Detectability of intraperitoneal fluid by ultrasonography. An experimental investigation

The detectability of intraperitoneal fluid was investigated by ultrasonography following injection of physiologic saline in conjunction with hysterosalpingography in 40 patients. It was invariably possible to identify 10 to 15 ml fluid in the pouch of Douglas with the patient in supine position and in Morison's pouch after Trendelenburg and right decubitus position. Ultrasonography is superior to conventional radiography for detection of minor intraperitoneal fluid.     

Gastrointestinal perforation: ultrasound diagnosis

Purpose: To investigate the spectrum of US findings as encountered in a consecutive series of patients referred with clinically suspected gastrointestinal perforation. Methods: Seventy-two consecutive patients (mean age: 42.9 years) with clinically suspected gastrointestinal perforation were prospectively examined with abdominal ultrasound (US). The US examinations were all performed by a certified senior radiologist, who was blind to other imaging findings. Patients were screened for the presence of free intraperitoneal gas (characteristic comet-tail artifacts, ring-down artifacts, and the “shifting phenomenon” were our diagnostic indicators of pneumoperitoneum). Other signs potentially suggestive of gastrointestinal perforation were also looked for, including free intraperitoneal fluid, thickening of bowel walls, gallbladder walls, gastric walls, or duodenal walls, or local peritoneal inflammation. Patients with equivocal or inconclusive findings on US were submitted to abdominal computed tomography (CT) 10–15 min after US examinations. Results: Of the 72 patients prospectively examined by US, 63 (87.5 %) underwent subsequent emergent surgery within next 2 days. A gastrointestinal perforation was found in all the 63 patients referred for operative treatment: overall, 41 gastroduodenal and 22 intestinal perforations were found. On US, in the 41 patients with surgically proven gastroduodenal perforation, the most common finding was free intraperitoneal gas (28/41, 68.3 %). The 13/41 patients (31.7 %) without evidence of free gas on US underwent preoperative abdominal CT assessment, which allowed the correct diagnosis of gastroduodenal perforation in 12/13 cases. In the 22 patients with surgically proven intestinal perforation the most common finding detected on US was free intraperitoneal fluid (14/22, 63.6 %); sonographic evidence of free intraperitoneal gas was seen in only 8/22 patients (36.4 %). The 14/22 patients (63.6 %) without free gas on US underwent preoperative abdominal CT assessment, which allowed the diagnosis of intestinal perforation in 12/14 cases. Conclusion: US examinations allow very rapid screening of patients referred with clinically suspected gastrointestinal perforation and for triage of patients who are to undergo more invasive imaging tests.     

Sonographic detection of subtle pelvic fluid collections

The sonographic demonstration of small quantities of free intraperitoneal fluid often indicates significant pelvic pathology. In a review of pelvic fluid collections in 146 female patients, however, it became apparent that an overly distended urinary bladder may mask small quantities of free intraperitoneal fluid. The "mass effect" of a distended bladder may cause fluid in the pouch of Douglas to migrate to other parts of the peritoneal cavity, such as the peritoneal reflection over the fundus of the uterus. Fluid in this location produces a characteristic triangular "cap" and was present in 42 patients (29% of the study group). In 10 patients (6.9%) this was the only visible fluid collection. In addition, sonograms obtained after partial voiding demonstrated small quantities of free pelvic fluid in 14 patients (9.6% of the study group) that were not detected on routine full bladder scans. The sonographic appearance of small amounts of intraperitoneal fluid seen over the uterine fundus and the value of post-void scans are stressed in the demonstration of small quantities of intraperitoneal fluid.     

