Sequential CT Research Articles

Establishment of institutional diagnostic reference level for CT imaging associated with multiple anatomical regions

Advancement of CT technology has increased the frequency of CT scanning in diagnosis. However, the concern on dose increment that related to radiation-associated health risk from CT also improved. The aim of this study was to establish an institutional diagnostic reference level (DRL) for computed tomography (CT) imaging associated with multiple or combined anatomical regions and compared with other international DRLs. CT dose data of 705 subjects were collected retrospectively from January 2015 until December 2017 at AMDI, USM, Malaysia. The most common CT examination of combined anatomical regions were neck-thorax-abdomen-pelvis (NTAP), thorax-abdomen (TA), thorax-abdomen-pelvis (TAP), and abdomen-pelvis (AP). CT dose data such as CTDIvol, CTDIw and dose-length product (DLP) were collected including contrast, non-contrast, single-phasic, and multiphasic examinations. The 50th and 75th percentile of dose distribution were calculated and compared with other established DRLs. TAP CT was the most frequently performed examination at AMDI (73%). The local dose values of multiphasic and non-contrast examinations were higher compared to single phasic and contrast study. The results show a weak correlation between different CT sequences and DRLs for AP examination. Local dose values reported for all CT examinations were below any international DRLs except for CT TAP (multiphasic) study. The institutional DRL for combined anatomical regions was established using the third quartile values of dose distribution and is categorized based on CT sequences.

Risk factors predictive of unfavorable distal aortic remodeling after surgical repair of type A thoracic aortic dissection.

One-third of the patients successfully treated for acute type A aortic dissection (AAD) require re-intervention secondary to the distal aortic disease progression. The aim of this study is to identify clinical and morphologic risk factors in the pre and postoperative AAD patients with respect to unfavorable aortic remodeling, reoperations and poor long term outcomes. One hundred and twenty-three consecutive patients who survived proximal AAD surgery were reviewed at a single institution. The medical charts and computed tomography (CT) studies of these patients were reviewed from 2005 to 2014. The short axis area of the true lumen (TL), false lumen (FL) and the total cross-sectional area were measured from reconstructed images using centerline technique at the largest segment each of the aortic arch (AA), descending thoracic aorta (TA), aorta proximal to the celiac artery (CA), and the abdominal aorta (AbA). Survival and time to first reoperation were analyzed with Kaplan Meier and Cox proportional-hazards models. Factors associated with radiologic change were evaluated using multiple linear regression models. A significant change was defined as >10% change (cm2) from the baseline CTA. At least one sequential CT scan was available for 62 (50%) of the 123 patients (40 male, 22 female; average age, 59.1±13.5 years). Mean interval (baseline and the comparison CT scan) was 779 days. In general, the TA and FL increased in size over the study period. Multivariate analysis showed that age >60 years and smoking were significantly associated with an increase in TL over time, while coronary artery disease (CAD) and chronic obstructive pulmonary disease (COPD) were associated with decrease TL (P=0.03). Hyperlipidemia and CAD were associated with an increase in FL size., while pre-existing aortic aneurysm, coronary surgery and hemodialysis were significant risk factors for reoperations (P=0.029). Age >60 (P=0.01), COPD (P=0.002), and male gender (P=0.02) were also associated with an increase in total area, signifying distal aneurysmal progression. Patient risk factors predict unfavorable long-term morphologic outcomes in the remaining aorta after AAD surgical repair. These factors can be used as markers to identify patients who may benefit from closer surveillance and possibly earlier endovascular intervention to the distal thoracic aorta.

A New CT Based Method for Post-operative Motion Analysis of Pelvic Fractures

Conventional X-ray is commonly used for pelvic fracture follow-ups, but has a precision of only ± 5 mm. Implantation of tantalum beads together with RSA has shown high precision but not applicable in clinical practice. CT scan has been shown a suitable substitute for RSA to follow the metal markers. We aimed to assess whether implantation of metal markers could be avoided using CT scan and merging of bone surface anatomy. A human cadaveric pelvis marked with 0.8 mm tantalum beads was fixed over the symphysis and the right SI-joint. Left hemi-pelvis was subsequently distracted using plastic spacers. Sequential CT exams was conducted and data were analyzed using Sectra® (Sectra AB), CTMA package. Examinations were repeated after 2 weeks. Bone registration showed better precision than registration based on tantalum beads. However, only the difference in angular changes was statistically significant (p = 0.008). The confidence interval of the repeatability was ± 0.5 mm for translation and ± 0.5° for rotation. This new non-invasive technique showed good precision and repeatability and might be a future option in clinical practice for post-operative follow-ups of patients with pelvic fractures.

