Diagnosis of pulmonary embolus using ventilation/perfusion lung scintigraphy: more than 0.5 segment of ventilation/perfusion mismatch is sufficient

Background: To determine the optimal diagnostic cut‐off point using a simplified criterion for the detection of pulmonary embolus (PE) and to evaluate the criterion’s utility and reporter reproducibility. Methods: Lung scintigraphy was carried out in 924 patients for the diagnosis of PE. This group consisted of 316 men and 608 women with median age of 63 years (range 18–94 years). Ventilation imaging was carried out with Tc‐99m Technegas followed by perfusion imaging using 190 MBq Tc‐99m macroaggregated albumin. Studies were classified using a 6‐category probability criterion of incremental ventilation/perfusion (V/Q) mismatch: A, normal; B, low (minor matched V/Q defects or segmental matched V/Q defects without opacity on chest X‐ray); C, low‐moderate (a partial segment of V/Q mismatch); D, moderate (1 segment of mismatch); E, moderate‐high (1–2 segments of V/Q mismatch) and F, high probability (=2 segments of V/Q mismatch). Clinical end‐points at 3 and 6 months were death by PE or PE treated with anticoagulation therapy. Three‐reporter reproducibility was determined by kappa statistic on a subgroup of patients (53/924). Results: A total of 122 patients (13%) had a confirmed diagnosis of PE at 3 months and no additional cases were registered at 6 months. The lung scintigraphy probability classification showed: normal 152 (16%), low 620 (67%), low‐moderate 20 (2%), moderate 28 (3%), moderate‐high 24 (3%) and high 80 (9%). The respective sensitivities and specificities, where the diagnostic cut‐offs were established at F, high; E, moderate‐high; D, moderate and C, low‐moderate probability, were F, 64 and 100%; E, 82 and 99%; D, 95 and 98% and C, 98 and 96%. The respective false‐negative cases for F, E, D and C cut‐offs were 44, 22, 7 and 3. Using the revised Prospective Investigation of Pulmonary Embolism Diagnosis reporting classification reporter agreement showed kappa values of 0.31–0.48. Using a simplified 2‐category (>0.5 segment of V/Q mismatch positive, all others negative) criterion resulted in a higher reporting agreement (kappa 0.74–0.83). There were only 3% of indeterminate cases if this was defined by the D category and a maximum of 8% if categories C, D and E were included. Conclusions: Using a simplified diagnostic criterion where all studies showing >0.5 segments of V/Q mismatch are regarded as positive and all others as negative, lung scintigraphy, incorporating Tc‐99m Technegas ventilation imaging or its equivalent, can achieve a very high diagnostic accuracy for the detection of PE. Using this technique, less than 5% of scans are indeterminate. A simplified, unambiguous approach to reporting is recommended.     

Myocardial perfusion imaging with positron emission tomography and single photon emission computed tomography: frequency and causes of disparate results

The purpose of this study was to compare rubidium-82 PET withthallium-201 SPECT imaging in 150 patients. Both techniquesfollowed a single dipyridamole-handgrip stress, and images weredisplayed using the same 3-dimensional format and quantitativecolour scale. Coronary arteriography was employed to assignthe correct diagnosis in situations of disparity. Results of PET and SPECT were at least partially concordantin 110 patients (73%), although 22 had more than one defect.A reversible perfusion defect was identified in 60 patients,but the scans were concordant in only 20 (33%). These disparitieswere chiefly due to false-negative SPECT imaging (22 patients,55%), and probable delayed thallium redistri bution (13 patients,33%). No patients had ischaemia correctly identified by SPECTin the presence of normal PET imaging. Persistent defects wereidentified in 91 patients, some of whom also had reversibledefects, and the results were consistent in 54 (59%). Otherthan the delayed thallium redistribution group, the major categoriescausing disparities were false-positive (6 patients, 16%), andfalse negative SPECT (8 patients, 22%), attributable to attenuationand scatter. PET appears able to identify smaller, less ischaemic areas subtendedby milder coronary stenoses. The availability of a true restingscan with Rb-PET enhances the discrimination between ischaemiaand infarction. Attenuation correction, and the high energyphotons of positron annihilation, yield more accurate evaluationof inferior wall defects and greater specificity in the presenceof soft tissue attenuation.     

Myocardial perfusion imaging with positron emission tomography and single photon emission computed tomography: frequency and causes of disparate results.

