Intra-Aortic Balloon Pump Simulating Thoracic Aortic Dissection.

We present a 70-year-old woman who had an intra-aortic balloon pump (IABP) in its deflated state in the aorta during a computed tomography angiogram scan. The scan was performed to assess for aortic dissection. The deflated IABP created a curvilinear filling defect in the aortic lumen that suggested an intimal flap. Herein, we described the finding and suggest key features that can help distinguish between this intra-aortic device and a true dissection. This distinction between the device and aortic dissection is not only important because of the potential pitfall of a false positive diagnosis but also because an IABP itself can lead to an aortic dissection and therefore its computed tomography features should be recognized in both its inflated and deflated state.

CT pulmonary angiogram quality comparison between early and later pregnancy.

PURPOSE: Pregnancy increases the risk for thromboembolic disease. CT pulmonary angiogram (CTPA) is widely used for the diagnosis of pulmonary embolus (PE); however, a significant number of scans are suboptimal or non-diagnostic in pregnant patients. This phenomenon is attributed to physiology during the gravid state. The aim of this study is to examine whether all stages of pregnancy are similarly at risk for suboptimal scans. METHODS: Pregnant patients who had CTPA scans between February 2008 and November 2014 were included. The attenuation in the major pulmonary arteries was compared among patients and controls. An attenuation of 200 Hounsfield units (HU) was used as a cutoff between adequate and suboptimal studies. Statistical analysis compared attenuation means and number of arteries with adequate versus suboptimal attenuation. RESULTS: Forty patients were included in the study. Nine were at or below 13 weeks of pregnancy and 31 between week 14 and term. A control group of 14 non-pregnant women of similar age were also included. All arteries showed a significantly higher attenuation in early pregnancy and in the control group compared to later in pregnancy, p < 0.05. Fewer suboptimal opacified arteries were found in early pregnancy (11.1%) and controls (5.7%) compared to later in pregnancy (33.3%), p < 0.01. CONCLUSION: Patients in early pregnancy are more likely to have a technically successful CTPA scan compared to later in pregnancy and show similar opacification to non-pregnant women. This suggests a possible paradigm shift from the current approach to suspected PE in pregnant patients.

Computed Tomography Pulmonary Angiogram Dynamic Parameter Correlation With Pulmonary Pressure and Pulmonary Hypertension Etiologies.

OBJECTIVE: Pulmonary hypertension (PH) is caused by etiologies that differ in pathophysiology. Patients with undiagnosed PH may have a computed tomography pulmonary angiography (CTPA) scan during workup. Static measurements on computed tomography correlate with PH; however, dynamic parameters have received less attention. We studied the correlation between CTPA dynamic parameters and PH and assessed whether these parameters differ among PH etiologies. We also propose a method for PH screening. METHODS: Patients who underwent right-heart catheterization and CTPA within 45 days of each other were included. Charts were reviewed for presence and etiology of PH. The time it took to reach the CTPA trigger threshold during bolus tracking (TT) was recorded and compared with pulmonary pressure measured on pulmonary artery catheterization. The correlation between TT values and pulmonary pressure was studied, as well as the sensitivity and specificity of TT for PH. RESULTS: Twenty-seven patients with 28 examinations were included. A significant correlation was found between pulmonary pressure and TT, as well as TT and right ventricular decreased function, P < 0.01. Left heart failure showed the longest TT among PH subgroups and significantly longer TT in patients with both PH and right ventricular decreased function. Time to trigger demonstrated a sensitivity range of 75% to 92% and specificity between 56% and 88% for pulmonary pressure of 40 mm Hg or greater. CONCLUSIONS: Dynamic parameters of flow measured on CTPA significantly correlate with pulmonary pressure and can potentially help screen for PH. Left heart failure seems to have the greatest impact on TT among patients with PH.

Occult Lung Cancer Occluding a Pulmonary Vein with Suspected Venous Infarction, Mimicking Pneumonia and a Pulmonary Embolus.

