Rafael Salvador

Pathways of Lymphatic Spread in Male Urogenital Pelvic Malignancies

Regional lymph node involvement in urogenital malignancies (category N in the TNM classification system) is a significant radiologic finding, with important implications for treatment and prognosis. Male urogenital pelvic cancers commonly spread to iliopelvic or retroperitoneal lymph nodes by following pathways of normal lymphatic drainage from the pelvic organs. The most likely pathway of nodal spread (superficial inguinal, pelvic, or paraaortic) depends on the tumor location in the prostate, penis, testis, or bladder and whether surgery or other therapy has disrupted normal lymphatic drainage from the tumor site; knowledge of both factors is needed for accurate disease staging. At present, lymph node status is most often assessed with standard anatomic imaging techniques such as multidetector computed tomography or magnetic resonance (MR) imaging. However, the detection of nodal disease with these techniques is reliant on lymph node size and morphologic characteristics, criteria that provide limited diagnostic specificity. Functional imaging techniques, such as diffusion-weighted MR imaging performed with or without a lymphotropic contrast agent and positron emission tomography, may allow a more accurate nodal assessment based on molecular or physiologic activity.

Multidetector CT of Living Renal Donors: Lessons Learned from Surgeons

Multidetector computed tomography (CT) is the choice technique for preoperative evaluation of living renal donors. Living donor transplantation, as opposed to cadaveric donation, is the best option for recipient and graft survival. The need for kidney transplantation has undergone exponential growth over the past 40 years, and cadaveric donations are inadequate to meet this ever-increasing demand. These factors have led to a continued increase in organ donation from living related donors. From January 2007 to October 2009, 199 potential renal donors were studied in one center with 64-row multidetector CT. Of these candidates, 94 were rejected for donation. The remaining 105 potential donors were evaluated by a multidisciplinary committee, and 101 donor-recipient couples were accepted for renal donation and transplantation. Laparoscopic nephrectomy is the preferred surgical procedure for harvesting kidneys from living donors. Radiologists are responsible for providing accurate anatomic information about the donors renal parenchyma, arteries, veins, and collecting system. Accurate reporting depends on the radiologists level of expertise, attention to detail, and commitment to careful image evaluation. Knowledge of the surgical techniques and the difficulties that surgeons face during laparoscopic nephrectomy and renal transplantation is essential for compiling accurate radiologic reports.

Diagnosis of bladder cancer: contrast-enhanced ultrasound

Contrast-enhanced ultrasound imaging represents a new approach to imaging tumoral neovascularity. This review describes the application of contrast-enhanced ultrasound in the detection, differential diagnosis, and staging of bladder cancer.

Utility of Multidetector CT in Severe Postpartum Hemorrhage

Postpartum hemorrhage is one of the leading causes of maternal mortality worldwide. According to the time when postpartum hemorrhage develops, it is classified as (a) primary, or early, postpartum hemorrhage (within the first 24 hours after delivery) or (b) secondary, or late, postpartum hemorrhage (>24 hours to 6 weeks after delivery). Primary postpartum hemorrhage may be caused by uterine atony (75%-90% of cases), trauma of the lower portion of the genital tract, uterine rupture, uterine inversion, bladder flap hematoma, retention of blood clots or placental fragments, and coagulation disorders. Secondary postpartum hemorrhage may be caused by uterine subinvolution, coagulopathies, and abnormalities of the uterine vasculature. Extrauterine sources of bleeding include rectus sheath hematoma, direct arterial injuries, and the HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome. Severe postpartum hemorrhage is a life-threatening condition that is diagnosed on the basis of the findings from clinical examination, with or without ultrasonography. Computed tomography (CT) and magnetic resonance imaging are useful in the characterization of postpartum hemorrhage when medical treatment fails. Multidetector CT has an important role when intraabdominal bleeding is suspected and can be considered in cases of recurrent bleeding after embolization, as well as for the evaluation of postsurgical complications. A proposed clinical and CT imaging algorithm for postpartum hemorrhage is presented. A multidisciplinary approach to postpartum hemorrhage is essential to optimize the role of diagnostic and interventional radiology in obstetric hemorrhage, to avoid hysterectomy and thus preserve fertility.

