Performance of intra-procedural 18-fluorodeoxyglucose PET/CT-guided biopsies for lesions suspected of malignancy but poorly visualized with other modalities

Purpose

We sought to evaluate the safety and the diagnostic success rate of percutaneous biopsies performed under intra-procedural ¹⁸?F-deoxyglucose (FDG) positron-emission tomography/computed tomography (PET/CT) guidance for lesions difficult to see with conventional cross-sectional imaging.

Methods

From 2011 to 2013, consecutive clinically indicated percutaneous PET/CT-guided biopsies of 106 masses (mean size, 3.3 cm; range, 0.7–15.9 cm; SD, 2.9 cm) in bones (n?=?33), liver (n?=?26), soft tissues (n?=?18), lung (n?=?15) and abdomen (n?=?14) were reviewed. The biopsy procedures were performed following injection of a mean of 255 MBq (SD, 74) FDG. Mean maximal standardized uptake value (SUV) of lesions was 8.8 (SD, 6.3). A systematic review of the histopathological results and outcomes was performed.

Results

Biopsies were positive for malignancy in 76 cases (71.7 %, 76/106) and for benign tissue in 30 cases (28.3 %, 30/106). Immediate results were considered adequate for 100 PET/CT biopsies (94.3 %, 100/106) requiring no further exploration, and for the six others (5.7 %, 6/106) benign diagnoses were confirmed after surgery (n?=?4) or follow-up (n?=?2). The consequent overall sensitivity and the diagnostic success of biopsy were therefore 100 %. No significant differences in terms of detection of malignancy were observed between the different locations. Lesions > 2 cm or with SUV?>?4 were not significantly more likely to be malignant. Complications occurred after four biopsies (3.7 %, 4/106).

Conclusion

Intra-procedural PET/CT guidance appears as a safe and effective method and allows high diagnostic success of percutaneous biopsies for metabolically active lesions.     

Value of 18F-FDG uptake on PET/CT and CEA level to predict epidermal growth factor receptor mutations in pulmonary adenocarcinoma

Purpose

The identification of the mutation status of the epidermal growth factor receptor (EGFR) is important for the optimization of treatment in patients with pulmonary adenocarcinoma. The acquisition of adequate tissues for EGFR mutational analysis is sometimes not feasible, especially in advanced-stage patients. The aim of this study was to predict EGFR mutation status in patients with pulmonary adenocarcinoma based on ¹⁸F-fluorodeoxyglucose (FDG) uptake and imaging features in positron emission tomography/computed tomography (PET/CT), as well as on the serum carcinoembryonic antigen (CEA) level.

Methods

We retrospectively reviewed 132 pulmonary adenocarcinoma patients who underwent EGFR mutation testing, pretreatment FDG PET/CT and serum CEA analysis. The associations between EGFR mutations and patient characteristics, maximal standard uptake value (SUVmax) of primary tumors, serum CEA level and CT imaging features were analyzed. Receiver-operating characteristic (ROC) curve analysis was performed to quantify the predictive value of these factors.

Results

EGFR mutations were identified in 69 patients (52.2 %). Patients with SUVmax ≥6 (p?=?0.002) and CEA level ≥5 (p?=?0.013) were more likely to have EGFR mutations. The CT characteristics of larger tumors (≥3 cm) (p?=?0.023) and tumors with a nonspiculated margin (p?=?0.026) were also associated with EGFR mutations. Multivariate analysis showed that higher SUVmax and CEA level, never smoking and a nonspiculated tumor margin were the most significant predictors of EGFR mutation. The combined use of these four criteria yielded a higher area under the ROC curve (0.82), suggesting a good discrimination.

Conclusion

The combined evaluation of FDG uptake, CEA level, smoking status and tumor margins may be helpful in predicting EGFR mutation status in patients with pulmonary adenocarcinoma, especially when the tumor sample is inadequate for genetic analysis or genetic testing is not available. Further large-scale prospective studies are needed to validate these results.     