The purpose of this study was to compare rubidium-82 PET with thallium-201 SPECT imaging in 150 patients. Both techniques followed a single dipyridamole-handgrip stress, and images were displayed using the same 3-dimensional format and quantitative colour scale. Coronary arteriography was employed to assign the correct diagnosis in situations of disparity. Results of PET and SPECT were at least partially concordant in 110 patients (73%), although 22 had more than one defect. A reversible perfusion defect was identified in 60 patients, but the scans were concordant in only 20 (33%). These disparities were chiefly due to false-negative SPECT imaging (22 patients, 55%), and probable delayed thallium redistribution (13 patients, 33%). No patients had ischaemia correctly identified by SPECT in the presence of normal PET imaging. Persistent defects were identified in 91 patients, some of whom also had reversible defects, and the results were consistent in 54 (59%). Other than the delayed thallium redistribution group, the major categories causing disparities were false-positive (6 patients, 16%), and false negative SPECT (8 patients, 22%), attributable to attenuation and scatter. PET appears able to identify smaller, less ischaemic areas subtended by milder coronary stenoses. The availability of a true resting scan with Rb-PET enhances the discrimination between ischaemia and infarction. Attenuation correction, and the high energy photons of positron annihilation, yield more accurate evaluation of inferior wall defects and greater specificity in the presence of soft tissue attenuation.     

Tumor necrosis factor-alpha and neuropsychiatric lupus erythematosus: relation to single photon emission computed tomography findings

This study was designed to highlight the relation of tumor necrosis factor- (TNF-) to neuropsychiatric lupus (NPLE) manifestations. The relation of TNF- to the type of single photon emission computed tomography (SPECT) findings in this context was also studied. Twenty-one systemic lupus erythematosus (SLE) females, mean age 27.57 ± 9.89 years, and twenty age-matched normal females (controls), were subjected to TNF- assessment. Different clinical and neuropsychiatric manifestations were evaluated. SPECT was carried out for all patients. The results showed that the mean TNF- level (pg/ml) was significantly raised in patients compared with controls (167.8 ± 102.5 versus 64 ± 50.2, respectively, P 0.005). Thirteen patients (69.1%) had NPLE manifestations. NPLE patients had a significantly higher mean TNF- than patients without NPLE (203 ± 102.8 versus 109 ± 47.3, respectively, P 0.03). Positive SPECT findings were found in 18 lupus patients (85.7%), including all 13 patients with NPLE (100% sensitivity), with a multiple focal pattern of hypoperfusion being the most frequent type (9/13), followed by diffuse (3/13), and then single focal pattern (1/13). The mean TNF- was significantly higher in patients with multiple focal pattern (P 0.001). In conclusion, results of this work support the hypothesis that TNF- could be involved in the pathogenesis of NPLE, and hence, it could be speculated that the evolving anti-TNF therapy can play a potential role in the management of this disease.     

Tumor necrosis factor-alpha and neuropsychiatric lupus erythematosus: relation to single photon emission computed tomography findings

Abstract

This study was designed to highlight the relation of tumor necrosis factor-α (TNF-α) to neuropsychiatric lupus (NPLE) manifestations. The relation of TNF-α to the type of single photon emission computed tomography (SPECT) findings in this context was also studied. Twenty-one systemic lupus erythematosus (SLE) females, mean age 27.57 ± 9.89 years, and twenty age-matched normal females (controls), were subjected to TNF-α assessment. Different clinical and neuropsychiatric manifestations were evaluated. SPECT was carried out for all patients. The results showed that the mean TNF-α level (pg/ml) was significantly raised in patients compared with controls (167.8 ± 102.5 versus 64 ± 50.2, respectively, P < 0.005). Thirteen patients (69.1%) had NPLE manifestations. NPLE patients had a significantly higher mean TNF-α than patients without NPLE (203 ± 102.8 versus 109 ± 47.3, respectively, P < 0.03). Positive SPECT findings were found in 18 lupus patients (85.7%), including all 13 patients with NPLE (100% sensitivity), with a multiple focal pattern of hypoperfusion being the most frequent type (9/13), followed by diffuse (3/13), and then single focal pattern (1/13). The mean TNF-α was significantly higher in patients with multiple focal pattern (P < 0.001). In conclusion, results of this work support the hypothesis that TNF-α could be involved in the pathogenesis of NPLE, and hence, it could be speculated that the evolving anti-TNF therapy can play a potential role in the management of this disease.     

