Prognostic Impact of Minimal Pelvic Fluid in Locally Advanced Pancreatic Cancer: A Multicenter Retrospective Study.

BACKGROUND/AIMS: Minimal pelvic fluid (MPF) is occasionally encountered on computed tomography (CT) scans during the initial staging of newly diagnosed pancreatic cancer. However, its clinical relevance has scarcely been studied. This study intends to explore the incidence of minimal pelvic fluid and its relevance in terms of survival in locally advanced pancreatic cancer (LAPC) patients. MATERIALS AND METHODS: The medical records of patients with LAPC at 4 tertiary referral institutions were retrospectively reviewed from January 2005 to December 2015. Minimal pelvic fluid was defined as a fluid collection volume in the pelvic cavity of <100 mL as determined by abdominal CT. The association between the presence of MPF and patient survival was evaluated. RESULTS: A total of 59 patients (male:female, 33:26; median age, 68 years; range 46-82 years) with LAPC were enrolled. Of the 59 patients, 22.0% (n = 13) had MPF, and 78.0% (n = 46) had no pelvic fluid (NPF). Baseline clinical characteristics in the 2 groups, including extent of the tumor stage, extent of spread to the lymph nodes stage, and pattern of treatments, were not significantly different. However, median overall survival was significantly less in the MPF group [9.7 months, (95% CI, 5.9-13.5)] than in the NPF group as determined by the log-rank test [16.9 months, (95% CI, 9.3-24.5)] (P = .002), and univariate and multivariate analyses showed that the presence of MPF independently predicted a poor prognosis. CONCLUSION: The presence of MPF was found to be significantly associated with reduced survival and an independent poor prognostic biomarker in LAPC patients.

Ectopic vascularization of the right kidney arising from contralateral common iliac artery.

BACKGROUND: Variant renal arteries have been reported in 20~30% of the entire population. The anatomic variations among advanced patients should be investigated when performing surgery or interventional procedures on the kidney. Most variant renal arteries originated from various level of the abdominal aorta. Very rarely, this case shows renal artery originated from the contralateral common iliac artery with other accessory arteries. CASE PRESENTATION: MDCT angiography revealed several anatomical variants of the right kidney. There were four right renal arteries. The main renal artery originated from the left proximal common iliac artery and other renal artery originated from the aortic bifurcation. The other two renal arteries arose from the abdominal aorta, lower thoracic T12 level and lower lumbar L4 level. The right kidney was located at the level of the third to fifth lumbar vertebra. And renal pelvis of the right kidney was laterally rotated. CONCLUSION: This case documented a rare anatomic variant, involving multiple accessory renal arteries, including the main artery originating from the contralateral iliac artery, caused by a specific renal embryological condition. These variants should be analysed to effectively perform surgical and interventional procedures.

The best predictive model for hepatocellular carcinoma in patients with chronic hepatitis B infection.

Chronic hepatitis B (CHB) seriously threatens human health. About 820,000 deaths annually are due to related complications such as hepatitis B and hepatocellular carcinoma (HCC). Recently, the use of oral antiviral agents has significantly improved the prognosis of patients with CHB infection and reduced the risk of HCC. However, hepatitis B virus still remains a major factor in the development of HCC, raising many concerns. Therefore, numerous studies have been conducted to assess the risk of HCC in patients with CHB infection and many models have been proposed to predict the risk of developing HCC. However, as each study has different models for predicting HCC development that can be applied depending on the use of antiviral agents or the type of antiviral agents, it is necessary to properly understand characteristics of each model when using it for the evaluation of HCC in patients with CHB infection. In addition, because different variables such as host factor, viral activity, and cirrhosis are used to evaluate the risk of HCC development, it is necessary to assess the risk by carefully verifying which variables are used. Recently, studies have also evaluated the risk of HCC using risk prediction models through transient elastography and artificial intelligence (AI) system. These HCC risk predication models are also noteworthy. In this review, we aimed to compare HCC risk prediction models in patients with CHB infection reported to date to confirm variables used and specificity between each model to determine an appropriate HCC risk prediction method.

Atypical iliac vein compression in patients with symptomatic May-Thurner syndrome.