Prone-position acquisition of myocardial 123I-metaiodobenzylguanidine (MIBG) SPECT reveals regional uptake similar to that found using 11C-hydroxyephedrine PET/CT

Objectives

¹²³I-metaiodobenzylguanidine (MIBG) has been used to estimate cardiac sympathetic nervous innervation. Heterogeneous MIBG distribution is mainly associated with high physiological MIBG uptakes in the liver. We postulate that prone position acquisition might be especially effective for MIBG, providing for separation from high liver uptake similar to that provided by perfusion single-photon emission computed tomography (SPECT). We investigated whether prone-position acquisition improved MIBG image quality by comparing our results to those acquired using supine MIBG and high-quality ¹¹C-hydroxyephedrine (HED) positron emission tomography/computed tomography PET/CT.

Methods

Ten male volunteers (body mass index (BMI) 22.7 ± 3.4) underwent prone and supine MIBG and HED PET. Relative regional tracer uptake was estimated in early MIBG and HED. Acquired images were divided into 17 segments and were grouped into 4 regions: anterior, inferior, septum, and lateral. For each patient, the inferior/anterior ratio was calculated.

Results

The quality of images acquired using prone MIBG was better than that using supine MIBG (p < 0.05). Inferior and septum relative MIBG uptake was reduced in comparison with anterior or lateral MIBG uptake in the supine position (inferior vs. anterior: 69.0 ± 5.6 vs. 82.3 ± 4.6 %, p < 0.01; septum vs. lateral: 66.2 ± 5.1 vs. 81.9 ± 5.4 %, p < 0.01). Prone MIBG showed a significantly higher inferior/anterior uptake ratio in comparison with supine MIBG (n = 24, seg: 92.2 ± 7.2 vs. 83.6 ± 5.7 %, p < 0.05). However, intergroup differences in uptake ratio were demonstrated among prone and supine MIBG and HED. HED PET/CT still showed a higher uptake ratio in comparison with prone MIBG SPECT (103.9 ± 8.0 vs. 92.2 ± 7.2 %, p < 0.05).

Conclusion

Even in normal male subjects, standard supine MIBG imaging showed reduced inferior and septum uptake. Uptake with prone MIBG imaging showed a significant improvement over that with supine imaging and was closer to uptake for HED PET/CT. This improvement may be the result of preventing intense uptake by the liver. Prone data acquisition may be a viable alternative in evaluating regional abnormalities using MIBG SPECT in men.     

Assessment of left ventricular mechanical dyssynchrony by phase analysis of gated-SPECT myocardial perfusion imaging and tissue Doppler imaging: Comparison between QGS and ECTb software packages

Background

Recently, the phase analysis of gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has become feasible via several software packages for the evaluation of left ventricular mechanical dyssynchrony. We compared two quantitative software packages, quantitative gated SPECT (QGS) and Emory cardiac toolbox (ECTb), with tissue Doppler imaging (TDI) as the conventional method for the evaluation of left ventricular mechanical dyssynchrony.

Methods and Results

Thirty-one patients with severe heart failure (ejection fraction ≤35%) and regular heart rhythm, who referred for gated-SPECT MPI, were enrolled. TDI was performed within 3 days after MPI. Dyssynchrony parameters derived from gated-SPECT MPI were analyzed by QGS and ECTb and were compared with the Yu index and septal-lateral wall delay measured by TDI. QGS and ECTb showed a good correlation for assessment of phase histogram bandwidth (PHB) and phase standard deviation (PSD) (r = 0.664 and r = 0.731, P < .001, respectively). However, the mean value of PHB and PSD by ECTb was significantly higher than that of QGS. No significant correlation was found between ECTb and QGS and the Yu index. Nevertheless, PHB, PSD, and entropy derived from QGS revealed a significant (r = 0.424, r = 0.478, r = 0.543, respectively; P < .02) correlation with septal-lateral wall delay.

Conclusion

Despite a good correlation between QGS and ECTb software packages, different normal cut-off values of PSD and PHB should be defined for each software package. There was only a modest correlation between phase analysis of gated-SPECT MPI and TDI data, especially in the population of heart failure patients with both narrow and wide QRS complex.     