Potential role of the ventilation and perfusion (V/Q) lung scan in the diagnosis of acute chest syndrome in adults with sickle cell disease

The current criteria for diagnosing ACS are chest pain and presence of a new infiltrate on the chest radiograph (CXR). This study was designed to evaluate the role of ventilation and perfusion (V/Q) scan to assist in the early diagnosis of ACS. An abnormal V/Q scan was associated with a diagnosis of ACS that reached a statistical significance (P < 0.038). The sensitivity and specificity were found to be 60% and 100%, respectively. We conclude that V/Q scan may play a role in the early diagnosis of ACS.     

The evaluation of an electrocardiographic myocardial ischemia acuteness score to predict the amount of myocardial salvage achieved by early percutaneous coronary intervention : Clinical validation with myocardial perfusion single photon emission computed tomography and cardiac magnetic resonance

Background

The time from symptom onset to reperfusion in acute myocardial infarction (MI) has been shown to be a poor predictor of patient outcome. Acute electrocardiographic (ECG) changes, however, have been shown useful for estimated acuteness of myocardial ischemia using the Anderson-Wilkins ECG ischemia acuteness score (AW-acuteness score). The aim was to study whether acute ischemic ECG changes can predict the amount of salvageable myocardium in patients with acute ST-elevation MI.

Methods

Thirty-eight patients treated with primary percutaneous coronary intervention for first-time ST-elevation MI were retrospectively enrolled. Myocardium at risk (MaR) was determined by myocardial perfusion single photon emission computed tomography acutely or by T2-weighted cardiac magnetic resonance after 1 week, at the same time when final MI size was determined by late gadolinium enhancement. Myocardial salvage was calculated as (MaR − MI size)/MaR and compared with AW-acuteness score and time from symptom onset to primary percutaneous coronary intervention.

Results

The AW-acuteness score correlated significantly with salvageable myocardium for right coronary artery (RCA) occlusions (r = −0.57; P = .02) but not for left anterior descending artery (LAD) occlusions (r = −0.04; P = .88). Time from symptom onset did not correlate with the amount of salvageable myocardium (LAD, r = 0.04 and P = .87; RCA, r = −0.40 and P = .13).

Conclusions

There is a moderate correlation between AW-acuteness score and salvageable myocardium in patients with acute RCA occlusion but not in patients with LAD occlusion.     

Quantitative evaluation of myocardial perfusion in patients with revascularized myocardial infarction: comparison between intravenous myocardial contrast echocardiography and 99mTc-sestamibi single photon emission computed tomography.

AIMS: This two-center study compared quantitative segmental perfusion mapping by intravenous myocardial contrast echocardiography (ivMCE) and scintigraphy (SPECT) in patients in the subacute phase of myocardial infarction (AMI). METHODS AND RESULTS: Sixteen patients underwent ivMCE using 1:1 intermittent harmonic imaging 24 h after first AMI treated with PTCA and stenting. Apical contrast echocardiograms were obtained after the injections of Sonazoid. Baseline-corrected peak myocardial videointensity (bcPMVI) was determined automatically in 16 segments. Resting 99mTc-sestamibi SPECT was performed within one day after ivMCE. SPECT images were reoriented matching the ivMCE views, and divided into the same segments as in ivMCE, from which mean count rate values were obtained. After exclusion due to artifacts or attenuation, 208/256 (82%) segments remained for analysis. Normalized SPECT count rate and bcPMVI correlated linearly: bcPMVI = 1.237 x SPECT - 35; r = 0.74, p < 0.0001. The relation remained identical in subgroup analysis based on participating center, echocardiographic view, perfusion territory, infarct zone, or function. Using SPECT as reference, mean bcPMVI was 77+/-19% in normal segments, 53+/-29% in mild-moderate defects and 25+/-18% in severe defects (p<0.001 for all comparisons). CONCLUSION: The videointensity increase observed in quantitative ivMCE clearly correlated with SPECT tracer uptake. This further substantiates the use of ivMCE as a valid technique for myocardial perfusion imaging.     

