Association of Baseline Magnetic Resonance Imaging Prostate Imaging Reporting and Data System Score With Prostate Cancer Active Surveillance Early Biopsy Reclassification: Data From the Michigan Urological Surgery Improvement Collaborative (MUSIC).

PURPOSE: The purpose of our study was to evaluate the association of baseline MRI Prostate Imaging Reporting and Data System (PI-RADS) score with biopsy reclassification in a multicenter active surveillance (AS) cohort. MATERIALS AND METHODS: We identified men in the Michigan Urological Surgery Improvement Collaborative registry (46 hospital-based/academic/private practice urology groups) with National Comprehensive Cancer Network (NCCN) low-risk and favorable intermediate-risk prostate cancer who underwent MRI within 6 months before or after initial biopsy and enrolled in AS from June 2016 to January 2021. The primary objective was to determine the association of baseline MRI PI-RADS score (≥4 lesion) with reclassification to high-grade prostate cancer (≥grade group 3) on surveillance biopsy. Multivariable Cox proportional hazards regression models were constructed and adjusted for pathologic, MRI, and clinical/biopsy factors, with landmark time of 6 months from diagnostic biopsy. We included an interaction term between PI-RADS score and NCCN group in the Cox model. RESULTS: A total of 1491 men were included with median age 64 years (IQR: 59-69) with median follow-up 11.0 months (IQR: 6.0-23.0) after landmark. Baseline PI-RADS ≥ 4 lesion was associated with an increased hazard of biopsy reclassification (HR: 2.3 [95% CI: 1.6-3.2], P < .001), along with grade group 2 vs 1 (HR: 2.5 [95% CI: 1.7-3.7], P < .001), and increasing age (per 10 years; HR: 1.8 [95% CI: 1.4-2.4], P < .001). The interaction between NCCN risk group with MRI findings was not significant (P = .7). CONCLUSIONS: In this multicenter cohort study of real-world data, baseline MRI PI-RADS score was significantly associated with early biopsy reclassification in men undergoing AS with NCCN low- or favorable intermediate-risk prostate cancer.

Impact of the bladder detrusor muscular ring on lower urinary tract symptoms due to benign prostatic hyperplasia: A quantitative MRI analysis.

BACKGROUND: The etiology of lower urinary tract symptoms secondary to benign prostatic hyperplasia (LUTS/BPH) remains uncertain. OBJECTIVE: The purpose of our study was to quantitatively analyze anatomic characteristics on magnetic resonance imaging (MRI) to assess novel independent factors for symptoms. METHODS: This retrospective single-institution study evaluated treatment-naïve men who underwent prostate MRI within 3 months of international prostate symptom score (IPSS) scoring from June 2021 to February 2022. Factors measured on MRI included: size of the detrusor muscular ring (DMR) surrounding the bladder outlet, central gland (CG) mean apparent diffusion coefficient (ADC), levator hiatus (LH) volume, intrapelvic volume, intravesicular prostate protrusion (IPP) volume, CG volume, peripheral zone (PZ) volume, prostate urethra angle (PUA), and PZ background ordinal score. Multivariable logistic regression and receiver operating characteristic analysis were used to analyze factors for moderate/severe (IPSS ≥ 8) and severe LUTS/BPH (IPSS ≥ 20). RESULTS: A total of 303 men (mean age: 66.1 [SD: 8.1]) were included: 154 demonstrated moderate or severe symptoms with 28 severe and 149 with asymptomatic/mild symptoms. Increasing age [p = 0.02; odds ratio (OR): 1.05 (1.01-1.08)], PUA [p = 0.02; OR: 1.05 (1.01-1.09)], LH volume [p = 0.04; OR: 1.02 (1.00-1.05)], and DMR size measured as diameter [p < 0.001; OR: 5.0 (3.01-8.38)] or area [p < 0.001; OR: 1.92 (1.47-2.49)] were significantly independently associated with moderate/severe symptoms, with BMI [p = 0.02; OR: 0.93 (0.88-0.99)] inversely related. For every one cm increase in DMR diameter, patients had approximately five times the odds for moderate/severe symptoms. Increasing DMR size [diameter p < 0.001; OR: 2.74 (1.76-4.27) or area p < 0.001; OR: 1.37 (1.18-1.58)] was independently associated with severe symptoms. Optimal criterion cutoff of DMR diameter for moderate/severe symptoms was 1.2 cm [sensitivity: 77.3; specificity: 71.8; AUC: 0.80 (0.75-0.84)]. Inter-reader reliability was excellent for DMR diameter [ICC = 0.92 (0.90-0.94)]. CONCLUSION: Expansion of the DMR surrounding the bladder outlet is a novel anatomic factor independently associated with moderate and severe LUTS/BPH, taking into account prostate volumes, including quantified IPP volume, which were unrelated. Detrusor ring diameter, easily and reliably measured on routine prostate MRI, may relate to detrusor dysfunction from chronic stretching of this histologically distinct smooth muscle around the bladder neck.

