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Biomedical subjects

W M Marks

Publications and source records attributed to W M Marks.

At least 19 recordsLinked to original sources
PubMed1988

Pancreatic ductal adenocarcinoma: diagnosis and staging with dynamic CT.

The authors assessed the accuracy of dynamic computed tomography (CT) in diagnosis and staging of ductal adenocarcinoma of the pancreas and analyzed the survival rates of patients with resectable and unresectable tumors. A correct diagnosis based on CT findings was made in 159 of 174 patients (91%) with 13 false-positive (8%) and two false-negative diagnoses (1%). The 13 false-positive diagnoses highlight the need for confirmation of diagnosis with biopsy. The accuracy of staging with CT was compared with that of angiography (42 patients) and surgery (51 patients). CT was more accurate than angiography in demonstrating tumor involvement of major peripancreatic vessels. Staging criteria were reliable: No unresectable tumors based on CT findings were found to be resectable during surgery (42 patients), while only three of nine resectable tumors based on CT findings were found to be unresectable. Thus, no tumors were incorrectly staged, which would potentially deny surgery for a patient. The average survival rate after resection was 14 months, while the survival rates after palliative (biliary or gastrointestinal bypass) or no treatment were 8 months and 5 months, respectively.

Angiography↗
PubMed1987

Meconium peritonitis: prenatal sonographic findings and their clinical significance.

Ultrasonographic (US) findings were correlated with clinical outcome in seven cases of meconium peritonitis detected with prenatal US during a 2-year period. Nineteen previously reported cases were also reviewed. US findings included intraabdominal calcifications (n = six cases), fetal ascites (n = 3), echogenic ascites without calcifications (n = 1), bowel dilatation (n = 2), and polyhydramnios (n = 5). Following delivery, six infants were still alive after a mean follow-up of 13 months (range, 6-26 months); the seventh died of hydrocephalus. Of the six, four required surgical correction of a small-bowel perforation and two did not. All six are thriving, and none has yet been found to have cystic fibrosis. In the 19 previously reported cases, there were only two cases of cystic fibrosis, neither with intraabdominal calcifications. The presence of calcifications was significantly associated with causes other than cystic fibrosis. Prenatally diagnosed cases of meconium peritonitis are associated with cystic fibrosis less frequently than previous studies suggest.

Ascites↗
PubMed1986

Colorectal carcinoma evaluation with CT: preoperative staging and detection of postoperative recurrence.

CT was performed prior to surgery in 103 patients with colorectal carcinoma to assess its value in staging the tumor. Preoperative IBD scans had sensitivities and specificities of 72.7% and 98.9% in detection of liver metastases, 25.9% and 96% in detection of lymph node metastases, and 61.2% and 80.6% in detection of local extension. Compared with the Duke's classification, CT correctly staged only 47.5% of patients: 16.6% were upstaged, and 83.3% were downstaged. Recurrent tumors developed in 11 of 67 patients followed for more than 24 months. CT depicted recurrence in six patients scanned prior to 12 months. Routine scans obtained at 12 months depicted unsuspected tumor recurrence in three of four patients with proved recurrent disease (one patient with pulmonary metastases did not undergo CT). This study indicates that because of the poor accuracy of CT in preoperative local staging of colorectal carcinoma, it has virtually no useful clinical role in this regard. However, preoperative CT evaluation of the liver can be useful. Routine postoperative CT, combined with fine-needle aspiration biopsy, is useful for detection of recurrent tumor.

Carcinoembryonic Antigen↗
PubMed1986

Hepatic perfusion abnormalities during CT angiography: detection and interpretation.

