The RSNA Pulmonary Embolism CT Dataset.

Supplemental material is available for this article.

CT Imaging of Complications Associated with Continuous-Flow Left Ventricular Assist Devices (LVADs).

Heart failure is becoming increasingly prevalent, and more patients are being treated with left ventricular assist devices (LVADs), either as a bridge to transplant or as destination therapy. The use of continuous-flow LVADs is on the rise. LVAD therapy is associated with several classes of complications, including bleeding, thrombosis, and infection. CT imaging can be used effectively to diagnose LVAD complications, including mediastinal hematomas and pericardial, abdominal wall, and retroperitoneal hemorrhage, inflow and outflow graft and aortic thrombi, and driveline and pump pocket infections. CT can also be helpful in cases of device malfunction and can detect outflow graft kinking and inflow cannula misalignment. When interpreting CT scans in patients with LVADs, accessory materials implanted with the device should not be mistaken for hemorrhage or calcification. With training in recognizing LVAD complications, radiologists can play an important role in the evaluation of patients with heart failure.

Variability in Patellofemoral Alignment Measurements on MRI: Influence of Knee Position.

OBJECTIVE: The purpose of this study was to determine the variability of distances between four distinct anatomic landmarks used for the evaluation of patellofemoral alignment while implementing controlled changes in patient positioning during MRI. MATERIALS AND METHODS: Limited MRI was performed of 12 knees in healthy volunteers (10 men, two women; mean age, 28 years) with the knees in four different positions. The four landmarks used were TT (the most anterior point of the osseous tibial tubercle), TG (the nadir of the cartilaginous trochlear groove), PT (the center of the patellar tendon insertion on the tibia), and PCL (the medial border of the posterior cruciate ligament at its insertion along the posterior tibia). TT-TG, PT-TG, TT-PCL, and PT-PCL distances were measured on the MR images. Each distance was measured with the knee at maximum patient comfort (rest), full extension, 15° of flexion, and 30° of flexion. Linear mixed models with random intercepts were implemented to determine variability between measurements and knee position. RESULTS: In general, measurements based on anatomic landmark and knee position varied greatly. The greatest variability in different knee positions was seen in mean TT-TG and PT-TG distances ± SD (TT-TG: rest, 18.1 ± 7.9 mm; full extension, 17.3 ± 5.3 mm; 15° of flexion, 11.4 ± 5.7 mm; 30° of flexion, 11.7 ± 6.0 mm; intraclass correlation coefficient [ICC] = 0.539; PT-TG: rest, 18.1 ± 6.3 mm; full extension, 17.9 ± 4.7 mm; 15° of flexion, 13.2 ± 5.2 mm; 30° of flexion, 11.8 ± 4.3 mm; ICC = 0.633). In contrast, knee position did not significantly affect distances for TT-PCL and PT-PCL (TT-PCL: rest, 23.5 ± 6.8 mm; full extension, 20.5 ± 5.5 mm; 15° of flexion, 22.8 ± 6.2 mm; 30° of flexion, 22.8 ± 6.7 mm; ICC = 0.484; PTPCL: rest, 23.4 ± 5.3 mm; full extension, 21.5 ± 4.5 mm; 15° of flexion, 22.3 ± 4.3 mm; 30° of flexion, 23.1 ± 4.8 mm; ICC = 0.509). CONCLUSION: On MRI, TT-PCL and PT-PCL measurements have significantly less variability compared with TT-TG and PT-TG measurements, regardless of knee position. Although further studies are warranted, the use of TT-PCL and PT-PCL measurements may offer more reliable assessment of tibial tubercle lateralization and patellofemoral alignment.

Image Sharing in Radiology-A Primer.