Computed Tomography Imaging of Iatrogenic Esophageal Injuries.

ABSTRACT: Knowledge of iatrogenic esophageal injuries is important given the variety of etiologies, including medical instrumentation (eg, endoscopes), radiotherapy, and anticoagulation. The clinical presentation and imaging findings of esophageal injuries depend on the mechanism and location of the injury. Imaging modalities commonly used for the evaluation of esophageal injuries include esophagram and computed tomography. Esophageal injuries should be considered in patients with acute chest symptoms. Recognizing an unsuspected esophageal injury on imaging can be critical to reaching the correct diagnosis given their nonspecific symptomatology. This review article highlights various iatrogenic esophageal injuries and their appearance on computed tomography imaging.

Radiologic Assessment of Native Renal Vasculature: A Multimodality Review.

A wide range of clinically important anatomic variants and pathologic conditions may affect the renal vasculature, and radiologists have a pivotal role in the diagnosis and management of these processes. Because many of these entities may not be suspected clinically, renal artery and vein assessment is an essential application of all imaging modalities. An understanding of the normal vascular anatomy is essential for recognizing clinically important anatomic variants. An understanding of the protocols used to optimize imaging modalities also is necessary. Renal artery stenosis is the most common cause of secondary hypertension and is diagnosed by using both direct ultrasonographic (US) findings at the site of stenosis and indirect US findings distal to the stenosis. Fibromuscular dysplasia, while not as common as atherosclerosis, remains an important cause of renal artery hypertension, especially among young female individuals. Fibromuscular dysplasia also predisposes individuals to renal artery aneurysms and dissection. Although most renal artery dissections are extensions of aortic dissections, on rare occasion they occur in isolation. Renal artery aneurysms often are not suspected clinically before imaging, but they can lead to catastrophic outcomes if they are overlooked. Unlike true aneurysms, pseudoaneurysms are typically iatrogenic or posttraumatic. However, multiple small pseudoaneurysms may be seen with underlying vasculitis. Arteriovenous fistulas also are commonly iatrogenic, whereas arteriovenous malformations are developmental (ie, congenital). Both of these conditions involve a prominent feeding artery and draining vein; however, arteriovenous malformations contain a nidus of tangled vessels. Nutcracker syndrome should be suspected when there is distention of the left renal vein with abrupt narrowing as it passes posterior to the superior mesenteric artery. Filling defects in a renal vein can be due to a bland or tumor thrombus. A tumor thrombus is most commonly an extension of renal cell carcinoma. When an enhancing mass is located predominantly within a renal vein, leiomyosarcoma of the renal vein should be suspected. ©RSNA, 2017.

Optimizing radiology remote reading: leveraging technology to improve efficiency.

Remote work has been increasingly utilized in the profession of radiology over recent years. Setting up your individual workstation offers an opportunity to tailor it to suit your preferences without the restriction of a universal setup to accommodate multiple users. Important considerations when setting up a home workstation include selecting the optimal work location, choosing the proper desk and chair, and configuring an ideal computer monitor layout. The use of peripheral devices, such as programmable mice and hands-free dictation tools can improve efficiency and reduce repetitive strain injuries. This article also explores the use of smart home devices and programmable scripts using AutoHotKey to further streamline workflow and maximize the benefits of a remote workstation.

