“Saved by the Pacing Catheter”: Gigantic Right Atrial Thromboembolus as a Cause of Pulmonary Embolism

Pulmonary embolism (PE) related to the presence of right heart thromboemboli entails a higher mortality rate than PE alone. Furthermore, right heart thromboemboli are often associated with deep venous thrombosis. The most effective therapy for haemodynamically stable patients remains unknown, although recent data suggest that thrombolytic therapy is associated with a better outcome. We describe the case of an 83-year-old woman, hospitalized with PE consequent to right heart thrombus-in-transit, in whom investigation revealed a concomitant deep venous thrombosis. She required thrombolysis, given the high mortality risk that is traditionally associated with this clinical entity.

Deep Venous Thrombosis (DVT) in Lower Extremity Amputation as Cause of Pulmonary Embolism

The authors describe the case of a 43-year-old man with a right-leg knee amputation performed 14 years prior. He presented to hospital with dyspnea. A pulmonary embolism was detected. A Doppler ultrasound test showed deep vein thrombosis (DVT), which affected the stump of the amputated limb. When a pulmonary embolism is detected in a patient with an amputated lower limb, an exploration of the stump should be performed to rule out this uncommon complication.

Simultaneous Acute Pulmonary Embolism and Isolated Septal Myocardial Infarction in a Young Patient

We report here the case of a young patient with a simultaneous isolated septal myocardial infarction (MI) and pulmonary embolism (PE). The aim was to describe a rare clinical entity and to explain why these two pathologies were present at the same time in a young patient.
 A review of literature was established. An interventional cardiologist, an interventional radiologist and a lung specialist were consulted. The diagnostic workup revealed only heterozygous Factor Leiden V mutation. This presentation was probably fortuitous, but worth reporting to our opinion.

Successful Surgical Pulmonary Embolectomy for Massive Perinatal Embolism after Emergency Cesarean Section.

Pregnant women are exposed to an increased risk for developing pulmonary embolism (PE), a main cause for maternal mortality. Surgical pulmonary embolectomy is one important therapeutic and potential life-saving armamentarium, considering pregnancy as a relative contraindication for thrombolysis. We present a case of a 36-year-old woman with massive bilateral PE after emergent caesarean delivery, requiring reanimation by external heart massage. The onset of massive intrauterine bleeding contraindicated thrombolysis and emergency surgical pulmonary embolectomy, followed by a hysterectomy, were preformed successfully. Acute surgical pulmonary embolectomy may be an option in critically diseased high-risk patients, requiring a multiteam approach, and should be part of the therapeutic armamentarium of the attending cardiac surgeon.

[Pulmonary microscopic tumor embolism syndrome]

HISTORY: A 76-year-old woman and a 62-year-old man were both referred to our clinic because of an unexplained weight loss, increasing dry cough and shortness of breath. INVESTIGATIONS: Investigations revealed an adenocarcinoma of the colon with retroperitoneal, mediastinal and supraclavicular lymph node metastasis and poorly differentiated carcinoma of the prostate with extensive bone metastases. During their hospital stay both patients developed increasing shortness of breath and clinical signs of right heart failure. Echocardiography confirmed severe pulmonary hypertension and dilatation of the right ventricle in both patients. Despite the high degree of clinical suspicion CT scans of the thorax could not demonstrate pulmonary embolism. DIAGNOSIS, TREATMENT AND COURSE: During the following days the patients condition deteriorated further and both patients' died from irreversible right heart failure. Both autopsies showed extensive metastatic adenocarcinoma with marked angiosis carcinomatosa of the lungs with numerous occlusions of small arteries and arterioles and resulting cor pulmonale. Thrombotic pulmonary embolism could not be detected. CONCLUSION: In patients with malignant neoplasms, especially adenocarcinomas, dyspnea and signs of increasing pulmonary artery pressure, the possibility of a microscopic pulmonary tumor embolism should be considered after exclusion of more usual causes especially thrombotic pulmonary embolism. In selected cases a cytologic examination of blood aspirated from a wedged pulmonary artery catheter can be performed to prove angiosis is carcinomatosa.

