Equivocal Computed Tomography Research Articles

Short Observation Period and Aggressive Discharge of Patients With Head Injury and Serial CT Scans.

Background: Many patients undergo two head computed tomography (CT) scans after mild traumatic brain injury (TBI). Radiographic progression without clinical deterioration does not usually alter management. Evidence-based guidelines offer potential for limited repeat imaging and safe discharge. This study characterizes patients who had two head CTs in the Emergency Department (ED), determines the change between initial and repeat CTs, and describes timing of repeat scans.Methods: This retrospective series includes all patients with head CTs during the same ED visit at an urban trauma center between May 1st, 2016 and April 30th, 2018. Radiographic interpretation was coded as positive, negative, or equivocal.Results: Of 241 subjects, the number of positive, negative, and equivocal initial CT results were 154, 50, and 37, respectively. On repeat CT, 190 (78.8%) interpretations were congruent with the original scan. Out of the 21.2% of repeat scans that diverged from the original read, 14 (5.8%) showed positive to negative conversion, 1 (.4%) showed positive to equivocal conversion, 2 (.88%) showed negative to positive conversion, 20 (8.3%) showed equivocal to negative conversion, and 14 (5.8%) showed equivocal to positive conversion. Average time between scans was 4.4 hours, and median length of stay was 10.2 hours.Conclusions: In this retrospective review, most repeat CT scans had no new findings. A small percentage converted to positive, rarely altering clinical management. This study demonstrates the need for continued prospective research to update clinical guidelines that could reduce admission and serial CT scanning for mild TBI.

Utility of Computed Tomography Overreading and Abdominal Ultrasound in Children With Suspected Appendicitis and Nondiagnostic Computed Tomography at Community Hospitals.

The aim of the study was to examine the ability of overreading of computed tomography (CT) and right lower quadrant ultrasound (RLQ US) to diagnose appendicitis for children with suspected appendicitis with equivocal CTs at community hospitals. This was a retrospective chart review of all children transferred to a children's hospital from community emergency departments with suspected appendicitis over 2 years for whom both CT and RLQ US were performed. One hundred eighty-four children were included with a median age of 10.8 years, and 57.6% were female. Community hospitals documented that CTs were equivocal for appendicitis in 110 (59.8%), positive in 63 (34.2%), and negative in 11 (6.0%). Ninety-seven CTs (88.1%) designated equivocal at community hospitals were later deemed interpretable by pediatric radiologists: 21 (19.1%) as appendicitis and 76 (69.1%) as normal. In 13 children (11.8%), both the community and children's hospital CT interpretations were equivocal. In equivocal cases, RLQ US was consistent with appendicitis in 6 (46.2%), normal in 5 (41.7%), and nondiagnostic in 2. κ value between CT interpretations at community versus children's hospital was 0.13 (95% confidence interval, 0.05-0.22), and κ value between CT interpretation at the children's hospital and RLQ US was 0.59 (95% confidence interval, 0.48-0.70). Most CTs deemed equivocal for appendicitis at community hospitals were interpretable by pediatric radiologists. In a few children for whom CTs were designated nondiagnostic, RLQ US provided a definitive diagnosis in almost 90% of cases. The first step in evaluation of children with suspected appendicitis for whom outside CTs are deemed equivocal should be to have the study reinterpreted by a pediatric radiologist.

Predictive Model for Operative Intervention after Blunt Abdominal Trauma in Children with Equivocal CT Findings: A Pilot Study