Assessing the Diagnostic Accuracy of TI-RADS in Pediatric Thyroid Nodules: A Multi-institutional Review.

PURPOSE: Thyroid nodules are uncommon in children and adolescents but carry an increased risk of malignancy when present. The Thyroid Imaging Reporting and Data System (TI-RADS) is an adult-validated ultrasound-based risk assessment providing a prediction of malignant potential for thyroid nodules, thereby guiding recommendations for fine needle aspiration biopsy (FNAB). Minimal data exist regarding the applicability of TI-RADS to predict malignancy in pediatric thyroid nodules. This study aims to analyze the performance of TI-RADS for children and adolescents with thyroid nodules, hypothesizing that applying TI-RADS criteria would improve accuracy and reduce the number of recommended FNAB compared to American Thyroid Association (ATA) size criteria alone. METHODS: A multi-institutional retrospective analysis was conducted including patients ≤21 years with a thyroid nodule by sonographic thyroid imaging between 2015 and 2020. TI-RADS scores were assigned at each institution by a pediatric radiologist trained in thyroid imaging and TI-RADS criteria. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy of TI-RADS scoring were compared to existing ATA size-based recommendation for performing a FNAB. Accounting for relative size differences between adults and children, a novel PED TI-RADS category was developed and tested, recommending FNAB for thyroid nodules with a TI-RADS 3 and ≥ 1.5 cm, TI-RADS 4 and ≥ 1.0 cm, and TI-RADS 5 any feasible size. RESULTS: 291 nodules from 260 patients (median age 14.9 years, 78.8% female) were assessed using TI-RADS. Applying adult TI-RADS criteria resulted in recommendation of FNAB for 35.1% of nodules, in contrast to 76.6% recommended by ATA guidelines (p < 0.0001) (Table). Utilizing the adult TI-RADS score ≥3 as an FNAB indicator resulted in 100% sensitivity and 28.5% specificity, with 0 cases of missed malignant nodules on pathology. When novel PED TI-RADS criteria were applied, 88 patients would have been spared an unnecessary FNAB with improved sensitivity and accuracy over ATA criteria. CONCLUSIONS: The application of adult and PED TI-RADS scoring to thyroid nodules in pediatric patients enhances the accuracy of malignancy prediction compared to current American Thyroid Association size criteria alone. The utilization of PED TI-RADS scoring eliminated unnecessary biopsies in many children while not missing a single thyroid malignancy. LEVEL OF EVIDENCE: Level III.

Magnetic Resonance Cholangiopancreatography (MRCP) Findings in a Patient With AIDS Cholangiopathy and Cryptosporidiosis.

AIDS cholangiopathy is a rare condition characterized by intra- and extra-hepatic ductal strictures causing biliary obstruction primarily in individuals with advanced HIV infection and low clusters of differentiation 4 (CD4) count. This case report presents a male patient with a history of HIV, poor adherence to antiretroviral therapy (ART), and chronic cryptosporidiosis infection, who exhibited clinical and radiological findings consistent with advanced immunocompromise and AIDS cholangiopathy. The patient presented with respiratory symptoms, weight loss, renal dysfunction, and elevated liver enzymes. Imaging studies, including ultrasound and magnetic resonance cholangiopancreatography (MRCP), revealed diffuse biliary dilatation and stricturing, indicative of cholangiopathy. Subsequent endoscopic retrograde cholangiopancreatography (ERCP) with stent placement was performed to manage the biliary obstruction. This case highlights the importance of considering AIDS cholangiopathy in HIV patients with poor ART compliance who present with biliary obstruction symptoms or cholestatic liver enzyme abnormalities. Prompt diagnostic evaluation using MRCP or ERCP can aid in confirming the diagnosis and guiding appropriate therapeutic interventions, including endoscopic management and initiation of ART.

Impact of a structured reporting template on the quality of HRCT radiology reports for interstitial lung disease.