Elevated Plasma Hemoglobin Levels Increase Nitric Oxide Consumption in Experimental and Clinical Acute Pulmonary Thromboembolism

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Low-dose pulmonary CT angiography: reduced radiation exposure and iodine load at low tube kilovoltage

CT pulmonary angiography is the currently accepted standard in ruling out acute pulmonary embolism. Issues of radiation dose received by patients via CT have been extensively disputed by radiologists and reported by the media. In recent years there has been considerable research performed to find ways for reducing radiation exposure from CT. Herein, we will discuss specific measures that have been shown to be valuable for CT pulmonary angiography. The limitations and the potential benefits of reduced CT peak tube kilovoltage will be detailed as this method is capable of reducing both radiation exposure and iodine load to the patient simultaneously. We discuss some of the emerging tools, which will hopefully play a significant role in wider acceptance of low-dose CT pulmonary angiography protocols.

Acute pulmonary embolectomy three days following a coronary artery bypass graft procedure

Pulmonary embolism is very rarely reported early after cardiac surgery, most probably due to full heparinisation during cardiopulmonary bypass. We report a 66-year-old man without thromboembolic history who presented three days after a coronary artery bypass grafting procedure with acute dyspnoea and haemodynamic instability. A CT scan confirmed paracentral bilateral pulmonary embolism requiring an urgent and successful embolectomy. Review of the literature confirms that pulmonary embolism may occur in up to 3% of post-cardiopulmonary bypass patients. The possibility of pulmonary embolism must be taken into consideration in post-cardiopulmonary bypass patients with acute onset of chest pain and respiratory insufficiency.

Effect of X-ray tube parameters, iodine concentration, and patient size on image quality in pulmonary computed tomography angiography: a chest-phantom-study

OBJECTIVES: The aim of this phantom study was to evaluate the contrast-to-noise ratio (CNR) in pulmonary computed tomography (CT)-angiography for 300 and 400 mg iodine/mL contrast media using variable x-ray tube parameters and patient sizes. We also analyzed the possible strategies of dose reduction in patients with different sizes. MATERIALS AND METHODS: The segmental pulmonary arteries were simulated by plastic tubes filled with 1:30 diluted solutions of 300 and 400 mg iodine/mL contrast media in a chest phantom mimicking thick, intermediate, and thin patients. Volume scanning was done with a CT scanner at 80, 100, 120, and 140 kVp. Tube current-time products (mAs) varied between 50 and 120% of the optimal value given by the built-in automatic dose optimization protocol. Attenuation values and CNR for both contrast media were evaluated and compared with the volume CT dose index (CTDI(vol)). Figure of merit, calculated as CNR/CTDIvol, was used to quantify image quality improvement per exposure risk to the patient. RESULTS: Attenuation of iodinated contrast media increased both with decreasing tube voltage and patient size. A CTDIvol reduction by 44% was achieved in the thin phantom with the use of 80 instead of 140 kVp without deterioration of CNR. Figure of merit correlated with kVp in the thin phantom (r = -0.897 to -0.999; P < 0.05) but not in the intermediate and thick phantoms (P = 0.09-0.71), reflecting a decreasing benefit of tube voltage reduction on image quality as the thickness of the phantom increased. Compared with the 300 mg iodine/mL concentration, the same CNR for 400 mg iodine/mL contrast medium was achieved at a lower CTDIvol by 18 to 40%, depending on phantom size and applied tube voltage. CONCLUSIONS: Low kVp protocols for pulmonary embolism are potentially advantageous especially in thin and, to a lesser extent, in intermediate patients. Thin patients profit from low voltage protocols preserving a good CNR at a lower exposure. The use of 80 kVp in obese patients may be problematic because of the limitation of the tube current available, reduced CNR, and high skin dose. The high CNR of the 400 mg iodine/mL contrast medium together with lower tube energy and/or current can be used for exposure reduction.