PURPOSE: We aimed to investigate the incidence, etiology, treatment, and clinical course of atypical iliac vein compressions (AIVCs) among patients with May-Thurner syndrome (MTS). METHODS: A total of 173 patients who presented with MTS were retrospectively analyzed at a single center. Computed tomographic venography (CTV) was used to diagnose MTS. An AIVC was defined as the compression of the left common iliac vein (LCIV) by structures other than the right common iliac artery (RCIA) or the compression of other venous structures in the pelvic cavity instead of the LCIV. The patients with AIVC were categorized into the LCIV compression group (category A) and non-LCIV compression group (category B). RESULTS: Ten patients with AIVC were identified (5.8%; male/female, 5/5), five in category A and five in category B. The median age of patients was 76 years (range, 51-94 years), and the median follow-up duration was 388 days (range, 12-4694 days). In category A, the LCIVs were compressed by the left common iliac artery (LCIA) (n=2), uterine leiomyoma (n=1), LCIA aneurysm (n=1), and RCIA aneurysm (n=1). In category B, the right common iliac veins were compressed by the RCIA (n=4) and L5 osteophyte (n=1). Endovascular treatment, including balloon angioplasty and stent placement, was performed in six patients, three from each group. Three patients underwent conservative treatment due to their advanced age and comorbidities. Endovascular aneurysm repair was performed in one patient with RCIA aneurysm. Follow-up images were available for six patients, and all of them had patent venous flow. CONCLUSION: The AIVC had an incidence of 5.8% (10/173) among symptomatic MTS patients and wide spectrum of etiologies. Pathogenesis-tailored endovascular treatments are safe and effective.

Characteristics, trend, and methodological quality of systematic reviews and meta-analyses in nuclear medicine: A bibliometric analysis of studies published between 2005 and 2016.

To evaluate the characteristics, trend, and quality of systematic reviews and meta-analyses in nuclear medicine.We performed a PubMed search to identify systematic reviews and meta-analyses published between 2005 and 2016 in the field of nuclear medicine. The following data were extracted: journal name, impact factor, type of study, topics with cancer type, imaging modalities, authors (number, country, affiliation, presence of nuclear medicine specialists and statisticians, discordance between the first and corresponding authors), funding, methodological quality, methods used for quality assessment, and statistical methods.We included 185 nuclear medicine articles. Meta-analyses (n = 164; 88.6%) were published about 7 times more frequently than systematic reviews. Oncology was the most commonly studied topic (n = 125, 67.6%). The first authors were most frequently located in China (n = 73; 39.5%). PET was the most commonly used modality (n = 150; 81.1%). Both the number of authors and the ratio of discordance between the first and corresponding authors tended to progressively increase over time.The mean AMSTAR score increased over time (5.77 in 2005-2008, 6.71 in 2009-2012, and 7.44 in 2013-2016). The proportion of articles with quality assessment increased significantly (20/26 in 2005-2008, 54/65 in 2009-2012, and 79/94 in 2013-2016). The most commonly used assessment tool was quality assessment of diagnostic accuracy studies (n = 85; 54.9%).The number and quality of systematic reviews and meta-analyses in nuclear medicine have significantly increased over the review period; however, the quality of these articles varies. Efforts to overcome specific weaknesses of the methodologies can provide opportunities for quality improvement.

Risk Factors of Amputation in Lower Extremity Trauma with Combined Femoropopliteal Arterial Injury.

PURPOSE: The clinical characteristics and results of femoropopliteal artery injury (FPAI) remain unclear. In this study, we evaluated the outcomes and risk factors of limb loss in patients treated for FPAI. MATERIALS AND METHODS: We retrospectively reviewed data from a database of patients who underwent revascularization for an FPAI at a single institution between January 2013 and December 2017. We reviewed and analyzed the characteristics, postoperative results, and factors that influence amputation rates. RESULTS: Twenty-four femoropopliteal arterial reconstructions in 24 patients were included in this study. Among the patients were 20 (83.3%) male with a first-quartile age of 28 years and a third-quartile age of 45 years (range, 15-68 years). The mean injury severity score (ISS) was 16 (range, 4-55), and 5 patients (20.8%) had ISSs of >20 points. The mean mangled extremity severity score (MESS) was 3.8 (range, 1-11), and 8 patients (33.3%) had MESSs of >5 points. In terms of arterial reconstruction methods, autogenous saphenous vein grafting, vein patching, and primary closure were performed in 9 patients (37.5%), 4 patients (16.7%), and 11 patients (45.8%), respectively. Despite arterial reconstruction, 5 patients (20.8%) underwent above-knee amputation. ISSs of >20, MESSs of >7, and orthopedic fixation were statistically significant factors associated with amputation. CONCLUSION: In cases of FPAI with ISSs of >20, MESSs of >7, and orthopedic fixation, amputations should be considered. We were also careful to attempt limb salvage in such cases.