By virtue of its information technology-oriented infrastructure, the specialty of radiology is uniquely positioned to be at the forefront of efforts to promote data sharing across the healthcare enterprise, including particularly image sharing. The potential benefits of image sharing for clinical, research, and educational applications in radiology are immense. In this work, our group-the Association of University Radiologists (AUR) Radiology Research Alliance Task Force on Image Sharing-reviews the benefits of implementing image sharing capability, introduces current image sharing platforms and details their unique requirements, and presents emerging platforms that may see greater adoption in the future. By understanding this complex ecosystem of image sharing solutions, radiologists can become important advocates for the successful implementation of these powerful image sharing resources.

Pathology of the Trachea and Central Bronchi.

A wide variety of disorders can affect the trachea and central bronchi. Computed tomography is the imaging modality of choice in the evaluation of tracheobronchial disease. Tracheobronchial abnormalities are sometimes incidentally detected on routine imaging or when imaging is performed for another reason. Abnormalities of the tracheobronchial tree, however, can be easily missed because they can be subtle. Furthermore, because symptoms in patients with tracheobronchial disorders often overlap symptoms of lung disease, radiologists may focus their attention on the lungs and overlook the tracheobronchial tree. In this article, we review a wide range of tracheobronchial diseases with emphasis on their computed tomographic appearances.

Spectrum of Fat-containing Soft-Tissue Masses at MR Imaging: The Common, the Uncommon, the Characteristic, and the Sometimes Confusing.

Fat-containing tumors are the most common soft-tissue tumors encountered clinically. The vast majority of fat-containing soft-tissue masses are benign. Lipomas are the most common benign fat-containing masses and demonstrate a characteristic appearance at magnetic resonance (MR) imaging. Less common benign soft-tissue masses include lipoblastoma, angiolipoma, spindle cell lipoma/pleomorphic lipoma, myolipoma, chondroid lipoma, lipomatosis of nerve, lipomatosis, hibernoma, and fat necrosis. Well-differentiated liposarcomas (WDLPSs)/atypical lipomatous tumors (ALTs) are locally aggressive soft-tissue masses that do not metastasize. Biologically more aggressive liposarcomas include myxoid, pleomorphic, and dedifferentiated liposarcomas. At MR imaging, lipomas typically resemble subcutaneous fat but may contain a few thin septa. The presence of thick, irregular, enhancing septa and nonfatty soft-tissue mass components suggests liposarcoma rather than lipoma. However, benign lipomatous lesions and WDLPS/ALT often have overlapping MR imaging findings. Distinguishing WDLPS/ALT from a benign lipomatous lesion or from fat necrosis at imaging can be challenging and often requires histologic evaluation. We present the spectrum of fat-containing masses, using the World Health Organization classification of adipocytic tumors, with an emphasis on commonly encountered lesions, characteristic MR imaging findings associated with specific tumors, and overlapping MR imaging findings of certain tumors that may require histologic sampling. We also briefly discuss the role of molecular markers in proper characterization and classification of fat-containing soft-tissue masses. (©)RSNA, 2016.

Uterine Rupture: A Seven Year Review at a Tertiary Care Hospital in New Delhi, India.

OBJECTIVE: To identify the obstetric risk factors, incidence, and causes of uterine rupture, management modalities, and the associated maternal and perinatal morbidity and mortality in one of the largest tertiary level women care hospital in Delhi. MATERIALS AND METHODS: A 7-year retrospective analysis of 47 cases of uterine rupture was done. The charts of these patients were analyzed and the data regarding demographic characteristics, clinical presentation, risk factors, management, operative findings, maternal and fetal outcomes, and postoperative complications was studied. RESULTS: The incidence of rupture was one in 1,633 deliveries (0.061%). The vast majority of patients had prior low transverse cesarean section (84.8%). The clinical presentation of the patients with rupture of the unscarred uterus was more dramatic with extensive tears compared to rupture with scarred uterus. The estimated blood loss ranged from 1,200 to 1,500 cc. Hemoperitoneum was identified in 95.7% of the patient and 83% of the patient underwent repair of rent with or without simultaneous tubal ligation. Subtotal hysterectomy was performed in five cases. There were no maternal deaths in our series. However, there were 32 cases of intrauterine fetal demise and five cases of stillbirths. CONCLUSIONS: Uterine rupture is a major contributor to maternal morbidity and neonatal mortality. Four major easily identifiable risk factors including history of prior cesarean section, grand multiparity, obstructed labor, and fetal malpresentations constitute 90% of cases of uterine rupture. Identification of these high risk women, prompt diagnosis, immediate transfer, and optimal management needs to be overemphasized to avoid adverse fetomaternal complications.