Sequential simulation computed tomography allows assessment of internal rectal movements during preoperative chemoradiotherapy in rectal cancer.

The purpose of this study was to assess the internal rectal movement and to determine the factors related to extensive internal rectal movement using sequential simulation computed tomography (CT) images. From 2010 to 2015, 96 patients receiving long-course preoperative chemoradiotherapy were included in our retrospective study. The initial simulation CT (Isim-CT) and follow-up simulation CT (Fsim-CT) for a boost were registered according to the isocenters and bony structure. The rectums on Isim-CT and Fsim-CT were compared on four different axial planes as follows: (1) lower pubis symphysis (AXVERYLOW), (2) upper pubis symphysis (AXLOW), (3) superior rectum (AXHIGH), and (4) middle of AXLOW and AXHIGH (AXMID). The involved rectum in the planning target volume was evaluated. The maximal radial distances (MRD), the necessary radius from the end of Isim-CT rectum to cover entire Fsim-CT rectum, and the common area rate (CAR) of the rectum (CAR, (Isim-CT∩Fsim-CT)/(Isim-CT)) were measured. Linear regression tests for the MRDs and logistic regression tests for the CARs were conducted. The mean ± standard deviation (mm) of MRDs and CAR <80% for AXVERYLOW, AXLOW, AXMID, and AXHIGH were 2.3 ± 2.5 and 8.9%, 3.0 ± 3.7 and 17.4%, 4.0 ± 5.2 and 27.1%, and 4.1 ± 5.2 and 25%, respectively. For MRDs and CARs, a higher axial level (AXVERYLOW/AXMID-HIGH, P = 0.018 and P = 0.034, respectively), larger bladder volume (P = 0.054 and P = 0.017, respectively), smaller bowel gas extent (small/marked, P = 0.014 and P = 0.001, respectively), and increased bowel gas change (decrease/increase, both P < 0.001) in rectum were associated with extensive internal rectal movement in multivariate analyses. As a result of following internal rectal movement through sequential simulation CT, the rectum above the pubis symphysis needs a larger margin, and bladder volume and bowel gas should be closely observed.

A Novel 4D-CT Sorting Method Based on Combined Mutual Information and Edge Gradient

Although mutual information is a general method usually being used to measure the similarity of two images, the robustness is questionable due to the absence of spatial information. The purpose of this study is to develop a feasible sorting technique for 4D-CT. A novel sorting algorithm named mutual information and edge gradient (MIEG), which includes spatial information by combining mutual information with a term based on the edge gradient of the image, was proposed to sort sequential CT images. The edge of image was extracted by calculating the wavelet transform modulus maxima, and the gradient similarity coefficient of the edge image was calculated and used to multiply by mutual information to form the final similarity metric. This sorting technique was validated by comparing the 4D-CTs reconstructed using MIEG and Real-time Position Management system (Varian Medical Systems, Inc., Palo Alto, CA). Tumor motion trajectories derived from 4D-CTs were analyzed in three orthogonal directions. Their correlation coefficients (CC) and differences in tumor motion magnitude (Ds) were determined. In addition, Dice similarity coefficient (DSC) was used to measure how well the tumor volumes segmented from the two 4D datasets overlapped with each other. For all patients, the mean CC values were >0.95 in all directions. The mean Ds were <0.64 mm in all directions. In addition, good overlapping was achieved between the segmented volumes with the mean DSC = 0.97 at end- and median-inspiration phases, respectively. This study proposed a feasible sorting method for 4D-CT, and its usefulness in imaging accurate tumor motion has been demonstrated.

Technical Note: Virtual CT for reducing CT dose in targeted radionuclide therapy dosimetry.

