Radiologic Progression of Interstitial Lung Abnormalities following Surgical Resection in Patients with Lung Cancer.

In this study, we aimed to assess the prevalence of interstitial lung abnormalities (ILAs) and investigate the rates and risk factors associated with radiologic ILA progression among patients with lung cancer following surgical resection. Patients who underwent surgical resection for lung cancer at our institution from January 2015 to December 2020 were retrospectively evaluated and grouped according to their ILA status as having no ILAs, equivocal ILAs, or ILAs. Progression was determined by simultaneously reviewing the baseline and corresponding follow-up computed tomography (CT) scans. Among 346 patients (median age: 67 (interquartile range: 60-74) years, 204 (59.0%) men), 22 (6.4%) had equivocal ILAs, and 33 (9.5%) had ILAs detected upon baseline CT. Notably, six patients (6/291; 2.1%) without ILAs upon baseline CT later developed ILAs, and 50% (11/22) of those with equivocal ILAs exhibited progression. Furthermore, 75.8% (25/33) of patients with ILAs upon baseline CT exhibited ILA progression (76.9% and 71.4% with fibrotic and non-fibrotic ILAs, respectively). Multivariate analysis revealed that ILA status was a significant risk factor for ILA progression. ILAs and equivocal ILAs were associated with radiologic ILA progression after surgical resection in patients with lung cancer. Hence, early ILA detection can significantly affect clinical outcomes.

Diagnostic Accuracy and Complication of Computed Tomography (CT)-Guided Percutaneous Transthoracic Lung Biopsy in Patients 80 Years and Older.

This research evaluated the diagnostic accuracy and complication rate of computed tomography (CT)-guided percutaneous transthoracic lung biopsy (PTNB) in patients 80 years and older. The study sought to identify risk factors for diagnostic failures or complications of PTNBs. We examined 247 CT-guided PTNBs performed from January 2017 through December 2020, noting patient demographics, lesion or procedure types, pathology reports, and other procedure-related complications. Study groups were divided into two: one with patients aged 80 years and older (Group 1) and the other with patients aged 60 to 80 years (Group 2). The research first determined each groups' diagnostic accuracy, sensitivity, specificity, diagnostic failure rate, and complication rate and then evaluated the risk factors for diagnostic failures and complications. The diagnostic accuracy, sensitivity, specificity, and diagnostic failure rates were 95.6%, 94.9%, 100%, and 18.9%, respectively, in Group 1. The overall and major complication rates in Group 1 were 29.6% and 3.7%, respectively. Lesion size was the only risk factor for diagnostic failure (adjusted odds ratio [OR], 0.46; 95% confidence interval [CI], 0.24-0.90). There was no significant risk factor for complications in Group 1. CT-guided PTNBs in patients 80 years and older indicate comparable diagnostic accuracy and complication rates.

Diagnostic performance of static single-scan stress perfusion cardiac computed tomography in detecting hemodynamically significant coronary artery stenosis: a comparison with combined invasive coronary angiography and cardiovascular magnetic resonance-myocardial perfusion imaging.

Background Non-invasive anatomical and physiological evaluations of coronary artery disease (CAD) may be obtained with static single-scan stress perfusion cardiac computed tomography (SSPCT). Purpose To determine the diagnostic performance of static SSPCT for identifying hemodynamically significant CAD. Material and Methods This prospective study included 29 patients with suspected or known CAD who underwent static SSPCT, cardiovascular magnetic resonance myocardial perfusion imaging (CMR-MPI), and invasive coronary angiography (ICA). CT was performed as follows: (i) coronary calcium scan; (ii) static SSPCT for both coronary artery (coronary CT angiography [CCTA]) and myocardial perfusion (perfusion CT [PCT]) during adenosine infusion; (iii) late-phase scan. The diagnostic performance of CCTA alone, PCT alone, and SSPCT for the detection of a hemodynamically significant CAD (a perfusion defect in a vascular territory subtended by a coronary vessel with ≥ 50% stenosis) was compared with that of combined ICA/CMR-MPI representing the standard of reference. Results Twenty-three (79%) patients and 47 (54%) vascular territories manifested ischemia-causing coronary stenoses by combined ICA/CMR-MPI. The per-vessel sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC) of the SSPCT were 92%, 88%, 90%, 90%, and 0.90, respectively, compared to those of the combined ICA/CMR-MPI. These values for the CCTA alone were 96%, 63%, 75%, 93%, and 0.79, respectively; and the values for the PCT alone were 94%, 83%, 86%, 92%, and 0.88, respectively. The AUC of SSPCT was significantly ( P = 0.013) higher than that of the CCTA alone. Conclusion Static SSPCT may facilitate detection of hemodynamically significant CAD.