BACKGROUND: Patients with lung cancer present to the emergency department (ED) in a variety of ways. Symptoms are often nonspecific and can lead to a delay in diagnosis. Here, a lung cancer mimicked two illnesses, adding to the diagnostic complexity. This case highlights diagnostic pitfalls as well as advantages and limitations of imaging utilized in the emergency setting. CASE REPORT: We report a case of an occult lung cancer occluding a pulmonary vein, which at first mimicked pneumonia and later a pulmonary embolism (PE) and arterial lung infarction. The patient presented to the ED with cough and a lung opacity on chest radiograph that was treated with antibiotics. However, recurrent visits to the ED with similar complaints were further investigated with computed tomography angiogram (CTA). At first the scan was considered positive for PE. Further inspection revealed that the CTA findings were not typical for PE, but rather a slow flow state likely caused by an occult mass occluding a pulmonary vein with venous infarction. Biopsy revealed a lung adenocarcinoma. In addition to the case presentation, the typical signs of PE on CTA with correlating images and diagnostic pitfalls are discussed. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report raises two themes that can be of interest to emergency physicians. The first is that lung cancer has many guises. Here it mimicked two distinctly different diseases, pneumonia and PE. The second is that, although CTA is highly sensitive and specific for diagnosing PE, it has limitations that may lead to false positive readings. When clinical signs and symptoms fail to correlate with the imaging diagnosis, alternative explanations should be sought.

Superior Vena Cava Obstruction in Hemodialysis Patients: Symptoms, Clinical Presentation and Outcomes Compared to Other Etiologies.

The incidence of superior vena cava (SVC) obstruction associated with non-malignant diseases is on the rise, and a large percentage of these patients are on hemodialysis (HD). The objective was to characterize the presentation, symptoms and outcomes of HD patients with SVC obstruction identified on computerized tomography (CT) compared to patients with other etiologies such as neoplasm. A search was performed through the PACS system using key words to identify patients with SVC obstruction. The CT scans and charts were reviewed for degree of obstruction, signs, symptoms and outcomes. Thirty-six patients were included in the study. Thirteen were on HD and of these, five had symptoms associated with SVC obstruction and one had concordant findings on physical exam. In comparison, thirteen patients with a chest neoplasm had symptoms and four had concordant findings on physical exam. On follow up, 31% of the HD patients died and of these 60% were symptomatic and died within 2 years. 29% of lung cancer patients died within 16 months. The majority of the HD patients had complete SVC obstruction (85%) as opposed to those with a chest neoplasm who mostly had partial SVC occlusion (67%). In conclusion, patients on HD with SVC obstruction are less often symptomatic than those with a neoplasm. However, these HD patients had a death rate similar to the patients with cancer. This risk seems to increase in those who are symptomatic. Diagnosis of SVC obstruction by CT in HD patients may help identify those with less favorable prognosis.

Cardiac Physiology for Radiologists: Review of Relevant Physiology for Interpretation of Cardiac MR Imaging and CT.

Cardiac computed tomography (CT) and magnetic resonance (MR) imaging provide clinicians with important insights into cardiac physiology and pathology. However, not all radiologists understand the language and concepts of cardiac physiology that are used daily by cardiologists. This review article covers basic cardiac physiology as it relates to cardiac CT and MR imaging. Topics include a review of the cardiac cycle and left ventricular pressure-volume loops as they relate to different pathologic states, evaluation of cardiac function, and calculation of key parameters such as left ventricular volumes and the ejection fraction. The hemodynamics of cardiac shunts are covered, with an emphasis on factors important to cardiologists, including the ratio of pulmonary flow to systemic flow. Additionally, valvular physiologic function is reexamined, with a focus on understanding pressure gradients within the heart and also the changes associated with valvular pathologic conditions, including measurement of regurgitant fractions in patients with valvular insufficiency. Understanding these basic concepts will help radiologists tailor the reporting of cardiac studies to clinically relevant information.

Downhill esophageal varices: a prevalent complication of superior vena cava obstruction from benign and malignant causes.