Impact of subcutaneous tunnels on peripherally inserted catheter placement: a multicenter retrospective study.

OBJECTIVE: To evaluate the impact of subcutaneous tunneling on peripherally inserted central catheter (PICC) placement in terms of central line-associated bloodstream infections (CLABSIs). METHODS: Our dual-facility central institutional review board approved this retrospective study. We compared 302 of 327 consecutive recipients (mean age [± SD], 68.0 ± 15.9 years; men, 134; women, 168) of tunneled PICCs (October 2017 to May 2018) with 309 of 328 consecutive recipients (mean age, 68.7 ± 14.6 years; men, 142; women, 167) of conventional PICCs (April 2016 to September 2017). Tunnels were made near puncture sites (~ 1 in. away) using hemostats or puncture needles. In each group, procedure times and rates of complications, including CLABSI, entry-site infection, dislocation, thrombophlebitis, and occlusion, were examined. Risk factors for CLABSI were analyzed via logistic and Cox regression models. RESULTS: Subcutaneous tunnels were achieved in all patients, enabling successful peripheral vein cannulations. Group procedure times were similar (p = 0.414). CLABSI proved to be significantly less frequent after tunneling (8/6972 catheter-days) than after conventional (28/7574 catheter-days) PICC placement (adjusted hazard ratio = 0.328; 95% confidence interval, 0.149-0.721). Other risk factors (i.e., age, gender, comorbidity, PICC duration, veins, hospital stay, and intensive care unit stay) showed no significant correlations with CLABSI. CONCLUSIONS: Compared with conventional means, a subcutaneous tunneling approach for PICC placement significantly reduces the rate of CLABSI. KEY POINTS: • Subcutaneous tunnels created to place peripherally inserted central catheters significantly reduced catheter-associated bloodstream infections. • Subcutaneous tunnel creation did not significantly prolong procedural time. • There were no subcutaneous tunnel-related complications.

Rhabdomyolysis revisited: Detailed analysis of magnetic resonance imaging findings and their correlation with peripheral neuropathy.

The objective is to evaluate the magnetic resonance imaging (MRI) findings in rhabdomyolysis in detail and determine their correlation with the development of peripheral neuropathy.Magnetic resonance images for 23 patients with confirmed rhabdomyolysis with (n = 11) or without (n = 12) peripheral neuropathy were retrospectively reviewed for the signal intensity on T1- and T2-weighted images, intramuscular hemorrhage, enhancement pattern, shape and margin in the longitudinal plane, edema in the deep fascia and overlying subcutaneous layer, multiplicity, and bilateral limb involvement. The collected data were statistically analyzed and the relationship between the imaging findings and the development of peripheral neuropathy was determined.Abnormal signal intensities on T1- or T2-weighted images were observed for all patients except one. Fourteen patients (60.9%) showed intramuscular hemorrhage. Stippled enhancement (11/23; 47.8%) was the most common enhancement pattern. Nineteen patients (86.4%) showed a well-defined rectangular shape with a ragged margin in the longitudinal plane. The affected muscle volume usually increased (17/23; 73.9%), with edema in the deep fascia and the overlying subcutaneous layer (13/23; 56.5%). Multiplicity within a muscle, compartment, and limb was observed in 7 (31.8%), 18 (81.8%), and 16 (72.7%) patients, respectively. Bilateral involvement was observed in 7 patients (30.4%). Only multiplicity within a compartment showed a statistically significant correlation with peripheral neuropathy development.Common MRI findings in rhabdomyolysis include intramuscular hemorrhage, stippled enhancement, a well-defined rectangular shape with a ragged margin in the longitudinal plane, and multiplicity. Multiplicity within a compartment may be a predictor of the development of peripheral neuropathy.

Acute gastroesophageal intussusception in a patient with pneumomediastinum, pneumoperitoneum, and extensive subcutaneous emphysema resulting from iatrogenic colonic perforation.

Acute gastroesophageal intussusception is a rare condition in which the stomach invaginates into the adjacent esophagus. We report a case of acute gastroesophageal intussusception with massive pneumomediastinum, pneumoperitoneum, and subcutaneous emphysema, effectively treated with conservative management.

Iatrogenic Iliofemoral Vein Dissection: A Rare Complication of Femoral Artery Puncture.