Previously we have shown that using sequential CT images is superior to sequential SPECT for nonrigid registration in three-dimensional (3D) targeted radionuclide therapy (TRT) dosimetry. However, sequential CTs are often not available due to radiation concerns. In this paper, we propose a virtual CT (vCT) method for attenuation and scatter correction, image registration, and segmentation for improved dosimetric accuracy with single CT acquisition. We used a population of nine XCAT phantoms with different In-111 Zevalin biokinetics and anatomical variations for the simulations. An analytical projector was used to simulate sequential SPECT/CT acquisitions for a medium energy general purpose collimator at 1, 12, 24, 72, and 144 h postinjection, modeling attenuation, scatter, and geometric collimator-detector response. The corresponding sequential attenuation maps of the phantoms served as real CT (rCT) images. For vCT generation, we investigated three registration methods, that is, (a) SPECT to SPECT; (b) SPECT to CT, and (c) CT to SPECT, and the optimal time point for single CT acquisition. Difference images and average normalized mean square errors (NMSE) were calculated between different vCTs and their corresponding rCTs. Absorbed dose and dose-volume histograms (DVHs) for critical organs were computed for the rCT, optimized vCT, and conventional single CT (1CT) protocols, respectively, for dosimetric analyses. For vCT generation, SPECT to SPECT registration with a single CT acquired at the first time point shows the smallest difference and NMSE. For organ absorbed doses, the results of vCT were similar to those of rCT and were superior to 1CT, that is, -0.24 ± 1.56% vs -0.49 ± 1.76% vs -6.37 ± 5.63% for the liver, -1.05 ± 2.89% vs -0.69 ± 2.74% vs -4.87 ± 4.35% for kidneys, respectively. The results of DVHs also showed improvement for all organs using vCTs as compared to the conventional 1CT protocol. The optimized vCT method can effectively increase the TRT dosimetric results if there is only a single CT available in the sequential imaging protocol, reducing the substantial increase in radiation burden from repeated CT scans.

Intraoperative Near-Infrared Fluorescence-Guided Peripheral Lung Tumor Localization in Rabbit Models

A novel liposomal nanoparticle, CF800, that co-encapsulates indocyanine green for near-infrared (NIR) imaging and iohexol for computed tomography (CT) imaging has shown preferential tumor accumulation after intravenous injection by the enhanced permeability and retention effect. We hypothesized that CF800-enhanced NIR imaging would facilitate intraoperative localization of small lung nodules. A rabbit VX2 lung tumor model was implemented. CF800 was injected intravenously, followed by sequential CT acquisitions to track the biodistribution of CF800. Eleven rabbits were used for NIR fluorescence evaluation after thoracotomy at time points until 7 days after injection by using a NIR fluorescence thoracoscope invivo. Organs of interests were removed for exvivo analysis by using NIR imaging. Tumor-to-background (inflated lung) ratio was calculated and compared among the time points. Both CT and NIR imaging indicated enhanced accumulation of CF800 within the VX2 tumor. NIR image analysis revealed the highest tumor-to-background ratio on days 4 and 5. High background at day 2 and low tumor signal at day 7 prevented distinct demarcation. Metastatic pulmonary small nodules (less than 2 mm in diameter) were successfully visualized by NIR imaging on day 4. However, NIR signal penetration was limited, resulting in localization failure for the few tumors deep (>0 mm) to the lung surface. NIR image-guided localization of small lung nodules appears to be feasible under certain conditions. However, further refinement will be required to increase tumor signal intensity and to reduce background signal from normal lung parenchyma, which is at least in part a consequence of persistent CF800 in the vasculature.

The Use of Distal Ulnar Hounsfield Units to Predict Future Fragility Fracture Risk.

Distal ulnar Hounsfield unit (HU) measurements obtained from computed tomography (CT) scans of the wrist can be used to accurately screen for low bone mineral density. It is unknown whether HU measurements can also predict the risk of future fragility fractures. Therefore, the purpose of this study was to determine if the HU values of the distal ulna correlate to fragility fracture risk. An electronic database of radiographs at a single institution was searched for all wrist CT scans, obtained for any reason, between January 1, 2002, and December 31, 2008, to allow a minimum of 5-year follow-up. Manual measurement of HU on sequential coronal CT slices of the distal ulnar head was taken, and mean values were recorded. Previously determined cutoff values for the diagnosis of low bone mineral density were implemented to stratify patients as at risk or not at risk for future fragility fracture. Medical records were then manually reviewed for the occurrence of any future fragility fracture (hip, spine, proximal humerus, or rib). There were 161 CTs in 157 patients and 34 fragility fractures in 21 patients, with a prevalence of 13.4%. The mean HU in the fragility fracture group was significantly lower(134.2 vs 197.1 HU). The percentage of low HU patients with fragility fractures was significantly higher (22.7% vs 3.8%). The odds ratio for fragility fracture in the low HU group was 7.4 (95% confidence interval, 2.1-26.2). Using previously determined cutoff values, the sensitivity and specificity of distal ulna HU values for identifying patients who would sustain at least 1 future fragility fracture were 85.7% and 55.2%, respectively. Patients with low distal ulnar HU were significantly more likely to sustain a subsequent fragility fracture. A determination of distal ulnar HUs represents a quick, simple tool to identify patients potentially at risk for fragility fractures. Prognostic IV.