PURPOSE: This QI study compared the completeness of HRCT radiology reports before and after the implementation of a disease-specific structured reporting template for suspected cases of interstitial lung disease (ILD). MATERIALS AND METHODS: A pre-post study of radiology reports for HRCT of the thorax at a multicenter health system was performed. Data was collected in 6-month period intervals before (June 2019-November 2019) and after (January 2021-June 2021) the implementation of a disease-specific template. The use of the template was voluntary. The primary outcome measure was the completeness of HRCT reports graded based on the documentation of ten descriptors. The secondary outcome measure assessed which descriptor(s) improved after the intervention. RESULTS: 521 HRCT reports before and 557 HRCT reports after the intervention were reviewed. Of the 557 reports, 118 reports (21%) were created using the structured reporting template. The mean completeness score of the pre-intervention group was 9.20 (SD = 1.08) and the post-intervention group was 9.36 (SD = 1.03) with a difference of -0.155, 95% CI [-0.2822, -0.0285, p < 0.0001]. Within the post-intervention group, the mean completeness score of the unstructured reports was 9.25 (SD = 1.07) and the template reports was 9.93 (SD = 0.25) with a difference of -0.677, 95% CI [-0.7871, -0.5671, p < 0.0001]. After the intervention, the use of two descriptors improved significantly: presence of honeycombing from 78.3% to 85.1% (p < 0.0039) and technique from 90% to 96.6% (p < 0.0001). DISCUSSION: Shifting to disease-specific structured reporting for HRCT exams of suspected ILD is beneficial, as it improves the completeness of radiology reports. Further research on how to improve the voluntary uptake of a disease-specific template is needed to help increase the acceptance of structured reporting among radiologists.

Acalculous variant of Mirizzi syndrome: Imaging and clinical characteristics.

PURPOSE: Mirizzi Syndrome is a rare disease that causes biliary obstruction in the setting of an impacted stone in the gallbladder neck or Hartmann's Pouch which exerts mass effect on the common duct; however, we have noticed inflammatory biliary narrowing in the absence of an offending gallstone in the setting of acute cholecystitis. The purpose of this study is to report the clinical and MRCP findings in a series of 10 patients with this variant of Mirizzi Syndrome. MATERIALS AND METHODS: A search of our institution's PACS and electronic medical record identified 10 patients with a diagnosis of acute cholecystitis and narrowing of the common duct on imaging in the absence of an impacted gallstone. Imaging and clinical findings were confirmed by two board-certified abdominal radiologists. RESULTS: All patients presented with abdominal pain and an average elevated total bilirubin of 3.0 mg/dL. Seven patients had MRCP findings of complete narrowing of the CBD. Nine patients had intrahepatic biliary ductal dilation. All nine patients with gadoliniumenhanced MRCP displayed biliary wall thickening with enhancement adjacent to the gallbladder. Nine patients underwent cholecystectomy, one patient underwent percutaneous cholecystostomy. Average bilirubin upon discharge was within normal limits at 0.9 mg/dL after intervention. Two patients had follow-up MRCP showing resolution of biliary narrowing. CONCLUSION: A variant of Mirizzi Syndrome occurs in the absence of an offending gallstone in the gallbladder neck or cystic duct to explain the biliary narrowing. We postulate that acute cholecystitis can cause a local inflammatory narrowing resulting in biliary obstruction.

Prostatic Urethral Length on MRI Potentially Predicts Late Genitourinary Toxicity After Prostate Cancer Radiation.