Iatrogenic iliac vein dissection secondary to femoral artery puncture is a rare complication that has not yet been documented. A 55-year-old woman presented to our institution with acute right iliofemoral thrombosis 2 weeks after transfemoral cerebral angiography. She was previously healthy and was not taking any medication. Right iliofemoral vein dissection was diagnosed by computed tomography angiography and confirmed by conventional venography. The patient was treated endovascularly with stent insertion, and the venous outflow was patent on the 6-month follow-up computed tomography angiogram.

Contralateral Deep Vein Thrombosis after Iliac Vein Stent Placement in Patients with May-Thurner Syndrome.

PURPOSE: To investigate the incidence and potential causes of contralateral deep vein thrombosis (DVT) after common iliac vein (CIV) stent placement in patients with May-Thurner syndrome (MTS). MATERIALS AND METHODS: Data of 111 patients (women: 73%) who had CIV stent implantation for symptomatic MTS at a single center were retrospectively analyzed. Mean patient age was 63.1 ± 15.2 years. Median follow-up was 36 months (range, 1-142 months). Stent location was determined by venogram and classified as extended to the inferior vena cava (IVC), covered the confluence, or confined to the iliac vein. Potential causes of contralateral DVT were presumed based on venographic findings. The relationship between stent location and contralateral DVT was analyzed. RESULTS: Ten patients (9%, men/women: 4/6) exhibited contralateral DVT at a median timing of 40 months (range, 6-98 months). Median age was 69 years (range, 42-85 years). Median follow-up was 73.5 months (range, 20-134 months). Potential causes were venous intimal hyperplasia (VIH) (n = 7), "jailing" (n = 2), and indeterminate (n = 1). All patients with VIH had previous CIV stents overextended to the IVC. Overextension of CIV stent was associated with contralateral DVT (P < .001). The primary patency rate of the contralateral CIV stent was 70% at 20 months. CONCLUSIONS: Contralateral DVT after CIV stent implantation has a relatively high incidence and often occurs late during follow-up. Overextension of the CIV stent to the IVC is associated with development of contralateral DVT, and VIH should be considered a potential cause.

Double left brachiocephalic vein with a preaortic course: a rare finding.

A double left brachiocephalic vein is an uncommon anatomic variation. Among these, a accessory branch with preaortic course is extremely rare. In this case, both branches of the left brachiocephalic vein were anterior to the aortic arch. We describe the computed tomography findings with volume-rendering imaging of this rare anatomic variation.

Evaluation of Delayed Endoleak Compared with Early Endoleak after Endovascular Aneurysm Repair.

PURPOSE: To identify prevalence and evaluate outcomes of delayed endoleak (DEL) compared with early endoleak (EEL) after endovascular aortic aneurysm repair (EVAR). MATERIALS AND METHODS: Data of 164 patients who underwent elective EVAR at a single center were retrospectively analyzed. DEL was defined as any type of endoleak that was first detected ≥ 12 months after EVAR. Patients who had < 1 year of follow-up were excluded. Endoleak was classified into a more aggressive category if a patient had > 1 type of endoleak. Analysis included 81 patients (82.7% male). Mean age was 73.1 years ± 9.3. Median follow-up duration was 43 months (range, 12-135 months). RESULTS: Endoleak was present in 32 patients (39.5%), including 21 EEL (25.9%) and 11 DEL (13.6%). DEL consisted of 2 type I, 5 type II, 1 type III, and 3 type V (endotension). Median time to detection was 45 months (range, 15-60 months), and median follow-up duration was 62 months (range, 37-104 months). Compared with EEL, DEL had larger aneurysm diameters and higher rates of non-type II endoleak and reintervention. Type II DEL also required more reintervention procedures than type II EEL. CONCLUSIONS: DEL had a noteworthy incidence and occurred late after EVAR. It predominantly consisted of non-type II endoleak and appeared to have more reinterventions than EEL. Meticulous long-term imaging surveillance to identify and manage DEL is critical.

Usefulness of Percutaneous Puncture in Insertion of Totally Implantable Venous Access Devices in Pediatric Patients.

