injection of technetium-99m ethyl cysteinate dimer without any intervention, and compared it with that of the BPI values obtained by graphical analysis (BPIG). The BPIS values in the first (x) and second sessions (y) correlated closely (y=0.921x+0.036; r=0.962; n=64; s.e.e.=0.058 min-1). Although the BPIG values in the first (x) and second sessions (y) also correlated (y=0.942x+0.040; r=0.916; n=64; s.e.e.=0.061 min-1), the correlation coefficient for BPIS was significantly higher than that for BPIG. The reproducibility was dependent on the injection dose ratio of the second session to the first (R). The difference in BPI between the first and second sessions tended to be smaller when 1.5

Late-phase enhancement of the upstream portion of pancreatic adenocarcinoma on dual-phase helical CT.

BACKGROUND: Late-phase enhancement of pancreatic parenchyma upstream (tail side) of pancreatic adenocarcinoma is found frequently on dual-phase helical computed tomography (CT). We measured the frequency of late-phase enhancement of the upstream portion of pancreatic adenocarcinoma and normal pancreatic parenchyma using dual-phase helical CT. METHODS: Twenty-one patients with pancreatic adenocarcinoma and nontumorous pancreas upstream of tumors were compared with 100 control patients without pancreatic disease. Early and late scans started at 25 and 75 s, respectively, after intravenous injection of contrast material. The attenuation values of normal and nontumorous pancreas upstream of tumors were assessed in three phases: precontrast, early, and late enhanced. Enhancement ratio (ER) was calculated as ER = (late phase - precontrast)/(early phase - precontrast). RESULTS: Late-phase enhancements (ER > 1.0) were seen in 86% of upstream pancreas and 10% of normal pancreas. The mean ER of upstream pancreas was significantly higher than that of normal pancreas (p < 0.01). CONCLUSION: Late-phase enhancement of the pancreas upstream of the tumor is frequently observed in patients with pancreatic adenocarcinoma. Late-phase enhancement and histology showed a correlation for chronic obstructing pancreatitis in five patients.

Two cases of pediatric bone disease (eosinophilic granuloma and Brodie's abscess) showing similar scintigraphic and radiographic findings.

Two 9-year-old patients with femoral bone lesions were referred to the authors' institution within a few days of each other. Both showed similar radiographic, magnetic resonance imaging, and scintigraphic findings. The radiographs showed osteolytic lesions in the right femoral diaphyses, and gadolinium-DTPA-enhanced magnetic resonance imaging revealed inhomogeneous enhancement. Tc-99m HMDP showed marked linear accumulation with relatively low central uptake in the right femoral shafts, and TI-201 scintigraphy showed considerable uptake corresponding to the area seen with Tc-99m HMDP. Histologic analysis confirmed eosinophilic granuloma in the first patient and Brodie's abscess in the second. The radiographic and scintigraphic findings in Brodie's abscess may be similar to those in eosinophilic granuloma.

Tc-99m PMT hepatobiliary scintigraphy in the differential diagnosis of extrahepatic metastases and hepatocellular carcinoma.

PURPOSE: The authors evaluated the utility of hepatobiliary scintigraphy for tissue characterization of extrahepatic metastases from hepatocellular carcinoma (HCC) using Tc-99m N-pyrydoxyl-5-methyltriptophane (Tc-99m PMT). METHODS: We examined 13 patients with HCC (29 extrahepatic metastases and 3 benign bone lesions) and 5 patients with other cancers (15 extrahepatic metastases). Thirty minutes to 6 hours after intravenous administration of Tc-99m PMT, planar (all 47 lesions) and SPECT (42 lesions) images were obtained. Accumulation of Tc-99m PMT in the lesion was evaluated visually by comparing bone scintigraphy, computed tomography, magnetic resonance imaging, or all of these. RESULTS: Findings were positive in 12 of 13 patients with HCC and extrahepatic metastases (16 of 29 on planar imaging and 21 of 26 on SPECT). Findings in all three benign bone lesions and 15 metastatic lesions from non-HCC primary lesions were negative (0 of 18 on planar imaging, 0 of 16 on SPECT). There were no false-positive findings in these lesions. Lesion-by-lesion sensitivity, specificity, accuracy, and positive and negative predictive values were 55%, 100%, 72%, 100%, and 58% by planar imaging and 81%, 100%, 88%, 100%, and 76% by SPECT, respectively. CONCLUSIONS: Because of the high specificity and reasonable sensitivity, Tc-99m PMT appears to be useful for the differential diagnosis of extrahepatic metastases from HCC. SPECT improves the detectability of small or faint accumulation in metastases from HCC.

