Francisco A. Quiroz

Ultrasonic Distinction of Abscesses from Other Intra-abdominal Fluid Collections

The nature of 103 intra-abdominal fluid collections examined by ultrasound was determined by autopsy, needle aspiration, spontaneous drainage or surgical exploration. Abscesses, chronic hematomas, lymphoceles, urinomas, cysts and fluid-filled bowel loops are all approximately elliptical or circular in cross section. Collections of ascites have a very irregular outline. Bowel loops appear as multiple circles, all of similar size. Chronic hematomas contain strongly echoing material, while lymphoceles, urinomas, renal and hepatic cysts and collections of ascites are echo-free. Ovarian cysts into which there has been bleeding may contain echoes. The walls of abscesses, chronic hematomas, and bowel loops are less sharp than the walls of other collections. Intrahepatic abscesses may have more ragged walls than abscesses elsewhere. Ultrasonic characteristics of abscesses and hematomas overlap. It is sometimes possible to distinguish the nature of the fluid by its ultrasonic properties, but atypical appearances are not rare.

Intermediate Results of Laparoscopic Cryoablation in 59 Patients at the Medical College of Wisconsin

PURPOSE We report our experience with LC for small renal tumors. MATERIALS AND METHODS Patients who underwent LC at our institution between February 2000 and September 2004 were included in the study. A retrospective chart review was done for perioperative and postoperative parameters as well as clinical outcomes. RESULTS A total of 65 LCs were performed in 59 patients during the period reviewed. Overall 81 renal tumors were cryoablated. Median patient age was 62 years. Median tumor size was 2.5 cm. Median operative time was 190 minutes. Median estimated blood loss was 50 ml. Median hospital stay was 2 days. Conversion to open surgery occurred in 2 patients. Nephrectomy for bleeding occurred in 1 patient. Median followup was 26.8 months. Two recurrences were identified after LC. CONCLUSIONS LC is an alterative modality to laparoscopic partial nephrectomy or open partial nephrectomy for small renal tumors. Tumor recurrence rates in the studies published to date are comparable to those of partial nephrectomy, although longer followup is needed.

Periportal halo: a CT sign of liver disease.

Periportal halos are defined as circumferential zones of decreased attenuation identified around the peripheral or subsegmental portal venous branches on contrast-enhanced computed tomography (CT). These halos probably represent fluid or dilated lymphatics in the loose areolar zone around the portal triad structures. While this CT finding is nonspecific, it is abnormal and should prompt close scrutiny of the liver in search of an underlying etiology. Periportal halos which may be due to blood are commonly seen in patients with liver trauma. Periportal edema may cause this sign in patients with congestive heart failure and secondary liver congesion, hepatitis, or enlarged lymph nodes and tumors in the porta hepatis which obstruct lymphatic drainage. This CT sign has also been observed in liver transplants (probably secondary to disruption and engorgement of lymphatic channels) and in recipients of bone marrow transplants who might develop liver edema from microvenous occlusive disease. While the precise pathophysiologic basis of periportal tracking has not been proven, it represents a potentially important CT sign of occult liver disease.

Ablation of liver metastasis: is preoperative imaging sufficiently accurate?

The recent introduction of cryotherapy and radiofrequency ablation of liver metastasis has expanded the indications for treatment. As technology has advanced, a percutaneous approach has been developed. Percutaneous treatment, however, requires accurate preoperative imaging. From 1993 to 1999, 179 patients underwent operative exploration for treatment of suspected hepatic metastases from colorectal carcinoma. One hundred seventy-seven patients were staged by preoperative CT, two patients were staged by MRI, and complete data were available in 176. Hepatic tumor count by preoperative imaging was compared to intraoperative tumor count obtained by inspection, palpation, ultrasonographic examination using a 3S/7.5 MHz T probe, and careful gross sectioning of the resected specimen. Post hoc analysis was performed on 35 CT scans by two radiologists who specialize in abdominal CT These radiologists were blinded to the intraoperative findings. Their interpretations were compared to the intraoperative counts and to each other. Thirty-four (19%) of 179 patients were deemed untreatable at operation because of unsuspected overwhelming liver involvement in 11 (6%) or extrahepatic metastases in 23 (13%). For the group, CT was accurate in 80 patients (45%), showed more lesions than were found in 16 (9%), and showed fewer metastases than were found in 80 (45%). When the preoperative scan predicted a solitary metastasis, it was correct in 45 (65%) of 69 patients and underestimated disease in 24 (35%). In the post hoc analysis, the mean numbers of lesions reported by the two radiologists did not differ from the mean number of tumors found; however, the radiologists’ counts agreed on 16 (59%) and disagreed on 11 (41 %) of the scans. The accuracy of CT decreased with increasing numbers of lesions. Regardless of the type of preoperative imaging, intraoperative findings altered the course of the operation in 96 (55%) of 176 patients. Preoperative imaging is not sufficiently accurate to permit adequate percutaneous treatment of hepatic metastases from colorectal carcinoma.

Indirect CT venography following CT pulmonary angiography: spectrum of CT findings.