RATIONALE AND OBJECTIVES: The purpose of our study was to evaluate pretreatment prostate quantitative magnetic resonance imaging (MRI) measurements and clinical characteristics in predicting genitourinary (GU) toxicity after radiotherapy (RT) for prostate cancer. MATERIALS AND METHODS: In this single-institution retrospective cohort study, we evaluated patients with prostate adenocarcinoma who underwent MRI within 6 months before completing definitive RT and follow-up information in our GU toxicity database from June 2016 to February 2023. MRI measurements included quantitative urethra, prostate, and bladder measurements. GU toxicity was physician-scored using the Common Terminology Criteria for Adverse Events (CTCAE v4.0) with acute toxicity defined as ≤180 days and late defined as >180 days. Multivariable logistic regression model was constructed for grade ≥2 acute toxicity and Cox proportional hazards regression for late toxicity, adjusted for clinical factors and RT method. RESULTS: A total of 361 men (median age 68 years, interquartile range [IQR] 62-73) were included; 14.4% (50/347) men experienced grade ≥2 acute toxicity. Brachytherapy (odds ratio [OR]: 2.9, 95% confidence interval [CI]: 1.5-5.8), P < 0.01) was associated with increased odds of acute GU toxicity, and longer MUL (OR: 0.41 [95%CI: 0.18-0.92], P = 0.03) with decreased odds. Median follow-up for late toxicity was 15.0 months (IQR: 9.0-28.0) with approximately 88.7% and 72.0% patients free of toxicity at 1 and 3 years, respectively. Only longer prostatic urethral length (hazard ratio [HR]: 1.6, 95%CI: 1.2-2.1, P < 0.01) was associated with increased risk of late GU toxicity, notably urinary frequency/urgency symptoms (HR: 1.7 [95%CI: 1.3-2.3], P < 0.01). CONCLUSION: Longer prostatic urethral length measured on prostate MRI is independently associated with higher risk of developing late grade ≥2 GU toxicity after radiation therapy for prostate cancer. This pretreatment metric may be potentially valuable in risk-stratification models for quality of life following prostate RT.

Factors influencing the total procedure time of CT-guided percutaneous core-needle biopsies of lung nodules: a retrospective analysis.

PURPOSE This study aims to investigate the factors that influence total procedure time when performing computed tomography (CT)-guided percutaneous core-needle lung biopsies. METHODS This is a cross-sectional study of 673 patients, who underwent a CT-guided percutaneous coreneedle biopsy at a tertiary care center from March 2014 to August 2016. Data on patient, nodule, and procedural factors and outcomes were collected retrospectively. Univariate linear regression and a multivariate stepwise linear regression were utilized for analysis. RESULTS Factors most strongly associated with prolonged procedure duration include 20-gauge needle use when compared with 18-gauge needle use (estimated difference in time=1.19), collecting additional core biopsies (estimated difference in time=1.10), decubitus nodule side up (DNSU; estimated difference in time=1.42), and supine positioning (estimated difference in time=1.16) relative to decubitus nodule side down positioning, and increased nodule distance from the skin surface (estimated difference in time=1.03). Increased nodule length (estimated difference in time=0.93) was associated with reductions in procedure duration. Prolonged procedure time was associated with an increased rate of pneumothorax (odds ratio (OR)=1.02; P < .0001) and decreased rate of pulmonary hemorrhage (OR=0.97; P < .0001). CONCLUSION The use of 20-gauge biopsy needle, collecting additional core biopsies, DNSU and supine positioning, smaller nodule size, and increasing nodule distance from the skin surface were associated with increased procedure time for CT-guided core needle biopsies of lung nodules. Prolonged procedure time is associated with a higher rate of pneumothorax and a lower rate of pulmonary hemorrhage.

Risk Factors for Pneumothorax Development Following CT-Guided Core Lung Nodule Biopsy.

BACKGROUND: This study aims to correlate nodule, patient, and technical risk factors less commonly investigated in the literature with pneumothorax development during computed tomography-guided core needle lung nodule biopsy. PATIENTS AND METHODS: Retrospective data on 671 computed tomography-guided percutaneous core needle lung biopsies from 671 patients at a tertiary care center between March 2014 and August 2016. Univariate and multivariable logistic regression analyses were used to identify pneumothorax risk factors. RESULTS: The overall incidence of pneumothorax was 26.7% (n=179). Risk factors identified on univariate analysis include anterior [odds ratio (OR)=1.98; P<0.001] and lateral (OR=2.17; P=0.002) pleural surface puncture relative to posterior puncture, traversing more than one pleural surface with the biopsy needle (OR=2.35; P=0.06), patient positioning in supine (OR=2.01; P<0.001) and decubitus nodule side up (OR=2.54; P=0.001) orientation relative to decubitus nodule side down positioning, and presence of emphysema in the path of the biopsy needle (OR=3.32; P<0.001). In the multivariable analysis, the presence of emphysematous parenchyma in the path of the biopsy needle was correlated most strongly with increased odds of pneumothorax development (OR=3.03; P=0.0004). Increased body mass index (OR=0.95; P=0.001) and larger nodule width (cm; OR=0.74; P=0.02) were protective factors most strongly correlated with decreased odds of pneumothorax development. CONCLUSION: Emphysema in the needle biopsy path is most strongly associated with pneumothorax development. Increases in patient body mass index and width of the target lung nodule are most strongly associated with decreased odds of pneumothorax.