Spinopelvic dissociation: multidetector computed tomographic evaluation of fracture patterns and associated injuries at a single level 1 trauma center.

The objective of the present study is to evaluate multidetector computed tomographic (MDCT) fracture patterns and associated injuries in patients with spinopelvic dissociation (SPD). Our institutional trauma registry database was reviewed from Jan. 1, 2006, to Sept. 30, 2012, specifically evaluating patients with sacral fractures. MDCT scans of patients with sacral fractures were reviewed to determine the presence of SPD. SPD cases were characterized into the following fracture patterns: U-shaped, Y-shaped, T-shaped, H-shaped, and burst. The following MDCT features were recorded: level of the horizontal fracture, location of vertical fracture, kyphosis between major fracture fragments, displacement of fracture fragment, narrowing of central spinal canal, narrowing of neural foramina, and extension into sacroiliac joints. Quantitative evaluation of the sacral fractures was performed in accordance with the consensus statement by the Spine Trauma Study Group. Medical records were reviewed to determine associated pelvic and non-pelvic fractures, bladder and bowel injuries, nerve injuries, and type of surgical intervention. Twenty-one patients had SPD, of whom 13 were men and eight were women. Mean age was 41.8 years (range 18.8 to 87.7). Five fractures (24 %) were U-shaped, six (29 %) H-shaped, four (19 %) Y-shaped, and six (29 %) burst. Nine patients (43 %) had central canal narrowing, and 19 (90 %) had neural foramina narrowing. Eleven patients (52 %) had kyphotic angulation between major fracture fragments, and seven patients (33 %) had either anterior (24 %) or posterior (10 %) displacement of the proximal fracture fragment. Fourteen patients (67 %) had associated pelvic fractures, and 20 (95 %) had associated non-pelvic fractures. Two patients (10 %) had associated urethral injuries, and one (5 %) had an associated colon injury. Seven patients (33 %) had associated nerve injuries. Six patients (29 %) had surgical fixation while 15 (71 %) were managed non-operatively. On trauma MDCT examinations, patients with SPD have characteristic fracture patterns. It is important to differentiate SPD from other pelvic ring injuries due to high rate of associated injuries. Although all SPD injuries are unstable and need fixation, the decision for operative management in an individual patient depends on the systemic injury pattern, specific fracture pattern, and the ability to attain stable screw fixation.

Intestinal obstruction associated with ovarian remnant in postmenopausal female.

Ovarian remnant syndrome (ORS) is a rare condition, in which the ovarian tissue is inadvertently left behind after difficult oophorectomy. The most common preexisting conditions associated for this complication include endometriosis, pelvic inflammatory disease, and prior abdominal surgery as in these conditions, removal of ovarian tissue becomes difficult. This is likely due to the presence of the dense fibrotic adhesions between an ovary and the surrounding structures. This residual ovarian tissue can become functional and cystic. A 56-year-old multigravida postmenopausal female was diagnosed with intestinal obstruction. She had multiple abdominal surgeries in the past, including cholecystectomy, appendectomy, hysterectomy, and bilateral salpingo-oophorectomy. Patient underwent exploratory laparotomy. Intraoperatively, extensive adhesions and scarring of bowel wall were present and approximately 15 cm proximal to the terminal ileum, a small bowel mesenteric nodule was present. Histopathology of the mesenteric nodule was consistent with the diagnosis of overian remnant. ORS can be prevented with careful resection of the entire ovarian tissue during the difficulty oophorectomy so that no ovarian tissue is left behind.

