Thoracic aortic trauma: role of dynamic CT.

Two protocols were developed to study the efficacy of both chest radiography and dynamic computed tomography (CT) of the thorax in screening for traumatic aortic injury. Both protocols demonstrated a definite role for dynamic CT in excluding aortic injury in patients with normal initial chest radiographs. The authors studied 164 patients, and preliminary results indicated a high reliability for this method. Their algorithm, with 6-month follow-up, yielded both 100% sensitivity and a 100% negative predictive value. Unnecessary aortography, with its associated morbidity and cost, was decreased by 73%.

Contrast media adversely affect oxyhemoglobin dissociation.

Effects of ionic (Hypaque-76) and nonionic (Isovue-370 and Omnipaque-350) contrast media on oxyhemoglobin dissociation of normal human red blood cells were evaluated. In series 1, 4-mL venous blood samples were obtained from 15 normal human volunteers. One blood sample served as control, and 1 mL of either of the three contrast media was added in vitro to the other 4-mL blood samples. P50 values were estimated from the linear portion of the oxyhemoglobin dissociation curve obtained by tonometry. Determinations of P50 were performed at either pH 7.4 or 7.2. At pH 7.4, P50 in the absence of contrast media was 26.3 +/- 0.4 mm Hg (mean +/- SEM). The contrast media caused comparable decreases in P50 from this value (Hypaque-76, 20.0 +/- 0.5 mm Hg; Omnipaque-350, 21.6 +/- 0.4 mm Hg; Isovue-370, 20.7 +/- 0.4 mm Hg). Reducing pH to 7.2 in the absence of contrast media increased P50 to 33.3 +/- 1.0 mm Hg, evidence of the Bohr effect. The presence of contrast media either completely abolished (Hypaque-76 and Omnipaque-350) or markedly attenuated (Isovue-370) this effect. In series 2 (five patients), blood samples were withdrawn from the external iliac artery during injection of Isovue-370 (60-78 mL) into the proximal abdominal aorta to evaluate peripheral vascular disease. Measurement of P50 of these samples yielded findings consistent with those of series 1. The present findings demonstrate that both ionic and nonionic contrast media increase the affinity of hemoglobin for oxygen and, therefore, that they may inhibit oxygen delivery to body tissues.

Involvement of the inferior vena cava in patients with renal cell carcinoma.

Inferior vena cavography plays an important role in the staging of renal cell carcinoma. The renal angiograms and inferior vena cavograms in a series of patients with renal cell carcinoma were reviewed to determine which patients require cavography. Our findings show that renal angiography is of great value in suggesting tumor involvement of the renal vein or vena cava, and that the decision to do cavography can be made from the angiographic findings. In the series of 172 patients with renal carcinoma, 15 or 9% had inferior vena cava involvement.

Angiographic patterns in renal oncocytomas.

Renal oncocytomas are benign tumors arising from proximal tubular epithelial cells. They appear radiographically as solid masses which are vascular on angiography. Angiograms of 13 cases of renal oncocytomas were reviewed, as well as those of 155 renal-cell carcinomas. The classic angiographic findings for the oncocytoma include a spoke-wheel pattern, a homogeneous nephrogram, and a sharp, smooth rim. The finding of a homogenous blush and/or a spoke-wheel pattern greatly increases the possibility of an oncocytoma, though a renal-cell carcinoma may have any or all of the classical findings described for an oncocytoma.

Replacement lipomatosis of the kidney.

Replacement lipomatosis and renal sinus lipomatosis are parts of a spectrum of fatty replacement of destroyed or atrophic renal tissue. When long-standing inflammation exists in a kidney, especially with calculus disease, replacement lipomatosis may be the end result. Awareness of this process along with the specific radiologic findings will allow a correct preoperative diagnosis.

Hemangiomas of the liver in patients with renal cell carcinoma.

Five patients with renal cell carcinoma were noted at angiography to have vascular hepatic lesions which resembled metastatic renal cell carcinoma but which proved to be benign hepatic hemangiomas. The angiographic differentiation between small hemangiomas and metastatic vascular neoplasms of the liver can be difficult; angiographic characteristics may not be definitive. Surgery to remove the renal tumor should not be deferred solely on the basis of vascular hepatic lesions found at angiography.

Infiltrating neoplasms of the kidney.