Measurement of waist circumference for retrospective studies – Prospective validation of use of CT images to assess abdominal circumference ☆

INTRODUCTION To validate the use of supine position and CT images for assessing abdominal circumference (AC). METHOD A prospective study in consecutive patients undergoing scheduled abdominal CT at our center between 17 and 25 September 2012. AC was measured four times: Measurements 1 and 2 were sequentially done by the same trained nurse before abdominal CT just above the iliac crest, while measurements 3 and 4 were done on the last abdominal CT slice not showing the iliac bone. Students t tests and Q-Q and Bland-Altman plots were used for statistical analysis. RESULTS A total of 102 patients were recruited. Mean age, 60 (35-78) years. Mean BMI, 25 (18-39) kg/m(2). Mean AC, 93.2 (73-135) cm. No significant differences were found between the four ACs measured (Students t test, P=0.83). Q-Q and Bland-Altman plots showed good overlapping for the low and central values (73-110 cm) with a greater scatter for extremely high values. For the ellipse estimation, R(2) was 0.987 with a mean error of 0.4 cm and a stretch dispersion between 1.1 and -0.3 cm. CONCLUSION Supine (either measured or estimated on CT images by free hand elliptical ROI or ellipse formula) and standing measurements appear to be equivalent for abdominal circumferences <110 cm.

Tuberculous Epididymo-orchitis After Intravesical BCG Therapy for Superficial Bladder Carcinoma Sonographic Findings

Intravesical instillation of BCG vaccine for superficial bladder carcinoma has been well established, and several reports have suggested superior effectiveness over other chemotherapy options. Complications after intravesical BCG therapy are rare, with local complications in the bladder being far more frequent than systemic complications. Few cases of tuberculous epididymo-orchitis after intravesical BCG therapy can be found in the literature, and sonographic findings, if described, are variable and nonspecific. We report a case of granulomatous epididymo-orchitis diagnosed after resection of sonographically suspected testicular cancer in a patient with a history of superficial bladder carcinoma treated with intravesical BCG instillation. To our knowledge, the presence of punctate calcifications within a nodular lesion has not been described before and mimics the sonographic findings expected in common tuberculous epididymo-orchitis.

Usefulness of MDCT to Differentiate Between Renal Cell Carcinoma and Oncocytoma: Development of a Predictive Model

OBJECTIVE The objective of our study was to identify the most useful parameters to differentiate between renal cell carcinoma (RCC) and oncocytoma using four-phase CT. MATERIALS AND METHODS Ninety-seven patients with solid renal lesions who underwent surgery with four-phase preoperative CT evaluation and with pathologic diagnosis of RCC or oncocytoma were included in the study. Features of tumors and the enhancement pattern in the four CT phases were evaluated and analyzed. Logistic regression models were used to assess independent predictors for malignancy. RESULTS Histopathologically, 13 tumors were oncocytomas and 84 were RCCs. RCCs were larger (6.20 cm vs 3.21 cm, p = 0.0004) and more often enhanced heterogeneously (66 vs 6, p = 0.02). Lesions that were larger than 4 cm showed a significantly higher risk of malignancy (p = 0.0046). Significant differences were found in intensity of nodule enhancement between the nephrographic and the excretory phases with respect to the unenhanced phase (p = 0.003 and p = 0.0026). At multivariate analysis, parameters that were independent predictors of malignancy were enhancement pattern, with RCCs more often having heterogeneous enhancement than oncocytomas (odds ratio [OR], 0.18; 95% CI, 0.04-0.90), and nodule enhancement in the excretory phase in relation to the unenhanced phase, with RCCs showing lower enhancement (OR, 0.93; 95% CI, 0.88-0.97), and a size larger than 4 cm (OR, 4.01; 95% CI, 0.70-23.14). CONCLUSION The combination of different CT parameters including lesion size larger than 4 cm, lesion enhancement in the excretory phase in relation to the unenhanced phase, and heterogeneous enhancement pattern helps distinguish RCC from oncocytoma.