BackgroundTo study the clinical and radiologic factors predicting the need for surgical intervention after blunt abdominal trauma (BAT) in children with equivocal computed tomography (CT) scan findings. MethodsWe performed a retrospective review of the trauma database at our level I pediatric trauma center between 2011 and 2019. We selected patients with BAT and equivocal findings for surgical intervention on CT scan. We studied five factors: abdominal wall bruising (AWB), abdominal pain/tenderness (APT), thoracolumbar fracture, the presence of free fluid (FF), and the presence of solid organ injury, all previously reported in the literature to predict the need for operative intervention. We used t-test, the Kruskal-Wallis test and logistic regression to study the association of these factors with the need for operation in our pediatric cohort. ResultsOf 3044 blunt trauma patients, 288 had abdominal CT scans with 61 patients demonstrating equivocal findings. Operation was performed for 12 patients (19.7%) confirming surgically correctable traumatic injuries. The need for surgical intervention was significantly associated with the age of the patients (P = 0.03), the presence of APT (P = 0.001), AWB (P = 0.01), and FF (P = 0.04). The presence of thoracolumbar fracture and solid organ injury were not significantly associated with the need for operation. For the subset of 37 patients who were injured in a motor vehicle crash, five (13.5%) required surgical intervention, which was significantly associated with the presence of AWB (P = 0.04), APT (P = 0.01), and FF (P = 0.03). A predictive model that used these factors produced a receiver operating characteristic curve of 0.86. ConclusionsIn cases of equivocal abdominal CT scan findings to evaluate BAT in children, the presence of abdominal wall tenderness, AWB, or FF may be significant factors predicting more accurately the need for operative intervention. A predictive model using the combination of clinical and image findings might determine with more certainty, the need for surgical intervention in children with BAT and equivocal CT findings. Validation on a larger multi-institutional data set should be done.

Evaluation of the diagnostic performance of a decision tree model in suspected acute appendicitis with equivocal preoperative computed tomography findings compared with Alvarado, Eskelinen, and adult appendicitis scores: A STARD compliant article.

This study evaluated the diagnostic performance of a new clinical approach based on decision tree (DT) analysis in adult patients with equivocal computed tomography (CT) findings of acute appendicitis (AA) compared with previous scoring systems.This retrospective study of 244 adult patients with equivocal CT findings included appendicitis (AG, n = 80) and non-appendicitis (NAG, n = 164) groups. The chi-squared automatic interaction detection algorithm was for AA prediction. A receiver operating characteristic curve analysis and area under the curve (AUC) were used to compare the DT analysis with Alvarado, Eskelinen score, and adult appendicitis scores (AAS).The following factors were selected for AA prediction: rebound tenderness severity, migration, urinalysis, symptom duration, leukocytosis, neutrophil count, and C-reactive protein levels. The DT comprised 11 final nodes with the following AA probabilities: node 1, 100% (16/16); node 2, 90% (9/10); node 3, 80% (8/10); node 4, 60.9% (14/23); node 5, 50% (3/6); node 6, 43.8% (7/16); node 7, 22.6% (12/53); node 8, 13% (10/77); node 9, 5.6% (1/18); node 10, 0% (0/12); and node 11, 0% (0/3). The AUC of the DT was higher (0.850 [95% confidence interval {CI}; 0.799–0.893]) than the Alvarado score (0.695 [95% CI; 0.633–0.752]), AAS (0.749 [95% CI; 0.690–0.802]), and the Eskelinen score (0.715 [95% CI; 0.654–0.770]). The results were statistically significant when compared with the AUCs of the Alvarado score, Eskelinen score, and AAS (P < .001, P < .001, P = .003, respectively).The DT-based approach facilitated AA diagnosis and determination of clinical status in patients with equivocal preoperative CT findings and ambiguous results.

Value of Additional Ultrasound Examination in Patients with Equivocal Computed Tomography Findings of Acute Appendicitis: Comparison with Computed Tomography Reassessment.

Objectives:The objective of this study was to find the diagnostic values of additional ultrasound (US) in patients with equivocal computed tomography (CT) findings of acute appendicitis, compared to CT reassessment.Materials and Methods:Patients with equivocal CT findings of acute appendicitis (n = 115), who underwent the US, were included in the study. Two abdominal radiologists reviewed CT scans independently. They analyzed CT findings and made a diagnosis of acute appendicitis. The patients were categorized into positive and negative appendicitis based on the previous US reports. The diagnostic performance, interobserver agreement of CT findings, and appendicitis likelihood were calculated.Results:The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of US (100%, 92.1%, 79.5%, and 100%, respectively) were higher than those of CT reassessment (reviewer 1: 51.9%, 87.5%, 56.1%, and 85.6%; reviewer 2: 66.7%, 85.2%, 58.1%, and 89.3%, respectively). In the coexistent inflammation group, the sensitivity, specificity, PPV, and NPV of US (reviewer 1: 100%, 98%, 91.5%, and 100%; reviewer 2: 100%, 98%, 87.7%, and 100%, respectively) were higher than those of CT reassessment (reviewer 1: 27.3%, 94.1%, 49.9%, and 85.8%; reviewer 2: 14.3%, 98.0%, 50.5%, and 88.9%, respectively).Conclusion:In patients with equivocal CT findings of acute appendicitis, US shows better diagnostic performance than CT reassessment, and helps differentiate with periappendicitis.