Relationship between regional severity of emphysema and coronary heart disease.

We analyzed the relationship between regional severity of emphysema, which was evaluated by three-dimensional fractal analysis (3D-FA) of Technegas SPECT images, and coronary heart disease (CHD). For 22 patients with emphysema who underwent Technegas SPECT, we followed up CHD events. The follow-up period was 5.4+/-0.5 (mean +/- SD) years. We defined the upper-lung fractal dimension (U-FD) and lower-lung fractal dimension (L-FD) obtained with 3D-FA of Technegas SPECT images as the regional severity of emphysema. FD became greater with the progression of emphysematous change. During the follow-up period, CHD events occurred in 6 (27%) of the 22 patients. The ratio of U-FD to L-FD for patients with CHD events (0.87+/-0.22) was significantly smaller than for patients without CHD events (1.52+/-0.38) (p = 0.0015). These findings suggest that severer emphysema in the lower lung indicates a higher risk of CHD than that in the upper lung.

CT-guided treatment of ultrasonically invisible hepatocellular carcinoma.

New techniques of CT-guided management were introduced to ablate ultrasonically invisible hepatocellular carcinomas. In six patients with HCC, a total of six nodules (8-30 mm in diameter) were treated under the guidance of CT. These lesions were not visualized by sonography but were visualized as Lipiodol spots on CT after chemoembolization. Tumor localization was successful in all patients without difficulty, using a thin needle or hookwire under the guidance of CT. Two patients underwent subsequent hepatic resection and/or microwave coagulation therapy (MCT) through a small incision after hookwire placement. Four patients received percutaneous MCT (n = 2) or ethanol injection (PEI) (n = 2) at the time of localization. The postoperative CT with contrast enhancement indicated that tumor ablation was complete in four of the five nodules treated with MCT or PEI. However, in one nodule (30 mm in diameter) treated with PEI, tumor ablation was not complete. There were no complications. There has been no local tumor recurrence 6-46 months after treatment in any of the patients. In conclusion, these CT-guided procedures were effective in treating ultrasonically invisible hepatocellular carcinomas that otherwise would have remained untreated.

Hyperoxia-induced diffuse alveolar damage in pigs: correlation between thin-section CT and histopathologic findings.

PURPOSE: To determine whether lung abnormalities at thin-section computed tomography (CT) in experimental hyperoxic lung injury correlate with the pathologic phases of diffuse alveolar damage (DAD). MATERIALS AND METHODS: Eighteen juvenile pigs were exposed to more than 80% oxygen-for 24, 48, 72, 96, or 120 hours-or room air in sealed cages. Their removed lungs were inflated with air infused through the trachea and examined with thin-section CT. Two independent observers, without knowledge of the exposure times, compared 63 areas selected on the CT scans with the corresponding pathologic and histologic findings, which were evaluated independently by two pathologists. RESULTS: CT findings correlated well with histologic findings (rho = 0.86, P <.001), which corresponded to the pathologic phases of DAD. All areas of normal CT attenuation, eight of nine spared regions within areas of opacity, and two of 15 areas of ground-glass opacity corresponded to the early exudative pathologic phase of DAD. All areas that showed traction bronchiolectasis at CT corresponded to the early proliferative pathologic phase. There was good observer agreement regarding the interpretation of CT findings (kappa statistic, >0.60) and histologic results (>/=0.70). CONCLUSION: Thin-section CT findings reflect the pathologic phases of DAD, although the early exudative phase cannot be specifically depicted by thin-section CT. Traction bronchiolectasis on a CT scan suggests progression to the proliferative phase.

Assessment of liver function in chronic liver diseases and regional function of irradiated liver by means of 99mTc-galactosyl-human serum albumin liver scintigraphy and quantitative spectral analysis.