Venous thromboembolism and occult malignancy: simultaneous detection during pulmonary CT angiography with CT venography

OBJECTIVE: We explored the potential for patients with proven venous thromboembolism or pulmonary embolism (PE) to have occult malignancies detected during the same CT examination. To verify this, we compared the presence of occult malignancies identified on pulmonary artery CT angiography (CTA) and CT venography (CTV) when venous thromboembolism (VTE) was present. SUBJECTS AND METHODS: Pulmonary artery CTA combined with CTV was performed on a 16-MDCT scanner on 186 adult patients suspected of having pulmonary embolism without any known malignancies. CTV was performed from the diaphragm to the knee 180 seconds after CTA. Two radiologists evaluated the presence of VTE, that is PE or deep venous thrombosis (DVT), and tumor lesions on both examinations in consensus. The malignant nature of the possibly identified tumors was confirmed by pathologic examination. RESULTS: VTE was found in 49 patients (26%). Malignant tumors were detected in 24 patients (13%). Eleven patients with malignant tumors had VTE (46% of patients with malignant tumors; 22% with VTE and 6% of all patients). There was correlation with presence of malignancies between both and DVT and DVT associated with PE but not between presence of malignancies and PE only. Patients with DVT and those with DVT associated with PE had a risk ratio of 3.2 and 3.3, respectively, for having a malignant tumor discovered simultaneously. CONCLUSION: A high number of malignant tumors can be incidentally discovered on pulmonary artery CTA, even more so with additional CTV. Radiologists should scrutinize scans to pick up unknown malignancies, especially in patients with identified VTE.

Patient exposure and image quality of low-dose pulmonary computed tomography angiography: comparison of 100- and 80-kVp protocols

OBJECTIVE: Measures to reduce radiation exposure and injected iodine mass are becoming more important with the widespread and often repetitive use of pulmonary CT angiography (CTA) in patients with suspected pulmonary embolism. In this retrospective study, we analyzed the capability of 2 low-kilovoltage CTA-protocols to achieve these goals. MATERIALS AND METHODS: Ninety patients weighing less than 100 kg were examined by a pulmonary CTA protocol using either 100 kVp (group A) or 80 kVp (group B). Volume and flow rate of contrast medium were reduced in group B (75 mL at 3 mL/s) compared with group A (100 mL at 4 mL/s). Attenuation was measured in the central and peripheral pulmonary arteries, and the contrast-to-noise ratios (CNR) were calculated. Entrance skin dose was estimated by measuring the surface dose in an ovoid-cylindrical polymethyl methacrylate chest phantom with 2 various dimensions corresponding to the range of chest diameters in our patients. Quantitative image parameters, estimated effective dose, and skin dose in both groups were compared by the t test. Arterial enhancement, noise, and overall quality were independently assessed by 3 radiologists, and results were compared between the groups using nonparametric tests. RESULTS: Mean attenuation in the pulmonary arteries in group B (427.6 +/- 116 HU) was significantly higher than in group A (342.1 +/- 87.7 HU; P < 0.001), whereas CNR showed no difference (group A, 20.6 +/- 7.3 and group B, 22.2 +/- 7.1; P = 0.302). Effective dose was lower by more than 40% with 80 kVp (1.68 +/- 0.23 mSv) compared with 100 kVp (2.87 +/- 0.88 mSv) (P < 0.001). Surface dose was significantly lower at 80 kVp compared with 100 kVp at both phantom dimensions (2.75 vs. 3.22 mGy; P = 0.027 and 2.22 vs. 2.73 mGy; P = 0.005, respectively). Image quality did not differ significantly between the groups (P = 0.151). CONCLUSIONS: Using 80 kVp in pulmonary CTA permits reduced patient exposure by 40% and CM volume by 25% compared with 100 kVp without deterioration of image quality in patients weighing less than 100 kg.

[Pulmonary thrombendarteriectomy]

BACKGROUND: Chronic thromboembolic pulmonary hypertension is a late sequela following acute pulmonary embolism. Incomplete resolution of thrombotic material results in persistent obstruction of the pulmonary arterial bed, which can be treated by pulmonary thrombendarterectomy. METHOD AND RESULTS: This desobliteration of the pulmonary arteries is performed under conditions of deep hypothermia and circulatory arrest. Currently, perioperative mortality ranges between 10 and 15% and is mainly limited by persistent diffuse pulmonary artery disease independent of central obstruction. Postoperatively, pulmonary vascular resistance is normalized. Exercise tolerance of the patients is likewise improved. CONCLUSION: Thus, pulmonary thrombendarterectomy is an effective treatment for chronic thromboembolic pulmonary hypertension with results superior to those of lung transplantation.