Ultrasound and MRI features of pyomyositis in children

Pyomyositis (PM) is an infectious disease of the skeletal muscle with a wide range of symptoms such as pain, fever or swelling, and is predominantly found in the tropics. In recent years PM has increasingly been diagnosed in Europe and in the U.S. Our objective is to describe the ultrasound and MRI features of PM in children. A retrospective analysis of 12 children with PM (2 girls and 10 boys; age range 1–13 years) admitted to our hospital between 1998 and 2002 was carried out. All children had a US exam and 8 children underwent MRI. Children with osteomyelitis and accompanying myositis were excluded from this study. In all patients who had MRI (n=8) the infected muscles were found to have the following features: hyperintensity on the T2-weighted images, diffuse borders and contrast enhancement. In the pelvis (n=4), only one PM could be detected with US, in the other 3 cases only US of the hip joint was performed based on the clinical symptoms. In the extremities (n=8) US always revealed an altered echogenicity of the affected muscles as well as fluid collection in 5 cases. Both US and MRI reveal characteristic changes of the PM. Ultrasound should be the first imaging modality in the extremities. In the pelvis MRI is the imaging modality of choice. The MRI is needed to differentiate pyomyositis from osteomyelitis. Electronic Publication     

The value of endorectal MR imaging to predict positive biopsies in clinically intermediate-risk prostate cancer patients

The aim of this study was to assess the effectiveness of endorectal MR imaging in predicting the positive biopsy results in patients with clinically intermediate risk for prostate cancer. We performed a prospective endorectal MR imaging study with 81 patients at intermediate risk to detect prostate cancer between January 1997 and December 1998. Intermediate risk was defined as: prostatic specific antigen (PSA) levels between 4 and 10 ng/ml or PSA levels in the range of 10–20 ng/ml but negative digital rectal examination (DRE) or PSA levels progressively higher (0.75 ng/ml year^–1). A transrectal sextant biopsy was performed after the endorectal MR exam, and also of the area of suspicion detected by MR imaging. The accuracies were measured, both singly for MR imaging and combined for PSA level and DRE, by calculating the area index of the receiver operating characteristics (ROC) curve. Cancer was detected in 23 patients (28 %). Overall sensitivity and specificity of endorectal MRI was 70 and 76 %, respectively. Accuracy was 71 % estimated from the area under the ROC curve for the total patient group and 84 % for the group of patients with PSA level between 10–20 ng/ml. Positive biopsy rate (PBR) was 63 % for the group with PSA 10–20 ng/ml and a positive MR imaging, and 15 % with a negative MR exam. The PBR was 43 % for the group with PSA 4–10 ng/ml and a positive MR study, and 13 % with a negative MR imaging examination. We would have avoided 63 % of negative biopsies, while missing 30 % of cancers for the total group of patients. Endorectal MR imaging was not a sufficient predictor of positive biopsies for patients clinically at intermediate risk for prostate cancer. Although we should not avoid performing systematic biopsies in patients with endorectal MR imaging negative results, as it will miss a significant number of cancers, selected patients with a PSA levels between 10–20 ng/ml or clinical-biopsy disagreement might benefit from endorectal MR imaging. Received: 8 February 2000/Revised: 7 July 2000/Accepted: 10 July 2000     

Subacute versus delayed reconstruction of the anterior cruciate ligament in the competitive athlete

The objective of this study was to compare the function and activity level in patients with anterior cruciate ligament injuries, who participated in competitive sports (Tegner activity level ≥ 7) and underwent a reconstruction of the anterior cruciate ligament, either subacute (2–12 weeks, group I) or late (12–24 months, group II) after the injury. The patients in group I (n = 97) were comparable with those in group II (n = 103) in terms of gender, age, pre-injury activity level, and the reconstruction technique. At the final follow-up (2–5.5 years after the operation), the Lysholm score, the IKDC evaluation system and the one-leg-hop test revealed no differences between the groups. There were also no differences between the groups in terms of the patients’ subjective evaluation or expectations. The Tegner activity level at follow-up was 8 (range 2–10) in group I and 6 (range 2–9) in group II (P = 0.0001). The same thing was found in terms of the desired Tegner activity level, which was 9 (range 4–9) in group I and 7 (range 3–10) in group II (P = 0.0002). The KT-1000 laxity meter revealed a total side-to-side difference of 1.5 mm (–3.5–8.5) in group I and 1.5 mm (–3.5–7) in group II (NS). Associated meniscal surgery between the index injury and the reconstruction, or during the reconstruction, was performed in 37/97 (38%) of the patients in group I and 59/103 (57%) of the patients in group II (P < 0.01). This study revealed that competitive athletes who underwent reconstruction at a subacute stage after the anterior cruciate ligament injury had a higher activity level 2–5.5 years after the index operation, as well as a higher desired level of activity compared to athletes who had the reconstruction delayed by 12–24 months. Furthermore, meniscal injuries were significantly more frequent if the reconstruction was delayed. Received: 10 May 1998 Accepted: 30 November 1998     