Big Data and the Future of Radiology Informatics.

Rapid growth in the amount of data that is electronically recorded as part of routine clinical operations has generated great interest in the use of Big Data methodologies to address clinical and research questions. These methods can efficiently analyze and deliver insights from high-volume, high-variety, and high-growth rate datasets generated across the continuum of care, thereby forgoing the time, cost, and effort of more focused and controlled hypothesis-driven research. By virtue of an existing robust information technology infrastructure and years of archived digital data, radiology departments are particularly well positioned to take advantage of emerging Big Data techniques. In this review, we describe four areas in which Big Data is poised to have an immediate impact on radiology practice, research, and operations. In addition, we provide an overview of the Big Data adoption cycle and describe how academic radiology departments can promote Big Data development.

Assisted breech vaginal delivery of dicephalus dipus dibrachius conjoined twins: a case report.

BACKGROUND: Conjoined twinning is a rare congenital anomaly. Even after significant advancement in the health care delivery system in developing countries, adequate antenatal care of pregnant patients and antenatal diagnosis of congenital malformations by radiological techniques like sonogram need to be emphasized. CASE: A 25-year-old woman (G1P0) at 38 weeks' gestation vaginally delivered stillborn dicephalus male twins with 2 heads, 2 necks, and a common trunk with 2 arms and 2 legs at Kasturba Hospital. The fetuses were in breech presentation and were delivered using assisted breech vaginal delivery. The conjoint nature of the fetuses remained undiagnosed antenatally and was clinically unsuspected during the intrapartum period. It was only confirmed after delivery. The intrapartum and postpartum course was uncomplicated, and the patient was discharged home on postpartum day 2. CONCLUSION: The diagnosis of conjoined twins can be missed without adequate antenatal care, leading to adverse fetomaternal outcome. Antepartum diagnosis of conjoined twins with sonography with or without MRI is essential for optimal obstetric and perinatal management, preoperative surgical planning, and parental counseling. Surgical separation of conjoined twins is possible in select cases and involves a multidisciplinary approach using several specialties.

High-resolution 3-T MRI of the fingers: review of anatomy and common tendon and ligament injuries.

OBJECTIVE. With high-resolution 3-T MRI, the complex anatomy of the fingers can be imaged in exquisite detail to provide an accurate diagnosis of clinically important ligament and tendon injuries. CONCLUSION. We present our 3-T MRI protocol using a dedicated hand-and-wrist coil and review normal MRI anatomy of the fingers. We emphasize a systematic approach to the interpretation of finger MRI examinations and illustrate this approach with examples of tendon and ligament abnormalities.

Somatostatin receptor molecular imaging for metastatic intracranial hemangiopericytoma.

Intracranial hemangiopericytomas (HPCs) are rare tumors that closely mimic meningiomas. However, in contrast to meningiomas, HPCs have a relatively high incidence of local recurrence and distant metastases, manifesting the need for sensitive noninvasive methods of detection that efficiently image the entire body. We present a rare case of a right optic nerve sheath HPC in which we identified a previously unknown distant metastasis in the thoracic spine on an 111In-pentetreotide scan. We detail the radiologic characteristics seen with somatostatin receptor imaging, FDG PET, and MRI and discuss how to exploit these findings to detect recurrence and metastatic disease in HPC.

PET/CT illustration of metastatic breast cancer to the left mandibular foramen.

Mental nerve neuropathy (numb chin/lip syndrome) is a sensory neuropathy presenting with numbness in the distribution of the inferior alveolar nerve/mental nerve (chin and lower lip). This is typically unilateral and can be secondary to dental disease or malignancy. When caused by malignancy, these symptoms can be either an initial presentation of an unsuspected tumor or progressive metastatic disease, both of which would indicate poor prognosis. We describe a 48-year-old female patient with a history of breast cancer who presented with left chin numbness and manifested a metastatic lesion involving the left mandibular foramen on PET/CT and subsequent MRI.