Can clinical scoring systems improve the diagnostic accuracy in patients with suspected adult appendicitis and equivocal preoperative computed tomography findings?

ObjectiveAdult appendicitis (AA) with equivocal computed tomography (CT) findings remains a diagnostic challenge for physicians. Herein we evaluated the diagnostic performance of several clinical scoring systems in adult patients with suspected appendicitis and equivocal CT findings.MethodsWe retrospectively evaluated 189 adult patients with equivocal CT findings. Alvarado, Eskelinen, appendicitis inflammatory response, Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA), and adult appendicitis score (AAS) scores were evaluated, receiver operating characteristic analysis was conducted, and the optimal, low, and high cut-off values were determined for patient classification into three groups: low, intermediate, or high.ResultsIn total, 61 patients were included in the appendicitis group and 128 in the non-appendicitis group. There were no significant differences between the area under the curve of the clinical scoring systems in the final diagnosis of AA for equivocal appendicitis on CT (Alvarado, 0.698; Eskelinen, 0.710; appendicitis inflammatory response, 0.668; RIPASA, 0.653; AAS, 0.726). A RIPASA score greater than 7.5 had a high positive predictive value (90.9) and an AAS score less than or equal to 5 had a high negative predictive value (91.7) in the diagnosis of AA.ConclusionThe accuracy of clinical scoring systems in the diagnosis of AA with equivocal CT findings was moderate. Therefore, a high RIPASA score may assist in the diagnosis of AA in patients with equivocal CT findings, and a low AAS score may be used as a criterion for patient discharge. Most patients presented with intermediate scores. The patients with equivocal CT findings may be considered as a third diagnostic category of AA.

Outcomes of CSF spectrophotometry in cases of suspected subarachnoid haemorrhage with negative CT: two years retrospective review in a Birmingham hospital

Aim: The aim of this study was to evaluate the adherence to current guidelines for the investigation of suspected subarachnoid haemorrhage and the prevalence and outcome of computed tomography (CT)-negative aneurysmal subarachnoid haemorrhage.Design: A retrospective review in a single large tertiary referral centre.Subjects: A total of 796 patients, aged 16–90 years, who underwent lumbar puncture (LP) for suspected subarachnoid haemorrhage (SAH) following a negative or equivocal CT scan between January 2012 and November 2013 (23 months).Methods: Xanthochromia reports were obtained using the hospital’s department of biochemistry database and clinical data for these patients were reviewed using patient notes.Results: Of 796 CSF reports reviewed, 728 (91%) were negative for xanthochromia, 31 (4%) were positive and 37 (5%) were equivocal. Only 2 out of the 31 patients with positive spectrophotometry results were subsequently found to have an underlying aneurysm on CT angiography. A further 9 out of these 31 patients underwent digital subtraction angiography, with no cerebral aneurysms being detected. Amongst the 37 patients with equivocal xanthochromia reports, 13 underwent CT angiography and only 1 cerebral aneurysm was detected.Conclusions: In patients with clinically suspected SAH but who have negative or questionable CT findings, CSF analysis is likely to be negative in the vast majority of cases, which was 91% in our series. In patients yielding positive or equivocal CSF results the likelihood of an aneurysm being detected is low, amounting to three out of 68 or approximately one in 23 (approximately 4%). Overall in suspected SAH cases where CT scan has been negative, the rate for the detection of cerebral aneurysm is three out of 796 cases (0.4%).