PURPOSE: Totally implantable venous access devices (TIVADs) are commonly used in pediatrics for the administration of chemotherapy, antibiotics, or parenteral nutrition. TIVADs can be implanted using various techniques, including surgical cutdown (SC) and percutaneous puncture (PP). Recently, percutaneous TIVAD became popular in adults, but studies comparing between PP and SC group in pediatric patients are rare. MATERIALS AND METHODS: Data were collected and analyzed retrospectively from 23 patients who underwent TIVAD at a single institution between January 2013 and December 2015. We examined the clinical characteristics, insertion techniques, and clinical outcome. We divided the patients into 2 groups and compared PP with ultrasonography and SC using the insertion technique. We compared success rate, procedural time, and the patency rate between the 2 groups. RESULTS: Eleven TIVADS were inserted using PP, and 12 TIVADs were inserted using SC. No statistically significant difference in characteristics was found between the 2 groups. The procedural time in the PP group was shorter than that in the SC group, but the difference was not statistically significant (P=0.685). During follow-up, 1 patient in the SC group had an occlusion, and 1 patient in the PP group had an infection. CONCLUSION: PP of the internal jugular vein with ultrasonography appears to be the method of choice for TIVAD insertion owing to its similar success rate in terms of implantation and complication rate to that in SC, with shorter procedural times in pediatric patients.

Association between relative liver enhancement on gadoxetic acid enhanced magnetic resonance images and histologic grade of hepatocellular carcinoma.

We evaluated the association between histologic grade of hepatocellular carcinoma (HCC) and degree of HCC enhancement on Gd-EOB-DTPA (Gadoxetic acid, Primovist)-enhanced magnetic resonance images (MRI) in HCC patients.A total of 121 patients who underwent curative surgical resection for HCC at our institution between January 2012 and March 2015 were retrospectively analyzed. Gadoxetic acid enhanced MRI was performed in all patients before surgery. Signal intensities of HCC and peri-HCC areas were measured using regions of interest. Relative intensity ratios of HCC lesions versus the surrounding non-HCC areas on unenhanced images (precontrast ratio) and on hepatobiliary phase images (postcontrast ratio) were calculated. Relative liver enhancement (RLE) ratios (post-contrast ratio/pre-contrast ratio) were also calculated. The Edmondson-Steiner (E-S) grading system was used to histologically grade HCC.E-S grades I, II, III, and IV were observed in 2 (1.7%), 14 (11.6%), 54 (44.6%), and 51 (42.1%) of the patients, respectively. For E-S grades I/II (n = 16), III (n = 54), and IV (n = 51), mean RLE (%) were 85.5, 84.9, and 71.2, respectively (P = .01), and for E-S grades I-III (n = 70) and IV (n = 51), mean RLE (%) were 85.1 and 71.2, respectively (P < .01). Barcelona Clinic Liver Cancer (BCLC) stage A (vs 0) (odds ratio 4.38, P = .03) and mean RLE (odds ratio 0.05, P < .01) were found to predict E-S grade IV.E-S grade IV was associated with a low level mean RLE in the gadoxetic acid enhanced MR images of HCC patients.

Associations between gene expression profiles of invasive breast cancer and Breast Imaging Reporting and Data System MRI lexicon.

PURPOSE: To evaluate whether the Breast Imaging Reporting and Data System (BI-RADS) MRI lexicon could reflect the genomic information of breast cancers and to suggest intuitive imaging features as biomarkers. METHODS: Matched breast MRI data from The Cancer Imaging Archive and gene expression profile from The Cancer Genome Atlas of 70 invasive breast cancers were analyzed. Magnetic resonance images were reviewed according to the BI-RADS MRI lexicon of mass morphology. The cancers were divided into 2 groups of gene clustering by gene set enrichment an alysis. Clinicopathologic and imaging characteristics were compared between the 2 groups. RESULTS: The luminal subtype was predominant in the group 1 gene set and the triple-negative subtype was predominant in the group 2 gene set (55 of 56, 98.2% vs. 9 of 14, 64.3%). Internal enhancement descriptors were different between the 2 groups; heterogeneity was most frequent in group 1 (27 of 56, 48.2%) and rim enhancement was dominant in group 2 (10 of 14, 71.4%). In group 1, the gene sets related to mammary gland development were overexpressed whereas the gene sets related to mitotic cell division were overexpressed in group 2. CONCLUSION: We identified intuitive imaging features of breast MRI associated with distinct gene expression profiles using the standard imaging variables of BI-RADS. The internal enhancement pattern on MRI might reflect specific gene expression profiles of breast cancers, which can be recognized by visual distinction.

Characteristics, Trends, and Quality of Systematic Review and Meta-Analysis in General Radiology between 2007 and 2015.