Twenty-seven perfusion abnormalities were detected in 17 of 50 patients who underwent computed tomographic angiography (CTA) of the liver. All but one of the perfusion abnormalities occurred in patients with primary or metastatic liver tumors. Perfusion abnormalities were lobar in nine cases, segmental in 11, and subsegmental in seven; 14 were hypoperfusion and 13 were hyperperfusion abnormalities. The causes for the abnormalities included nonperfusion of a replaced hepatic artery (n = 11), cirrhosis and nodular regeneration (n = 3), altered hepatic hemodynamics (e.g., siphoning, laminar flow) caused by tumor (n = 7), contrast media washout from a nonperfused vessel (n = 1), compression of adjacent hepatic parenchyma (n = 1), and unknown (n = 4). Differentiation of perfusion abnormalities from tumor usually can be made by comparing the morphology of the known tumor with the suspected perfusion abnormality, changes of each on delayed CTA scans, and review of initial angiograms and other imaging studies.

Angiography↗
PubMed1986

Patterns of contrast enhancement of benign and malignant hepatic neoplasms during bolus dynamic and delayed CT.

Bolus dynamic and delayed computed tomographic (CT) scans of the liver were evaluated in 43 patients with 54 hepatic hemangiomas and 111 patients with primary or secondary malignant hepatic neoplasms. Twelve patterns of contrast enhancement were recognized during the bolus dynamic phase and delayed scanning. A "typical" CT pattern for hemangiomas (present in 29 of 54 hemangiomas [53.7%]) was established: (a) diminished attenuation prior to intravenous contrast medium administration (excluding lesions arising in a liver with diffuse fatty infiltration), (b) peripheral contrast enhancement during the bolus dynamic phase, and (c) complete isodense fill-in on delayed scan images. Using these criteria, we distinguished hemangiomas from malignant neoplasms in most patients. Only one of 63 (1.6%) malignant neoplasms manifested these typical CT criteria of hemangioma. There is an 86% chance that a lesion with the typical CT appearance of hemangioma is actually a hemangioma, even when found in a patient with a known nonhepatic primary neoplasm.

Carcinoma, Hepatocellular↗
PubMed1986

Hepatic hemangioma: dynamic bolus CT.

Forty-seven patients with 58 hepatic hemangiomas were studied prospectively with a dynamic bolus CT protocol (single-level or incremental scans) that included precontrast scans, rapid-sequence scanning during the IV bolus injection of 150 ml of 60% contrast agent, and delayed scans taken as long as 60 min after contrast. Three CT criteria are believed to be necessary to make a specific diagnosis of hemangioma: lesion with diminished attenuation on precontrast scan; peripheral contrast enhancement during the dynamic bolus phase of scanning; and complete isodense fill-in on delayed scans obtained up to 60 min after contrast. These CT criteria were seen in only 32 (55%) of 58 hemangiomas, making CT a relatively poor imaging technique for diagnosis.

Adult↗
PubMed1984

Prospective management of exstrophy of the cloaca and myelocystocele following prenatal ultrasound recognition of neural tube defects in identical twins.

We describe identical twins concordant for exstrophy of the cloaca and myelocystocele. Their management and subsequent course was strongly influenced by prenatal ultrasound recognition of neural tube defects in both twins and severe renal dysplasia in one of the fetuses. The genetic aspects of this case are consistent with existing causal theories of exstrophy of the cloaca.

Abnormalities, Multiple↗
PubMed1984

Endoscopic retrograde biliary drainage.

Endoscopic retrograde biliary drainage (ERBD) was completed in 30 of 34 attempts (88.2%). Sixteen patients are alive with functioning stents one to 14 months following insertion of the catheters. Eight patients died with functioning stents two weeks to four months following placement. Six stents were replaced due to sepsis or rising bilirubin one to eight months following initial insertion. The only immediate complication was sepsis, which developed in one patient. Since ERBD circumvents many of the complications associated with percutaneous transhepatic drainage, it has replaced this technique in our institution as the primary non-operative modality for biliary decompression. Percutaneous transhepatic drainage is now reserved for ERBD failures.

Adult↗
PubMed1983

Computed tomographic arteriography of the liver.