A high-resolution computed tomography-based scoring system to differentiate the most infectious active pulmonary tuberculosis from community-acquired pneumonia in elderly and non-elderly patients

Objective

The objective of this study was to use high-resolution computed tomography (HRCT) imaging to predict the presence of smear-positive active pulmonary tuberculosis (PTB) in elderly (at least 65 years of age) and non-elderly patients (18–65 years of age).

Methods

Patients with active pulmonary infections seen from November 2010 through December 2011 received HRCT chest imaging, sputum smears for acid-fast bacilli and sputum cultures for Mycobacterium tuberculosis. Smear-positive PTB was defined as at least one positive sputum smear and a positive culture for M. tuberculosis. Multivariate logistic regression analyses were performed to determine the HRCT predictors of smear-positive active PTB, and a prediction score was developed on the basis of receiver operating characteristic curve analysis.

Results

Of 1,255 patients included, 139 were diagnosed with smear-positive active PTB. According to ROC curve analysis, the sensitivity, specificity, positive predictive value, negative predictive value, false positive rates and false negative rates were 98.6 %, 95.8 %, 78.5 %, 99.8 %, 4.2 % and 1.4 %, respectively, for diagnosing smear-positive active PTB in elderly patients, and 100.0 %, 96.9 %, 76.5 %, 100.0 %, 3.1 % and 0.0 %, respectively, for non-elderly patients.

Conclusions

HRCT can assist in the early diagnosis of the most infectious active PTB, thereby preventing transmission and minimizing unnecessary immediate respiratory isolation.

Key Points

? HRCT can assist in the early diagnosis of the infectious active PTB ? HRCT imaging is useful to predict the presence of smear-positive active PTB ? Predictions from the HRCT imaging are valid even before sputum smear or culture results     

Diagnostic Value of 68Ga-DOTATATE PET/CT in Liver Metastases of Neuroendocrine Tumours of Unknown Origin

Purpose

In neuroendocrine liver metastases of unknown primary, a multimodality approach is usually adopted and consists of transabdominal ultrasound, endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine techniques, endoscopy and exploratory surgery. The purpose of the study is to evaluate the diagnostic value of ⁶⁸Ga-DOTATATE positron emission tomography (PET)/CT as part of a multimodality approach in neuroendocrine liver metastases of unknown primary.

Materials and Methods

Six patients (M:F?=?5:1, age range 28–56 years) with immunohistochemically proven neuroendocrine liver metastases but inconclusive initial CT work-up were retrospectively analysed. Clinical finding, histopathology, comparative imaging and follow-up were used to validate the results when ethically justified.

Results

⁶⁸Ga-DOTATATE PET/CT identified the primary tumour in five out of six (83.3 %) patients: pancreas (n?=?4) and stomach (n?=?1). Out of three patients with indeterminate primary on initial CT, two patients were confirmed by ⁶⁸Ga-DOTATATE PET/CT. Absence of uptake in indeterminate primary of one patient was later confirmed negative by histopathology. In another three patients with undetected primary on initial CT, primary site was demonstrated in all patients with unsuspected metastases in two patients on ⁶⁸Ga-DOTATATE PET/ CT. No further work-up was done to confirm the primary in patients with distant metastases. Change of management was observed in three out of six (50 %) patients.

Conclusion

Our small study indicates that ⁶⁸Ga-DOTATATE PET/CT is a promising diagnostic option in the multimodality approach to neuroendocrine liver metastases of unknown primary origin.     

Comparison of CT-Guided Percutaneous Biopsy with and Without Registration of Prior PET/CT Images to Diagnose Mediastinal Tumors

Purpose

To compare computed tomography (CT)-guided percutaneous biopsy with and without registration of prior positron emission tomography (PET)/CT images in the diagnosis of mediastinal tumors.

Methods

We performed clinically indicated percutaneous biopsy in 106 patients with mediastinal tumors in the anterior (n = 61), posterior (n = 21), middle (n = 16), and superior mediastinum (n = 8). The final diagnosis was based on surgical outcomes, or imaging findings and the results of at least 6-month follow-up. The patients underwent CT-guided percutaneous biopsy with (group 1, n = 56) or without (group 2, n = 50) registration of prior PET/CT images obtained no more than 22 days earlier. The registered images were used to plan the procedure and help target the tumors.