Pulmonary embolism (PE) and deep venous thrombosis (DVT) represent two manifestations of the same syndrome, venous thromboembolism. Contrast-enhanced computed tomography (CT) angiography is a practical, efficient alternative to conventional imaging for PE. Following the pulmonary examination, the inferior vena cava (IVC) and the iliac, femoral, and popliteal veins can be studied with CT without additional intravenous contrast administration. Indirect CT venography (CTV) after CT pulmonary angiography (CTPA) simplifies and shortens venous thromboembolism work-up. Initial studies indicate that CTV is comparable to ultrasound in the evaluation of femoral/popliteal DVT. CTV has the advantage of evaluating the iliac veins and inferior vena cava, vessels poorly seen on sonography and venography. Combining CTV with CTPA increases confidence in withholding treatment when results for both the pulmonary arteries and leg veins are negative and increases the diagnosis of venous thromboembolism by 25% over CTPA alone. This pictorial essay will review the normal venous anatomy, CTV technique, and the findings of acute and chronic DVT. Interpretive pitfalls and alternative diagnoses are also reviewed.

The role of sonography in imaging of the biliary tract.

Sonography is the recommended initial imaging test in the evaluation of patients presenting with right upper quadrant pain or jaundice. Dependent upon clinical circumstances, the differential diagnosis includes choledocholithiasis, biliary stricture, or tumor. Sonography is very sensitive in detection of mechanical biliary obstruction and stone disease, although less sensitive for detection of obstructing tumors, including pancreatic carcinoma and cholangiocarcinoma. In patients with sonographically documented cholelithiasis and choledocholithiasis, laparoscopic cholecystectomy with operative clearance of the biliary stone disease is usually performed. In patients with clinically suspected biliary stone disease, without initial sonographic documentation of choledocholithiasis, endoscopic ultrasound or magnetic resonance cholangiopancreatography is the next logical imaging step. Endoscopic ultrasound documentation of choledocholithiasis in a postcholecystectomy patient should lead to retrograde cholangiography, sphincterotomy, and clearance of the ductal calculi by endoscopic catheter techniques. In patients with clinical and sonographic findings suggestive of malignant biliary obstruction, a multipass contrast-enhanced computed tomography (CT) examination to detect and stage possible pancreatic carcinoma, cholangiocarcinoma, or periductal neoplasm is usually recommended. Assessment of tumor resectability and staging can be performed by CT or a combination of CT and endoscopic ultrasound, the latter often combined with fine needle aspiration biopsy of suspected periductal tumor. In patients whose CT scan suggests hepatic hilar or central intrahepatic biliary tumor, percutaneous cholangiography and transhepatic biliary stent placement is usually followed by brushing or fluoroscopically directed fine needle aspiration biopsy for tissue diagnosis. Sonography is the imaging procedure of choice for biliary tract intervention, including cholecystostomy, guidance for percutaneous transhepatic cholangiography, and drainage of peribiliary abscesses.

The utility of routine preoperative cervical ultrasonography in patients undergoing thyroidectomy for differentiated thyroid cancer

BACKGROUND Preoperative ultrasonography (US) is recommended in all patients with differentiated thyroid cancer (DTC) to evaluate for clinically occult metastatic lymphadenopathy. The purpose of this study was to examine the influence of preoperative US findings on the initial operative management of patients with DTC. METHODS This is a retrospective review of 70 patients with biopsy-proven DTC who underwent total thyroidectomy between February 2010 and January 2012. All patients underwent preoperative cervical US (thyroid, central, and lateral neck lymph node compartments). RESULTS Palpable lateral neck adenopathy was thought to be present in 5 (7%) of the 70 patients, but confirmed by US in only 3; 2 patients avoided lateral compartment neck dissection (LCND). Of 65 patients with no palpable lymphadenopathy, 14 (22%) had abnormal lymphadenopathy on preoperative US. All 14 patients underwent total thyroidectomy with central compartment neck dissection (CCND); 12 patients with abnormal US findings in the lateral compartment(s) also underwent LCND. Metastatic disease was confirmed in 13 (93%) of the 14 patients: 13 of 14 who underwent CCND and 11 (92%) of 12 who underwent LCND. CONCLUSION This study confirms the importance of preoperative, high-quality cervical US in patients with DTC because it changed the operative management in 16 of 70 patients (23%); 13 had a more complete operation for pathologically confirmed, clinically occult, lymph node metastases, 2 avoided nontherapeutic LCND, and 1 had false-positive US results.

Scrotal ultrasonography with emphasis on the extratesticular space: anatomy, embryology, and pathology.

Sonography is the imaging modality of choice in detecting and characterizing pathologic conditions affecting the extratesticular space. Although most abnormalities are benign, many may simulate or represent malignant processes. Accurate diagnosis is therefore essential and must be based not only on the sonographic findings but also on accurate clinical history and physical examination findings. This article reviews the anatomy, embryologic development, and pathologic conditions affecting the extratesticular space.

Demonstration of the normal extrahepatic biliary tract with computed tomography.

When optimum computed tomography (CT) technique and computed angiotomography are utilized, the normal extrahepatic biliary ducts (equal to or less than 6 mm in diameter in patients without cholecystectomy) can be demonstrated in approximately 30% of clinical scans. Measurement of the anteroposterior diameter of the bile duct is more accurate than recording the transverse diameter, since the apparent transverse dimension will vary depending on the orientation of the duct in the plane of section. Phantom studies indicate that the absolute error of measurement is approximately one pixel diameter irrespective of duct diameter. The normal and abnormally dilated extrahepatic biliary ducts should be distinguished with CT.

Sagittal and Coronal Image Reconstruction: Application in Pancreatic Computed Tomography

The application of coronal and sagittal image reconstruction in the display of the normal pancreas and peripancreatic region is illustrated. The use of standard reproducible reference points for multiplanar reconstruction is suggested. Reconstruction computed tomography displays more anatomic structures in the coronal and sagittal planes than ultrasonography and accurately displays the craniocaudad extent of pancreatic pathology.