CT colonography: optimisation,diagnostic performance and patient acceptability of reduced-laxative regimens using barium-based faecal tagging

To establish the optimum barium-based reduced-laxative tagging regimen prior to CT colonography (CTC). Ninety-five subjects underwent reduced-laxative (13 g senna/18 g magnesium citrate) CTC prior to same-day colonoscopy and were randomised to one of four tagging regimens using 20 ml 40%w/v barium sulphate: regimen A: four doses, B: three doses, C: three doses plus 220 ml 2.1% barium sulphate, or D: three doses plus 15 ml diatriazoate megluamine. Patient experience was assessed immediately after CTC and 1 week later. Two radiologists graded residual stool (1: none/scattered to 4: >50% circumference) and tagging efficacy for stool (1: untagged to 5: 100% tagged) and fluid (1: untagged, 2: layered, 3: tagged), noting the HU of tagged fluid. Preparation was good (76–94% segments graded 1), although best for regimen D (P = 0.02). Across all regimens, stool tagging quality was high (mean 3.7–4.5) and not significantly different among regimens. The HU of layered tagged fluid was higher for regimens C/D than A/B (P = 0.002). Detection of cancer (n = 2), polyps ≥6 mm (n = 21), and ≤5 mm (n = 72) was 100, 81 and 32% respectively, with only four false positives ≥6 mm. Reduced preparation was tolerated better than full endoscopic preparation by 61%. Reduced-laxative CTC with three doses of 20 ml 40% barium sulphate is as effective as more complex regimens, retaining adequate diagnostic accuracy.     

A double-blind, prospective, randomized, multicenter group comparison study of iopromide 240 vs iohexol 240 in myelography

The aim of this study was to evaluate the safety and efficacy of iopromide 240 mgI/ml in comparison with iohexol 240 mgI/ml in myelography. A total of 421 patients in seven centers and four countries received an average of 11.9 ml of either iopromide 240 (278 patients) or iohexol 240 (143 patients) for X-ray and/or CT myelography in a randomized (2:1), prospective, double-blind study. All patients were followed up 3–4 h after the procedure, and 327 patients remained hospitalized for 24 h. In 82 patients an EEG was recorded prior to as well as 3–4 h and 24 h after myelography. Physical examinations, including measurement of vital signs, were performed in all patients at these time points. The results were subject to statistical analysis with the primary variable being the incidence of adverse events. Both contrast media (CM) were equally effective in terms of opacification. The rating for opacity was “good” or “excellent” in 88 % for both CM. Four patients (iopromide group: n = 3; iohexol group: n = 1) had transient EEG changes but did not show clinical symptomatology. The overall rate of patients experiencing any adverse event (AE) was 16.9 % for iopromide 240 and 14.0 % for iohexol 240. Equivalence testing was inconclusive; however, the results indicated equivalence. The rate for AEs considered as study-drug related was slightly lower with iopromide 240 than with iohexol 240 (7.2 vs 7.7 %, respectively). Neither unknown nor unexpected AEs known for myelographic X-ray CM nor serious adverse events were observed. Iopromide 240 and iohexol 240 are equally safe and effective and can be recommended for myelography. Received: 19 August 1998; Revision received: 26 November 1998; Accepted: 4 February 1999     

Acetic acid as a sclerosing agent for renal cysts: Comparison with ethanol in follow-up results

Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents. Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6–76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 31 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 11.7%–25% (4–100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1–49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications. Results: The mean volume after sclerotherapy of the 17 cysts followed for 3–4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day. Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol.     