Impact of pre-operative positron emission tomography in gallbladder cancer

BackgroundCurrent pre-operative staging methods for gallbladder cancer (GBC) are suboptimal in detecting metastatic disease. Positron emission tomography (PET) may have a role but data are lacking. MethodsPatients with GBC and PET assessed by a hepatobiliary surgeon in clinic between January 2001 and June 2013 were retrospectively reviewed. Computed tomography (CT)/magnetic resonace imaging (MRI) were correlated with PET scans and analysed for evidence of metastatic or locally unresectable disease. Medical records were reviewed to determine if PET scanning was helpful by preventing non-therapeutic surgery or enabling resection in patients initially deemed unresectable. ResultsThere were 100 patients including 63 incidental GBC. Thirty-eight patients did not proceed to surgery, 35 were resected and 27 patients were explored but had unresectable disease. PET was positive for metastatic disease in 39 patients (sensitivity 56%, specificity 94%). Five patients definitively benefitted from PET: in 3 patients PET found disease not seen on CT, and 2 patients with suspicious CT findings had negative PET and successful resections. In a further 12 patients PET confirmed equivocal CT findings. Three patients had additional invasive procedures performed owing to PET avidity in other sites. Utility of PET was higher in patients with suspicious nodal disease on CT [odds ratio (OR) 7.1 versus no nodal disease, P = 0.0004], and in patients without a prior cholecystectomy (OR 3.1 versus post-cholecystectomy, P = 0.04). ConclusionAddition of PET to conventional cross-sectional imaging has a modest impact on management pre-operatively particularly in patients without a prior cholecystectomy and to confirm suspicious nodal disease on CT.

Is any test 100% specific and 100% sensitive for serious injury?

Resnickandcolleagues1haveperformedaprospectiveobservational trial during a 17-month period assessing the accuracy of cervical spine computed tomography (CT) in the evaluation of patients with blunt trauma. The population included patientsata level I traumacenter with persistent cervical tenderness or a focal neurologic deficit. They have also evaluated theusefulnessofperformingmagnetic resonance imaging(MRI) inthesepatients.TheauthorsboldlyconcludethatadvancedgenerationalCTscanning is 100%sensitiveand100%specific indetecting significant cervical spine injuries and thatMRI is of no useexceptmaybe inpatientswith focalmotordeficits.Noneof thepatientsevaluatedinthisstudyhadfocalmotordeficits.This is a very important study because it suggests that MRI is not needed inthispatientpopulation,whichsignificantlysimplifies their care.However, several issuesneedtobeconsideredbefore accepting the authors’ conclusions at face value. Thiswas a very select population ofminimally injured patients with amean Injury Severity Score of 3.3. No patient had anAbbreviated Injury Score greater than 3, andno patient had anInjurySeverityScoregreater than25.Theseresultscannotbe generalized tomoresignificantly injuredpatients.Thevastmajority of patients admitted to level 1 trauma centers would not beincludedinthisstudybecausetheyaremoreseverely injured. The definition of significant injuries was the need for surgical intervention, a halo, or a hard cervical collar for ligamentous injury. Forty-two of 100 MRIs performed showed a ligamentous injury, and the treatment used for these patients is not clear. Five patients with a negative CT who had ligamentous injuries received a cervical collar. However, these patients were not included in the significantly injured group for analysis, and why they were excluded is not clearly presented in the Methods section of the article. Most (61.0%) MRIs were performed as a result of equivocal CT results, and only 26.0%were performed for evaluation of cervical tenderness or focal neurologic findings. This study ismore focusedonequivocalCT findings thanonhowtoevaluate patients with persistent tenderness or a focal neurologic deficit. Finally, theauthorsdonot address theevaluationandcare of patientswithmotor deficits andpotential cervical spine injuries because there were none in the study. This fact remains a significant limitation of the study. Although it would be ideal to dispense with MRI as a diagnostic test in patients with potential cervical spine injuries, this study leavesmanyunansweredquestions. I look forward to more prospective data on this topic from this group of investigators.

Magnetic resonance imaging of traumatic brain injury: a pictorial review.

Traumatic brain injury (TBI) is a significant source of major morbidity and mortality in blunt trauma patients. Computed tomography (CT) is the primary imaging modality of choice for patients with potential brain injury in the acute setting, with magnetic resonance imaging (MRI) playing a role in evaluating equivocal CT findings and may help with determining long-term prognosis and recovery. MRI is being utilized more commonly in the acute and subacute setting of TBI; therefore, radiologists should be familiar with the MRI appearance of the various manifestations of TBI. Here, we review the imaging of common intracranial injuries with illustrative cases comparing CT and MRI.