Computed tomographic arteriography (CTA) is one method of evaluating hepatic masses. It consists of simultaneous infusion of 30% iodinated contrast medium into the hepatic artery during computed tomography (CT). Twenty-two patients with suspected resectable hepatic tumors were evaluated prior to surgery. Initial imaging procedures included conventional CT, ultrasonography, scintigraphy, and selective angiography. CTA identified additional tumor nodules in 12 out of 22 patients (55%), rendering the initially detected neoplasms unresectable. However, 2 other patients were found to have a normal liver and thus were spared unnecessary laparotomy.

Adult↗
PubMed1982

Impact of high-resolution computed tomography of the pancreas on utilization of endoscopic retrograde cholangiopancreatography and angiography.

The impact of computed tomography (CT) on utilization of other diagnostic procedures was studied by comparing the results obtained in two groups of patients: (a) 278 patients studied prior to the availability of CT, and (b) 300 patients studied using CT. CT enabled an accurate diagnosis in 74% of patients without the use of additional examinations. Utilization of CT as the initial imaging procedure resulted in a decrease in the utilization of endoscopic retrograde cholangiopancreatography (ERCP) and angiography by 68% and 54%, respectively. This resulted in a 47% decrease in the overall cost of radiologic diagnosis.

Angiography↗
PubMed1982

Adenocarcinoma of the gastroesophageal junction: barium and CT examination.

Seventy-seven patients with adenocarcinoma of the gastroesophageal junction were evaluated with upper gastrointestinal barium studies (single-contrast, 40: double-contrast, 37) and 21 of these had preoperative computed tomography for staging. Single- and double-contrast studies were equally sensitive in detecting exophytic tumors, but double-contrast studies were slightly more sensitive (25 of 26) than single-contrast examinations (21 of 25) in detecting infiltrating tumors. Computed tomography accurately staged 18 (86%) of 21 cases (16 unresectable, two resectable). The most reliable computed tomographic findings of tumor unresectability were metastases (liver, adrenal) and local tumor extension, both found in 10 (48%) of 21 cases, and regional adenopathy, present in eight (38%) of 21 cases. The presence or absence of the periesophageal soft-tissue planes was an unreliable finding and led to both false-positive (two cases) and false-negative (four cases) diagnoses. CT-guided percutaneous fine-needle aspiration biopsy was used successfully in four cases to obtain a cytologic diagnosis of metastatic adenocarcinoma.

Adenocarcinoma↗
PubMed1981

The oblique bending view in oral cholecystography.

The oblique bending projection, when incorporated into routine radiographs during oral cholecystography, was found to be at least as effective as fluoroscopic spot radiographs in obtaining information about the gallbladder.

Cholecystography↗
PubMed1981

Gastroesophageal region: source of confusion on CT.

Prominent soft-tissue density is often seen in the region of the gastroesophageal junction on CT scans of the upper abdomen. This was seen retrospectively in 38% of randomly selected patients when scans were obtained at 1-2 cm intervals and in 33% of patients evaluated prospectively with scans obtained at 1 cm intervals. The possible source of confusion of the normal but prominent-appearing gastroesophageal junction with a pathological mass and the normal anatomic relationships as seen during computed tomography are discussed.

Carcinoma↗
PubMed1981

Dermoid cysts of the ovary: their ultrasonographic appearances.

Ultrasonograms of 45 patients with 51 surgically proved benign cystic teratomas (dermoid cysts) of the ovary were reviewed to evaluate the ultrasonographic appearance of this entity. Contrary to several recent reports stressing a "typical" appearance for ovarian dermoid cysts, ie, an echogenic focus with acoustic shadowing situated within a predominantly cystic mass, the authors observed a much broader spectrum of appearances. Thirty-three percent of the cases demonstrated "typical" findings, 23.5% were predominantly solid, 20% were almost entirely cystic, and 23.5% were not visible. Ultrasound and conventional radiography in patients with dermoid cysts were compared: Ultrasonography contributed significantly to the correct diagnosis in the majority of cases. Because ultrasonography lacks ionizing radiation, and its use may reveal unrelated pelvic pathology, it should be the initial diagnostic modality in the examination of patients with suspected dermoid cysts of the ovary.

Dermoid Cyst↗