Small bowel diverticulitis - Spectrum of CT findings and review of the literature.

PURPOSE: To review the CT findings and complications of small bowel diverticulitis (SBD) and discuss clinical presentations and outcomes. METHODS: A text search of radiology reports within our health system for cases of small bowel diverticulitis yielded 95 cases. All cases were reviewed by an abdominal radiologist with equivocal cases reviewed by a second abdominal radiologist for consensus. Retrospective analysis of CT imaging findings was performed on 67 convincing cases of SBD. RESULTS: Small bowel diverticulitis most often affected the jejunum (58%) and the duodenum (26%). The most common imaging feature was peridiverticular inflammation manifested by peridiverticular edema, diverticular wall thickening, bowel wall thickening, and fascial thickening. Edema was typically seen along the mesenteric border of the bowel with relative sparing of the anti-mesenteric side. When a prior CT was available, the affected diverticulum was identified in 95% of cases. Fecalized content within the affected diverticulum was observed in 51% of cases. Perforation (6%) and abscess (6%) were the most common complications. CONCLUSION: Small bowel diverticulitis is an uncommon cause of abdominal pain which can mimic an array of abdominal pathologies, although the reported mortality rate of 40-50% may no longer be accurate. The "fecalized diverticulum" sign can be helpful in identifying the culprit diverticulum and aid diagnosing SBD. Findings of perforation and or abscess formation are critical as they may impact management.

Anomalous Circumrenal Inferior Vena Cava Associated With Horseshoe Kidney.

A 69-year-old male presented with periumbilical pain radiating across his abdomen, with associated nausea and emesis. CT imaging of his abdomen and pelvis revealed calculi in the right and left ureterovesical junctions with hydroureteronephrosis bilaterally. Furthermore, the imaging revealed that the patient had a horseshoe kidney with an associated anomalous inferior vena cava (IVC) that split superiorly to the horseshoe kidney at the L1 level and rejoined inferior to the horseshoe kidney at the L5 level. The IVC took on a "circumrenal" course, as it traversed the right kidney with an anterior and posterior portion. Furthermore, the patient's right ureter was compressed between the anterior portion of the IVC and the right kidney. We hypothesize that the development of the horseshoe kidney around the 7 to 8th week of gestation created a path of resistance for the forming of IVC around the same time. While surgical correction is not warranted, recognition of this circumrenal IVC variant could have major implications for planning of procedures, such as IVC filter placement.

Discrepant Reporting Style Preferences Between Clinicians and Radiologists.

RATIONALE AND OBJECTIVES: To compare preferences in reporting styles between radiologists and clinicians in structured vs unstructured reporting styles in order to facilitate better communication. METHODS: An online survey was distributed to 5280 clinicians, radiologists, and physicians in training surveying respondent preference for three different reporting styles: expanded structured, minimized structured, and unstructured. RESULTS: A 7.5% response rate was achieved. Overall, the expanded structured reporting style was the most preferred (47%, 186/394). This contrasted with radiologists who preferred the unstructured reporting style (41%), whereas nonradiologists preferred the expanded structured reporting style (51%; P < 0.001). There was significance in emergency medicine physicians preferring the minimized structured reporting style (51%, 27/43), whereas all other specialties preferred the expanded structured report (49%, 168/341; P = 0.0038). DISCUSSION: There is a discrepant reporting style preference between clinicians and radiologists. A structured reporting style with expanded standard statements is preferred by most physicians. Radiologists could consider using a structured reporting style with minimized normal statements in the emergency room setting.

Dynamic lung compliance imaging from 4DCT-derived volume change estimation.