Results

CT-guided percutaneous needle biopsy yielded adequate samples in 101 of 106 (95 %) patients (group 1, n = 53; group 2, n = 48); in 95 patients (94 %), the diagnosis was confirmed by specific histological typing (group 1, n = 51; group 2, n = 44). The diagnostic accuracy of CT-guided percutaneous biopsy with and without the registration of prior PET/CT images was not statistically different (group 1, 96 %; group 2, 93 %, p = 0.324).

Conclusion

CT-guided percutaneous biopsy is an easy and safe procedure that can provide a precise diagnosis in the majority of mediastinal tumors. PET/CT-guided biopsy yielded no special diagnostic advantages.     

Relationship of decreased accumulation of 99mTc-tetrofosmin on myocardial single-photon emission computed tomography images between QRS duration in dilated cardiomyopathy patient with left bundle branch block

Purpose

This study aimed to clarify the relationship between severity of conduction delay in the left ventricle and myocardial uptake of ^99mTc-tetrofosmin (TF) in dilated cardiomyopathy (DCM) patients with left bundle branch block (LBBB).

Methods and Results

Thirty-two DCM patients with LBBB underwent electrocardiography and ^99mTc-TF myocardial single-photon emission computed tomography (SPECT). SPECT images were acquired at 30 min (early images) and 3 h (late images) after injection. We calculated the total defect score (TDS) using a 20-segment model with a 5-point scoring system. The TDS in early and late images was defined as the summed early score (SES) and summed late score (SLS), respectively. On early images, 29 of 32 patients (91%) had decreased tracer uptake in the septum. All patients showed a decreased tracer uptake in the septum on late images. A significant correlation was observed between TDS (both SES and SLS) and QRS duration, with SLS showing an excellent correlation (SES: r = 0.554, P < 0.001; SLS: r = 0.779, P < 0.0001).

Conclusions

These findings suggest that in DCM patients with LBBB, hypoperfusion and myocardial damage in the septum might occur in accordance with an increase in the QRS duration.     

Bone marrow oedema on MR imaging indicates ARCO stage 3 disease in patients with AVN of the femoral head

Objectives

To test the hypothesis that bone marrow oedema (BME) observed on MRI in patients with avascular necrosis (AVN) of the femoral head represents an indicator of subchondral fracture.

Methods

Thirty-seven symptomatic hips of 27 consecutive patients (53 % women, mean age 49.2) with AVN of the femoral head and associated BME on magnetic resonance (MR) imaging were included. MR findings were correlated with computed tomography (CT) of the hip and confirmed by histopathological examination of the resected femoral head. Imaging studies were analysed by two radiologists with use of the ARCO classification.

Results

On MR imaging a fracture line could be identified in 19/37 (51 %) cases, which were classified as ARCO stage 3 (n?=?15) and stage 4 (n?=?4). The remaining 18/37 (49 %) cases were classified as ARCO stage 2. However, in all 37/37 (100 %) cases a subchondral fracture was identified on CT, indicating ARCO stage 3/4 disease. The extent of subchondral fractures and the femoral head collapse was graded higher on CT as compared to MRI (P?Histopathological analysis confirmed bone necrosis and subchondral fractures.

Conclusions

In patients with AVN, BME of the femoral head represents a secondary sign of subchondral fracture and thus indicates ARCO stage 3 disease.

Key Points

? BME on MRI in AVN of femoral head indicates a subchondral fracture. ? BME in AVN of the femoral head represents ARCO stage 3/4 disease. ? CT identifies subchondral fractures and femoral head collapse better than MR imaging. ? This knowledge helps to avoid understaging and to trigger adequate treatment.     

Assessment of in vivo loading history of the patellofemoral joint: a study combining patellar position,tilt, alignment and bone SPECT/CT

Purpose

The current study investigates whether patella height and tilt or leg alignment influence the intensity values as well as the distribution pattern of single photon emission computerized tomography/computerized tomography (SPECT/CT) tracer uptake in the patellofemoral joint.