Helical computed tomography diagnosis of gastrointestinal perforation in the elderly patient

Purpose: To determine the value of helical CT in a consecutive series of elderly patients referred with clinically suspected gastrointestinal perforation. Methods: Our series comprised 34 consecutive elderly patients (mean age: 68 years) presenting with acute abdominal symptoms potentially suggestive of gastrointestinal perforation. All the patients were prospectively subjected to abdominal computed tomography (CT). On helical CT, the presence of free air was considered diagnostic of gastrointestinal perforation. Other findings such as intraperitoneal free fluid, thickening of bowel wall, streaky density within the mesentery, “dirty fat” sign, and focal collection of extraluminal fecal matter (“dirty mass”) were considered indirect findings of perforation. Results: At surgery, the following sites of perforation were found: duodenum (38.2 %), stomach (29.4 %), ileum (8.8 %), sigmoid colon (8.8 %), rectum (5.8 %), and jejunum, appendix, and transverse colon (2.9 % of cases each). CT demonstrated the presence of free air in 94.1 % of cases; intraperitoneal free fluid was present in 76.4 % of patients and thickening of bowel wall in 50 %. Streaky density within the mesentery was found in one patient. Conclusion: CT is a reliable diagnostic method by which to assess gastrointestinal perforation, because it provides excellent contrast resolution to depict the presence of even small amounts of free air in the abdomen. This is particularly helpful where elderly patients are concerned.     

Breast carcinoma in women previously treated for Hodgkin's disease: clinical and mammographic findings

The aim of this study was to describe the radiological characteristics of breast cancers occurring after treatment of Hodgkin's disease (HD). This study identified 23 women (age range 28–70 years, mean age 40 years) with 29 breast cancers (22 infiltrating carcinomas, 5 in situ, 1 sarcoma, 1 indeterminate) who had previously undergone mantle irradiation (35–40 Gy) for HD. Clinical and mammographic data were reviewed by two radiologists. Dosimetry was available for 16 patients. Time from treatment of HD to the occurrence of breast cancer ranged from 15 months to 35 years (mean 18 years); 79 % were younger than 45 years and 76 % of cancers occurred between 10 and 25 years of follow-up. The physical examination was positive in 76 % and 6 patients had bilateral tumors (synchronous, n = 2; metachronous, n = 4). Eighty-three percent of mammograms (n = 24) were abnormal (microcalcifications, n = 72 %; opacity, n = 54 %; two inflammatory breast cancers). Seven cancers were only detected by mammography, but mammograms were normal in 4 patients. Breast cancer was located beyond or was overlapping radiation fields in 75 % of cases. Starting 10 years after mantle irradiation of women with HD, the follow-up should include annual clinical breast examination and mammography. Received: 27 July 1998; Revision received: 15 January 1999; Accepted: 16 March 1999     

Sterile Fluid Collections in Acute Pancreatitis: Catheter Drainage Versus Simple Aspiration

Purpose To compare the clinical outcome of needle aspiration versus percutaneous catheter drainage of sterile fluid collections in patients with acute pancreatitis. Methods We reviewed the clinical and imaging data of patients with acute pancreatic fluid collections from 1998 to 2003. Referral for fluid sampling was based on elevated white blood cell count and fevers. Those patients with culture-negative drainages or needle aspirations were included in the study. Fifteen patients had aspiration of 10–20 ml fluid only (group A) and 22 patients had catheter placement for chronic evacuation of fluid (group C). We excluded patients with grossly purulent collections and chronic pseudocysts. We also recorded the number of sinograms and catheter changes and duration of catheter drainage. The CT severity index, Ranson scores, and maximum diameter of abdominal fluid collections were calculated for all patients at presentation. The total length of hospital stay (LOS), length of hospital stay after the drainage or aspiration procedure (LOS-P), and conversions to percutaneous and/or surgical drainage were recorded as well as survival. Results The CT severity index and acute Ransom scores were not different between the two groups (p = 0.15 and p = 0.6, respectively). When 3 crossover patients from group A to group C were accounted for, the duration of hospitalization did not differ significantly, with a mean LOS and LOS-P of 33.8 days and 27.9 days in group A and 41.5 days and 27.6 days in group C, respectively (p = 0.57 and 0.98, respectively). The 60-day mortality was 2 of 15 (13%) in group A and 2 of 22 (9.1%) in group C. Kaplan–Meier survival curves for the two groups were not significantly different (p = 0.3). Surgical or percutaneous conversions occurred significantly more often in group A (7/15, 47%) than surgical conversions in group C (4/22, 18%) (p = 0.03). Patients undergoing catheter drainage required an average of 2.2 sinograms/tube changes and kept catheters in for an average of 52 days. Aspirates turned culture-positive in 13 of 22 patients (59%) who had chronic catheterization. In group A, 3 of the 7 patients converted to percutaneous or surgical drainage had infected fluid at the time of conversion (total positive culture rate in group A 3/15 or 20%). Conclusions There is no apparent clinical benefit for catheter drainage of sterile fluid collections arising in acute pancreatitis as the length of hospital stay and mortality were similar between patients undergoing aspiration versus catheter drainage. However, almost half of patients treated with simple aspiration will require surgical or percutaneous drainage at some point. Disadvantages of chronic catheter drainage include a greater than 50% rate of bacterial colonization and the need for multiple sinograms and tube changes over an average duration of about 2 months.     