Background. Lung compliance (LC) is the ability of the lung to expand with changes in pressure and is one of the earliest physiological measurements to be altered in patients with parenchymal lung disease. Therefore, compliance monitoring could potentially identify patients at risk for disease progression. However, in clinical practice, compliance measurements are prohibitively invasive for use as a routine monitoring tool.Purpose. We propose a novel method for computing dynamic lung compliance imaging (LCI) from non-contrast computed tomography (CT) scans. LCI applies image processing methods to free-breathing 4DCT images, acquired under two different continuous positive airway pressures (CPAP) applied using a full-face mask, in order to compute the lung volume change induced by the pressure change. LCI provides a quantitative volumetric map of lung stiffness.Methods. We compared mean LCI values computed for 10 patients with idiopathic pulmonary fibrosis (IPF) and 7 non-IPF patients who were screened for lung nodules. 4DCTs were acquired for each patient at 5 cm and 10 cm H20 CPAP, as the patients were free breathing at functional residual capacity. LCI was computed from the two 4DCTs. Mean LCI intensities, which represent relative voxel volume change induced by the change in CPAP pressure, were computed.Results.The mean LCI values for patients with IPF ranged between [0.0309, 0.1165], whereas the values ranged between [0.0704, 0.2185] for the lung nodule cohort. Two-sided Wilcoxon rank sum test indicated that the difference in medians is statistically significant (pvalue = 0.009) and that LCI -measured compliance is overall lower in the IPF patient cohort.Conclusion. There is considerable difference in LC scores between patients with IPF compared to controls. Future longitudinal studies should look for LC alterations in areas of lung prior to radiographic detection of fibrosis to further characterize LCI's potential utility as an image marker for disease progression.

An assessment of the correlation between robust CT-derived ventilation and pulmonary function test in a cohort with no respiratory symptoms.

OBJECTIVE: To evaluate CT-ventilation imaging (CTVI) within a well-characterized, healthy cohort with no respiratory symptoms and examine the correlation between CTVI and concurrent pulmonary function test (PFT). METHODS: CT scans and PFTs from 77 Caucasian participants in the NORM dataset (clinicaltrials.gov NCT00848406) were analyzed. CTVI was generated using the robust Integrated Jacobian Formulation (IJF) method. IJF estimated total lung capacity (TLC) was computed from CTVI. Bias-adjusted Pearson's correlation between PFT and IJF-based TLC was computed. RESULTS: IJF- and PFT-measured TLC showed a good correlation for both males and females [males: 0.657, 95% CI (0.438-0.797); females: 0.667, 95% CI (0.416-0.817)]. When adjusting for age, height, smoking, and abnormal CT scan, correlation moderated [males: 0.432, 95% CI (0.129-0.655); females: 0.540, 95% CI (0.207-0.753)]. Visual inspection of CTVI revealed participants who had functional defects, despite the fact that all participant had normal high-resolution CT scan. CONCLUSION: In this study, we demonstrate that IJF computed CTVI has good correlation with concurrent PFT in a well-validated patient cohort with no respiratory symptoms. ADVANCES IN KNOWLEDGE: IJF-computed CTVI's overall numerical robustness and consistency with PFT support its potential as a method for providing spatiotemporal assessment of high and low function areas on volumetric non-contrast CT scan.

A prospective study to validate pulmonary blood mass changes on non-contrast 4DCT in pulmonary embolism patients.

PURPOSE: Limited diagnostic options exist for patients with suspected pulmonary embolism (PE) who cannot undergo CT-angiogram (CTA). CT-ventilation methods recover respiratory motion-induced lung volume changes as a surrogate for ventilation. We recently demonstrated that pulmonary blood mass change, induced by tidal respiratory motion, is a potential surrogate for pulmonary perfusion. In this study, we examine blood mass and volume change in patients with PE and parenchymal lung abnormalities (PLA). METHODS: A cross-sectional analysis was conducted on a prospective, cohort-study with 129 consecutive PE suspected patients. Patients received 4DCT within 48 h of CTA and were classified as having PLA and/or PE. Global volume change (VC) and percent global pulmonary blood mass change (PBM) were calculated for each patient. Associations with disease type were evaluated using quantile regression. RESULTS: 68 of 129 patients were PE positive on CTA. Median change in PBM for PE-positive patients (0.056; 95% CI: 0.045, 0.068; IQR: 0.051) was smaller than that of PE-negative patients (0.077; 95% CI: 0.064, 0.089; IQR: 0.056), with an estimated difference of 0.021 (95% CI: 0.003, 0.038; p = 0.0190). PLA was detected in 57 (44.2%) patients. Median VC for PLA-positive patients (1.26; 95% CI: 1.22, 1.30; IQR: 0.15) showed no significant difference from PLA-negative VC (1.25; 95% CI: 1.21, 1.28; IQR: 0.15). CONCLUSIONS: We demonstrate that pulmonary blood mass change is significantly lower in PE-positive patients compared to PE-negative patients, indicating that PBM derived from dynamic non-contrast CT is a potentially useful surrogate for pulmonary perfusion.