Methods

99mTc-HDP-SPECT/CT and radiographs of consecutive 84 knees were prospectively obtained. Lateral radiographs were analyzed in terms of patellar height, Insall-Salvati index and modified Insall-Salvati index. Skyline views were analyzed for Laurin’s lateral patellofemoral angle. On long-leg radiographs, the mechanical leg alignment was classified as varus, valgus or neutral. SPECT/CT was analyzed for each anatomical region using a previously validated SPECT/CT localization and grading algorithm. Mean, standard deviation, minimum and maximum of grading for each area of the localization scheme were recorded. Nonparametric Spearman’s correlations were used to correlate patellar height, lateral patellar angle and leg alignment with the tracer uptake intensity. Chi-square statistics were used for categorical data (p < 0.05).

Results

A patella baja correlated significantly with higher SPECT/CT tracer uptake in all patellar and lateral femoral regions (p < 0.001). A higher lateral patellar tilt correlated significantly with higher tracer uptake in the superior lateral femoral parts and the tibial tubercle. In mechanically varus aligned knees, there was significantly higher SPECT/CT tracer uptake on the medial and in valgus knees on the lateral part of the patellofemoral joint (p < 0.05).

Conclusions

As the intensity and distribution of the SPECT/CT significantly correlated with patella baja and patellar tilt, SPECT/CT might be considered as imaging modality for evaluating patients with patellofemoral disorders and for follow-up of patients after patellofemoral realignment procedures.

Level of evidence

Diagnostic study, Level II.     

Safety of ventilation/perfusion single photon emission computed tomography for pulmonary embolism diagnosis

Purpose

The aim of this management outcome study was to assess the safety of ventilation/perfusion single photon emission computed tomography (V/Q SPECT) for the diagnosis of pulmonary embolism (PE) using for interpretation the criteria proposed in the European Association of Nuclear Medicine (EANM) guidelines for V/Q scintigraphy.

Methods

A total of 393 patients with clinically suspected PE referred to the Nuclear Medicine Department of Brest University Hospital from April 2011 to March 2013, with either a high clinical probability or a low or intermediate clinical probability but positive D-dimer, were retrospectively analysed. V/Q SPECT were interpreted by the attending nuclear medicine physician using a diagnostic cut-off of one segmental or two subsegmental mismatches. The final diagnostic conclusion was established by the physician responsible for patient care, based on clinical symptoms, laboratory test, V/Q SPECT and other imaging procedures performed. Patients in whom PE was deemed absent were not treated with anticoagulants and were followed up for 3 months.

Results

Of the 393 patients, the prevalence of PE was 28 %. V/Q SPECT was positive for PE in 110 patients (28 %) and negative in 283 patients (72 %). Of the 110 patients with a positive V/Q SPECT, 78 (71 %) had at least one additional imaging test (computed tomography pulmonary angiography or ultrasound) and the diagnosis of PE was eventually excluded in one patient. Of the 283 patients with a negative V/Q SPECT, 74 (26 %) patients had another test. The diagnosis of PE was finally retained in one patient and excluded in 282 patients. The 3-month thromboembolic risk in the patients not treated with anticoagulants was 1/262: 0.38 % (95 % confidence interval 0.07–2.13).

Conclusion

A diagnostic management including V/Q SPECT interpreted with a diagnostic cut-off of “one segmental or two subsegmental mismatches” appears safe to exclude PE.     

Ultrafast cone-beam computed tomography imaging and postprocessing data during image-guided therapeutic practice

Objective

Our objective was to evaluate ultrafast cone-beam computed tomography (u-CBCT) image data using cross-sectional images, perfusion blood volume (PBV), and image fusion during tumour detection at the course of transarterial chemoembolization.

Methods

One hundred and fifty patients (63?±?20 years; 33–82) were examined from February to October 2013 with u-CBCT. Tumour delineation and conspicuity were determined using u-CBCT cross-sectional PBV and u-CBCT-magnetic resonance imaging (MRI) fused data sets for hyperenhanced (HYET), heterogeneously enhanced (HEET), and unenhanced (UET) tumour categories. Catheter localisation and tumour feeding vessels were assessed using all data sets. Quantitative and qualitative analyses were performed using appropriate statistical tests.