Paraquat induced acute kidney injury and lung fibrosis: a case report from Bangladesh

BackgroundSince Bangladesh government issued a ban on the use of highly toxic WHO Class I pesticides, annual consumption of herbicides like Paraquat have been sharply increasing in the markets. Paraquat poisoning is an emerging public health threat and its high mortality rate is responsible for a significant number of deaths. Diagnostic limitations and unavailable sample at presentation have resulted in under-reporting and lack of awareness among the treating physicians, making Paraquat poisoning one of the most neglected toxicological emergencies. Herein, we present a case of Paraquat induced multi-organ failure and emphasis on pitfalls in the management.Case presentationAn 18-years-old healthy male was admitted in Sylhet M.A.G Osmani Medical College Hospital with history of attempted suicide by Paraquat ingestion. On admission, he had high serum creatinine but otherwise asymptomatic. He was discharged on day 10 when his renal functions returned to normal. But On day 15, he started having respiratory symptoms—unresponsive to any of the local treatments he received, and by day 30, he developed overt lung fibrosis. We present sequential blood picture, radiographs and CT scans demonstrating Paraquat induced kidney and lung injury over the course of 30 days.ConclusionParaquat poisoning can lead to death and fatal long-term consequences. All cases of Paraquat poisoning, regardless of symptoms, must be hospitalized and observed for early detection of complications. Distribution of Paraquat should be restricted and/or banned as 38 other countries have done so, which we believe will greatly reduce poisoning related mortality.

Su1430 USE OF CT TO PREDICT SUCCESS OF ENDOSCOPIC ULTRASOUND GUIDED CHOLECYSTOENTEROSTOMY

Endoscopic ultrasound guided endoluminal gallbladder decompression is an evolving treatment for patients with gallbladder disease. The procedure is usually performed in patients medically unfit for surgery. Currently there are no predictive models to determine the likelihood of success of the procedure. Our study proposes a scoring system using CT imaging to determine eligibility for the procedure. This is a retrospective examination of 150 sequential CT scans with contrast of the abdomen performed between January 2015 and January 2016. Images were assessed using non-diagnostic monitors with a web based PACS system browser (Sectra, Linköping, Sweden). The gallbladder was identified (when present) and its closest relationship to the stomach and duodenum was also identified. The relationship between the gallbladder and the stomach and the gallbladder and duodenum were quantified using on-line measuring tools, including the length, breadth and area of the approximation. A scoring system (CT assisted score - CAS ) relating area to breadth was devised to create a numerical value inversely proportional to favorability, with a score of 1 being the most favorable. Of the 150 scans reviewed, 45 (30%) patients had previous cholecystectomy. Five were excluded due to prior gastric surgery. Of the remaining 100, 63 demonstrated preferential approximation of the gallbladder to the duodenum. Sole gastric approximation was observed in only two patients. Figure 1. The CT assisted score ranged from 1 to 36, with 54 scans being 1, predicting success. Figure 2. Twelve were probable with scores calculated between 2 and 4. The remaining 34 ranged between 5 and 36 and were deemed questionable. The duodenal bulb was the most frequently approximated to the gallbladder wall compared to the second portion of the duodenum or gastric antrum. The CT assisted score may be a valuable tool to predict candidacy for endoscopic ultrasound guided endoluminal gallbladder decompression. Accessing the gallbladder from the duodenal bulb may be preferential.Figure 2. CT demonstrating favorability for cholecystoenterostomy with a CT assisted score (CAS) of 1.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Prospective-triggered high-pitch spiral versus sequential dual-source CT coronary angiography: comparison of image quality and radiation dose

Prospective-triggered high-pitch spiral versus sequential dual-source CT coronary angiography: comparison of image quality and radiation dose

