Three-dimensional Contrast-enhanced Magnetic Resonance Imaging Research Articles

Three-dimensional ultrasound VOCAL combined with contrast-enhanced ultrasound: an alternative to contrast-enhanced magnetic resonance imaging for evaluating ablation of benign uterine lesions

Objective This study explores the feasibility and value of three-dimensional ultrasound virtual organ computer-aided analysis (3D-VOCAL) combined with contrast-enhanced ultrasound (CEUS) for measuring the non-perfused volume (NPV) after microwave ablation (MWA) of benign uterine lesions. Methods Fifty-six patients with uterine myoma (UM) and adenomyosis (AM) treated with MWA were enrolled. NPV measurements were obtained postoperatively using two-dimensional CEUS (2D-CEUS), 3D-VOCAL combined with CEUS and three-dimensional contrast-enhanced magnetic resonance imaging (3D-CEMRI). Bland–Altman analysis and intraclass correlation coefficient (ICC) values were used to analyze the agreement of NPV measurements obtained via 2D-CEUS and the combined method with 3D-CEMRI. The inter- and intra-observer agreements of the NPV values obtained with all three methods were also analyzed. Results Considering 3D-CEMRI as the standard, 3D-VOCAL showed greater agreement than 2D-CEUS and higher ICCs (ICC, 0.999 vs. 0.891) than 2D-CEUS for different lesion types and sizes of non-perfusion areas (p < 0.001 for all comparisons). NPV measurements obtained via 2 D-CEUS and 3 D-CEMRI differed significantly for AM and non-perfusion areas with maximum diameter ≥5 cm (p < 0.05) and showed no significant differences (p > 0.05) for UM and non-perfusion areas with maximum diameter <5 cm. The NPV measurements obtained via 3D-VOCAL and 3D-CEMRI did not differ significantly (p > 0.05). The intra- and inter-observer agreements of 3D-VOCAL measurements were better than those of 2D-CEUS and slightly lower than those of 3D-CEMRI. Conclusions 3D-VOCAL combined with CEUS provides accurate estimates of NPV after MWA of benign uterine lesions, and offers a reliable, simple and efficient alternative to CEMRI.

Quantification of regional deformation of the lungs by non-rigid registration of three-dimensional contrast-enhanced magnetic resonance imaging.

Assessment of lung function is vital for the diagnosis of a variety of pathological conditions. Research has been proposed to study pulmonary mechanics and kinematics using two-dimensional (2D) magnetic resonance imaging (MRI). This allows estimation of regional lung tissue mechanics but is limited to 2D information. An approach based on three-dimensional (3D) contrast-enhanced MR angiogram of pulmonary blood vessels and a non-rigid image registration technique is proposed for quantification of lung regional deformations, which can potentially be used for assessment of pulmonary parenchymal mechanics and regional ventilation for disease diagnosis without ionizing radiation. On three volunteers, an end-expiration scan and end-inspiration scan was acquired successively for each volunteer using a 3D breath-hold contrast-enhanced MRI sequence several minutes after gadolinium injection. Subsequently, a rectangle box lung mask is manually selected for each end-expiration scan, applying non-rigid registration algorithms using cubic B-splines as transformations to align each pair of images. This incorporates the Normalized Correlation Coefficient similarity with the bending energy term as cost function with a multi-resolution multi-grid approach. Finally, the lung regional 3D deformations were obtained using the transformations obtained by registration. The alignment accuracy after non-rigid registration was estimated by using a set of branch points of pulmonary blood vessels as anatomical landmarks for each pair of images. With contrast enhancement, the pulmonary blood vessel signal was enhanced, which greatly facilitated the non-rigid registration in the lung parenchyma. The average landmarks distances in three pairs of datasets are reduced from 17.9, 20.3 and 16.3 mm, to 1.0, 1.6 and 1.2 mm, respectively, by non-rigid registration. After registration, the average distances error of each pair of datasets was less than 0.6 mm in the right-to-left (RL) direction, less than 0.9 mm in the inferior-to-superior (IS) direction, and less than 1.2 mm in the anterior-to-posterior (AP) direction. Results demonstrated that the proposed method can accurately register lungs with large deformations to evaluate lung regional deformation. It may be used for quantitative assessment of 3D lung regional ventilation avoiding ionizing radiation.