Quantifying pulmonary perfusion from noncontrast computed tomography.

PURPOSE: Computed tomography (CT)-derived ventilation methods compute respiratory induced volume changes as a surrogate for pulmonary ventilation. Currently, there are no known methods to derive perfusion information from noncontrast CT. We introduce a novel CT-Perfusion (CT-P) method for computing the magnitude mass changes apparent on dynamic noncontrast CT as a surrogate for pulmonary perfusion. METHODS: CT-Perfusion is based on a mass conservation model which describes the unknown mass change as a linear combination of spatially corresponding inhale and exhale HU estimated voxel densities. CT-P requires a deformable image registration (DIR) between the inhale/exhale lung CT pair, a preprocessing lung volume segmentation, and an estimate for the Jacobian of the DIR transformation. Given this information, the CT-P image, which provides the magnitude mass change for each voxel within the lung volume, is formulated as the solution to a constrained linear least squares problem defined by a series of subregional mean magnitude mass change measurements. Similar to previous robust CT-ventilation methods, the amount of uncertainty in a subregional sample mean measurement is related to measurement resolution and can be characterized with respect to a tolerance parameter τ . Spatial Spearman correlation between single photon emission CT perfusion (SPECT-P) and the proposed CT-P method was assessed in two patient cohorts via a parameter sweep of τ . The first cohort was comprised of 15 patients diagnosed with pulmonary embolism (PE) who had SPECT-P and 4DCT imaging acquired within 24 h of PE diagnosis. The second cohort was comprised of 15 nonsmall cell lung cancer patients who had SPECT-P and 4DCT images acquired prior to radiotherapy. For each test case, CT-P images were computed for 30 different uncertainty parameter values, uniformly sampled from the range [0.01, 0.125], and the Spearman correlation between the SPECT-P and the resulting CT-P images were computed. RESULTS: The median correlations between CT-P and SPECT-P taken over all 30 test cases ranged between 0.49 and 0.57 across the parameter sweep. For the optimal tolerance τ = 0.0385, the CT-P and SPECT-P correlations across all 30 test cases ranged between 0.02 and 0.82. A one-sample sign test was applied separately to the PE and lung cancer cohorts. A low Spearmen correlation of 15% was set as the null median value and two-sided alternative was tested. The PE patients showed a median correlation of 0.57 (IQR = 0.305). One-sample sign test was statistically significant with 96.5 % confidence interval: 0.20-0.63, P < 0.00001. Lung cancer patients had a median correlation of 0.57(IQR = 0.230). Again, a one-sample sign test for median was statistically significant with 96.5 percent confidence interval: 0.45-0.71, P < 0.00001. CONCLUSION: CT-Perfusion is the first mechanistic model designed to quantify magnitude blood mass changes on noncontrast dynamic CT as a surrogate for pulmonary perfusion. While the reported correlations with SPECT-P are promising, further investigation is required to determine the optimal CT acquisition protocol and numerical method implementation for CT-P imaging.

A practical guide to managing CT findings in the breast.

While it is well accepted that CT is not an optimal imaging study to evaluate the breasts, findings on chest CT may be the first indication of an occult malignancy. The nonspecific appearance of breast findings and the lack of consensus guidelines for managing incidental breast findings may dissuade radiologists from thoroughly evaluating the breasts on CT. We review commonly encountered breast findings on CT and present an algorithm for managing incidentally detected breast findings.