Diagnostic Performance of Coronary CT Angiography, Stress Dual-Energy CT Perfusion, and Stress Perfusion Single-Photon Emission Computed Tomography for Coronary Artery Disease: Comparison with Combined Invasive Coronary Angiography and Stress Perfusion Cardiac MRI.

OBJECTIVE: To investigate the diagnostic performance of coronary computed tomography angiography (CCTA), stress dual-energy computed tomography perfusion (DE-CTP), stress perfusion single-photon emission computed tomography (SPECT), and the combinations of CCTA with myocardial perfusion imaging (CCTA + DE-CTP and CCTA + SPECT) for identifying coronary artery stenosis that causes myocardial hypoperfusion. Combined invasive coronary angiography (ICA) and stress perfusion cardiac magnetic resonance (SP-CMR) imaging are used as the reference standard. MATERIALS AND METHODS: We retrospectively reviewed the records of 25 patients with suspected coronary artery disease, who underwent CCTA, DE-CTP, SPECT, SP-CMR, and ICA. The reference standard was defined as ≥ 50% stenosis by ICA, with a corresponding myocardial hypoperfusion on SP-CMR. RESULTS: For per-vascular territory analysis, the sensitivities of CCTA, DE-CTP, SPECT, CCTA + DE-CTP, and CCTA + SPECT were 96, 96, 68, 93, and 68%, respectively, and specificities were 72, 75, 89, 85, and 94%, respectively. The areas under the receiver operating characteristic curve (AUCs) were 0.84 ± 0.05, 0.85 ± 0.05, 0.79 ± 0.06, 0.89 ± 0.04, and 0.81 ± 0.06, respectively. For per-patient analysis, the sensitivities of CCTA, DE-CTP, SPECT, CCTA + DE-CTP, and CCTA + SPECT were 100, 100, 89, 100, and 83%, respectively; the specificities were 14, 43, 57, 43, and 57%, respectively; and the AUCs were 0.57 ± 0.13, 0.71 ± 0.11, 0.73 ± 0.11, 0.71 ± 0.11, and 0.70 ± 0.11, respectively. CONCLUSION: The combination of CCTA and DE-CTP enhances specificity without a loss of sensitivity for detecting hemodynamically significant coronary artery stenosis, as defined by combined ICA and SP-CMR.

Differences in Aortic Valve and Left Ventricular Parameters Related to the Severity of Myocardial Fibrosis in Patients with Severe Aortic Valve Stenosis.

OBJECTIVE: This study investigated the morphological and functional characteristics of the aortic valve and the left ventricular (LV) systolic functional parameters and myocardial mass related to the severity of myocardial fibrosis (MF) in patients with severe aortic valve stenosis (AS). MATERIALS AND METHODS: We retrospectively enrolled 81 patients (48 men; mean age: 59±12 years) with severe AS who underwent transthoracic echocardiography (TTE), cardiac computed tomography (CCT), and cardiovascular magnetic resonance (CMR) within 1 month and subsequent aortic valve surgery. Degree of MF was determined on delayed contrast-enhanced CMR with visual sub-segmental analysis-based quantification and was classified into three groups (no, mild, and severe) for identifying the differences in LV function and characteristics of the aortic valve. One-way ANOVA, Chi-square test or Fisher's exact test were used to compare variables of the three groups. Univariate multinomial logistic regression analysis was performed to determine the association between the severity of MF and variables on imaging modalities. RESULTS: Of 81 patients, 34 (42%) had MF (mild, n = 18; severe, n = 16). Aortic valve calcium volume score on CCT, aortic valve area, LV mass index, LV end-diastolic volume index on CMR, presence of mild aortic regurgitation (AR), transaortic mean pressure gradient, and peak velocity on TTE were significantly different among the three groups and were associated with severity of MF on a univariate multinomial logistic regression analysis. Aortic valve calcium grade was different (p = 0.008) among the three groups but not associated with severity of MF (p = 0.375). CONCLUSIONS: A multi-imaging approach shows that severe AS with MF is significantly associated with more severe calcific AS, higher LV end-diastolic volume, higher LV mass, and higher prevalence of mild AR.