Taux de fixation de la pointe du ventricule gauche et correction d’atténuation TEMP/TDM dans la scintigraphie myocardique de perfusion chez les patients non ischémiques

IntroductionAttenuation correction (AC) has been shown to improve the accuracy of myocardial perfusion single photon emission computed scintigraphy (SPECT). It often reveals a decrease in apical uptake in the AC of the left ventricular (LV) in non-ischemic patients. We aimed to identify the parameters that could affect the apical radiotracer uptake in non-ischemic patients. Materials and methodsProspectively, we included 340 consecutive non-ischemic patients. They underwent sequential CT and myocardial SPECT imaging. We studied the apical uptake with the AC (combined to scatter correction, resolution recovery and noise regularization) and its correlation with various parameters related to patient and the technique. ResultsThe apical uptake with AC was lower than with filtered back projection (FBP). On univariate analysis, several parameters correlated to apical uptake with AC, of which only 4 remained significant on step-by-step regression analysis: uptake with FBP, angle of the LV in the frontal plane, type of stress, arm's position at acquisition. These four parameters explain 51% of the variation of apical uptake with CA. ConclusionsApical uptake in myocardial perfusion scintigraphy is lower with AC compared with RPF in non-ischemic patients. The apical uptake with AC is correlated to that of FBP, angle of the LV in the frontal plane, type of stress and arm's position at acquisition.

Unipedal Diagnostic Lymphangiography Followed by Sequential CT Examinations in Patients With Idiopathic Chyluria: A Retrospective Study

The objective of our study was to investigate the clinical value of diagnostic lymphangiography followed by sequential CT examinations in patients with idiopathic chyluria. Thirty-six patients with idiopathic chyluria underwent unipedal diagnostic lymphangiography and then underwent sequential CT examinations. The examinations were reviewed separately by two radiologists. Abnormal distribution of contrast medium, lymphourinary leakages, and retrograde flow were noted, and the range and distribution of lymphatic vessel lesions were recorded. The stage of idiopathic chyluria based on CT findings and the stage based on clinical findings were compared. Therapeutic management and follow-up were recorded. Statistical analyses were performed. Compared with CT studies performed after lymphangiography, diagnostic lymphangiography showed a unique capability to depict lymphourinary leakages in three patients. Lymphourinary fistulas and abnormal dilated lymphatic vessels were found in and around kidney in all patients. CT depicted retrograde flow of lymph fluid in 47.2% of patients. The consistency in staging chyluria based on CT findings and clinical findings was fair (κ = 0.455). Twenty-nine patients underwent conservative therapy, and seven underwent surgery. Surgical therapy was superior to conservative management (no recurrence, 85.7% of patients who underwent surgery vs 62.1% of patients who underwent conservative therapy; p = 0.025). From assessing the drainage of contrast medium on unipedal diagnostic lymphangiography and the redistribution of contrast medium on sequential CT examinations, it is possible to detect the existence of lymphourinary fistulas, the precise location of lymphatic anomalies, the distribution of collateral lymphatic vessels, and hydrodynamic pressure abnormality in the lymph circulation in patients with idiopathic chyluria. CT staging of chyluria provides additional information that can be used to guide therapeutic management.

Sequential 3-dimensional computed tomography analysis of implant position following total shoulder arthroplasty

Detection of postoperative component position and implant shift following total shoulder arthroplasty (TSA) can be challenging using routine imaging. The purpose of this study was to evaluate glenoid component position over time using 3-dimensional computed tomography (CT) analysis with minimum 2-year follow-up. Twenty patients underwent primary TSA with sequential CT scanning of the shoulder: a preoperative study, an immediate postoperative study within 2 weeks of surgery, and a postoperative study performed at minimum 2-year follow-up (CT3). Postoperative glenoid component position and central peg osteolysis were assessed across the immediate postoperative CT scan and CT3. Glenoids with evidence of component shift and/or grade 1 central peg osteolysis on CT3 were considered at risk of loosening. Of the patients, 7 (35%) showed evidence of glenoid components at risk of loosening on CT3, 6 with component shift (3 with increased inclination alone, 1 with increased retroversion alone, and 2 with both increased inclination and retroversion). Significantly more patients with glenoid component shift had grade 1 central peg osteolysis on CT3 compared with those without shift (83% vs 7%, P = .002). One clinical failure occurred, with the patient undergoing revision to reverse TSA for rotator cuff deficiency. Three-dimensional CT imaging analysis following TSA identified changes in glenoid component position over time, with inclination being the most common direction of shift and grade 1 central peg osteolysis commonly associated with shift. These findings raise concern for glenoids at risk of loosening, but further follow-up is needed to determine the long-term clinical impact of these findings.

