Routine Preoperative Imaging Research Articles

A case report of B-cell lymphoma masquerading as superior mesenteric artery syndrome

Superior mesenteric artery (SMA) syndrome is a rare cause of intestinal obstruction, especially in children, whereas intussusception is far more common. We report the case of a child, who after an episode of acute weight loss presented with features suggestive of SMA syndrome. This child subsequently was shown at operation to have disseminated lymphoma causing a secondary high jejunal intussusception and tumor involvement of retroperitoneal lymph nodes causing compression of the third part of the duodenum. This case emphasizes that the SMA syndrome should be considered a sign rather than a diagnosis in itself. As such, an active search should be made to determine the cause of the condition. Routine preoperative imaging is recommended.

Localizing and Lateralizing Language in Patients with Brain Tumors: Feasibility of Routine Preoperative Functional MR Imaging in 81 Consecutive Patients1

To prospectively assess the feasibility of standardized presurgical functional magnetic resonance (MR) imaging for localizing the Broca and Wernicke areas and for lateralizing language function. The study was approved by the responsible ethics commission, and patients gave written informed consent. Eighty-one patients (36 female and 45 male patients; age range, 7-75 years) with different brain tumors underwent blood oxygen level-dependent functional MR imaging at 1.5 T with two paradigms: sentence generation (SG) and word generation (WG). Functional MR imaging measurements, data processing, and evaluation were fully standardized by using dedicated software. Four regions of interest were evaluated in each patient: the Broca and Wernicke areas and their anatomic homologues in the right hemisphere. Statistics were calculated. The SG and WG paradigms were successfully completed by all (100%) and 70 (86%) patients, respectively. Success rates in localizing and lateralizing language were 96% for the Broca and Wernicke areas with the SG paradigm, 81% for the Broca area and 80% for the Wernicke area with the WG paradigm, and 98% for both areas when the SG and WG paradigms were used in combination. Functional localizations were consistent for SG and WG paradigms in the inferior frontal gyrus (Broca area) and the superior temporal, supramarginal, and angular gyri (Wernicke area). Surgery was not performed in seven patients (9%) and was modified in two patients (2%) because of functional MR imaging findings. Functional MR imaging proved to be feasible during routine diagnostic neuroimaging for localizing and lateralizing language function preoperatively.

Randomized clinical trial of routine preoperative duplex imaging before varicose vein surgery

Randomized clinical trial of routine preoperative duplex imaging before varicose vein surgery

Prognostic value of perfusion-weighted imaging in brain glioma: a prospective study

Biopsy targeting based on MR imaging alone may fail to identify malignant areas in brain gliomas. Considering the differences in relative Cerebral Blood Volume (rCBV) ratios reported among tumour grades, we evaluated whether perfusion-weighted MR imaging (PWI) could usefully implement the routine preoperative imaging by detecting those areas bearing a higher yield for malignancy to guide the stereotactic biopsy or the surgical removal. We studied a series of 55 consecutive patients with newly diagnosed brain glioma using both conventional MR imaging and PWI in the preoperative assessment. The pathological diagnosis was established by stereotactic biopsy in 29 cases and by craniotomy in 24 cases. We evaluated the patient survival to detect undergrading. Independent from contrast-enhancement, perfusion-weighted MR imaging improved the target selection in stereotactic biopsy guidance and the removal of malignant areas in tumours amenable to surgery. Particularly sensitive to the perfused part of the tumour as to small regional changes, rCBV maps allowed a better detection of malignant areas. The rCBV ratios correlated significantly to the tumour grade and the final outcome (p < 0.01). We found PWI valuable in the preoperative assessment of brain gliomas, discriminating high from low-grade gliomas. PWI can easily be performed on widely available MR imaging systems as part of the routine imaging of gliomas.

Randomized clinical trial of routine preoperative duplex imaging before varicose vein surgery (Br J Surg 2005; 92: 688–694)

Abstract The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses can be sent electronically via the BJS website (http://www.bjs.co.uk) or by post. All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length. Letters submitted by post should be typed on A4-sized paper in double spacing and should be accompanied by a disk.