Indirect CT Venography at 80 kVp with Sinogram-Affirmed Iterative Reconstruction Compared to 120 kVp with Filtered Back Projection: Assessment of Image Quality and Radiation Dose.

OBJECTIVE: To evaluate the image quality and radiation dose of indirect computed tomographic venography (CTV) using 80 kVp with sinogram-affirmed iterative reconstruction (SAFIRE) and 120 kVp with filtered back projection (FBP). MATERIALS AND METHODS: This retrospective study was approved by our institution and informed consent was waived. Sixty-one consecutive patients (M: F = 27: 34, mean age 60 ± 16, mean BMI 23.6 ± 3.6 kg/m2) underwent pelvic and lower extremity CTVs [group A (n = 31, 120 kVp, reconstructed with FBP) vs. group B (n = 30, 80 kVp, reconstructed with SAFIRE)]. The vascular enhancement, image noise, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were compared. Subjective image analysis for image quality and noise was performed by two radiologists. Radiation dose was compared between the two groups. RESULTS: Compared with group A, higher mean vascular enhancement was observed in the group B (group A vs. B, 118.8 ± 15.7 HU vs. 178.6 ± 39.6 HU, p < 0.001), as well as image noise (12.0 ± 3.8 HU vs. 17.9 ± 6.1 HU, p < 0.001) and CNR (5.1 ± 1.9 vs. 7.6 ± 3.0, p < 0.001). The SNRs were not significantly different in both groups (11.2 ± 4.8 vs. 10.8 ± 3.7, p = 0.617). There was no significant difference in subjective image quality between the two groups (all p > 0.05). The subjective image noise was higher in the group B (p = 0.036 in reader 1, p = 0.005 in reader 2). The inter-observer reliability for assessing subjective image quality was good (ICC 0.746~0.784, p < 0.001). The mean CT dose index volume (CTDIvol) and mean dose length product (DLP) were significantly lower in group B than group A [CTDIvol, 6.4 ± 1.3 vs. 2.2 ± 2.2 mGy (p < 0.001); DLP, 499.1 ± 116.0 vs. 133.1 ± 45.7 mGy × cm (p < 0.001)]. CONCLUSIONS: CTV using 80 kVp combined with SAFIRE provides lower radiation dose and improved CNR compared to CTV using 120 kVp with FBP.

Color radiography in lung nodule detection and characterization: comparison with conventional gray scale radiography.

BACKGROUND: To compare the capability of lung nodule detection and characterization between dual-energy radiography with color-representation (DCR) and conventional gray scale chest radiography (GSR). METHODS: A total of 130 paired chest radiographs (DCR and GSR) obtained from 65 patients (14 with normal scans and 51 with pulmonary nodules) were evaluated. After analysis, 45 non-calcified and 21 calcified nodules were identified. DCR was obtained by adding color space within material-decomposed data (blue for high attenuation and red for low attenuation) and by compounding the manipulated data to one color image. Three radiologists marked suggested nodules on radiographic images and assessed the level of confidence of lesion presence and probability of nodule calcification by using a nine-point rating scale. The jackknife active free-response receiver operating characteristics (JAFROC) analysis was used to evaluate lesion detectability, and multi-reader multi-case receiver operating characteristics (MRMC ROC) analysis was used for the evaluation of the accuracy of nodule calcification prediction. RESULTS: Figures of merit (FOM) from JAFROC was 0.807 for DCR and 0.811 for GSR, respectively; nodule detectability was not significantly different between DCR and GSR (p = 0.93). Areas under curve (AUC) from MRMC ROC were 0.944 for DCR and 0.828 for GSR, respectively; performance of DCR in predicting lung nodule calcification was significantly higher than that of GSR (p = 0.04). CONCLUSIONS: DCR showed similar performance in terms of lung nodule detection compared with GSR. However, DCR does provide a significant benefit in predicting the presence of nodule calcification.