Some neoplastic processes which involve the kidney develop not as a distinct localized mass, but rather as an infiltrating process which replaces the renal parenchyma, causes little or no mass effect, and contains little if any neovascularity. These neoplasms include (1) carcinoma of the renal pelvis when it invades the parenchyma (transitional cell and squamous cell); (2) blood-borne metastatic squamous cell carcinoma to the kidney (most frequently from the lung): (3) renal lymphoma of the infiltrating variety; and (4) infiltrating sarcomatous type of hypernephroma. While the urographic and angiographic appearance of these infiltrating lesions can be similar, clinical aspects are usually sufficient to differentiate them. Radiographic findings include amputation of portions of the collecting system on urography and encasement of vessels with a loss of nephrogram on angiography.

Epinephrine-enhanced renal angiography in renal mass lesions: is it worth performing?

In our experience, properly performed epinephrine-enhanced angiography is a useful technique to improve accuracy in the angiographic diagnosis of renal masses. This pharmacologic enhancement is helpful in establishing the benignity of some lesions, clearly establishing malignancy in those questionable by routine angiography, and actually detecting malignant lesions not seen at all on unenhanced angiograms. Six examples of these situations are illustrated. The basic principles and pitfalls in the performance of the technique as well as its limitations are discussed.

Inferior vena caval occlusion: characteristic radiographic changes on excretory urography and barium enema examination.

Acute occlusion of the inferior vena cava produces characteristic radiographic findings on intravenous urogram and barium enema examination. The urinary bladder is compressed anteriorly and superiorly giving an inverted pear-shaped appearance, and the distal ureters are medially displaced. Barium enema examinations demonstrate narrowing and elevation of the rectosigmoid region along with an increase in the presacral space. Four cases are described to illustrate the usefulness of these findings in suggesting the correct diagnosis.

The pear-shaped bladder.

The tear-drop or pear-shaped bladder was originally described in cases of pelvic hematoma. It may also be seen, however, with a variety of other entities, including pelvic lipomatosis, inferior vena cava occlusion, lymphocysts, and enlarged pelvic lymph nodes. Pertinent radiographic findings of these conditions are reviewed.

Carcinoma of the gallbladder: a diagnosis aided by endoscopic retrograde and percutaneous hepatic cholangiography.

In a patient with obstructive jaundice, extrinsic compression of the common bile duct (Mirizzi syndrome) due to squamous cell carcinoma of the gallbladder was documented with the combination of endoscopic retrograde cholangiography and pancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC).

New diagnostic and therapeutic techniques in the management of pyogenic liver abscesses.

An unexplained increase in the frequency of pyogenic liver abscesses of unknown etiology has, fourtunately, been paralleled by significant advances in diagnostic and therapeutic methods. This report reviews experience with 14 patients operated upon at NYU Medical Center since 1971. Eight cases (57%) were cryptogenic. Other abscesses were associated with biliary disease (3); abdominal sepsis (2); and trauma (1). Abscesses were present on hospitalization in 12 patients. Clinical findings included fever (101-108 F); 100%; leucocytosis, 71%; anorexia and vomiting, 50%; localized tenderness and hepatomegaly, 50%; hypoalbuminemia, 86%; hypocholesterolemia, 78%; elevated SGOT, 71%; and elevated aikaline phosphatase, 43%. Technetium hepatic scintiscans showed focal defects in 10 of 12 patients (83%), but did not detect multiple abscesses in 2 of these. Hepatic arteriography performed in 10 patients was highly accurate, outlining single abscesses in 6 and multiple abscesses in 4. Furthermore, in one patient a false positive scintiscan was demonstrated by negative arteriography, confirmed by autopsy. In 4 patients, arteriography indicated an abscess in the posterior-superior area of the right hepatic lobe. With precise anatomical localization, a trans-thoracic approach permitted uncomplicated drainage in each case. This approach provides excellent exposure and direct drainage for abscesses in this area. An additional therapeutic adjunct in two patients, with 4 and 11 abscesses each, was postoperative intraportal infusion of antibiotics through the umbilical vein. Thirteen patients (83%) recovered, one dying from pulmonary embolism. Primary hepatic abscesses occur with increasing frequency. Primary hepatic abscesses occur with increasing frequency. Primary hepatic abscesses occur with increasing frequency. The methods described allow more precise preoperative diagnosis and direct surgical drainage.