Prognostic value of metabolic parameters measured by pretreatment dual-time-point 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with intrahepatic or perihilar cholangiocarcinoma: A STROBE study

The purpose of this study was to determine the glucose metabolism at delay phase measured by pretreatment dual-time-point ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/ computed tomography (CT) provides prognostic information independent of well-known prognostic factors in patients with intrahepatic or perihilar cholangiocarcinoma (ICC or PCC).From July 2012 to December 2017, 55 patients (men 27, women 28, mean age 68 ± 11 years) with pathologically proven ICC or PCC were enrolled in this retrospective study. The dual-time-point ¹⁸F-FDG PET/CT as part of a staging workup was performed in all patients. The patient''s data includes age, sex, serum CA19-9, presence of LN or distant metastasis, early SUVmax (early maximum standardized uptake value [eSUV]), delay SUVmax (delay maximum standardized uptake value [dSUV]), retention index of SUVmax (percent change of maximum standardized uptake values [ΔSUV]), neutrophil to lymphocyte ratio (NLR) and histopathology including pCEA, p53, Ki-67 index. The analysis of the relationship between metabolic parameters and survival was done using the Kaplan–Meier curve and Cox proportional hazards regression model.Median survival for all patients was 357 days. Median early and delay SUVmax was 5.2 (range: 2.0–21.4) and 6.5 (range 2.7–24.5), respectively. The overall survival was found to be significantly related to eSUV, dSUV, ΔSUV, age, serum CA19-9 and NLR in univariate analysis. In multivariate analysis, dSUV (P = .014, 95%CI; 1.30–10.7, HR 3.74) and ΔSUVmax (P = .037, 95%CI; 1.05–6.12, HR 2.5) were independent factors of overall survival. Kaplan–Meier curve analysis clearly showed the significant difference of overall survival between 2 groups (high eSUV, low eSUV + high ΔSUV vs low eSUV and ΔSUV, P < .001) among the comparisons of the SUV parameters on FDG PET. In the receiver operating characteristic analysis using combinations of the SUV parameters, the 2 groups [eSUV + ΔSUV (P = .0001, area under the curve [AUC] 0.68) and dSUV + ΔSUV (P = .0002, AUC 0.71)] showed significantly larger AUC than the other groups applying eSUV or dSUV alone (AUC 0.61 and AUC 0.68).dSUV and ΔSUV on pretreatment dual-time-point ¹⁸F-FDG PET/CT can be useful parameters in the prediction of survival in patients with ICC or PCC.     

Positron emission tomography/computed tomography and endobronchial ultrasound-guided transbronchial needle aspiration to evaluate the status of N2 in preoperative non-small cell lung cancer: a diagnostic test

BackgroundAs a minimally invasive method, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was more accurate than non-invasive methods such as positron emission tomography (PET) and computed tomography (CT) to evaluate the lymph nodes in preoperative non-small cell lung cancer (NSCLC). PET/CT has more anatomical advantages than PET scanning and is more accurate in lung cancer staging. However, no relevant studies have comparatively evaluated PET/CT and EBUS-TBNA for NSCLC patients.MethodsA total of 112 patients were included in this retrospective analysis. The golden diagnosis of N2 status was postoperative pathological results. In EBUS-TBNA puncture specimens, if clear malignant tumor cells could be seen, the results were taken as positive. In PET/CT image analysis, the CT values, short diameter, and maximum standardized uptake value (SUVmax) of each lymph node were recorded to evaluate N2 status. The results of PET/CT and EBUS-TBNA were compared with the final pathological results, and respective sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. - Then, the patients were divided into adenocarcinoma group and squamous cell carcinoma group -and the results were calculated and compared with the above method.ResultsThe results showed that EBUS-TBNA had a higher diagnostic value for mediastinal lymph nodes than PET/CT, and the difference was statistically significant (P<0.001). In NSCLC patients, the results showed that the sensitivity (P=0.013), specificity (P<0.001), PPV (P<0.001), NPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than that of PET/CT (AUC =0.954 and 0.636, respectively). In adenocarcinoma cases, specificity (P<0.001), PPV (P<0.001), NPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than that of PET/CT (AUC =0.957 and 0.596, respectively).In cases with squamous cell carcinoma, specificity (P=0.003), PPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than PET/CT (AUC =0.952 and 0.657, respectively).ConclusionsFor preoperative diagnosis of mediastinal lymph node metastases in NSCLC, EBUS-TBNA is more accurate than PET/CT. For those patients with suspected mediastinal lymph node metastasis, EBUS-TBNA should be preferred method to evaluate the status of mediastinal lymph nodes.