Effect of cardiac hybrid 15O-water PET/CT imaging on downstream referral for invasive coronary angiography and revascularization rate

This study evaluates the impact of hybrid imaging on referral for invasive coronary angiography (ICA) and revascularization rates. A total of 375 patients underwent hybrid (15)O-water positron emission tomography (PET)/computed tomography (CT)-based coronary angiography (CTCA) imaging for the evaluation of coronary artery disease (CAD). Downstream treatment strategy within a 60-day period after hybrid PET/CTCA imaging for ICA referral and revascularization was assessed. CTCA examinations were classified as showing no (obstructive) CAD, equivocal (borderline test result), or obstructive CAD, while the PET perfusion images were classified into normal or abnormal. On the basis of CTCA imaging, 182 (49%) patients displayed no (obstructive) CAD. Only 10 (5%) patients who showed no (obstructive) CAD on CTCA were referred for ICA, which were all negative. An equivocal CT study was observed in 80 (21%) patients, among whom 56 (70%) showed normal myocardial perfusion imaging (MPI), resulting in referral rates for ICA of 18% for normal MPI and 71% for abnormal MPI, respectively. No revascularizations were performed in the presence of normal MPI, while 59% of those with abnormal MPI were revascularized. CTCA indentified obstructive CAD in 113 (30%) patients accompanied in 59 (52%) patients with abnormal MPI. Referral rate for ICA was 57% for normal MPI and 88% for those with abnormal MPI, resulting in revascularization rates of 26% and 72%, respectively. Hybrid (15)O-water PET/CTCA imaging impacts clinical decision-making with regard to referral for ICA and revascularization procedures. Particularly, in the presence of an equivocal or abnormal CTCA, MPI could guide in the decision to refer for ICA and revascularization.

Added value of ultrasound re-evaluation for patients with equivocal CT findings of acute appendicitis: a preliminary study

To prospectively estimate the additional diagnostic value of ultrasound (US) re-evaluation for patients with equivocal computed tomography (CT) findings of acute appendicitis. Between April 2011 and October 2011, 869 consecutive patients with suspected appendicitis who were referred for CT were included. The likelihood of appendicitis was prospectively categorized into five categories. US re-evaluation was recommended for patients in the 'equivocal appendix' and 'probably not appendicitis' groups. The overall negative appendectomy rate during the study period was compared with the rate of the previous year, and negative appendectomy rates of the US and non-US evaluation groups were also compared. Among 869 patients, 71 (8.2 %) had equivocal appendicitis findings and 63 (7.2 %) were diagnosed as probably not appendicitis. The sensitivity and specificity of CT combined with US re-evaluation group (100 % and 98.1 %, respectively) exceeded those of the CT alone group (93 % and 99 %; equivocal group considered as negative appendicitis, 100 % and 89.9 %; as positive, respectively, P < 0.0001). After adding US re-evaluation, the overall negative appendectomy rate in our institution decreased from 3.4 to 2.3 %. For patients with equivocal CT findings of acute appendicitis, US re-evaluation can improve diagnostic accuracy and decrease the rate of negative appendectomies. • Misdiagnosis of appendicitis still occurs, especially in patients with equivocal radiological findings. • The sensitivity and specificity of CT followed by US exceeded those of CT alone. • After US re-evaluation, the negative appendectomy rate decreased from 3.4 to 2.3 %. • US re-evaluation in equivocal cases helps diagnostic confidence and further management.

Role of FDG-PET scans in staging, response assessment, and follow-up care for non-small cell lung cancer

The integral role of positron-emission tomography (PET) using the glucose analog tracer fluorine-18 fluorodeoxyglucose (FDG) in the staging of non-small cell lung cancer (NSCLC) is well established. Evidence is emerging for the role of PET in response assessment to neoadjuvant therapy, combined-modality therapy, and early detection of recurrence. Here, we review the current literature on these aspects of PET in the management of NSCLC. FDG-PET, particularly integrated 18F-FDG-PET/CT, scans have become a standard test in the staging of local tumor extent, mediastinal lymph node involvement, and distant metastatic disease in NSCLC. 18F-FDG-PET sensitivity is generally superior to computed tomography (CT) scans alone. Local tumor extent and T stage can be more accurately determined with FDG-PET in certain cases, especially in areas of post-obstructive atelectasis or low CT density variation. FDG-PET sensitivity is decreased in tumors <1 cm, at least in part due to respiratory motion. False-negative results can occur in areas of low tumor burden, e.g., small lymph nodes or ground-glass opacities. 18F-FDG-PET-CT nodal staging is more accurate than CT alone, as hilar and mediastinal involvement is often detected first on 18F-FDG-PET scan when CT criteria for malignant involvement are not met. 18F-FDG-PET scans have widely replaced bone scintography for assessing distant metastases, except for the brain, which still warrants dedicated brain imaging. 18F-FDG uptake has also been shown to vary between histologies, with adenocarcinomas generally being less FDG avid than squamous cell carcinomas. 18F-FDG-PET scans are useful to detect recurrences, but are currently not recommended for routine follow-up. Typically, patients are followed with chest CT scans every 3–6 months, using 18F-FDG-PET to evaluate equivocal CT findings. As high 18F-FDG uptake can occur in infectious, inflammatory, and other non-neoplastic conditions, 18F-FDG-PET-positive findings require pathological confirmation in most cases. There is increased interest in the prognostic and predictive role of FDG-PET scans. Studies show that absence of metabolic response to neoadjuvant therapy correlates with poor pathologic response, and a favorable 18F-FDG-PET response appears to be associated with improved survival. Further work is underway to identify subsets of patients that might benefit individualized management based on FDG-PET.