Pathways of Lymphatic Spread in Gynecologic Malignancies

Precise radiologic evaluation of regional adenopathic involvement in pelvic gynecologic tumors is fundamental to clinical practice because of its prognostic and therapeutic significance. Likewise, the identification of metastatic adenopathies at posttreatment imaging is essential for assessing response and detecting recurrence. Similar to urologic neoplasms, gynecologic neoplasms most often spread regionally to the pelvic and retroperitoneal lymph nodes, following the normal drainage pathways of the pelvic organs. Familiarity with routes of dissemination, treatment options, and means of analyzing lymph node characteristics is crucial to determine the extent of disease. Two staging systems can be used in characterizing gynecologic malignancies: the FIGO (International Federation of Gynecology and Obstetrics) system, which is the most commonly and universally used, and the TNM (tumor, node, metastasis) system, which is based on clinical and/or pathologic classification. Anatomic assessment with multidetector computed tomography (CT) and magnetic resonance (MR) imaging is still the most commonly used technique for the detection of lymph node spread, which is mainly based on morphologic criteria, the most important of which is nodal size. However, size has limited diagnostic specificity. Consequently, functional imaging techniques such as diffusion-weighted MR imaging, positron emission tomography combined with CT, lymphoscintigraphy, and sentinel lymph node mapping, which are based on molecular and physiologic activity and allow more precise evaluation, are often incorporated into diagnostic imaging protocols for staging of gynecologic malignancies.

Abdominal Computed Tomography—A New Tool for Predicting Recurrent Stone Disease

PURPOSE To evaluate whether CT-identified Randall plaques can be used to foresee the recurrence of stone disease (SD); to define a cut point that could identify a high-risk population. MATERIALS AND METHODS A retrospective study of patients attended for SD from January 2004 to December 2009 was conducted. Study population was patients with a first episode of calcium SD that was diagnosed by abdominal CT. Papillae tip attenuation was measured in Hounsfield units (HU) on unenhanced abdominal CT images. Patients with recurrent SD were identified; t test, Pearson correlation, and receiver operating characteristic (ROC) curve analysis were used. RESULTS A total of 543 patients were evaluated; 187 fulfilled the criteria and were included, and 49 (26.2%) had recurrent SD. Mean follow-up: 5 years (3-7 years). Papillae tip attenuation was significantly higher in the recurrent group (46.2 HU vs 40.1 HU, P=0.01) and correlated well with the possibility of developing SD (R=0.83). Attenuation >43 HU showed a ROC curve area under the curve=0.87 with sensitivity=77% and specificity=84% separating patients with a RR=8.7 of development of recurrent SD. The number of papillae >43 HU correlated with recurrent SD (RR=11.2 for ≥3 papillae vs <3 papillae with density >43 HU). CONCLUSIONS The presence of the Randall plaques can be used as a marker for predicting SD recurrence. A cut point of 43 HU could be used to identify a high-risk population.

Accuracy of unenhanced magnetic resonance angiography for the assessment of renal artery stenosis

Purpose To evaluate the accuracy of unenhanced magnetic resonance angiography (U-MRA) using balanced steady-state free precession (SSFP) sequences with inversion recovery (IR) pulses for the evaluation of renal artery stenosis. Materials and methods U-MRA was performed in 24 patients with suspected main renal artery stenosis. Two radiologists evaluated the quality of the imaging studies and the ability of U-MRA to identify hemodynamically significant main renal artery stenosis (RAS) defined as a stenosis ≥50% when compared to gold standard tests: contrast-enhanced magnetic resonance angiography (CE-MRA) (18 patients) or digital subtraction arteriography (DSA) (6 patients). Results A total of 44 main renal arteries were evaluated. Of them, 32 renal arteries could be assessed with U-MRA. When CE-MRA or DSA was used as the reference standard, nine renal arteries had hemodynamically significant RAS. U-MRA correctly identified eight out of nine arteries as having ≥50% RAS, and correctly identified 22 out of 23 arteries as not having significant RAS, with a sensitivity of 88.8%, a specificity of 95.65%, positive and negative predictive value of 88.8% and 95.65%, respectively, and an accuracy of 93.75%. Renal artery fibromuscular dysplasia (FMD) was observed in the two misclassified arteries. Conclusion U-MRA is a reliable diagnostic method to depict normal and stenotic main renal arteries. U-MRA can be used as an alternative to contrast-enhanced magnetic resonance angiography or computer tomography angiography in patients with renal insufficiency unless FMD is suspected.