OBJECTIVE: Downhill esophageal varices (DEV) usually develop secondary to superior vena cava (SVC) obstruction. Downhill esophageal varices have been less well characterized compared to uphill varices. The aim of the study was to characterize the anatomy and etiology of DEV by contrast-enhanced computed tomography. METHODS: Patients with SVC obstruction were included in the study. Downhill esophageal varices were defined as discrete esophageal submucosal or mucosal vessels. Ten random computed tomographic scans were assessed as controls. RESULTS: Downhill esophageal varices were seen in 11 of 36 patients. Three types of varices were observed. Between 1 and 6 varices were seen in each patient with a diameter of 1 to 5 mm. CONCLUSIONS: Downhill esophageal varices can be seen in 30% of patients with SVC obstruction. They have several patterns and are mostly systemic-to-systemic collaterals. The most common etiology associated with DEV is renal failure. Downhill esophageal varices are of small caliber, this may in part account for less frequent bleeding compared to uphill varices.

Pulmonary hypertension detection using dynamic and static measurable parameters on CT angiography.

OBJECTIVE: The aim was to assess dynamic and static parameters on routine computed tomography pulmonary angiography (CTPA) that may detect pulmonary hypertension (PH). METHODS: Fifty patients underwent CTPA and echocardiograms. Twenty-six patients had PH, and 24 patients did not have PH. The following parameters were measured on CTPA: density of the pulmonary artery (PA), ratio between the density in the PA and the thoracic aorta (TA), the time between the start of contrast injection to the time the scan trigger density was reached, and PA diameter. RESULTS: All measured parameters showed significant correlation with PH detected by echocardiogram. The best combination of parameters for detection of PH was contrast density ratio between PA and thoracic aorta of greater than or equal to 1.5 and/or a time to scan trigger of greater than or equal to 8 seconds. CONCLUSIONS: The parameters measured correlate well with PH by echocardiography. This suggests that CTPA can potentially be used to detect PH.

Prevalence and etiology of focal liver opacification in patients with superior vena cava obstruction.

OBJECTIVE: This study aimed to assess the prevalence and etiologies of focal liver opacification (FLO) in the setting of superior vena cava (SVC) obstruction. METHODS: An archival search using key words to identify patients with SVC obstruction or severe narrowing and who had computed tomographic scans with intravenous contrast was performed at our institution. RESULTS: Thirty-one patients were included. Focal liver opacification was identified in 9 (29%). The most common direct causes of FLO and SVC obstruction were benign. CONCLUSIONS: Focal liver opacification caused by SVC obstruction is relatively common. Focal liver opacification is more commonly associated with benign causes of obstruction such as end-stage renal disease. Identifying FLO is important not only as an indirect sign of SVC obstruction but also must be distinguished from avidly enhancing liver masses. This study also reflects the overall recent increase in benign causes of SVC obstruction.

Penetrating atherosclerotic aortic ulcer rupture causing a right hemothorax; a rare presentation of acute aortic syndrome.

Acute aortic syndrome is a spectrum of diseases that have similar presentation and clinical background and include aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcer. Presented here is an 82-year-old woman with a medical history of diabetes, hypertension, nephrectomy, and chronic renal failure who complained of sudden abdominal pain radiating to epigastrium and back. At presentation, the patient was hemodynamically stable with a hemoglobin level of 10.2 and white blood cell count of 12. Chest x-ray showed a right pleural effusion and lung opacity with interstitial pulmonary edema. Computed tomography demonstrated an aortic penetrating atherosclerotic ulcer that ruptured into the right pleural space resulting in right hemothorax. A percutaneous endostent was placed with subsequent discharge of the patient 10 days after admission.

99mTc-methylene diphosphonate single photon emission tomography of the knees: intensity of uptake and its correlation with arthroscopic findings.

OBJECTIVE: To examine whether single photon emission computed tomography (SPECT) can determine the severity of knee pathology, based on intensity of uptake and, therefore, possibly substituting this technique for more invasive and expensive diagnostic procedures, such as arthroscopy, in certain patient populations. METHODS: The study results of patients referred for knee SPECT followed by an arthroscopy at our institution were evaluated retrospectively. The scintigraphic and arthroscopic findings for the menisci and femoral condyles were each graded on a numeric scale. One numeric scale corresponded to the level of uptake in the SPECT and the other to the severity of the pathology visualized at arthroscopy. Statistical correlation between both scales, representing the SPECT and arthroscopy findings, was performed. RESULTS: Forty-one patients were included in the study. A positive and statistically significant correlation was found between the intensity of uptake on the SPECT and the severity of the arthroscopic findings in the menisci and medial femoral condyle. CONCLUSION: The degree of uptake in the knee, as determined by SPECT, positively correlates with the severity of pathology seen at arthroscopy. The data can potentially be used to assist in decision-making before proceeding to surgery, especially where there is severe pathology that may be less amenable to arthroscopic therapy.