Result

Qualitative and quantitative tumour delineation showed significant difference (all P?P?P?Conclusion Tumour delineation was clearly possible using u-CBCT cross sections with contrast material. PBV uses color-coded images to increase detection and produces good tumour differentiation. Image fusion helps accurately identify tumour and feeding vessels and locate contrast material injection sites and catheter tips without additional data acquisition.

Key points

? Ultrafast CBCT cross-sectional data provide good tumour delineation with contrast material ? Postprocessed PBV using u-CBCT increased detectability and tumour differentiation ? u-CBCT cross-sectional PBV and u-CBCT-MRI data helps image guidance during chemoembolization ? u-CBCT-MRI can identify tumours and feeding vessels and locate catheter tip accurately     

Performance of 18F-FDG PET/CT as a postoperative surveillance imaging modality for asymptomatic advanced gastric cancer patients

Objective

The purpose of this study was to investigate the diagnostic performance of postoperative fluorine-18 fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) as a surveillance modality for advanced gastric cancer patients who were asymptomatic and negative by conventional follow-up.

Methods

We retrospectively collected 46 advanced gastric cancer patients who received approximately 1-year-postoperative ¹⁸F-FDG PET/CT surveillance following curative resection (mean age 60.6 ± 11.5 years). ¹⁸F-FDG PET/CT was interpreted by nuclear medicine physicians who were blind to the clinical information. Final confirmation was determined by clinical follow-up using tumor markers, conventional CT scan, upper gastrointestinal endoscopy and with/without subsequent histopathologic diagnosis.

Results

Four patients developed recurrence (8.7 %; 1 local and 3 distant recurrences). For local recurrence, ¹⁸F-FDG PET/CT found four hypermetabolic lesions and one was local recurrence. For distant recurrence, seven hypermetabolic lesions were found in six patients and true-positive was three lesions. False-positive cases were mainly turned out to be physiologic small bowel uptake. Regardless of the recurrence site, the sensitivity, specificity, positive predictive value and negative predictive value of ¹⁸F-FDG PET/CT were 100 % (4/4, 95 % confidence interval (CI) 39.6–100 %), 88.1 % (37/42, 95 % CI 73.6–95.5 %), 44.4 % (4/9, 95 % CI 15.3–77.3 %) and 100 % (37/37, 95 % CI 88.3–100 %), respectively in the patient-based analysis.

Conclusion

Our study showed good specificity of postoperative surveillance ¹⁸F-FDG PET/CT for detecting recurrence. Careful caution should be made for interpreting some false-positive hypermetabolic lesions in postoperative ¹⁸F-FDG PET/CT, especially at the local anastomosis site.     

Methods for measuring the renal uptake rate of99mTc-dimercaptosuccinic acid (DMSA) : a comparative study

A comparative study of the renal uptake rate of^99mTc-dimercaptosuccinic acid (DMSA) was performed using a phantom study and clinical data from 100 patients (200 kidneys) with a variety of renal diseases. The measurement methods for renal uptake rate studied here include a posterior-view method, a conjugate-view method, and a method using single photon emission computed tomography (SPECT). The renal uptake rates obtained by the posterior-view method significantly (P<0.001) depended on kidney depth correction. With the SPECT method, the cut-off level for delineating the kidney was changed according to the background count ratio using the results of the phantom study. The renal uptake rates obtained by the SPECT method correlated significantly (P<0.001) with those obtained by other methods, and there were no significant differences as compared with those obtained by the conjugate-view method. An analysis of error with the above methods indicated that the error relating to the sensitivity to body thickness was smallest for the SPECT method and greatest for the posterior-view method. In terms of measurement of renal uptake rate only, the conjugate-view method is considered the most useful because it needs no kidney depth correction and requires very little additional effort or examination time.     

A randomized study of the effect of carbonated water prior to myocardial SPECT

Objective

In myocardial perfusion single-photon emission computed tomography (SPECT), abdominal activity often interferes with the evaluation of perfusion in the inferior wall, especially after pharmacological stress. In this randomized study, we examined the effect of carbonated water intake versus still water intake on the quality of images obtained during myocardial perfusion images (MPI) studies.