The Effect of Abdominal Pain Duration on the Accuracy of Diagnostic Imaging for Pediatric Appendicitis

Advanced imaging with computed tomography (CT) or ultrasonography is frequently used to evaluate for appendicitis. The duration of the abdominal pain may be related to the stage of disease and therefore the interpretability of radiologic studies. Here, we investigate the influence of the duration of pain on the diagnostic accuracy of advanced imaging in children being evaluated for acute appendicitis. A secondary analysis of a prospective multicenter observational cohort of children aged 3 to 18 years with suspected appendicitis who underwent CT or ultrasonography was studied. Outcome was based on histopathology or telephone follow-up. Treating physicians recorded the duration of pain. Imaging was coded as positive, negative, or equivocal according to an attending radiologist's interpretation. A total of 1,810 children were analyzed (49% boys, mean age 10.9 years [SD 3.8 years]); 1,216 (68%) were assessed by CT and 832 (46%) by ultrasonography (238 [13%] had both). The sensitivity of ultrasonography increased linearly with increasing pain duration (test for trend: odds ratio=1.39; 95% confidence interval 1.14 to 1.71). There was no association between the sensitivity of CT or specificity of either modality with pain duration. The proportion of equivocal CT readings significantly decreased with increasing pain duration (test for trend: odds ratio=0.76; 95% confidence interval 0.65 to 0.90). The sensitivity of ultrasonography for appendicitis improves with a longer duration of abdominal pain, whereas CT demonstrated high sensitivity regardless of pain duration. Additionally, CT results (but not ultrasonographic results) were less likely to be equivocal with longer duration of abdominal pain.

Prospective evaluation of selective nonoperative management of torso gunshot wounds

Selective nonoperative management (NOM) has been increasingly used for torso gunshot wounds (GSWs). The optimal observation time required to exclude a hollow viscus injury is not clear. The purpose of this study was to determine the safe period of observation before discharge. All patients aged 16 years and older sustaining a torso GSW undergoing a trial of NOM were prospectively enrolled (January 2009 to January 2011). Patient demographics, initial computed tomography (CT) results, time to failure of NOM, operative procedures, and outcomes were collected. Failure of NOM was defined as the need for operation. A total of 270 patients sustained a GSW to the torso. Of those, 25 patients (9.3%) died in the emergency department and were excluded leaving 245 patients available for the analysis. Mean age was 26.5 years ± 9.9 years (16-62 years), 92.7% (227) were men, and mean Injury Severity Score scale was 13.8 ± 11.3 (1-45). Overall, 115 patients (46.9%) underwent immediate exploratory laparotomy based on clinical criteria (72.2% had peritonitis, 27.8% hypotension, 10.4% unevaluable, and 4.3% evisceration), and 130 patients (53.1%) underwent evaluation with CT for possible NOM. Of those, 39 patients (30.0%) had a positive CT and were subsequently operated on. All had significant intra-abdominal injuries requiring surgical management. A total of 91 patients (70.0%) underwent a trial of NOM (47 had equivocal CT findings and 44 had a negative examination). Of these, 8 patients (8.8%) failed NOM and underwent laparotomy (all had equivocal CT scans). Two patients had a nontherapeutic laparotomy; the remainder had stomach (50.0%), colon (25.5%), and rectal (12.5%) injuries. The mean time from admission to development of clinical or laboratory signs of NOM failure was 2 hours:43 minutes ± 2 hours:23 minutes (0 hour:31 minutes-6 hours:58 minutes). All patients failed within 24 hours of admission. In the initial evaluation of patients sustaining a GSW to the torso, clinical examination is essential for identifying those who will require emergency operation. For those undergoing a trial of NOM, all failures occurred within 24 hours of hospital admission, setting a minimum required observation period before discharge.