Scintigraphy with 99mTc-diethylenetriamine pentaacetic acid galactosyl human serum albumin (99mTc-GSA) was performed on 102 patients, then the hepatic extraction fraction (HEF), the rate constant for liver uptake of the tracer from the blood (K1) and the hepatic blood flow index (HBFI) were determined by spectral analysis. The HEF, K1 and HBFI values correlated moderately or closely with various indices of hepatic function, and the HEF and K1 values decreased according to the stage of liver dysfunction. The HEF and K1 values linearly and nonlinearly correlated with HH15 and LHL15, respectively. The HEF, K1 and HBFI values for the irradiated portion of 20 patients before and alter irradiation were compared. The HEF value in patients with a cirrhotic liver significantly (p < 0.002) decreased compared with that in patients with a normal liver at a dose of less than 40 Gy, whereas the HBFI value in patients with a normal liver significantly (p < 0.05) decreased compared with that in patients with a cirrhotic liver at a dose of 40 Gy or greater. This method appears to be a simple, non-invasive and useful tool with which to quantitatively evaluate liver function and it also helps clarify changes in regional function of the irradiated liver.

An alternative approach to estimation of the brain perfusion index for measurement of cerebral blood flow using technetium-99m compounds.

Cerebral blood flow (CBF) has been quantified non-invasively using the brain perfusion index (BPI) determined from radionuclide angiographic data generated by technetium-99m hexamethylpropylene amine oxime( )((99m)Tc-HMPAO) or technetium-99m ethyl cysteinate dimer( )((99m)Tc-ECD). The BPI is generally calculated using graphical analysis (GA). In the present study, BPI was measured using spectral analysis (SA), and its usefulness evaluated in comparison with GA. The BPI was calculated from the sum of spectral data obtained by SA. We applied this method to radionuclide angiographic data collected from the bilateral brain hemispheres of 20 patients with various brain diseases using (99m)Tc-HMPAO and from those of 20 patients using (99m)Tc-ECD. We also measured BPI using GA. The BPI values obtained by SA (BPI(S)) (x) and by GA (BPI(G)) (y) correlated closely (y=0.708x+0.038, r=0.945 for (99m)Tc-HMPAO and y=0.559x+0.093, r=0.931 for (99m)Tc-ECD). However, the BPI(G) values were underestimated by 22.9%+/-6.6% (mean+/-SD) for (99m)Tc-HMPAO and by 27.9%+/-7.5% for (99m)Tc-ECD as compared with the BPI(S) values. The extent of underestimation tended to increase with increasing BPI(S) values. These findings were considered to be a result of the BPI(G) values being affected by the first-pass extraction fraction of the tracer. We also compared the BPI(S) and BPI(G) values with those of CBF measured using N-isopropyl-p-[(123)I]iodoamphetamine (CBF(IMP)) in 16 patients (six for (99m)Tc-HMPAO and ten for (99m)Tc-ECD). Although both BPI(S) and BPI(G) values correlated significantly with the CBF(IMP) values, the correlation coefficient in BPI(S) was always better than that in BPI(G) (r=0.869 for (99m)Tc-HMPAO and r=0.929 for (99m)Tc-ECD in BPI(S), r=0.629 for (99m)Tc-HMPAO and r=0.856 for (99m)Tc-ECD in BPI(G)). These results suggest that SA can provide a more reliable BPI for quantifying CBF using (99m)Tc-HMPAO or (99m)Tc-ECD than the conventional method using GA. Our method will be useful especially when using a tracer with a low first-pass extraction fraction and/or when performing activation studies using pharmacological intervention.

Evaluation of cerebral perfusion from bypass arteries using selective intraarterial microsphere tracer after vascular reconstructive surgery.

BACKGROUND AND PURPOSE: To detect areas of cerebral perfusion from bypass arteries after vascular reconstruction, we administered selective intraarterial microsphere tracer into the external carotid arteries and determined (via single-photon emission computed tomography [IA-SPECT]) whether the distribution of radiotracer matched the arteriographic distribution of contrast material as shown on external carotid angiograms. METHODS: We compared the extent of regional distribution of tracer after external carotid artery injection of 20 to 40 MBq of 99mTc-HMPAO or 99mTc-ECD with that of contrast medium on the external carotid angiograms in 582 cortical regions in 12 patients with atherosclerotic occlusive disease and in 18 patients with moyamoya disease. RESULTS: Marked accumulation of tracer was found only in the expected, specific, newly developed areas of cerebral perfusion from bypass arteries. The regional distribution of tracer corresponded to that of contrast medium in 523 regions (90%) and did not correspond in 59 regions (10%). Significant overestimation of the distribution of contrast material relative to that of tracer was observed in the patients with moyamoya disease. CONCLUSION: SPECT showed slightly different distribution of tracer from that predicted by conventional angiography. IA-SPECT should enhance the analysis of newly developed areas of cerebral perfusion from the bypass arteries.