Methods

A total of 467 MIBI studies were randomized into a carbonated water group and a water group. The presence of intestinal activity adjacent to the inferior wall was evaluated by two observers. Furthermore, a semi-quantitative analysis was performed in the adenosine subgroup, using a count ratio of the inferior myocardial wall and adjacent abdominal activity.

Results

The need for repeated SPECT in the adenosine studies was 5.3 % in the carbonated water group versus 19.4 % in the still water group (p = 0.019). The inferior wall-to-abdomen count ratio was significantly higher in the carbonated water group compared to the still water group (2.11 ± 1.00 vs. 1.72 ± 0.73, p < 0.001). The effect of carbonated water during rest and after exercise was not significant.

Conclusions

This randomized study showed that carbonated water significantly reduced the interference of extra-cardiac activity in adenosine SPECT MPI.     

Postnephrectomy pseudoaneurysm with arteriovenous fistula

Sonography detected a paraaortic pulsatile tubular mass in a patient 10 years after “stump” nephrectomy, which was subsequently confirmed as a renal artery-renal vein fistula by computed tomography, angiography, and laparotomy.     

Congenital cystic lung disease: prenatal ultrasound and postnatal multidetector computer tomography evaluation. Correlation with surgical and pathological data

Purpose

The aim of this study was to evaluate the diagnostic accuracy of postnatal multidetector computed tomography (MDCT) compared with prenatal ultrasound (US), surgical findings, and histology, in 33 patients with congenital cystic lung disease.

Methods

Thirty-three patients, 17 males and 16 females, were evaluated by MDCT. Twenty-seven of these patients underwent prenatal US between week 18 and 22, and between week 32 and 35 of gestation. Lung lobectomy, segmentectomy, atypical resection, lesion resection were performed in 31 patients and surgical specimens were analysed.

Results

Prenatal US and MDCT correctly diagnosed 76.9 and 94 % of the lesions, respectively. Disagreement occurred in six lesions with prenatal US and in two lesions with MDCT. No statistically significant differences were observed between the two techniques (P = 0.122).

Conclusions

As most surgeons consider the surgical resection of these lesions mandatory, our study underscores the essential role of imaging, in particular CT, in providing invaluable preoperative information on congenital cystic lung diseases recognised in uterus.     

Role of [18F]FDG PET in prediction of KRAS and EGFR mutation status in patients with advanced non-small-cell lung cancer

Purpose

The tumour molecular profile predicts the activity of epidermal growth factor receptor (EGFR) inhibitors in non-small-cell lung cancer (NSCLC). However, tissue availability and tumour heterogeneity limit its assessment. We evaluated whether [¹⁸F]FDG PET might help predict KRAS and EFGR mutation status in NSCLC.

Methods

Between January 2005 and October 2011, 340 NSCLC patients were tested for KRAS and EGFR mutation status. We identified patients with stage III and IV disease who had undergone [¹⁸F]FDG PET/CT scanning for initial staging. SUVpeak, SUVmax and SUVmean of the single hottest tumour lesions were calculated, and their association with KRAS and EGFR mutation status was assessed. A receiver operator characteristic (ROC) curve analysis and a multivariate analysis (including SUVmean, gender, age and AJCC stage) were performed to identify the potential value of [¹⁸F]FDG PET/CT for predicting KRAS mutation.

Results

From 102 patients staged using [¹⁸F]FDG PET/CT, 28 (27 %) had KRAS mutation (KRAS+), 22 (22 %) had EGFR mutation (EGFR+) and 52 (51 %) had wild-type KRAS and EGFR profiles (WT). KRAS+ patients showed significantly higher [¹⁸F]FDG uptake than EGFR+ and WT patients (SUVmean 9.5, 5.7 and 6.6, respectively; p?18F]FDG uptake between EGFR+ patients and WT patients. ROC curve analysis for KRAS mutation status discrimination yielded an area under the curve of 0.740 for SUVmean (p?Conclusion NSCLC patients with tumours harbouring KRAS mutations showed significantly higher [¹⁸F]FDG uptake than WT patients, as assessed in terms of SUVpeak, SUVmax and SUVmean. A multivariate model based on age, gender, AJCC stage and SUVmean might be used as a predictive marker of KRAS mutation status in patients with stage III or IV NSCLC.     