RATIONALE AND OBJECTIVES: To evaluate the trends, characteristics, and quality of systematic review and meta-analysis in general radiology journals. MATERIALS AND METHODS: We performed a PubMed search to identify systematic reviews and meta-analyses that had been carried out in the field of radiology between 2007 and 2015. The following data were extracted: journal, impact factor, type of research, year of publication, radiological subspecialty, imaging modalities used, number of authors, affiliated department of the first and corresponding authors, presence of a radiologist and a statistician among the authors, discordance between the first and corresponding authors, funding, country of first author, methodological quality, methods used for quality assessment, and statistics. RESULTS: Ultimately, we included 210 articles from nine general radiology journals. The European Journal of Radiology was the most common journal represented (47 of 210; 22.4%). Meta-analyses (n = 177; 84.3%) were published about five times more than systematic reviews without meta-analysis (n = 33; 15.7%). Radiology of the gastrointestinal tract was the most commonly represented subspecialty (n = 49, 23.3%). The first authors were most frequently located in China (n = 64; 30.3%). In terms of modality, magnetic resonance imaging was used most often (n = 59; 28.1%). The number of authors tended to progressively increase over time, and the ratio of discordance between the first and corresponding authors also increased significantly, as did the proportion of research that has received funding from an external source. The mean AMSTAR assessment score improved over time (5.87/11 in 2007-2009, 7.11/11 in 2010-2012, and 7.49/11 in 2013-2015). In this regard, the journal Radiology had the highest score (7.59/11). CONCLUSIONS: The quantity and quality of radiological meta-analyses have significantly increased over the past 9 years; however, specific weak areas remain, providing the opportunity for quality improvement.

Spontaneous dissections of multiple visceral arteries: an extremely rare case.

Spontaneous dissections of visceral arteries without aortic involvement are very rare. The etiologies of these entities are unclear and their clinical managements remain controversial. We report a case of spontaneous multiple dissections affecting 4 visceral arteries including the superior mesenteric artery, the celiac artery and the bilateral renal arteries. The patient was managed conservatively and endovascularly. The clinical manifestation markedly improved and laboratory tests returned to normal limits within 1 week. The regular follow-up suggested a good clinical and radiological outcome until 84 months.

Magnetic Resonance Imaging Findings of Mumps Meningoencephalitis with Bilateral Hippocampal Lesions without Preceding Acute Parotitis: A Case Report.

Meningitis is a common central nervous system (CNS) complication of the mumps, a viral infection, but encephalitis and meningoencephalitis are less common in mumps. We describe magnetic resonance imaging findings of acute mumps meningoencephalitis in a 32-year-old male who showed bilateral hippocampal lesions without preceding parotitis. Although it is rare, hippocampal involvement should be considered a CNS complication of mumps infection.

Incidental thyroid nodules on thoracic contrast-enhanced computed tomography in clinical practice during a 10-year period: Characteristics, clinical outcomes, and factors contributing to further evaluation.

The purposes of this study were to assess the prevalence, malignancy rate, and characteristics of incidental thyroid nodules (ITNs), and to identify factors that contribute the additional workup by ultrasound.The medical records and imaging features of ITNs reported via thoracic computed tomography (CT) were retrospectively reviewed to determine the size, multiplicity, attenuation, shape, and presence of calcification. To identify the factors associated with additional workup, we compared the workup and non-workup groups in terms of nodule characteristics, indications, and CT slices. We identified factors that could distinguish malignant ITNs from non-malignant nodules.A total of 60,921 thoracic CT scans met the inclusion criteria, and ITNs were reported using formal radiology in 2733 patients (4.5%). Among all patients with reported ITNs, 546 (20.0%) underwent further workup. Of these patients, 62 (2.3%, 62/2773) were diagnosed with malignant nodules. Multivariable analysis identified multiple factors associated with additional workup, including female sex, younger age, larger nodule size, calcification, anteroposterior to transverse dimension ratio >1, heterogeneous attenuation in the nodule, and scanning indications such as infection or screening. However, only calcification was associated with malignant nodules (odds ratio [OR] = 2.313; 95% confidence interval [CI], 1.301-4.113).We observed discordance between the numbers of reported ITNs and case with additional workup and identified multiple factors associated with additional workup. We have, therefore, demonstrated a need for reliable subsequent evaluation guidelines and note that the appearance of calcification in an ITN on imaging may be a factor indicating the need for additional workup.