Regional cerebral blood flow levels as measured by xenon-CT in vascular territorial low-density areas after subarachnoid hemorrhage are not always ischemic

Introduction The aim of this study was to assess regional cerebral blood flow (rCBV) in areas of CT hypoattenuation appearing in the postoperative period in patients treated for aneurysmal subarachnoid hemorrhage (SAH) using xenon-enhanced CT scanning (Xe-CT).Methods We analyzed 15 patients (5 male and 10 female; mean age 49.7±12.1 years) with SAH on CT performed on admission to hospital and who showed a low-density area within a well-defined vascular territory on CT scans after clipping or coiling of a saccular aneurysm. All zones of hypoattenuation were larger than 1 cm² and showed signs of a mass effect suggesting a subacute phase of evolution. Two aneurysms were detected in two patients. Aneurysms were located in the middle cerebral artery (n=7), in the anterior communicating artery (n=6), in the internal carotid artery (n=3), and in the posterior communicating artery (n=1). Treatments were surgical (n=8), endovascular (n=2) or both (n=1). A total of 36 Xe-CT studies were performed and rCBF values were measured in two different regions of interest (ROI): the low-density area, and an area of normal-appearing brain tissue located symmetrically in the contralateral hemisphere.Results rCBF levels were significantly lower in the low-density area than in the contralateral normal-appearing area (P<0.01). In the low-density areas, irreversible ischemia (CBF <10 ml/100 g per minute) was present in 11/36 lesions (30.6%), ischemic penumbra (CBF 10–20 ml/100 g per minute) and oligemia (CBF 20–34 ml/100 g per minute) in 8/36 lesions (22.2%), relative hyperemia (CBF 34–55 ml/100 g per minute) in 7/36 lesions (19.4%), and absolute hyperemia (CBF >55 ml/100 g per minute) in 2/36 lesions (5.6%).Conclusion Our study confirmed that rCBF is reduced in new low-density lesions related to specific vascular territories. However, only about one-third of the lesions showed rCBF levels consistent with irreversible ischemia and in a relatively high proportion of lesions, rCBF levels indicated penumbral, oligemic and hyperemic areas.     

MRI gadolinium enhancement of bone marrow: age-related changes in normals and in diffuse neoplastic infiltration

 Objective: To quantify gadolinium-related enhancement in the bone marrow of the spine in normals and in patients with homogeneous diffuse malignant bone marrow infiltration. Design and patients: The patients consisted of two groups: group 1 comprised 94 healthy adults (18–86 years) without bone marrow disease and group 2 comprised 30 patients with homogeneous diffuse malignant bone marrow infiltration due to myeloma (n=20) or breast carcinoma (n=10). All patients received intravenous gadopentetate dimeglumine (Gd-DTPA), 0.1 mmol/kg body weight. Pre- and postcontrast signal intensity (SI) on T1-weighted spin-echo (SE) images (TR/TE: 572 ms/15 ms) was measured over a region of interest (ROI) and the percentage SI increase was calculated. The results were confirmed by bone marrow biopsy (n=20) and clinical parameters (n=10). Dynamic contrast-enhanced studies using a spoiled gradient-recalled-echo (GRE) sequence (TR/TE/α: 68 ms/6 ms 75°) were performed in 10 controls with normal bone marrow. Results and conclusion: Contrast material enhancement in healthy persons can vary greatly (range 3–59%, mean 21%, SD 11%). With increasing age there is a significant decrease in contrast enhancement (Pearson’s correlation, P<0.01). The percentage SI increase in patients with intermediate-grade (biopsy 20–50 vol%) and high-grade (biopsy >50 vol%) diffuse malignant bone marrow infiltration was significantly higher than in normals (mean 67%, SD 34%, P<0.001). Low-grade (biopsy <20 vol%) diffuse malignant bone marrow infiltration can not be assessed by non-enhanced T1-weighted SE images or Gd-DTPA application. In conclusion, contrast material enhancement in healthy persons can vary greatly and is dependent on age, while intermediate-grade and high-grade diffuse malignant bone marrow infiltration can be objectively assessed with SI measurements.     