A Novel Triage Tool: Optic Nerve Sheath Diameter in Traumatic Brain Injury and its Correlation to Rotterdam Computed Tomography (CT) Scoring.

SummaryBackgroundOptic nerve sheath diameter (ONSD) evaluated in CT imaging as well as Rotterdam CT Score (RCTS) are proven independent predictors of outcome in patients with traumatic brain injury (TBI). To date, no study has correlated ONSD on admission CT scan with RCTS.Material/MethodsRetrospective cohort study comprised of consecutive patients undergoing CT imaging for traumatic brain injury recruited between January and October 2015. Bilateral ONSD was measured 3 mm behind the eyeball in axial and sagittal planes and mean value was calculated. RCTS was assessed on the same CT images, bias was eliminated by blinding RCTS to ONSD measurement.Results150 patients were included; mean age in the group was 42.94±16.7 years. ONSD in mild TBI, RCTS 2 and 3 were 3.3 mm (SD 0.39 mm) and 4.1 mm (0.047 mm), respectively. Mean ONSD in moderate and severe TBI (RCTS score 4 and above) was 4.83 mm and above, SD 0.4 mm. Mean ONSD correlated with occurrence of diffuse cerebral oedema, presence of subdural and extradural hematoma; however in isolation there was no statistical significance.ConclusionsHigher ONSD was observed in patients with moderate and severe TBI, correlating with admission RCTS of 4 and above. Subsequent increase in ONSD was also found with increase in RCTS. ONSD could serve as an initial triage tool in the emergency department as well as a method of determining the need for sequential CT in patients with mild TBI.

Osmotic Shifts, Cerebral Edema, and Neurologic Deterioration in Severe Hepatic Encephalopathy.

We sought to determine the effect of acute electrolyte and osmolar shifts on brain volume and neurologic function in patients with liver failure and severe hepatic encephalopathy. Retrospective analysis of brain CT scans and clinical data. Tertiary care hospital ICUs. Patients with acute or acute-on-chronic liver failure and severe hepatic encephalopathy. Clinically indicated CT scans and serum laboratory studies. Change in intracranial cerebrospinal fluid volume between sequential CT scans was measured as a biomarker of acute brain volume change. Corresponding changes in serum osmolality, chemistry measurements, and Glasgow Coma Scale were determined. Associations with cerebrospinal fluid volume change and Glasgow Coma Scale change for initial volume change assessments were identified by Spearman's correlations (rs) and regression models. Consistency of associations with repeated assessments was evaluated using generalized estimating equations. Forty patients were included. Median baseline osmolality was elevated (310 mOsm/Kg [296-321 mOsm/Kg]) whereas sodium was normal (137 mEq/L [134-142 mEq/L]). Median initial osmolality change was 9 mOsm/kg (5-17 mOsm/kg). Neuroimaging consistent with increased brain volume occurred in 27 initial assessments (68%). Cerebrospinal fluid volume change was more strongly correlated with osmolality (r = 0.70; p = 4 × 10) than sodium (r = 0.28; p = 0.08) change. Osmolality change was independently associated with Glasgow Coma Scale change (p = 1 × 10) and cerebrospinal fluid volume change (p = 2.7 × 10) in initial assessments and in generalized estimating equations using all 103 available assessments. Acute decline in osmolality was associated with brain swelling and neurologic deterioration in severe hepatic encephalopathy. Minimizing osmolality decline may avoid neurologic deterioration.