Virtual Non-Contrast CT Using Dual-Energy Spectral CT: Feasibility of Coronary Artery Calcium Scoring.

OBJECTIVE: To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. MATERIALS AND METHODS: This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses. RESULTS: Coronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Measured coronary calcium volumes from VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Among the three VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p < 0.001 for all pairs). CONCLUSION: The use of VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC.

Indeterminate pulmonary nodules in colorectal cancer.

AIM: To investigate the clinicopathologic parameters of pulmonary metastasis in colorectal cancer (CRC) patients after lung operation of indeterminate pulmonary nodules (IPNs). METHODS: From a prospective database of CRC patients, 40 cases that underwent lung operation between November 2008 and December 2012 for suspicious metastatic pulmonary nodules on chest computed tomography (CT) were enrolled. The decision to perform a lung operation was made if the patient met the following criteria: (1) completely resected or resectable primary CRC; (2) completely resectable IPNs; (3) controlled or controllable extrapulmonary metastasis; and (4) adequate general condition and pulmonary function to tolerate pulmonary operation. Lung operation was performed by a thoracic surgeon without CT-guided biopsy for pathologic confirmation. RESULTS: A total of 40 cases of lung resection was performed in 29 patients. Five patients underwent repeated lung resection. The final pathology result showed metastasis from the CRC in 30 cases (75%) and benign pathology in 10 cases (25%). The primary tumor site was the rectum in 26/30 (86.6%) cases with pulmonary metastasis, but only 3/10 (30%) cases in the benign group had a primary rectal cancer (P = 0.001). Positron emission tomography (PET)-CT was performed for 22/30 (73.4%) patients in the lung metastasis group and for 6/10 (60.0%) patients in the benign group. PET-CT revealed hot uptake of (18)fluorine 2-fluoro-2-deoxy-D-glucose with all IPNs in both groups. The group with pulmonary metastasis had a higher incidence of primary rectal cancer (P = 0.001), a more advanced tumor stage (P = 0.011), and more frequent lymphatic invasion of tumor cells (P = 0.005). Six cases with previous liver metastasectomy were present in the lung metastasis group. Serum carcinoembryonic antigen levels before lung operation were not elevated in any of the patients. CONCLUSION: The stage and location of the primary tumor and tumor cell infiltration of lymphatics provide useful indicators for deciding on lung resection of IPNs in CRC.

Detection of skeletal muscle metastasis: torso FDG PET-CT versus contrast-enhanced chest or abdomen CT.