Nuclear myocardial perfusion imaging with a cadmium–telluride semiconductor detector gamma camera in patients with acute myocardial infarction

Objective

Since myocardial perfusion imaging (MPI) with conventional sodium iodine (NaI) device has low spatial resolution, there have been some cases in which small structures such as non-transmural myocardial infarction could not be properly detected. The purpose of this study was to evaluate potential usefulness of cadmium–telluride (CdTe) semiconductor detector-based high spatial resolution gamma cameras in detecting myocardial infarction sites, especially non-transmural infarction.

Methods

A total of 38 patients (mean age ± SD: 64 ± 21 year) who were clinically diagnosed with acute myocardial infarction were included. Twenty-eight cases of them were with ST segment elevation myocardial infarction (STEMI) and 10 cases with non-ST segment elevation myocardial infarction (NSTEMI). In all patients, myocardial perfusion single photon emission computed tomography images were acquired with Infinia (NaI device) and R1-M (CdTe device), and the images were compared concerning the detectability of acute myocardial infarction sites.

Results

The detection rates of the myocardial infarction site in cases with STEMI were 100 % both by NaI and CdTe images. In cases with NSTEMI, detection rate by NaI images was 50 %, while that of CdTe images was 100 % (p = 0.033). The summed rest score (SRS) value derived from CdTe images was significantly higher than that from NaI images in cases with STEMI [NaI images: 12 (7–18) versus CdTe images: 14 (9–20)] (p < 0.001). SRS derived from CdTe images was significantly higher than that derived from NaI images in cases with NSTEMI [NaI images: 2 (0–5) versus CdTe images: 6 (6–8)] (p = 0.006).

Conclusions

These results indicate that MPI using CdTe-semiconductor device will provide a much more accurate assessment of acute myocardial infarction in comparison to current methods.     

Perfusion-metabolism coupling in recurrent gliomas: a prospective validation study with 13N-ammonia and 18F-fluorodeoxyglucose PET/CT

Introduction

We assessed the validity of “perfusion-metabolism coupling” hypothesis in recurrent glioma with ¹³N-ammonia (¹³N-NH₃) PET/CT and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/CT.

Methods

Fifty-six consecutive patients (age, 38.8?±?12.1 years; 62.5 % males) with histologically proven and previously treated glioma presenting with clinical suspicion of recurrence were prospectively enrolled and evaluated with ¹³N-NH₃ PET/CT and ¹⁸F-FDG PET/CT. PET/CT images were evaluated both qualitatively and semiquantitatively. Tumor to white matter uptake ratio (T/W) and tumor to gray matter uptake ratio (T/G) were calculated and analyzed for both the modalities. A combination of clinico-radiological follow-up, repeated imaging, and biopsy (when available) were considered as the reference standard.

Results

Based on the reference standard, 27/56 patients had recurrence. ¹³N-NH₃ PET/CT and ¹⁸F-FDG PET/CT were concordant in 55/56 patients. Overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ¹³N-NH₃PET/CT were 77.8, 86.2, 84.0, 80.7, and 82.1 %, respectively, and for ¹⁸F-FDG PET/CT were 77.8, 89.7, 87.5, 81.2, and 83.9 %, respectively. There was excellent agreement between results of ¹³N-NH₃ PET/CT and ¹⁸F-FDG PET/CT (??=?0.964; P?13N-NH₃ PET/CT and ¹⁸F-FDG PET/CT were not significantly different between high-grade and low-grade glioma (P?=?1.000). A strong positive correlation was noted between the uptake ratios derived on the two modalities (ρ?=?0.866, P?ρ?=?0.918, P?Conclusion A combination of ¹³N-NH₃ PET/CT and ¹⁸F-FDG PET/CT demonstrates that perfusion and metabolism are coupled in recurrent gliomas. These tracers target two different but interrelated aspects of the same pathologic process and can be used as surrogates for each other.