P290 Determination of small-bowel patency in Crohn’s disease - a prospective study

Patency capsule (PC) is usually performed to establish small-bowel patency, previously to capsule endoscopy (CE), in patients with an increased risk of CE retention. Notably, the reported patency capsule retention rate is significantly higher than the expected for Crohn’s disease (CD). Our aims were to assess small-bowel patency in CD patients, to determine the precise location of the retained PC, as well as to evaluate predictive factors for PC retention. Prospective single-centre study including CD patients with indication for small-bowel CE, between December 2015 and February 2017. PillCam® patency capsule was performed in all patients to access small-bowel patency; PC was ingested, after a 12-h fasting period, without previous bowel preparation. In all patients with a positive radiofrequency identification tag (RFIT) scanner identification of the PC, at 30 h after ingestion, an abdominal-CT was performed in order to determine its precise location. Fifty-four patients were included. 65% of patients were female and the mean age was 40.5 ± 11.1 years. Twelve (22%) patients had a known or suspected small-bowel stenosis detected by previous ileocolonoscopy or abdominal imaging. Twelve (22%) patients had a history of abdominal surgery (intestinal resection: n = 7). The PC retention rate at 30 h was 20% (11 patients). These patients were then submitted to abdominal-CT, which revealed a small-bowel retention only in 5 (9%) cases. Higher CRP levels, penetrating disease and a history of abdominal surgery were associated with increased risk of PC retention (p = 0.007, p = 0.011 and p = 0.033, respectively). On multivariate analysis, there was an independent association between small-bowel patency capsule retention and CRP levels >5mg/dL (OR = 15.5; p = 0.03). The PC small-bowel retention rate in CD was 9%, and even higher in patients with increased CRP levels. Our results show that, with this sequential CT protocol, the false positive cases of RFIT scanner or plain abdominal X-ray may be avoided. This may contribute to a more effective application of CE without the risk of small-bowel retention.

Sequential CT Findings in Two Cases of Immunoglobulin G4-Related Lung Disease: Focused on Disease Progression

Sequential CT Findings in Two Cases of Immunoglobulin G4-Related Lung Disease: Focused on Disease Progression

Multiresolution image registration for multimodal brain images and fusion for better neurosurgical planning

BackgroundImaging modalities in medicine gives complementary information. Inadequacy in clinical information made single imaging modality insufficient. There is a need for computer-based system that permits rapid acquisition of digital medical images and performs multi-modality registration, segmentation and three-dimensional planning of minimally invasive neurosurgical procedures. In this regard proposed article presents multimodal brain image registration and fusion for better neurosurgical planning. MethodsIn proposed work brain data is acquired from Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) modalities. CT and MRI images are pre-processed and given for image registration. BSpline deformable registration and multiresolution image registration is performed on the CT and MRI sequence. CT is fixed image and MRI is moving image for registration. Later end result is fusion of CT and registered MRI sequences. ResultsBSpline deformable registration is performed on the slices gave promising results but on the sequences noise have been introduced in the resultant image because of multimodal and multiresolution input images. Then multiresolution registration technique is performed on the CT and MRI sequence of the brain which gave promising results. ConclusionThe end resultant fused images are validated by the radiologists and mutual information measure is used to validate registration results. It is found that CT and MRI sequence with more number of slices gave promising results. Few cases with deformation during misregistrations recorded with low mutual information of about 0.3 and which is not acceptable and few recorded with 0.6 and above mutual information during registration gives promising results.

Sequential CT Findings in Patients With Non–small-cell Lung Cancer Receiving Nivolumab

BackgroundNivolumab is a novel immunotherapy that was recently approved for treatment of advanced non–small-cell lung cancer (NSCLC). Patients treated with checkpoint inhibitors may show variable computed tomography (CT) features on follow-up imaging, and it is unclear how reliable conventional response criteria are to determine patient management and outcomes. We report the spectrum of sequential CT findings in patients with advanced stage lung cancer who received nivolumab in an effort to better inform appropriate imaging strategies. Materials and MethodsWe identified all patients at our institution with advanced NSCLC who received nivolumab. Pre- and posttreatment CT scans were reviewed and categorized based on radiographic response to therapy. Demographic data as well as survival data were recorded. ResultsThere were 34 patients with advanced NSCLC who received nivolumab with sufficient follow-up data. Nineteen patients were classified as responders to treatment; 6 (32%) of 19 showed improvement on their initial follow-up CT and had an average survival of 11.2 months, whereas 13 (68%) of 19 responders initially had stable or progressive disease on CT with an average survival of 11.6 months. Fifteen patients were classified as nonresponders to treatment with an average survival of 3.4 months. ConclusionNovel immunotherapies such as nivolumab mechanistically differ from conventional chemotherapy. Some patients have improved survival despite initial radiographic progression of disease. Our findings underscore the heterogeneous radiographic appearance at follow-up CT in patients with lung cancer who ultimately respond to nivolumab.