Pre-operative imaging of rectal cancer and its impact on surgical performance and treatment outcome

Aim To discuss the ability of pre-operative MRI to have a beneficial effect on surgical performance and treatment outcome in patients with rectal cancer. Methods A description on how MRI can be used as a tool so select patients for differentiated neoadjuvant treatment, how it can be used as an anatomical road map for the resection of locally advanced cases, and how it can serve as a tool for quality assurance of both the surgical procedure and overall patient management. As an illustration the proportion of microscopically complete resections of the period 1993–1997, when there was no routine pre-operative imaging, is compared to that of the period 1998–2002, when pre-operative MR imaging was standardized. Results The proportion of R0 resections increased from 92.5 to 97% ( p=0.08) and the proportion of resections with a lateral tumour free margin of >1 mm increased from 84.4 to 92.1% ( p=0.03). The incomplete resections in the first period were mainly due to inadequate surgical management of unsuspected advanced or bulky tumours, whereas in the second period insufficient consideration was given to extensive neoadjuvant treatment when the tumour was close to or invading the mesorectal fascia on MR. Conclusions There are good indications that in our setting pre-operative MR imaging, along with other improvements in rectal cancer management, had a beneficial effect on patient outcome. Audit and discussion of the incomplete resections can lead to an improved operative and perioperative management.

Randomized clinical trial of routine preoperative duplex imaging before varicose vein surgery

Duplex imaging is used increasingly for preoperative evaluation of varicose veins, but its value in terms of the long-term results of surgery is not clear. Patients with primary varicose veins were randomized to operation with or without preoperative duplex imaging. Reoperation rates, clinical and duplex findings were compared at 2 months and 2 years after surgery. Two hundred and ninety-three patients (343 legs) had varicose vein surgery after duplex imaging (group 1; 166 legs) or no imaging (group 2; 177 legs). In 44 legs (26.5 per cent), duplex examination suggested a different surgical procedure than had been considered on clinical grounds; the procedure was changed accordingly for 29 legs. At 2 months, incompetence was detected at the saphenofemoral or saphenopopliteal junction (or both) in 14 legs (8.8 per cent) in group 1 and in 44 legs (26.5 per cent) in group 2 (P < 0.001). At 2 years, two legs (1.4 per cent) had undergone or were awaiting reoperation in group 1, and 14 legs (9.5 per cent) in group 2 (P = 0.002). In the remainder, major incompetence was found in 19 legs (15.0 per cent) in group 1 and in 53 (41.1 per cent) in group 2 (P < 0.001). Routine preoperative duplex examination led to an improvement in results 2 years after surgery for patients with primary varicose veins.

Multidetector CT arteriography with volumetric three-dimensional rendering to evaluate patients with metastatic colorectal disease for placement of a floxuridine infusion pump.

We sought to evaluate the usefulness of multidetector CT (MDCT) arteriography with volumetric three-dimensional (3D) rendering to depict the hepatic vascular anatomy. Our study population was patients who had undergone arterial mapping in preparation for placement of a hepatic arterial floxuridine infusion pump for treatment of metastatic hepatic colorectal carcinoma. We retrospectively reviewed the medical records of 26 patients with hepatic colorectal metastases who had been scheduled for implantation of a hepatic artery pump. Before surgery, all patients underwent MDCT arteriography with volumetric 3D rendering of the hepatic vessels. The axial and 3D arteriograms were evaluated for their usefulness in depicting hepatic arterial anatomy. Subsequently, three patients also underwent catheter angiography. Twenty-two of the 26 patients imaged had a hepatic artery floxuridine infusion pump implanted. Results of the CT arteriography were correlated with findings at surgery or on catheter angiography if surgery was not performed. MDCT arteriography correctly revealed hepatic arterial anatomy in all 25 patients with angiographic or surgical confirmation. One patient with aberrant hepatic arterial anatomy did not have angiographic or surgical confirmation. Classic hepatic arterial anatomy was identified in 16 (64%) of 25 patients. The following hepatic arterial variants were found in one patient each: the common hepatic artery arising directly from the aorta; a replaced left hepatic artery; an accessory right hepatic artery; a replaced left hepatic artery and accessory right hepatic artery; a replaced right hepatic artery; a right hepatic arterial branch arising early (before the origin of the gastroduodenal artery); and replaced right and left hepatic arteries. Three patients were not suitable candidates for placement of a hepatic artery floxuridine pump. The patient who had no angiographic or surgical confirmation was also not considered a good surgical candidate because of replaced right and left hepatic arteries. Two patients (8%) had an accessory left hepatic artery. MDCT arteriography with volumetric 3D rendering is an accurate, noninvasive method of depicting hepatic arterial anatomy and, therefore, of selecting patients with colorectal metastatic disease who could benefit from hepatic artery pump implantation. Catheter angiography provides no additional information, and we have eliminated it as a routine preoperative imaging examination.