Prognostic value of dipyridamole-thallium myocardial scintigraphy in patients with Kawasaki disease.

BACKGROUND: Although coronary artery lesions are critical complications of Kawasaki disease, their long-term outcome is still unclear. It is sometimes difficult to monitor progressive changes from aneurysms to stenotic lesions because coronary angiography (CAG) cannot be repeated very often, especially in infants. Our prospective study was designed to evaluate the prognostic value of dipyridamole-thallium single-photon-emission CT (SPECT) in the long-term follow-up of patients with Kawasaki disease. METHODS AND RESULTS: Of 459 consecutive patients with Kawasaki disease, coronary aneurysms were detected in 90 cases by echocardiography during the acute stage. After paired studies of selective CAG and SPECT were conducted, all patients were followed up and monitored for the occurrence of any cardiac events for > or =8 years. During the follow-up interval, there were 15 cardiac events (1 death, 5 infarctions, 2 coronary artery bypass graft operations, and 7 occurrences of unstable angina). Of patients who had some event, thallium redistribution was found on SPECT in 14 (93%, P<0.001). Of the various clinical and scintigraphic image variables, the presence of thallium redistribution was the best multivariate independent predictor of a late cardiac event (chi2=57.8, P<0.0001). The number of aneurysms detected on CAG added minimal statistical improvement to the model (chi2=1.9, P=0.0009). CONCLUSIONS: Dipyridamole-thallium SPECT is safely performed and is useful and important for risk stratification in the long-term follow-up of patients with Kawasaki disease.

[Estimation of integral value of input function for the quantification of cerebral blood flow with 123I-IMP using one-point arterial blood sampling].

Cerebral blood flow (CBF) has been measured using a microsphere model with octanol-extracted radioactivity counts (integral value of input function). We developed a new method estimating the integral value of input function. First, we fitted the whole brain time-activity curves early after intravenous injection of N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) by the least-squares method. Second, we differentiated this equation. Third, we calibrated it using octanol-extracted radioactivity counts of the arterial blood sampled at 5 min. Finally, we integrated it. A significant correlation was found between the integral values obtained using a new method and those obtained using the continuous arterial blood sampling data (y = 1.048x-1206, r = 0.984). The errors between the CBF values obtained using a new method and those obtained using the 5-min continuous arterial blood sampling was 6.88 +/- 4.78%. Measurement of integral values of the input function using a new method with one-point arterial blood sampling is less invasive and convenient, and is not influenced by cardiopulmonary disease or smoking. Therefore, it would be useful for the routine measurement of CBF.

[Clinical usefulness of 201Tl-chloride scintigraphy for the evaluation of metastatic bone lesions].

201Tl-Chloride scintigraphy (early and delayed images) was performed in 40 patients with suspected metastatic bone lesions. The sensitivity and specificity of 201Tl scanning for detecting metastatic bone lesions were 66.7% and 77.4%, respectively. The uptake ratio of 201Tl per voxel of the lesions to the normal site was significantly different between the metastatic bone lesion and benign lesions. In 20 sites of 15 patients, 201Tl-Chloride scintigraphy was performed before and after radio- or radiothermotherapy. There was a significant difference in the mean uptake ratios in the early and delayed scans between before and after therapy. The mechanism of intracellular uptake of 201Tl is considered to be one of active transport, which might make 201Tl an accurate indicator of the viability of tumor cells and metabolic activity as long as there is sufficient blood flow to prompty transport 201Tl to tumor cells. Thus it would seem that decreased uptake of 201Tl and change in retention index after therapy depends partially on tumor blood flow. In conclusion, 201Tl-Chloride scintigraphy is very useful not only for clinically detecting metastatic bone lesions but also for assessing the therapeutic effects.

A method for estimating the integral of the input function for the quantification of cerebral blood flow with 123I-IMP using one-point arterial blood sampling.

