Prospective Comparison of Standard- Versus Low-Radiation-Dose CT Enterography for the Quantitative Assessment of Crohn Disease.

OBJECTIVE: CT enterography (CTE) is sensitive and specific for active inflammatory changes of Crohn disease (CD), but its use has been limited by exposure to ionizing radiation. The objective of this study is to show the noninferiority of a model-based iterative reconstruction (MBIR) technique using lower radiation doses compared with standard-dose CTE in the assessment of CD. SUBJECTS AND METHODS: Patients referred to a hospital radiology department for CTE for the evaluation of CD underwent both a standard examination (used to generate filtered back-projection and adaptive statistical iterative reconstruction [ASIR] images) and low-dose MBIR CTE performed in a random sequence on the same day. Images were reviewed by two radiologists for signs of small-bowel CD. Radiologic findings obtained using ASIR and clinical assessments of disease activity served as the reference standard for comparison with low-dose CTE findings. RESULTS: A total of 163 patients, 92 (56.4%) of whom had active disease, underwent CTE. MBIR was found to be noninferior to the two standard-dose techniques, with no significant differences noted between the three types of images when compared with the clinical reference standard. As compared with the radiologic standard of ASIR, the very-low-dose scans had a high degree of accuracy, with sensitivity ranging from 0.85 to 0.94 and specificity ranging from 0.84 to 0.97 depending on the reader. A significant reduction in radiation exposure was noted with MBIR (mean [± SD] reduction, 3.30 ± 3.17 mSv) versus standard-dose imaging (7.16 ± 4.61 mSv; p < 0.001). CONCLUSION: Low-dose CTE using MBIR is sensitive and specific for the detection of active inflammatory changes of CD while utilizing radiation doses substantially lower than those associated with standard techniques.

Do we really need to thank the Beatles for the financing of the development of the computed tomography scanner?

It is commonly believed that the revenues from the selling of the Beatles' records by Electric and Musical Industries (EMI) allowed the company to develop the computed tomography (CT) scanner. Some went to define this as the Beatles' gift to medicine. However, significant controversies and discrepancies arise from analysis of this statement, making its correctness doubtful. The details of financing required for the CT development and the part of EMI in financial input have never been publicly announced. This work analyzes the financial contributions to the CT development and investigates if the revenues received from the sales of the Beatles' records were used for the creation of the CT scanner. Timeline of the development of the EMI CT scanner and the financial inputs of EMI and British Department of Health and Social Security (DHSS) were assessed. Without salary expenses to Godfrey Hounsfield and his team, the development of the CT scanner cost EMI approximately £100,000. The British DHSS's expenses were £606,000. Hence, the financial contribution of DHSS into the development of the CT scanner was significantly bigger than that of EMI. Accordingly, British tax payers and officials of British DHSS are to be thanked for the CT scanner. The Beatles' input into the world's culture is valuable and does not require decoration by nonexistent connection to the development of CT. A positive aspect to this misconception is that it keeps in public memory the name of the company that developed the CT scanner.

Stone foreign body--radiographic and CT appearance.

Mineral foreign bodies (stones) are infrequent findings in clinical and radiological practice. However, a growing number of reports indicate that they raise clinical and diagnostic concern in ophthalmology, neurosurgery, maxillofacial surgery, otolaryngology, gastroenterology, and vascular surgery. Dense finding in the soft tissue without clear history of foreign body penetration may represent diagnostic challenge mimicking calcifications or bony fragments. The aim of this work is to analyze the appearance of stone foreign bodies on radiographs and computed tomography. A collection of minerals and rocks was used for analysis. The clinical case of a stony foreign body which penetrated into the soft tissue of the leg is used to demonstrate the diagnostic challenge and management. Available literature describing imaging characteristics of stones was reviewed. The results of this work will help in diagnostic interpretation and assessment of stone foreign body composition.

How to measure scapholunate and Cobb's angles on MRI and CT.

The measurement of angles between anatomical structures is common in radiological and orthopedic practice. Frequently used measurements include scapholunate angle for assessment of wrist instability and Cobb's angle used for assessment of scoliosis. Measurements of these angles are easily performed on plain X-ray radiographs. However, the situation is more complicated when these measurements are to be performed on cross-sectional (CT or MRI) examinations. On some of the diagnostic workstations, it is not possible to perform angle measurements between the structures if they are not identified on the same image and are located on different images of the same projection or plane. We present a simple solution to measure angles between structures on different images that can be used both in CT and MR.