Introducing fluorine-18 fluoromisonidazole positron emission tomography for the localisation and quantification of pig liver hypoxia

Fluorine-18 labelled fluoromisonidazole ([¹⁸F]FMISO) has been shown to accumulate in hypoxic tissue in inverse proportion to tissue oxygenation. In order to evaluate the potential of [¹⁸F]FMISO as a possible positron emission tomography (PET) tracer for imaging of liver tissue hypoxia, we measured the [¹⁸F]FMISO uptake in 13 domestic pigs using dynamic PET scanning. Hypoxia was induced by segmental arterial hepatic occlusion. During the experimental procedure the fractional concentration of inspired oxygen (FiO₂) was set to 0.67 in group A (n=6) and to 0.21 in group B (n=7) animals. Before and after arterial occlusion, the partial pressure of O₂ in tissue (TPO₂) and the arterial blood flow were determined in normal flow and flow-impaired liver segments. Standardised uptake values [SUV=kBq tissue (in g) / body weight (in kg) × injected dose (in kBq)] for [¹⁸F]FMISO were calculated from PET images obtained 3 hours after injection of about 10 MBq/kg body weight [¹⁸F]FMISO. Immediately before PET scanning, the mean arterial blood flow was significantly decreased in arterially occluded segments [group A: 0.41 (0.32–0.52); group B: 0.24 (0.16–0.33) ml min^–1 g^–1] compared with normal flow segments [group A: 1.05 (0.76–1.46); group B: 1.14 (0.83–1.57) ml min^–1 g^–1; geometric mean (95% confidence limits); P<0.001 for both groups]. After PET scanning, the TPO₂ of occluded segments (group A: 5.1 (4.1–6.4); group B: 3.5 (2.6–4.9) mmHg] was significantly decreased compared with normal flow segments [group A: 26.4 (21.2–33.0); group B: 18.2 (13.3–25.1) mmHg; P<0.001 for both groups]. During the 3-h PET scan, the mean [¹⁸F]FMISO SUV determined in occluded segments increased significantly to 3.84 (3.12–4.72) in group A and 5.7 (4.71–6.9) in group B, while the SUV remained unchanged in corresponding normal liver tissue [group A: 1.4 (1.14–1.71); group B: 1.31 (1.09–1.57); P<0.001 for both groups]. Regardless of ventilation conditions, a significant inverse exponential relationship was found between the TPO₂ and the [¹⁸F]FMISO SUV (r ²=0.88, P<0.001). Our results suggest that because tracer delivery to hypoxic tissues was maintained by the portal circulation, the [¹⁸F]FMISO accumulation in the liver was found to be directly related to the severity of tissue hypoxia. Thus, [¹⁸F]FMISO PET allows in vivo quantification of pig liver hypoxia using simple SUV analysis as long as tracer delivery is not critically reduced. Received 27 July and in revised form 28 September 1998     

Comparison of somatostatin receptor imaging, computed tomography and ultrasound in the clinical management of neuroendocrine gastro-entero-pancreatic tumours