Circulating tumor cells (CTCs) as a predictor of metastatic disease in patients with biochemical recurrence (BR) of prostate cancer with equivocal scan results.

239 Background: Staging for BR is challenging since the yield of computed tomography (CT) and bone scans are low, especially in patients with low prostate specific antigens (PSA) levels. We examined the utility of circulating tumor cells (CTCs) to predict metastatic disease in a cohort of patients who presented with BR (Aragon-Ching, et. al. ASCO GU 2011;abstr 60). Methods: 33 pts enrolled from May 2010 to September 2011 with BR, defined as patients (pts) who have undergone primary treatment with PSA rise to &gt;/= 0.2 from a prior undetectable level for prior prostatectomy or &gt; 2 mg/dl rise from post-nadir radiotherapy, were included. PSA doubling time (PSADT), scan results, Gleason scores, age, testosterone levels were all obtained. CTCs were evaluated in 7.5 mL of peripheral blood using the CTC CellSearch test. BR patients with equivocal CT and/or bone scan results who were biopsiable and consentable underwent bone biopsy to confirm metastatic disease. Results: The median age for 33 patients was 71 y/o (range: 51 – 91), median PSA of 1.7 ng/mL (range 0.2 – 65.8), testosterone levels of 315.5 ng/dL (range: 31 – 727), Gleason score of 7, hemoglobin of 13.78 g/dL, BMI of 27.72 and alkaline phosphatase of 68 IU/L. Prostatectomy was the primary treatment in 23 pts, radiotherapy in 9 pts and Cyberknife in 1 pt. Median PSADT varied between 0.35 to 55.2 months. Only a small number of patients had either biopsy confirmed metastatic disease (n=2) or detectable CTC (n=3). Both of the 2 patients with metastatic disease had detectable CTC (sensitivity = 1.00, 95% CI: .34, 1.00). For the patients without signs or confirmation of metastatic disease, 30/31 had no detectable CTC (specificity = .97, 95% CI: .84, .99). Conclusions: While most pts with BR have negative blood CTCs, patients with detectable CTCs and equivocal findings on scans should raise suspicion and prompt a search for metastatic disease, given increasing available treatment options for metastatic prostate cancer. However, the limited number of patients may preclude reliable statistical evaluation of CTCs in this population. Supported by IRG-08-091-01 from ACS to GWU Cancer Institute.

Reassessment of CT images to improve diagnostic accuracy in patients with suspected acute appendicitis and an equivocal preoperative CT interpretation

To identify CT features that discriminate individuals with and without acute appendicitis in patients with equivocal CT findings, and to assess whether knowledge of these findings improves diagnostic accuracy. 53 patients that underwent appendectomy with an indeterminate preoperative CT interpretation were selected and allocated to an acute appendicitis group or a non-appendicitis group. The 53 CT examinations were reviewed by two radiologists in consensus to identify CT findings that could aid in the discrimination of those with and without appendicitis. In addition, two additional radiologists were then requested to evaluate independently the 53 CT examinations using a 4-point scale, both before and after being informed of the potentially discriminating criteria. CT findings found to be significantly different in the two groups were; the presence of appendiceal wall enhancement, intraluminal air in appendix, a coexistent inflammatory lesion, and appendiceal wall thickening (P < 0.05). Areas under the curves of reviewers 1 and 2 significantly increased from 0.516 and 0.706 to 0.677 and 0.841, respectively, when reviewers were told which CT variables were significant (P = 0.0193 and P = 0.0397, respectively). Knowledge of the identified CT findings was found to improve diagnostic accuracy for acute appendicitis in patients with equivocal CT findings. • Numerous patients with clinically equivocal appendicitis do not have acute appendicitis • Computed tomography (CT) helps to reduce the negative appendectomy rate • CT is not always infallible and may also demonstrate indeterminate findings • However knowledge of significant CT variables can further reduce negative appendectomy rate • An equivocal CT interpretation of appendicitis should be reassessed with this knowledge.