Hepatic artery aneurysm: incidental diagnosis with abdominal ultrasonography and treatment by coil embolization

Hepatic artery aneurysm (HAA) was first reported at autopsy in 1809, represents one fifth of visceral aneurysms and the mortality from spontaneous rupture is high in most of cases. We are reporting a case of an asymptomatic 48-year-old woman with an extrahepatic HAA, diagnosed initially and incidentally with abdominal ultrasonography, confirmed by a three-dimensional contrast-enhanced magnetic resonance imaging and angiography. Endovascular treatment was considered feasible and was successfully treated with coil embolization.

Massive hemoperitoneum due to rupture of an artery overlying a uterine leiomyoma: a case report

Hemoperitoneum is usually caused by ectopic pregnancy, ruptured corpus luteum, or adnexal torsion (1). Acute bleeding from a blood vessel overlying a uterine myoma occurs rarely and may be life threatening unless promptly treated by surgery. In most cases the bleeding is the result of trauma or torsion; spontaneous rupture of a superficial uterine blood vessel is extremely rare (2) and the involved vessel was reported to be a vein (1, 2). We describe the spontaneous rupture of a superficial uterine artery overlying a subserous myoma. To the best of our knowledge, this is the first such report in the literature. A 48-year-old woman, gravida 3, para 3, presented herself to our emergency department with complaints of sudden-onset lower abdominal pain of several hours' duration. She was in her fifth day of her menstruation. There were no accompanying genitourinary, gastrointestinal, or inflammatory symptoms, and the woman denied any precedent abdominal trauma. Her past medical history was uneventful. Examination revealed an afebrile woman in moderate distress. Blood pressure was 90/45 mmHg and pulse was 138 beats/min. Urine beta-human chorionic gonadotropin was negative. Hemoglobin measured 13·7 g/dl. No signs of acute abdomen were present. Pelvic examination revealed mild vaginal bleeding and a tender 16-gestational-week-sized uterus. Sonography demonstrated a large (14 cm) uterus and an excessive amount of fluid in the pelvic cavity. As the woman soon became hemodynamically unstable (decrease in hemoglobin to 10·3 g/dl and in blood pressure to 60/29 mmHg), immediate laparotomy was performed under general anesthesia. During surgery, 2000 cm3 of blood were drained from the abdominal cavity. A pulsatile bleeding superficial artery, approximately 0·5 in diameter, was noted, located on the serosal surface of a fundal myoma on a 16-gestational-week-sized uterus (Fig. 1). The bleeding artery was ligated. A thorough search of the pelvic and abdominal cavities revealed no other source of bleeding or pathology. Subtotal transabdominal hysterectomy and bilateral salpingo-ophorectomy (subtotal TAH + BSO) were performed. The postoperative course was uneventful, and the woman was discharged on the fifth postoperative day in good condition. The pathologic diagnosis confirmed that the ruptured vessel was an artery and that there were no abnormalities of the artery or the uterus and adnexae other than the uterine myoma. Specimen of uterus and adnexae. The ligated ruptured artery overlying a myoma is seen in the center of the uterus. There are two theories for the cause of spontaneous rupture of a uterine vessel, and both refer to veins. The first claims that spontaneous rupture of blood vessels occurs only in the presence of myomas larger than 10 cm in diameter, and the tear in the overlying vessel is caused by the underlying pressure exerted by the growing myoma (1). The second theory relates the tear in the blood vessel to uterine contractions during menstruation that may distend the blood vessel to the breaking point (1). This theory is supported by the feeling that the majority of women with ruptured uterine vessels (including our patient) were menstruating when the rupture occurred. The reason for spontaneous tear of a superficial uterine artery overlying a myoma remains unclear, but the data of our case match both theories. Hemoperitoneum, caused by active bleeding, is an emergency situation and calls for immediate diagnosis and treatment to lower morbidity and mortality (3). The two state-of-the-art modalities for accurate diagnosis of intra-abdominal bleeding are contrast-enhanced two- and three-dimensional sonography (3) and three-dimensional contrast-enhanced magnetic resonance imaging (4). Treatment consists of laparotomy or laparoscopy. Laparoscopic surgery is considered to be as safe and effective as laparotomy, but it is usually contraindicated in the presence of active bleeding and hemodynamic instability (5). Nevertheless, there are reports of successful laparoscopy for intra-abdominal bleeding in women with ectopic pregnancy who were in hypovolemic shock (5). In our case, we used sonography for diagnosis and laparotomy for treatment. Considering the age and parity of our patient and her hemodynamic instability, we opted for subtotal TAH + BSO in order to shorten the operating time. However, conservative myomectomy might be attempted in such cases if future fertility is desired (1). The authors thank Gloria Ginzach for her editorial assistance.