A proposed anatomic typing of the right internal spermatic vein: importance for percutaneous sclerotherapy of varicocele.

PURPOSE: To classify the anatomic types of the right internal spermatic vein (ISV). METHODS: We evaluated venograms obtained in 150 consecutive patients with idiopathic varicocele referred for transfemoral sclerotherapy. RESULTS: Six anatomic types of the right internal spermatic vein (ISV) were recognized. These were classified by the location of their orifices and the tributary venous patterns. In roughly half the patients (53%), the ISV appeared as a simple vein with no remarkable retroperitoneal interconnections. In the remainder, complex retroperitoneal anastomoses were encountered. CONCLUSION: By understanding these anatomic variations, the angiographer can approach treatment of right-sided varicocele with foreknowledge of the nature of these types and the presence of valves and collaterals.

Ultrasonography in patients without trauma in the emergency department: impact on discharge diagnosis.

OBJECTIVE: The aim of this study was to examine to what extent findings on ultrasonography performed in the emergency department (ED) after hours confirm or alter the referral diagnosis in patients without trauma as reflected in the discharge diagnosis. METHODS: In this prospective study, data from 136 ultrasonographic examinations performed in patients without trauma after hours in the ED during January and February 2002 were evaluated against the suspected preimaging diagnosis of the referring ED physician and the actual discharge diagnosis from the ED or after hospitalization. The rate of preimaging and postimaging concordance was statistically analyzed and compared by calculation of confidence intervals and by the McNemar test. RESULTS: Normal ultrasonographic findings were documented in 54 patients (40%), and pathologic findings were documented in 82 (60%). Thirty-four (25%) of the 136 examinations were concordant with the initial referring physician's diagnosis. Of the 102 studies that were not concordant with the initial referral suspected diagnoses, that is, being either a study with normal findings or offering an alternative diagnosis, 81 (79.4%) were concordant with the discharge diagnosis. CONCLUSIONS: After-hours ultrasonographic findings in patients without trauma seen in the ED seem to have a high impact on the discharge diagnosis and are concordant with it in more than 80% of cases.

Balloon angioplasty of popliteal and crural arteries in elderly with critical chronic limb ischemia.

OBJECTIVE: Elderly patients with extensive infrainguinal peripheral vascular disease and critical chronic limb ischemia (CCLI) are poor surgical candidates. Our purpose was to evaluate angiographic and clinical results of popliteal, infrapopliteal, and multi-level disease percutaneous transluminal angioplasty (PTA) in such patients. DESIGN: Retrospective study of angiographic and clinical files in selected group. MATERIALS AND METHODS: Between 1996 and 2002, 38 elderly patients aged 80-94 years old (mean age 83.3) with critical leg ischemia were treated with PTA. All patients were at high surgical risk. 31/38 (81.5%) patients had chronic non-healing wounds, and 14/38 (37%) had multi-level disease of superficial femoral, popliteal and crural arteries. One hundred and two lesions were treated by angioplasty. Immediate angiographic and 1 year clinical results were retrospectively analyzed. RESULTS: The overall procedural success rate was 32/38 (84.2%). There were three major complications (7.9%), but no deaths, and three technical failures, all were of infrapopliteal lesions. After 1 year, 27 patients could be followed, five patients died during the first year of unrelated causes. Twenty-three patients (85.2%), were clinically re-occluded within 1 year, but complete and partial wound healing was achieved in 80% (16/20) and rest pain improvement in 57% (4/7), so that overall limb salvage was 74% (20/27). CONCLUSIONS: Elderly patients with multi-level CCLI have a short patency term following angioplasty of 14.8% after 1 year. Nevertheless, this temporary vascular patency enables wound healing or improvement in 74% of these patients, thus such endovascular interventions are recommended in this age group.