BACKGROUND: Skeletal muscle metastasis (SMM) in cancer patients has not been sufficiently evaluated regarding prevalence and proper method of detection. PURPOSE: To determine the prevalence of SMM and compare the diagnostic competencies for SMM of torso F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) and contrast-enhanced chest or abdomen CT. MATERIAL AND METHODS: We investigated 18,225 PET-CT studies of 6359 cancer patients performed from 2005 to 2012. The PET-CT studies describing potential SMM were retrieved and the corresponding medical records were reviewed. The gold standard for SMM was histopathologically-proven SMM or imaging study-based disease progression. The detectability of SMM was compared between PET-CT and contrast-enhanced CT. RESULTS: Twenty-six patients had 84 SMM lesions, representing a SMM prevalence of 0.41%. Lung cancer was the most common SMM-associated malignancy (54%) and the gluteal/pelvic girdle muscle was the most frequently involved SMM site (37%). All 84 SMM lesions were visualized on PET-CT (100%). Of these PET-CT positive 84 SMM lesions, 51 lesions were in the CT field of view (FOV) (61%), whereas 33 lesions were out of the CT FOV (39%). Among these 51 lesions, 17 lesions showed rim-enhancing nodules/masses (33%), eight lesions showed homogeneously enhancing nodules (16%), three lesions showed heterogeneously enhancing nodules (6%), and 23 SMM lesions (45%) were non-diagnostic by CT. All 51 SMM lesions within CT FOV were detected on PET-CT (100%), whereas only 28 were visualized on CT (54.9%), resulting in a significant difference (P < 0.005). On average, 2.6 more organs with concomitant metastases were found when SMM was revealed by PET-CT. CONCLUSION: The prevalence of SMM was as low as 0.41% in the current large cohort of cancer patients. Torso PET-CT was a more competent modality than contrast-enhanced CT in the detection of SMM.

Acute coccydynia related to precoccygeal calcific tendinitis.

Symptomatic deposits of calcium hydroxyapatite have been reported in various sites other than the shoulders or hips. Sudden-onset coccydynia can lead to the discovery of calcific deposition in the precoccygeal region. We present the case of precoccygeal calcific tendinitis in a patient with acute coccydynia.

Sonography of acute right lower quadrant pain: importance of increased intraabdominal fat echo.

OBJECTIVE: The purpose of our study was to assess the diagnostic usefulness of increased intraabdominal fat echo during the sonographic evaluation of patients with acute right lower quadrant (RLQ) pain. SUBJECTS AND METHODS: A total of 328 consecutive patients (132 male and 196 female; mean age, 28+/-15 [SD] years) with acute RLQ pain prospectively underwent transabdominal sonography by one of three experienced radiologists. The radiologists prospectively graded intraabdominal fat echo using a 3-point scale: 1, normal; 2, slight increase; and 3, marked and diffuse increase. Final diagnoses were made using surgical or pathologic findings or by clinical follow-up. Of the 328 patients, 11 were lost to follow-up and excluded from analysis. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of increased intraabdominal fat echo were calculated for a positive final diagnosis. RESULTS: Final diagnoses were negative (n=103), acute appendicitis (n=137), right colonic diverticulitis (n=18), mesenteric lymphadenitis (n=13), enteritis (n=26), and others (n=20). Grades of intraabdominal fat echo were grade 1 (n=158), grade 2 (n=35), and grade 3 (n=124). Overall, fat echo grades 2 or 3 were more frequently observed in patients with a positive final diagnosis (73% [157/214] vs 2% [2/103], p<0.001) than in those with a negative final diagnosis. Sensitivity, specificity, accuracy, PPV, and NPV of increased intraabdominal fat echo for a positive final diagnosis were 73%, 98%, 81%, 99%, and 64%. Increased intraabdominal fat echo was documented in 89% (122/137) of cases of acute appendicitis and in 100% (18/18) of cases of right colonic diverticulitis. CONCLUSION: An increased intraabdominal fat echo on sonography is highly specific for the presence of RLQ inflammatory disease.

Chest CT of incidental breast lesions.

Chest computed tomography (CT) is routinely used for the evaluation of diseases of the chest involving the lung, mediastinum, pleura, chest wall, and diaphragm. Benign and malignant breast lesions are not uncommonly encountered incidentally on chest CT. The chest CT radiologist should be aware of the different breast pathologies and their CT appearances as some can be diagnosed by chest CT, whereas others, such as breast cancer, should not be overlooked. The purpose of this pictorial essay is to show various common and uncommon breast conditions encountered while interpreting chest CT scans in our daily practice.

Fluoroscopy-guided transurethral removal and exchange of ureteral stents in female patients: technical notes.