Radiologic signs of weapons and munitions: How will noncombatants recognize them?

OBJECTIVE: The purpose of this work was to show the radiologic signs named after weapons and munitions along with their military counterparts to help radiologists recognize these signs, which will allow confident interpretation and diagnosis. CONCLUSION: Numerous pathologic conditions have classic radiologic manifestations that resemble weapons and ammunition. Most of these signs are highly memorable and easy to recognize. However, the names of the weapons (some of them antique and some not commonly known) may confuse radiologists who are not familiar with the appearance of such weapons as the scimitar, bayonet, or dagger. The value of the signs is reduced if the radiologist is unfamiliar with the appearance of the corresponding weapon.

Displacement of the temporomandibular joint disk: correlation between clinical findings and MRI characteristics.

BACKGROUND AND OBJECTIVE: Disk displacement frequently causes dysfunction of the temporomandibular joint (TMJ). Magnetic resonance imaging (MRI) of the TMJ is 95% accurate in the assessment of disk position and form. Various restorative procedures are used for treatment of disk displacement. However, several authors have noted a lack of correlation between MRI findings of disk displacement and the extent of pain and dysfunction of the TMJ. The purpose of this study was to evaluate whether MRI findings of various degrees of disk displacement could be correlated with the presence of clinical signs and symptoms in patients with a clinical disorder of the TMJ. MATERIALS AND METHODS: One hundred and forty-four TMJs (in 72 patients) were imaged. Displacement of the posterior band in relation to the condyle was quantified as mild or significant. RESULTS: Disk displacement was found in 45 (54%) of the 84 symptomatic joints and 13 (22%) of the 60 asymptomatic joints. Among the 84 symptomatic joints, 31 (37%) had disk displacement with reduction and 14 (17%) had disk displacement without reduction. In the latter group, 11 (79%) of the 14 joints had significant displacement of the posterior band (8 or 9 o'clock) and 21% had mild displacement of the posterior band (10 o'clock). Of the 60 clinically asymptomatic joints, 47 (78%) had no signs of disk displacement on MRI, whereas 13 (22%) had disk displacement with reduction. None of the asymptomatic joints had disk displacement without reduction. The difference in occurrence of disk displacement between symptomatic and asymptomatic joints was statistically significant (54% vs. 22%; p < 0.001). However, the difference in occurrence of disk displacement with reduction of the disk on mouth opening was not statistically significant (37% vs. 22%; p = 0.06). CONCLUSIONS: Disk displacement on MRI correlated well with clinical symptoms in cases of significant disk displacement and in cases of disk displacement without reduction. When disk displacement with reduction was mild, there was no statistically significant difference between symptomatic and asymptomatic joints, which suggests that other causes should be considered.

Safety and Feasibility of Using Magnetic Resonance Imaging Criteria to Identify Patients With "Good Prognosis" Rectal Cancer Eligible for Primary Surgery: The Phase 2 Nonrandomized QuickSilver Clinical Trial.

IMPORTANCE: Chemoradiotherapy (CRT), followed by surgery, is the recommended approach for stage II and III rectal cancer. While CRT decreases the risk of local recurrence, it does not improve survival and leads to poorer functional outcomes than surgery alone. Therefore, new approaches to better select patients for CRT are important. OBJECTIVE: To conduct a phase 2 study to evaluate the safety and feasibility of using magnetic resonance imaging (MRI) criteria to select patients with "good prognosis" rectal tumors for primary surgery. DESIGN, SETTING, AND PARTICIPANTS: Prospective nonrandomized phase 2 study at 12 high-volume colorectal surgery centers across Canada. From September 30, 2014, to October 21, 2016, a total of 82 patients were recruited for the study. Participants were patients newly diagnosed as having rectal cancer with MRI-predicted good prognosis rectal cancer. The MRI criteria for good prognosis tumors included distance to the mesorectal fascia greater than 1 mm; definite T2, T2/early T3, or definite T3 with less than 5 mm of extramural depth of invasion; and absent or equivocal extramural venous invasion. INTERVENTIONS: Patients with rectal cancer with MRI-predicted good prognosis tumors underwent primary surgery. MAIN OUTCOMES AND MEASURES: The primary outcome was the proportion of patients with a positive circumferential resection margin (CRM) rate. Assuming a 10% baseline probability of a positive CRM, a sample size of 75 was estimated to yield a 95% CI of ±6.7%. RESULTS: Eighty-two patients (74% male) participated in the study. The median age at the time of surgery was 66 years (range, 37-89 years). Based on MRI, most tumors were midrectal (65% [n = 53]), T2/early T3 (60% [n = 49]), with no suspicious lymph nodes (63% [n = 52]). On final pathology, 91% (n = 75) of tumors were T2 or greater, 29% (n = 24) were node positive, and 59% (n = 48) were stage II or III. The positive CRM rate was 4 of 82 (4.9%; 95% CI, 0.2%-9.6%). CONCLUSIONS AND RELEVANCE: The use of MRI criteria to select patients with good prognosis rectal cancer for primary surgery results in a low rate of positive CRM and suggests that CRT may not be necessary for all patients with stage II and III rectal cancer. TRIAL REGISTRATION: ISRCTN.com identifier: ISRCTN05107772.