We have developed a new method to replace the conventional method of quantitatively measuring cerebral blood flow (CBF), in which octanol-extracted radioactivity counts are measured in continuous arterial blood samples. With the new method, the whole-brain time-activity curves early after the intravenous injection of N-isopropyl-p-[123I]iodoamphetamine were first obtained by the least-squares curve-fitting method. The equation thus obtained was differentiated and the radioactivity counts were corrected by the 5-min octanol-extracted radioactivity counts of the arterial blood sample obtained at a single time point. In the present study, the value obtained by integrating the equation from 0 to 5 min, which was obtained by curve-fitting, was compared with the octanol-extracted radioactivity counts obtained by 5-min continuous arterial blood sampling in 160 patients with cerebrovascular disorders. The results showed good agreement between the values obtained by the two procedures (y = 1.049x - 1522.4; r = 0.987). Using the CBF obtained by the 5-min continuous arterial blood sampling as the standard, the errors using the present integral values of the input function were 7.1 +/- 4.9%. Measurements of the integral of the input function by the present one-point arterial blood sampling method has the potential for use in the routine measurement of CBF, because it is less invasive and more convenient than the conventional method, and it is unaffected by cardiopulmonary disease or smoking.

Computed tomography of the retropancreatic peritoneal recess: a case of gastric leiomyosarcoma.

We report computed tomography of the retropancreatic peritoneal recess in a case in which gastric leiomyosarcoma developed. Because of its location behind the pancreas, an abnormal finding in the retropancreatic peritoneal recess may be radiologically mistaken for a retroperitoneal abnormality. Knowledge of anatomy of posterior peritoneal recesses and understanding of fetal development are important in the radiological diagnosis of the lesions behind the pancreas.

Acute interstitial pneumonia: high-resolution CT findings correlated with pathology.

OBJECTIVE: The purpose of this study was to evaluate the relation between pathologic phases and high-resolution CT (HRCT) findings in patients with acute interstitial pneumonia (AIP). MATERIALS AND METHODS: Our retrospective review found 14 patients with AIP who were included in this study. Three patients were pathologically diagnosed as having AIP by open lung biopsy, and the other 11 patients were confirmed at autopsy. In eight of the 11 autopsy patients, the postmortem lungs were inflated and fixed by Heitzman's method, and a postmortem HRCT scan was obtained on all 11 autopsy patients. Paying special attention to the disease stage, we selected 27 areas of the lung from antemortem or postmortem HRCT and correlated them with pathologic findings. RESULTS: Nine areas of the lung that showed increased attenuation without traction bronchiectasis were associated with either the exudative (n = 5) or early proliferative (n = 4) phase of AIP. Eleven areas of increased attenuation with traction bronchiectasis were associated with either the proliferative (n = 4) or fibrotic (n = 7) phase of AIP. Honey-combing, observed in one area of the lung, corresponded to restructuring of distal airspaces and dense interstitial fibrosis. Six spared areas, within or adjacent to areas of increased attenuation, showed pathologic findings of the exudative phase. CONCLUSION: HRCT findings were not specific for the pathologic findings in our patients with AIP. Nevertheless, the findings of traction bronchiectasis in areas of increased attenuation suggested the proliferative or fibrotic phase.

MR arthrography of elbow: evaluation of the ulnar collateral ligament of elbow.

OBJECTIVE: The purpose of this study was to evaluate ulnar collateral ligament (UCL) injury of the elbow in throwing athletes by MRI and MR arthrography. DESIGN: Ten elbows of throwing athletes were examined on both plain MRI and MR saline arthrography and the injuries subsequently surgically proven. Spin-echo (SE) T1-weighted and fast SE T2-weighted coronal images were obtained. RESULTS: The UCL was unclear in all ten cases on T1-weighted MRI. In five cases an avulsion fracture was also found on T1-weighted MRI. On T2-weighted MRI, abnormal high-intensity areas were identified in or around the UCL. On T2-weighted MR arthrography images, extracapsular high-intensity areas, which represent extracapsular leakage, were found in four of five cases with avulsion fracture. At surgery, all these four cases showed avulsion fractures with instability; the other case had a fracture but it was stable and adherent to the humerus. On T2-weighted MR arthrography images, an extracapsular high-intensity area was found in one of the five cases without avulsion fracture. At surgery this patient had a complete tear of the UCL itself. CONCLUSION: MR arthrography provided additional information for evaluating the degree of UCL injury.