Neuroendocrine tumours displaying somatostatin receptors have been successfully visualised with somatostatin receptor imaging (SRI). However, there may be differences in sensitivity depending on the site of the primary tumour and/or its metastases. We studied 131 patients affected by neuroendocrine tumours of the gastro-entero-pancreatic (GEP) tract. A pathological diagnosis was obtained in 116 patients, while in 15 the diagnosis was based on instrumental results and follow-up. Fifty-one patients were examined for staging purposes, 80 were in follow-up. Images were acquired 24 and 48 h after the injection of 150–220 MBq of indium-111 pentetreotide. Whole-body and SPET images were obtained in all patients. Patients were also studied with computed tomography (CT), ultrasound (US), and other procedures. Tumours were classified according to their site of origin: pancreas n = 39, ileum n = 32, stomach n = 16, appendix n = 9, duodenum n = 5, jejunum n = 5, rectum n = 3, biliary tract n = 2, colon n = 2, caecum n = 1, liver metastases from unknown primary = 15, widespread metastases from unknown primary = 2. Sensitivity for primary tumour localisation was as follows: SRI = 62%; CT = 43%; US = 36%; other procedures = 45%. Sensitivity for liver metastases: SRI = 90%; CT = 78%; US = 88%; other procedures = 71%. Sensitivity for the detection of extrahepatic soft tissue lesions was: SRI = 90%; CT = 66%; US = 47%; other procedures = 61%. Sensitivity for the detection of the primary tumour in patients with metastases from unknown primary sites: SRI 4/17; CT 0/13; US 0/12; other procedures 1/10. In 28% of the patients SRI revealed previously unknown lesions, and in 21% it determined a modification of the scheduled therapy. Our study confirms the important role of SRI in the management of GEP tumours. However, we feel that a critical investigation should address its role in locating primary tumours, in particular in patients with metastases from unknown primary sites. Received 1 May and in revised form 29 June 1998     

In vitro and in vivo spin echo diffusion imaging characteristics of synovial fluid: potential non-invasive differentiation of inflammatory and degenerative arthritis

Objective. This study was undertaken to analyse the diffusion characteristics of synovial fluid in degenerative and inflammatory arthropathies. Design and patients. Ten in vitro specimens of synovial fluid from patients with both degenerative and inflammatory arthropathy were studied at body temperature with a navigator-corrected spin echo diffusion sequence (B values 0–512 s/mm²), on a Philips 1.5-T Gyroscan. Subsequently synovial fluid from knee joint effusions of 25 patients (10 patients with osteoarthritis, 10 patients with effusions following trauma and 5 patients with effusions secondary to inflammatory arthritis) was evaluated with the same navigator-corrected spin echo diffusion sequence. Results. Both in vitro and in vivo study demonstrated decreased diffusion in patients with effusions secondary to degenerative joint disease (less than 2.40×10^–5 cm²/s) relative to patients with effusions accompanying knee trauma (greater than 2.75×10^–5 cm²/s) and inflammatory arthritis (in vitro and in vivo greater than 3.00×10^–5 cm²/s). Conclusion. Synovial fluid in degenerative arthritis shows less diffusion or free water movement than synovial fluid in inflammatory arthritis. Diffusion characteristics of synovial fluid may be used to predict the nature of the underlying form of arthritis in patients presenting with knee joint effusions. Received: 22 October 1999 Revision requested: 10 January 2000 Revision received: 10 March 2000 Accepted: 14 March 2000     

Blunt abdominal trauma: should US be used to detect both free fluid and organ injuries?

PURPOSE: To evaluate abdominal ultrasonography (US) for indirect (with free fluid analysis only) and direct (with free fluid and parenchymal analysis) detection of organ injury in patients with blunt abdominal trauma, with findings at computed tomography (CT) and/or surgery as the standard of diagnosis. MATERIALS AND METHODS: Abdominal US was performed at hospital admission in consecutive patients with blunt abdominal trauma. The presence of free peritoneal fluid and organ injury were recorded and compared with results of abdominal CT in all hemodynamically stable patients. When US results were considered false-negative for free fluid or organ injury compared with CT results, repeat US was performed within 6 hours. Admission and second US results were compared with CT and/or surgical results to determine sensitivity, specificity, negative predictive value, and positive predictive value of US with regard to the presence of free intraperitoneal fluid and/or organ injury. RESULTS: Two hundred five hemodynamically stable patients underwent abdominal US and CT. CT revealed free fluid in 83 patients and organ injury in 99. Thirty-one (31%) of 99 patients with organ injury did not have free fluid at CT. Three (10%) of the 31 patients required surgery or angiographic embolization. The sensitivity of admission US was 93% (77 of 83 cases) for the diagnosis of free fluid, 41% (39 of 99) for directly demonstrating organ injury, and 72% (71 of 99) for suggesting organ injury by means of both free fluid and organ analysis. At second US, these sensitivities were 96% (80 of 83 cases), 55% (54 of 99) and 84% (83 of 99), respectively. CONCLUSION: US is highly sensitive for the detection of free intraperitoneal fluid but not sensitive for the identification of organ injuries. In hemodynamically stable patients, the value of US is mainly limited by the large percentage of organ injuries that are not associated with free fluid.     