Renal function outcomes for multifocal renal neoplasms managed by radiofrequency ablation.

PURPOSE: To evaluate renal function changes related to radiofrequency ablation (RFA) for the treatment of multifocal renal neoplasms. METHODS: This is an institutional review board-approved, Health Insurance Portability and Accountability Act compliant retrospective study of all patients treated with computed tomography guided RFA for multifocal renal neoplasms at one institution. Fifty-seven subjects, mean age 70 (range 37-88) years, underwent RFA of 169 renal neoplasms (average size 2.0 cm). Subjects had between 2 and 8 (mean 2.96) neoplasms ablated. Estimated glomerular filtration rate (eGFR) was measured before and after RFA. Complications related to RFA were recorded. RESULTS: eGFR decreased on average of 4.4 % per tumor treated and 6.7 % per ablation session (average 1.76 tumors treated per session). For subjects with the largest neoplasm measuring >3 cm, eGFR decreased an average of 14.5 % during the course of their treatment. If the largest neoplasm measured 2-3 cm, eGFR decreased an average of 7.7 %, and if the largest neoplasm measured <2 cm, eGFR decreased an average of 3.8 %. Subjects with reduced baseline renal function were more likely to have a greater decline in eGFR after RFA. There was a minor complication rate of 6.3 % (6 of 96 sessions), none of which required treatment, and a major complication rate of 4.2 % (4 of 96 sessions). CONCLUSION: RFA for the treatment of multifocal renal neoplasms results in mild decline of renal function.

Imaging of infective endocarditis with cardiac CT angiography.

Infective endocarditis (IE) is a disease characterized by high rates of morbidity and mortality that can present with a spectrum of clinical and imaging findings. Cardiac-gated computed tomographic angiography (CTA) has been shown to be highly accurate in evaluation of both coronary artery disease and structural heart disease and is now considered an appropriate preoperative imaging modality in patients undergoing noncoronary cardiac surgery. This review discusses the use of cardiac-gated CTA in preoperative evaluation of patients with IE, with emphasis on imaging findings of valvular and perivalvular complications. Topics include technique tips specific to valve imaging with cardiac-gated CTA, potential benefits of cardiac-gated CTA compared with other imaging modalities such as echocardiography, limitations of imaging patients with IE with cardiac-gated CTA, and an overview of potential findings in patients with IE, including vegetations, valve perforations, perivalvular abscesses, perivalvular pseudoaneurysms, and fistulas. Throughout this review, cardiac-gated CTA findings of IE are presented with echocardiographic and operative correlation to emphasize that cardiac-gated CTA may in select cases provide incremental benefit in the preoperative assessment of patients with IE.

Evolution of a ureteric stone from the renal pelvis to the ureter on skeletal scintigraphy with CT correlation.

Because bone-seeking radiopharmaceuticals are excreted into the urine by the kidneys, normal kidneys and bladder are well visualized on skeletal scintigrams leading to incidental detection of urinary tract abnormalities in up to 15% of bone scans. Although the findings pertaining to the urinary tract on skeletal scintigraphy are seldom suggestive of a definitive diagnosis, they are highly specific for renal disease, with fewer than 2% false-positive studies reported. In the presented case, we demonstrate the evolution of a ureteric stone from the renal pelvis into the ureter on sequential skeletal scintigraphy with CT correlation.

Prenatal diagnosis of thoracopagus fetus: a case report with brief review of literature.

Conjoined twins are uncommon and refer to monozygotic, monoamniotic and monochorionic twins with varying degree and sites of fusion between the twins. In this report, we illustrate a case of thoracopagus twins highlighting the prenatal sonographic and magnetic resonance imaging appearance. Emphasis is laid on the role of appropriate imaging strategy in prognostic assessment and postnatal surgical treatment planning of these cases.