Positron emission tomography with F-18-FDG: a new tool in the evaluation of patients with head and neck tumors

Positron emission tomography using fluoro-deoxyglucose (PET-FDG) imaging has been shown to be effective in detecting and staging malignancies based on tumor glucose metabolism. The aim of the study was to evaluate the use of PET-FDG for the detection of metastatic lesions as well as early recurrence in patients with head and neck tumors. Eleven patients were examined with PET-FDG to study the reliability of PET in assessing regional nodal status and in identifying distant metastasis (group I) and 37 patients who had previously received curative treatment and who presented differential diagnostic problems were imaged to differentiate between scar and residual or recurrent cancer (group II). PET-FDG studies were compared to results of computed tomography (CT) in 35 patients, magnetic resonance imaging (MRI) in 4 patients and both techniques in 6 patients. All PET-FDG studies were positive in group I, while CT failed to detect metastatic lesions in three patients. In group II PET-FDG accurately detected recurrent disease in 22/25 patients, while CT/MRI were negative in 4 cases and equivocal in 6 cases. However, there was a false positive PET study with equivocal CT in a patient with local infection. PET-FDG was highly effective in detecting metastatic cervical lymph nodes in head and neck tumours. It was most helpful in differentiating residual or recurrent tumour from scar sequelae and it enhanced the diagnostic accuracy when CT and MRI were equivocal due to anatomical distortions.

Comparison of Dual-Energy Computed Tomography of the Heart With Single Photon Emission Computed Tomography for Assessment of Coronary Artery Stenosis and of the Myocardial Blood Supply

To evaluate the performance of dual-energy computed tomography (CT) for integrative imaging of the coronary artery morphology and the myocardial blood supply, 36 patients (15 women, mean age 57 +/- 11 years) with equivocal or incongruous single photon emission CT (SPECT) results were investigated by a single-contrast medium-enhanced, retrospectively electrocardiographic-gated dual-energy CT (DECT) scan with simultaneous acquisition of high and low x-ray spectra. Thirteen patients subsequently underwent invasive coronary angiography (ICA). The DECT data were used to reconstruct anatomic coronary CT angiographic images and to map the myocardial iodine distribution within the left ventricular myocardium. Two independent observers analyzed all DECT studies for stenosis and myocardial iodine defects. A segmental comparison was performed between the stress/rest SPECT perfusion defects and DECT iodine defects and between the ICA and coronary CT angiographic findings for stenosis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were estimated, along with the kappa statistics. Overall, DECT had 92% sensitivity and 93% specificity, with 93% accuracy for detecting any type of myocardial perfusion defect seen on SPECT. Contrast defects at DECT correctly identified 85 (96%) of 89 fixed and 60 (88%) of 68 reversible myocardial perfusion defects. The interobserver agreement was very good (weighted kappa = 0.87). Compared with ICA, coronary CT angiography had 90% sensitivity, 94% specificity, and 93% accuracy for the detection of >50% stenosis. In conclusion, our initial experience suggests that DECT, as a single examination, might be promising for the integrative analysis of the coronary artery morphology and the myocardial blood supply and is in good agreement with ICA and SPECT.

Imaging of blunt pancreatic trauma

Blunt pancreatic trauma is an exceedingly rare but life-threatening injury with significant mortality. Computed tomography (CT) is commonly employed as the initial imaging modality in blunt trauma patients and affords a timely diagnosis of pancreatic trauma. The CT findings of pancreatic trauma can be broadly categorized as direct signs, such as a pancreatic laceration, which tend to be specific but lack sensitivity and indirect signs, such as peripancreatic fluid, which tend to be sensitive but lack specificity. In patients with equivocal CT findings or ongoing clinical suspicion of pancreatic trauma, magnetic resonance cholangiopancreatography (MRCP) may be employed for further evaluation. The integrity of the main pancreatic duct is of crucial importance, and though injury of the duct may be strongly suggested upon initial CT, MRCP provides clear delineation of the duct and any potential injuries. This article aims to review and illustrate the CT and magnetic resonance imaging findings of blunt pancreatic trauma and delineate the integration of these modalities into the appropriate imaging triage of severely injured blunt trauma patients.