Chest radiographic and CT manifestations of chronic granulomatous disease in adults.

OBJECTIVE: The purpose of this study was to describe the thoracic radiologic findings of chronic granulomatous disease in adults. MATERIALS AND METHODS: We retrospectively analyzed the chest radiographic and CT findings in four adults with chronic granulomatous disease during five episodes of lower respiratory tract infection. RESULTS: Chest radiographic findings included areas of consolidation (60%), diffuse reticulonodular opacities (40%), pleural effusion (20%), and pulmonary artery enlargement (20%). CT findings included areas of consolidation (60%), pulmonary nodules in a random distribution (60%), centrilobular nodules (60%), tree-in-bud opacities (40%), areas of scarring and traction bronchiectasis (100%), emphysematous changes (75%), areas of decreased attenuation and vascularity associated with air trapping on expiratory CT (50%), mediastinal and/or hilar lymphadenopathy (60%), pulmonary artery enlargement (50%), and pleural effusion (20%). Areas of consolidation and nodules were the most prominent findings and at histologic examination were found to be associated with infection or granulomatous inflammation. CONCLUSION: The pulmonary radiologic findings of chronic granulomatous disease include consolidation, nodules, areas of scarring, traction bronchiectasis, emphysema, air trapping, mediastinal and hilar lymphadenopathy, pulmonary artery enlargement, and pleural effusion.

Computer-aided detection of pulmonary embolism on CT angiography: initial experience.

OBJECTIVE: To evaluate the performance of a computer-aided detection (CAD) system for diagnosis of pulmonary embolism on computed tomography (CT) pulmonary angiography. MATERIALS AND METHODS: One hundred and four pulmonary CT angiograms for pulmonary emboli (PE) were reviewed both by radiologists and a CAD detection system (ImageChecker CT V2.0, R2 Technology Inc, Sunnyvale, CA). CT scans, read and reported by radiologists in a routine daily clinical setting, were later processed by the CAD system. The performance of the CAD system was analyzed. RESULTS: Forty-five PE were identified by the radiologists in 15 patients. The CAD system revealed 123 findings, interpreted by the system as PE. Twenty-six of them, detected in 8 patients, represented true-positive results. Ninety-seven (78.9%) CAD findings were not true PE and were defined as false-positive. Nineteen true PE in 7 patients were missed by the CAD system constituting 42% false-negative rate. Sensitivity of the CAD system was 53.3% and the specificity was 77.5%. The positive predictive value of CAD system was 28.5% and the negative predictive value was 90.7%. CONCLUSIONS: With the evaluated CAD system, it is relatively simple and fast to check all detected findings and decide if they represent true PE. However, high false-negative results demand technologic improvement, to increase the sensitivity of the system. It is anticipated to become a promising supplement to the work and eyes of the radiologist in detecting PE on pulmonary CT angiography.

Is it a fibroid? Are you sure? Sonography with MRI assistance.

Uterine fibroids are common benign lesions. Other common benign masses include renal cysts, renal angiomyolipomas, hepatic cysts, hepatic hemangiomas, thyroid cysts, adrenal incidentalomas, pulmonary granulomas and hamartomas, ovarian cysts, and dermoids. All these conditions, especially in asymptomatic patients, almost never have clinical significance. However, it is important to differentiate them from more sinister or even malignant lesions. In general, when a lesion is described as a fibroid, no further evaluation is performed. So if we say that a lesion is a fibroid, we have to be sure. Endometrial fibroids may mimic endometrial polyps or endometrial cancer. Subserous, especially pedunculated fibroids, may need further evaluation to differentiate them from ovarian pathology, colonic pathology, or even müllerian duct anomalies. Pelvic magnetic resonance imaging may be helpful in these cases.