The role of magnetic resonance imaging in routine decision making for meniscal surgery

This clinical study evaluated factors affecting the decision for meniscal surgery in a patient population seen routinely at a trauma clinic. The study hypothesis was that patients who sustain a traumatic injury to the knee or have a long history of clinical symptoms are likelier to be operated on. We investigated 149 patients clinically and by magnetic resonance imaging (MRI). Group A (n = 62) underwent arthroscopic surgery and group B (n = 87) were treated conservatively. Multiple logistic regression analysis was used to examine correlations with regard to age, gender, injury pattern, period between the injury and first clinical examination, and MRI results. We found no significant difference between the two groups with regard to gender (P = 0.1), injury pattern (P = 0.44), or period between injury and first clinical examination (P = 0.5). Patients in group A were significantly older than those in group B (P = 0.044), and, as expected, MRI signal alterations were significantly higher in group A than in group B (P = 0.001). In acutely injured patients MRI helps to establish an accurate diagnosis, and in cases of positive MRI findings in a symptomatic patient, the surgeon should not wait 4–6 weeks but should immediately recommend surgery. Received: 9 October 1998 Accepted: 10 May 1999     

Role of positron emission tomography using fluorine-18 fluoro-2-deoxyglucose in predicting improvement in left ventricular function in patients with idiopathic dilated cardiomyopathy

Improvement in left ventricular (LV) function in patients with idiopathic dilated cardiomyopathy (DCM) by medical treatment has been suggested. Thus, it is important to evaluate which patients will respond to medical therapy. Positron emission tomography (PET) with fluorine-18 fluoro-2-deoxyglucose (FDG) and cardiac catheterization were performed in 20 patients with DCM before the initiation of medical therapy. The regional myocardial glucose utilization rate (rMGU) was measured with FDG PET. Subjects were divided into two groups, group 1 (event-free patients, n=10) and group 2 (clinical cardiac events, n=10). Haemodynamic and PET parameters before the initiation of medication were compared between the two groups and between patients with and patients without improvement in LV function. Ejection fraction (EF) was significantly higher in group 1 (35.8%±9.0%) than in group 2 (24.8%±7.0%) and LV end-diastolic pressure (LVEDP) was significantly lower in group 1 (8.4±1.7 mmHg) than in group 2 (11.6±3.5 mmHg). Average rMGU (mg min^–1 100 g^–1) was similar in group 1 (11.2±2.5 mg min^–1 100 g^–1) and group 2 (11.2±2.9 mg min^–1 100 g^–1), while %CV of rMGU was significantly lower in group 1 (11.1%±6.3%) than in group 2 (29.9%±13.9%, P<0.01). Furthermore, LV function normalized in seven patients in group 1. In these seven patients, EF (35.1%±10.9%), LVEDP (8.2±2.0 mmHg) and average rMGU (11.8±2.7 mg min^–1 100 g^–1) were comparable with those in patients without LV functional improvement (EF: 31.6%±9.1%; LVEDP: 10.7±3.3 mmHg; average rMGU: 10.8± 2.7 mg min^–1 100 g^–1). However,% CV of rMGU in patients with LV functional improvement (9.6%±5.6%) was significantly lower than in those without such improvement (26.3%±14.1%, P<0.01). %CV of rMGU <13.6% predicted prognosis with a sensitivity of 80%, a specificity of 100% and an accuracy of 90%. %CV of rMGU <13.6% also predicted improvement in LV function, with a sensitivity of 75%, a specificity of 92% and an accuracy of 85%. However, EF failed to predict improvement of LV function. In is concluded that homogeneous myocardial glucose utilization rate can predict both prognosis and improvement in LV function achieved by medical therapy in patients with DCM. Received 9 December 1997 and in revised form 11 March 1998