Pulmonary intimal sarcoma: a rare differential diagnosis for arterial filling defects on a chest CT

We present a rare case of pulmonary intimal sarcoma mimicking pulmonary embolism in a 40-year-old woman. Although extremely rare, these tumors must be considered in patients who present inappropriate imaging findings that suggest embolism. Chest computed tomography is the modality of choice to determine the extent of the tumor. We present a female patient with suspected embolism that was in fact found to be an endothelial sarcoma of the pulmonary arteries.

Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients.

AIM To compare image quality and diagnostic confidence of 100 kVp CT pulmonary angiography (CTPA) in patients with body weights (BWs) below and above 100kg. MATERIALS AND METHODS The present retrospective study comprised 216 patients (BWs of 75-99kg, 114 patients; 100-125kg, 88 patients; >125kg, 14 patients), who received 100 kVp CTPA to exclude pulmonary embolism. The attenuation was measured and the contrast-to-noise ratio (CNR) was calculated in the pulmonary trunk. Size-specific dose estimates (SSDEs) were evaluated. Three blinded radiologists rated subjective image quality and diagnostic confidence. Results between the BW groups and between three body mass index (BMI) groups (BMI <25kg/m(2), BMI = 25-29.9kg/m(2), and BMI ≥30kg/m(2), i.e., normal weight, overweight, and obese patients) were compared using the Kruskal-Wallis test. RESULTS Vessel attenuation was higher and SDDE was lower in the 75-99kg group than at higher BWs (p-values between <0.001 and 0.03), with no difference between the 100-125 and >125kg groups (p = 0.892 and 1). Subjective image quality and diagnostic confidence were not different among the BW groups (p = 0.225 and 1). CNR was lower (p < 0.006) in obese patients than in normal weight or overweight subjects. Diagnostic confidence was not different in the BMI groups (p = 0.105). CONCLUSION CTPA at 100 kVp tube voltage can be used in patients weighing up to 125kg with no significant deterioration of subjective image quality and confidence. The applicability of 100 kVp in the 125-150kg BW range needs further testing in larger collectives.

Prospective randomised comparison of diagnostic confidence and image quality with normal-dose and low-dose CT pulmonary angiography at various body weights.

OBJECTIVES To find a threshold body weight (BW) below 100 kg above which computed tomography pulmonary angiography (CTPA) using reduced radiation and a reduced contrast material (CM) dose provides significantly impaired quality and diagnostic confidence compared with standard-dose CTPA. METHODS In this prospectively randomised study of 501 patients with suspected pulmonary embolism and BW <100 kg, 246 were allocated into the low-dose group (80 kVp, 75 ml CM) and 255 into the normal-dose group (100 kVp, 100 ml CM). Contrast-to-noise ratio (CNR) in the pulmonary trunk was calculated. Two blinded chest radiologists independently evaluated subjective image quality and diagnostic confidence. Data were compared between the normal-dose and low-dose groups in five BW subgroups. RESULTS Vessel attenuation did not differ between the normal-dose and low-dose groups within each BW subgroup (P = 1.0). The CNR was higher with the normal-dose compared with the low-dose protocol (P < 0.006) in all BW subgroups except for the 90-99 kg subgroup (P = 0.812). Subjective image quality and diagnostic confidence did not differ between CT protocols in all subgroups (P between 0.960 and 1.0). CONCLUSIONS Subjective image quality and diagnostic confidence with 80 kVp CTPA is not different from normal-dose protocol in any BW group up to 100 kg. KEY POINTS • 80 kVp CTPA is safe in patients weighing <100 kg • Reduced radiation and iodine dose still provide high vessel attenuation • Image quality and diagnostic confidence with low-dose CTPA is good • Diagnostic confidence does not deteriorate in obese patients weighing <100 kg.