Sestamibi parathyroid imaging

Since the introduction of technetium-99m (99mTc) sestamibi (hexakis-2-methoxyisobutyl isonitrile) as a parathyroid imaging agent in 1989, many investigators using several different imaging protocols have reported uniformly excellent results for localization of parathyroid adenomas. Exact localization of hyperplastic parathyroid glands has not met with as much success. However, the results of multiple comparative studies suggest that the diagnostic utility of sestamibi protocols equals or exceeds other noninvasive, nonscintigraphic imaging strategies, including high-resolution ultrasound, computed tomography, and magnetic resonance imaging. Two different, but not necessarily mutually exclusive imaging strategies have been used: subtraction imaging using iodine-123 (123I) or 99mTc sodium pertechnetate as the thyroid agent, and sestamibi dual-phase imaging, which takes advantage of differential washout of sestamibi from thyroid and parathyroid tissue. Sestamibi subtraction imaging has been shown to have greater sensitivity for abnormal parathyroid glands compared with thallium-201 subtraction imaging using pooled data, 87% versus 71%, respectively. Dual-phase sestamibi imaging protocols are much more variable in their conduct and have a much greater variability in sensitivity, 43% to 91%, but with a pooled sensitivity of 73%. Data suggest that dual phase techniques are at least as sensitive, and in optimized protocols, superior to, thallium-201 subtraction techniques. This superiority is attributed to the favorable washout kinetics of sestamibi and the superior imaging characteristics of the 99mTc label. Specificity and positive predictive value for both sestamibi techniques are very high, typically greater than 90% and at least equal to thallium-subtraction protocols, although specificity may be slightly lower for sestamibi subtraction techniques. Therefore, sestamibi protocols are the scintigraphic procedure of choice for parathyroid imaging. Dual-phase sestamibi protocols are more robust and lend themselves to single photon emission computer tomography (SPECT) imaging, and may be followed sequentially by subtraction techniques if results are inconclusive. Despite the excellent results of sestamibi parathyroid imaging, it is unclear whether this accuracy can compete with the even better success of an experienced surgeon in initial surgeries for hyperparathyroidism, and routine preoperative imaging before initial surgery is still controversial. However, sestamibi parathyroid imaging is an excellent addition to a correlative imaging approach in reoperations for persistent and recurrent hyperparathyroidism.

Intraarterial calcium stimulation test for detection of insulinomas.

Occult insulinomas are adenomas not visualized by routine preoperative imaging studies, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and arteriography. Reliance for detecting occult insulinomas has been placed on portal venous sampling (PVS), a sensitive (> 75%) but invasive procedure that requires considerable experience to enable sampling of small veins about the pancreatic head. For the past 2 years we have attempted to localize insulinomas by stimulating the release of insulin with a selective intraarterial injection of calcium gluconate and sampling for insulin gradients in the hepatic veins. This study replaces PVS by indicating the region of the pancreas within which the tumor lies, although, like PVS, it does not directly visualize the tumor. Our experience in 9 patients with surgically proved insulinomas is reviewed, comparing the results with PVS as well as with US, CT, MRI, and arteriography.

Is pre-operative imaging of the urinary tract worthwhile in the assessment of prostatism?

The reports of routine pre-operative imaging investigations performed on patients presenting with symptoms of uncomplicated benign prostatic hypertrophy were compared with management decisions and clinical outcome. In 175 patients with prostatism no urological abnormality which altered management was discovered on plain films of the abdomen and pelvis and ultrasound of the urinary tract which were performed routinely. Post-micturition residual volume (PMRV), estimated by ultrasound, was compared with the maximum urine flow rate (Q max) in 57 patients. PMRV showed negative correlation with Q max. Both high PMRV and low Q max were associated with the urologist's decision to operate, but multiple logistic regression revealed that ultrasound residual volume was not a significant predictor of operation when adjusted for Q max. Urologists in this hospital therefore use flow rates as the primary indication of the need to operate. We suggest that no routine pre-operative imaging need be performed in patients presenting with prostatism.