Computer-aided detection in screening CT for pulmonary nodules.

OBJECTIVE: Our objective was to evaluate the performance of a computer-aided detection (CAD) system for pulmonary nodule detection using low-dose screening CT images. MATERIALS AND METHODS: One hundred fifty consecutive low-dose screening CT examinations were independently evaluated by a radiologist and a CAD pulmonary nodule detection system (R2 Technology) designed to identify nodules larger than 4 mm in maximum long-axis diameter. All discrepancies between the two techniques were reviewed by one of another two radiologists working in consensus with the initial interpreting radiologist, and a "true" nodule count was determined. Detected nodules were classified by size, density, and location. The performance of the initial radiologist and the CAD system were compared. RESULTS: The radiologist detected 518 nodules and the CAD system, 934 nodules. Of the 1,106 separate nodules detected using the two techniques, 628 were classified as true nodules on consensus review. Of the true nodules present, the radiologist detected 518 (82%) of 628 nodules and the CAD, 456 (73%) of 628 nodules. All 518 radiologist-detected nodules were true nodules, and 456 (49%) of 934 of CAD-detected nodules were true nodules. The radiologist missed 110 true nodules that were only detected by CAD. In six patients, these were the only nodules detected in the examination, changing the imaging follow-up protocol. CAD identified 478 lesions that on consensus review were false-positive nodules, a rate of 3.19 (478/150) per patient. CONCLUSION: CAD detected 72.6% of true nodules and detected nodules in six (4%) patients not identified by radiologists, changing the imaging follow-up protocol of these subjects. In this study, the combined review of low-dose CT scans by both the radiologist and CAD was necessary to identify all nodules.

T2 mapping of articular cartilage of glenohumeral joint with routine MRI correlation--initial experience.

The evaluation of articular cartilage currently relies primarily on the identification of morphological alterations of the articular cartilage. Unlike anatomic imaging, T2 mapping is sensitive to changes in the chemical composition and structure of the cartilage. Clinical evaluation of T2 mapping of the glenohumeral joint has not been previously reported. The objectives of this study were to evaluate the feasibility of magnetic resonance T2 mapping of the glenohumeral joint in routine clinical imaging, to assess the normal T2 mapping appearance of the glenohumeral joint, and to compare the findings on T2 maps to conventional MR pulse sequences. Magnetic resonance imaging (MRI) examinations of 27 shoulders were performed in a routine clinical setting. All studies included acquisition of T2 mapping using a dedicated software. The T2 maps were analyzed along with the routine MR exam and correlation of cartilage appearance on T2 map and on conventional MR sequences. T2 imaging maps were obtained successfully in all patients. T2 maps and routine MRI correlated in cases of normal cartilage and prolonged T2 values and cartilage defects. In four cases, increased T2 relaxation times in the cartilage and cartilage defects were more apparent on T2 maps. Acquisition of T2 maps at the time of routine MRI scanning is feasible and not time-consuming.

Emergency endovascular treatment of thoracic aortic rupture in three accident victims with multiple injuries.

PURPOSE: To report an experience with emergency endovascular treatment of traumatic thoracic aortic ruptures in multi-injured patients. CASE REPORTS: Three victims of motor vehicle accidents with multiple head, chest, and abdominal injuries in addition to fractures were treated urgently for thoracic aortic lacerations with transluminal placement of an endovascular graft during the initial emergent laparotomy. In all cases, ruptured visceral organs were treated first and the abdomen closed. Femoral artery access was gained through a cutdown, and the endografts were delivered with no systemic heparinization. The endovascular component of the surgical session took approximately 50 minutes. All patients survived to discharge. Two patients are alive at 5 and 12 months with sustained endovascular exclusion of the pseudoaneurysm, but one patient with severe brain damage died 9 months after treatment from respiratory insufficiency. CONCLUSIONS: Acute endovascular treatment of thoracic aortic ruptures is feasible and has the advantage of avoiding thoracotomy in otherwise severely injured patients.