PURPOSE: To describe simple and safe techniques for transurethral removal and for exchange of ureteral stents in female patients under fluoroscopic guidance. MATERIALS AND METHODS: During a period of 33 months, the authors removed 4 and exchanged 34 double-J ureteral stents in 17 female patients. Four techniques were implemented to remove or exchange these stents: simple snare technique, modified snare technique, guide-wire lasso technique, and direct grasping technique. RESULTS: All stents were either exchanged or removed successfully. The average time elapsed per procedure was 21.5 minutes. Simple snare techniques were used with 19 (50%) stents, and modified snare techniques were used with 13 (34%) stents where grasping the tip of a stent was not possible with the snare alone. Lasso and direct grasping techniques were each used with three (8%) stents. Self-limited microscopic hematuria was observed in all subjects after the procedure, but none reported gross hematuria. CONCLUSIONS: Fluoroscopy-guided transurethral removal and exchange of ureteral stents is a safe and effective procedure, and it can be considered as an alternative to cystoscopic removal and exchange.

Comparison of cystographic findings of intrinsic sphincteric deficiency with urethral hypermobility causing urinary incontinence.

OBJECTIVES: To evaluate the usefulness of standing and lateral cystograms for differentiation of intrinsic sphincter deficiency (ISD) from urethral hypermobility (UH) causing stress urinary incontinence (SUI). MATERIALS AND METHODS: 67 female patients with urinary incontinence undergoing measurement of the Valsalva leak point pressure (VLPP) were included. 14 patients with VLPP <60 cm H2O were operated for ISD causing SUI while 53 patients with VLPP >100 cm H2O were operated for UH causing SUI. Three radiologists compared the cystographic findings. RESULTS: The changes in posterior urethrovesical angle (PUVA) between stress and resting states were 12 +/- 7.5 degrees in ISD causing SUI and 32.8 +/- 12.7 degrees in UH causing SUI, and showed a statistically significant difference (p < 0.01). The beaking signs of the vesical neck on anteroposterior (AP) projection of the cystogram during a resting state were seen in 76% of ISD causing SUI. The difference was also statistically significant (p < 0.01). The existence of cystocele or the mean PUVA in two groups did not show a statistically significant difference. CONCLUSION: ISD should be considered in female patients with symptoms of urinary incontinence where there are changes in PUVA <20 degrees on a lateral cystogram between a stress state and resting state in addition to the beaking sign of the vesical neck during a resting state.

Focal uptake of fluorodeoxyglucose by the thyroid in patients undergoing initial disease staging with combined PET/CT for non-small cell lung cancer.

PURPOSE: To retrospectively evaluate the prevalence of focal fluorodeoxyglucose (FDG) uptake by the thyroid gland on combined positron emission tomographic (PET) and computed tomographic (CT) scans in patients undergoing staging of newly diagnosed non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Institutional review board approval was obtained, informed consent was waived, and the study was Health Insurance Portability and Accountability Act-compliant. Whole-body PET/CT scans and medical records of 140 consecutive patients with newly diagnosed NSCLC (80 men, 60 women; mean age, 66 years; range, 39-89 years) were retrospectively reviewed by two experienced PET/CT scan readers. Maximum standardized uptake value (SUV) was calculated for FDG-avid thyroid foci. Corresponding thyroid CT findings were recorded in patients with focal increased FDG thyroid uptake. RESULTS: PET results showed that six patients (4.3%) had seven foci of increased FDG uptake in the thyroid. Five of the seven foci (in four patients) corresponded to a low-attenuation thyroid lesion on the non-enhanced CT scan. Lesions ranged in diameter from 0.8 to 2.5 cm. Four of the lesions were found to be papillary thyroid cancers at fine-needle aspiration biopsy. The fifth lesion was found to be benign at thyroidectomy. The remaining two patients did not have histologic confirmation of their thyroid lesion because no specific biopsy site was visualized on CT or sonographic images and lesions were considered benign. Maximum SUV of the thyroid cancers ranged from 3.0 to 32.9 (mean, 13.7). Maximum SUV of benign thyroid lesions ranged from 4.6 to 6.2 (mean, 5.4). CONCLUSION: Focal thyroid FDG uptake found during the initial staging of NSCLC at PET/CT indicates a high likelihood of primary thyroid cancer.